//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "instsimplify"
-#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/ConstantFolding.h"
-#include "llvm/Analysis/Dominators.h"
+#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/Analysis/ValueTracking.h"
-#include "llvm/Support/PatternMatch.h"
-#include "llvm/Support/ValueHandle.h"
-#include "llvm/Target/TargetData.h"
+#include "llvm/IR/ConstantRange.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/Dominators.h"
+#include "llvm/IR/GetElementPtrTypeIterator.h"
+#include "llvm/IR/GlobalAlias.h"
+#include "llvm/IR/Operator.h"
+#include "llvm/IR/PatternMatch.h"
+#include "llvm/IR/ValueHandle.h"
+#include <algorithm>
using namespace llvm;
using namespace llvm::PatternMatch;
+#define DEBUG_TYPE "instsimplify"
+
enum { RecursionLimit = 3 };
STATISTIC(NumExpand, "Number of expansions");
-STATISTIC(NumFactor , "Number of factorizations");
STATISTIC(NumReassoc, "Number of reassociations");
-static Value *SimplifyAndInst(Value *, Value *, const TargetData *,
- const DominatorTree *, unsigned);
-static Value *SimplifyBinOp(unsigned, Value *, Value *, const TargetData *,
- const DominatorTree *, unsigned);
-static Value *SimplifyCmpInst(unsigned, Value *, Value *, const TargetData *,
- const DominatorTree *, unsigned);
-static Value *SimplifyOrInst(Value *, Value *, const TargetData *,
- const DominatorTree *, unsigned);
-static Value *SimplifyXorInst(Value *, Value *, const TargetData *,
- const DominatorTree *, unsigned);
+namespace {
+struct Query {
+ const DataLayout *DL;
+ const TargetLibraryInfo *TLI;
+ const DominatorTree *DT;
+ AssumptionCache *AC;
+ const Instruction *CxtI;
+
+ Query(const DataLayout *DL, const TargetLibraryInfo *tli,
+ const DominatorTree *dt, AssumptionCache *ac = nullptr,
+ const Instruction *cxti = nullptr)
+ : DL(DL), TLI(tli), DT(dt), AC(ac), CxtI(cxti) {}
+};
+} // end anonymous namespace
+
+static Value *SimplifyAndInst(Value *, Value *, const Query &, unsigned);
+static Value *SimplifyBinOp(unsigned, Value *, Value *, const Query &,
+ unsigned);
+static Value *SimplifyFPBinOp(unsigned, Value *, Value *, const FastMathFlags &,
+ const Query &, unsigned);
+static Value *SimplifyCmpInst(unsigned, Value *, Value *, const Query &,
+ unsigned);
+static Value *SimplifyOrInst(Value *, Value *, const Query &, unsigned);
+static Value *SimplifyXorInst(Value *, Value *, const Query &, unsigned);
+static Value *SimplifyTruncInst(Value *, Type *, const Query &, unsigned);
+
+/// getFalse - For a boolean type, or a vector of boolean type, return false, or
+/// a vector with every element false, as appropriate for the type.
+static Constant *getFalse(Type *Ty) {
+ assert(Ty->getScalarType()->isIntegerTy(1) &&
+ "Expected i1 type or a vector of i1!");
+ return Constant::getNullValue(Ty);
+}
+
+/// getTrue - For a boolean type, or a vector of boolean type, return true, or
+/// a vector with every element true, as appropriate for the type.
+static Constant *getTrue(Type *Ty) {
+ assert(Ty->getScalarType()->isIntegerTy(1) &&
+ "Expected i1 type or a vector of i1!");
+ return Constant::getAllOnesValue(Ty);
+}
+
+/// isSameCompare - Is V equivalent to the comparison "LHS Pred RHS"?
+static bool isSameCompare(Value *V, CmpInst::Predicate Pred, Value *LHS,
+ Value *RHS) {
+ CmpInst *Cmp = dyn_cast<CmpInst>(V);
+ if (!Cmp)
+ return false;
+ CmpInst::Predicate CPred = Cmp->getPredicate();
+ Value *CLHS = Cmp->getOperand(0), *CRHS = Cmp->getOperand(1);
+ if (CPred == Pred && CLHS == LHS && CRHS == RHS)
+ return true;
+ return CPred == CmpInst::getSwappedPredicate(Pred) && CLHS == RHS &&
+ CRHS == LHS;
+}
/// ValueDominatesPHI - Does the given value dominate the specified phi node?
static bool ValueDominatesPHI(Value *V, PHINode *P, const DominatorTree *DT) {
// Arguments and constants dominate all instructions.
return true;
+ // If we are processing instructions (and/or basic blocks) that have not been
+ // fully added to a function, the parent nodes may still be null. Simply
+ // return the conservative answer in these cases.
+ if (!I->getParent() || !P->getParent() || !I->getParent()->getParent())
+ return false;
+
// If we have a DominatorTree then do a precise test.
- if (DT)
+ if (DT) {
+ if (!DT->isReachableFromEntry(P->getParent()))
+ return true;
+ if (!DT->isReachableFromEntry(I->getParent()))
+ return false;
return DT->dominates(I, P);
+ }
// Otherwise, if the instruction is in the entry block, and is not an invoke,
// then it obviously dominates all phi nodes.
/// Also performs the transform "(A op' B) op C" -> "(A op C) op' (B op C)".
/// Returns the simplified value, or null if no simplification was performed.
static Value *ExpandBinOp(unsigned Opcode, Value *LHS, Value *RHS,
- unsigned OpcToExpand, const TargetData *TD,
- const DominatorTree *DT, unsigned MaxRecurse) {
+ unsigned OpcToExpand, const Query &Q,
+ unsigned MaxRecurse) {
Instruction::BinaryOps OpcodeToExpand = (Instruction::BinaryOps)OpcToExpand;
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
- return 0;
+ return nullptr;
// Check whether the expression has the form "(A op' B) op C".
if (BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS))
// It does! Try turning it into "(A op C) op' (B op C)".
Value *A = Op0->getOperand(0), *B = Op0->getOperand(1), *C = RHS;
// Do "A op C" and "B op C" both simplify?
- if (Value *L = SimplifyBinOp(Opcode, A, C, TD, DT, MaxRecurse))
- if (Value *R = SimplifyBinOp(Opcode, B, C, TD, DT, MaxRecurse)) {
+ if (Value *L = SimplifyBinOp(Opcode, A, C, Q, MaxRecurse))
+ if (Value *R = SimplifyBinOp(Opcode, B, C, Q, MaxRecurse)) {
// They do! Return "L op' R" if it simplifies or is already available.
// If "L op' R" equals "A op' B" then "L op' R" is just the LHS.
if ((L == A && R == B) || (Instruction::isCommutative(OpcodeToExpand)
return LHS;
}
// Otherwise return "L op' R" if it simplifies.
- if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, TD, DT,
- MaxRecurse)) {
+ if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, Q, MaxRecurse)) {
++NumExpand;
return V;
}
// It does! Try turning it into "(A op B) op' (A op C)".
Value *A = LHS, *B = Op1->getOperand(0), *C = Op1->getOperand(1);
// Do "A op B" and "A op C" both simplify?
- if (Value *L = SimplifyBinOp(Opcode, A, B, TD, DT, MaxRecurse))
- if (Value *R = SimplifyBinOp(Opcode, A, C, TD, DT, MaxRecurse)) {
+ if (Value *L = SimplifyBinOp(Opcode, A, B, Q, MaxRecurse))
+ if (Value *R = SimplifyBinOp(Opcode, A, C, Q, MaxRecurse)) {
// They do! Return "L op' R" if it simplifies or is already available.
// If "L op' R" equals "B op' C" then "L op' R" is just the RHS.
if ((L == B && R == C) || (Instruction::isCommutative(OpcodeToExpand)
return RHS;
}
// Otherwise return "L op' R" if it simplifies.
- if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, TD, DT,
- MaxRecurse)) {
+ if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, Q, MaxRecurse)) {
++NumExpand;
return V;
}
}
}
- return 0;
-}
-
-/// FactorizeBinOp - Simplify "LHS Opcode RHS" by factorizing out a common term
-/// using the operation OpCodeToExtract. For example, when Opcode is Add and
-/// OpCodeToExtract is Mul then this tries to turn "(A*B)+(A*C)" into "A*(B+C)".
-/// Returns the simplified value, or null if no simplification was performed.
-static Value *FactorizeBinOp(unsigned Opcode, Value *LHS, Value *RHS,
- unsigned OpcToExtract, const TargetData *TD,
- const DominatorTree *DT, unsigned MaxRecurse) {
- Instruction::BinaryOps OpcodeToExtract = (Instruction::BinaryOps)OpcToExtract;
- // Recursion is always used, so bail out at once if we already hit the limit.
- if (!MaxRecurse--)
- return 0;
-
- BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS);
- BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS);
-
- if (!Op0 || Op0->getOpcode() != OpcodeToExtract ||
- !Op1 || Op1->getOpcode() != OpcodeToExtract)
- return 0;
-
- // The expression has the form "(A op' B) op (C op' D)".
- Value *A = Op0->getOperand(0), *B = Op0->getOperand(1);
- Value *C = Op1->getOperand(0), *D = Op1->getOperand(1);
-
- // Use left distributivity, i.e. "X op' (Y op Z) = (X op' Y) op (X op' Z)".
- // Does the instruction have the form "(A op' B) op (A op' D)" or, in the
- // commutative case, "(A op' B) op (C op' A)"?
- if (A == C || (Instruction::isCommutative(OpcodeToExtract) && A == D)) {
- Value *DD = A == C ? D : C;
- // Form "A op' (B op DD)" if it simplifies completely.
- // Does "B op DD" simplify?
- if (Value *V = SimplifyBinOp(Opcode, B, DD, TD, DT, MaxRecurse)) {
- // It does! Return "A op' V" if it simplifies or is already available.
- // If V equals B then "A op' V" is just the LHS. If V equals DD then
- // "A op' V" is just the RHS.
- if (V == B || V == DD) {
- ++NumFactor;
- return V == B ? LHS : RHS;
- }
- // Otherwise return "A op' V" if it simplifies.
- if (Value *W = SimplifyBinOp(OpcodeToExtract, A, V, TD, DT, MaxRecurse)) {
- ++NumFactor;
- return W;
- }
- }
- }
-
- // Use right distributivity, i.e. "(X op Y) op' Z = (X op' Z) op (Y op' Z)".
- // Does the instruction have the form "(A op' B) op (C op' B)" or, in the
- // commutative case, "(A op' B) op (B op' D)"?
- if (B == D || (Instruction::isCommutative(OpcodeToExtract) && B == C)) {
- Value *CC = B == D ? C : D;
- // Form "(A op CC) op' B" if it simplifies completely..
- // Does "A op CC" simplify?
- if (Value *V = SimplifyBinOp(Opcode, A, CC, TD, DT, MaxRecurse)) {
- // It does! Return "V op' B" if it simplifies or is already available.
- // If V equals A then "V op' B" is just the LHS. If V equals CC then
- // "V op' B" is just the RHS.
- if (V == A || V == CC) {
- ++NumFactor;
- return V == A ? LHS : RHS;
- }
- // Otherwise return "V op' B" if it simplifies.
- if (Value *W = SimplifyBinOp(OpcodeToExtract, V, B, TD, DT, MaxRecurse)) {
- ++NumFactor;
- return W;
- }
- }
- }
-
- return 0;
+ return nullptr;
}
/// SimplifyAssociativeBinOp - Generic simplifications for associative binary
/// operations. Returns the simpler value, or null if none was found.
static Value *SimplifyAssociativeBinOp(unsigned Opc, Value *LHS, Value *RHS,
- const TargetData *TD,
- const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
Instruction::BinaryOps Opcode = (Instruction::BinaryOps)Opc;
assert(Instruction::isAssociative(Opcode) && "Not an associative operation!");
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
- return 0;
+ return nullptr;
BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS);
BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS);
Value *C = RHS;
// Does "B op C" simplify?
- if (Value *V = SimplifyBinOp(Opcode, B, C, TD, DT, MaxRecurse)) {
+ if (Value *V = SimplifyBinOp(Opcode, B, C, Q, MaxRecurse)) {
// It does! Return "A op V" if it simplifies or is already available.
// If V equals B then "A op V" is just the LHS.
if (V == B) return LHS;
// Otherwise return "A op V" if it simplifies.
- if (Value *W = SimplifyBinOp(Opcode, A, V, TD, DT, MaxRecurse)) {
+ if (Value *W = SimplifyBinOp(Opcode, A, V, Q, MaxRecurse)) {
++NumReassoc;
return W;
}
Value *C = Op1->getOperand(1);
// Does "A op B" simplify?
- if (Value *V = SimplifyBinOp(Opcode, A, B, TD, DT, MaxRecurse)) {
+ if (Value *V = SimplifyBinOp(Opcode, A, B, Q, MaxRecurse)) {
// It does! Return "V op C" if it simplifies or is already available.
// If V equals B then "V op C" is just the RHS.
if (V == B) return RHS;
// Otherwise return "V op C" if it simplifies.
- if (Value *W = SimplifyBinOp(Opcode, V, C, TD, DT, MaxRecurse)) {
+ if (Value *W = SimplifyBinOp(Opcode, V, C, Q, MaxRecurse)) {
++NumReassoc;
return W;
}
// The remaining transforms require commutativity as well as associativity.
if (!Instruction::isCommutative(Opcode))
- return 0;
+ return nullptr;
// Transform: "(A op B) op C" ==> "(C op A) op B" if it simplifies completely.
if (Op0 && Op0->getOpcode() == Opcode) {
Value *C = RHS;
// Does "C op A" simplify?
- if (Value *V = SimplifyBinOp(Opcode, C, A, TD, DT, MaxRecurse)) {
+ if (Value *V = SimplifyBinOp(Opcode, C, A, Q, MaxRecurse)) {
// It does! Return "V op B" if it simplifies or is already available.
// If V equals A then "V op B" is just the LHS.
if (V == A) return LHS;
// Otherwise return "V op B" if it simplifies.
- if (Value *W = SimplifyBinOp(Opcode, V, B, TD, DT, MaxRecurse)) {
+ if (Value *W = SimplifyBinOp(Opcode, V, B, Q, MaxRecurse)) {
++NumReassoc;
return W;
}
Value *C = Op1->getOperand(1);
// Does "C op A" simplify?
- if (Value *V = SimplifyBinOp(Opcode, C, A, TD, DT, MaxRecurse)) {
+ if (Value *V = SimplifyBinOp(Opcode, C, A, Q, MaxRecurse)) {
// It does! Return "B op V" if it simplifies or is already available.
// If V equals C then "B op V" is just the RHS.
if (V == C) return RHS;
// Otherwise return "B op V" if it simplifies.
- if (Value *W = SimplifyBinOp(Opcode, B, V, TD, DT, MaxRecurse)) {
+ if (Value *W = SimplifyBinOp(Opcode, B, V, Q, MaxRecurse)) {
++NumReassoc;
return W;
}
}
}
- return 0;
+ return nullptr;
}
/// ThreadBinOpOverSelect - In the case of a binary operation with a select
/// evaluating it on both branches of the select results in the same value.
/// Returns the common value if so, otherwise returns null.
static Value *ThreadBinOpOverSelect(unsigned Opcode, Value *LHS, Value *RHS,
- const TargetData *TD,
- const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
- return 0;
+ return nullptr;
SelectInst *SI;
if (isa<SelectInst>(LHS)) {
Value *TV;
Value *FV;
if (SI == LHS) {
- TV = SimplifyBinOp(Opcode, SI->getTrueValue(), RHS, TD, DT, MaxRecurse);
- FV = SimplifyBinOp(Opcode, SI->getFalseValue(), RHS, TD, DT, MaxRecurse);
+ TV = SimplifyBinOp(Opcode, SI->getTrueValue(), RHS, Q, MaxRecurse);
+ FV = SimplifyBinOp(Opcode, SI->getFalseValue(), RHS, Q, MaxRecurse);
} else {
- TV = SimplifyBinOp(Opcode, LHS, SI->getTrueValue(), TD, DT, MaxRecurse);
- FV = SimplifyBinOp(Opcode, LHS, SI->getFalseValue(), TD, DT, MaxRecurse);
+ TV = SimplifyBinOp(Opcode, LHS, SI->getTrueValue(), Q, MaxRecurse);
+ FV = SimplifyBinOp(Opcode, LHS, SI->getFalseValue(), Q, MaxRecurse);
}
// If they simplified to the same value, then return the common value.
}
}
- return 0;
+ return nullptr;
}
/// ThreadCmpOverSelect - In the case of a comparison with a select instruction,
/// result in the same value. Returns the common value if so, otherwise returns
/// null.
static Value *ThreadCmpOverSelect(CmpInst::Predicate Pred, Value *LHS,
- Value *RHS, const TargetData *TD,
- const DominatorTree *DT,
+ Value *RHS, const Query &Q,
unsigned MaxRecurse) {
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
- return 0;
+ return nullptr;
// Make sure the select is on the LHS.
if (!isa<SelectInst>(LHS)) {
}
assert(isa<SelectInst>(LHS) && "Not comparing with a select instruction!");
SelectInst *SI = cast<SelectInst>(LHS);
+ Value *Cond = SI->getCondition();
+ Value *TV = SI->getTrueValue();
+ Value *FV = SI->getFalseValue();
// Now that we have "cmp select(Cond, TV, FV), RHS", analyse it.
// Does "cmp TV, RHS" simplify?
- if (Value *TCmp = SimplifyCmpInst(Pred, SI->getTrueValue(), RHS, TD, DT,
- MaxRecurse)) {
- // It does! Does "cmp FV, RHS" simplify?
- if (Value *FCmp = SimplifyCmpInst(Pred, SI->getFalseValue(), RHS, TD, DT,
- MaxRecurse)) {
- // It does! If they simplified to the same value, then use it as the
- // result of the original comparison.
- if (TCmp == FCmp)
- return TCmp;
- Value *Cond = SI->getCondition();
- // If the false value simplified to false, then the result of the compare
- // is equal to "Cond && TCmp". This also catches the case when the false
- // value simplified to false and the true value to true, returning "Cond".
- if (match(FCmp, m_Zero()))
- if (Value *V = SimplifyAndInst(Cond, TCmp, TD, DT, MaxRecurse))
- return V;
- // If the true value simplified to true, then the result of the compare
- // is equal to "Cond || FCmp".
- if (match(TCmp, m_One()))
- if (Value *V = SimplifyOrInst(Cond, FCmp, TD, DT, MaxRecurse))
- return V;
- // Finally, if the false value simplified to true and the true value to
- // false, then the result of the compare is equal to "!Cond".
- if (match(FCmp, m_One()) && match(TCmp, m_Zero()))
- if (Value *V =
- SimplifyXorInst(Cond, Constant::getAllOnesValue(Cond->getType()),
- TD, DT, MaxRecurse))
- return V;
- }
+ Value *TCmp = SimplifyCmpInst(Pred, TV, RHS, Q, MaxRecurse);
+ if (TCmp == Cond) {
+ // It not only simplified, it simplified to the select condition. Replace
+ // it with 'true'.
+ TCmp = getTrue(Cond->getType());
+ } else if (!TCmp) {
+ // It didn't simplify. However if "cmp TV, RHS" is equal to the select
+ // condition then we can replace it with 'true'. Otherwise give up.
+ if (!isSameCompare(Cond, Pred, TV, RHS))
+ return nullptr;
+ TCmp = getTrue(Cond->getType());
+ }
+
+ // Does "cmp FV, RHS" simplify?
+ Value *FCmp = SimplifyCmpInst(Pred, FV, RHS, Q, MaxRecurse);
+ if (FCmp == Cond) {
+ // It not only simplified, it simplified to the select condition. Replace
+ // it with 'false'.
+ FCmp = getFalse(Cond->getType());
+ } else if (!FCmp) {
+ // It didn't simplify. However if "cmp FV, RHS" is equal to the select
+ // condition then we can replace it with 'false'. Otherwise give up.
+ if (!isSameCompare(Cond, Pred, FV, RHS))
+ return nullptr;
+ FCmp = getFalse(Cond->getType());
}
- return 0;
+ // If both sides simplified to the same value, then use it as the result of
+ // the original comparison.
+ if (TCmp == FCmp)
+ return TCmp;
+
+ // The remaining cases only make sense if the select condition has the same
+ // type as the result of the comparison, so bail out if this is not so.
+ if (Cond->getType()->isVectorTy() != RHS->getType()->isVectorTy())
+ return nullptr;
+ // If the false value simplified to false, then the result of the compare
+ // is equal to "Cond && TCmp". This also catches the case when the false
+ // value simplified to false and the true value to true, returning "Cond".
+ if (match(FCmp, m_Zero()))
+ if (Value *V = SimplifyAndInst(Cond, TCmp, Q, MaxRecurse))
+ return V;
+ // If the true value simplified to true, then the result of the compare
+ // is equal to "Cond || FCmp".
+ if (match(TCmp, m_One()))
+ if (Value *V = SimplifyOrInst(Cond, FCmp, Q, MaxRecurse))
+ return V;
+ // Finally, if the false value simplified to true and the true value to
+ // false, then the result of the compare is equal to "!Cond".
+ if (match(FCmp, m_One()) && match(TCmp, m_Zero()))
+ if (Value *V =
+ SimplifyXorInst(Cond, Constant::getAllOnesValue(Cond->getType()),
+ Q, MaxRecurse))
+ return V;
+
+ return nullptr;
}
/// ThreadBinOpOverPHI - In the case of a binary operation with an operand that
/// it on the incoming phi values yields the same result for every value. If so
/// returns the common value, otherwise returns null.
static Value *ThreadBinOpOverPHI(unsigned Opcode, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
- return 0;
+ return nullptr;
PHINode *PI;
if (isa<PHINode>(LHS)) {
PI = cast<PHINode>(LHS);
// Bail out if RHS and the phi may be mutually interdependent due to a loop.
- if (!ValueDominatesPHI(RHS, PI, DT))
- return 0;
+ if (!ValueDominatesPHI(RHS, PI, Q.DT))
+ return nullptr;
} else {
assert(isa<PHINode>(RHS) && "No PHI instruction operand!");
PI = cast<PHINode>(RHS);
// Bail out if LHS and the phi may be mutually interdependent due to a loop.
- if (!ValueDominatesPHI(LHS, PI, DT))
- return 0;
+ if (!ValueDominatesPHI(LHS, PI, Q.DT))
+ return nullptr;
}
// Evaluate the BinOp on the incoming phi values.
- Value *CommonValue = 0;
+ Value *CommonValue = nullptr;
for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) {
Value *Incoming = PI->getIncomingValue(i);
// If the incoming value is the phi node itself, it can safely be skipped.
if (Incoming == PI) continue;
Value *V = PI == LHS ?
- SimplifyBinOp(Opcode, Incoming, RHS, TD, DT, MaxRecurse) :
- SimplifyBinOp(Opcode, LHS, Incoming, TD, DT, MaxRecurse);
+ SimplifyBinOp(Opcode, Incoming, RHS, Q, MaxRecurse) :
+ SimplifyBinOp(Opcode, LHS, Incoming, Q, MaxRecurse);
// If the operation failed to simplify, or simplified to a different value
// to previously, then give up.
if (!V || (CommonValue && V != CommonValue))
- return 0;
+ return nullptr;
CommonValue = V;
}
/// incoming phi values yields the same result every time. If so returns the
/// common result, otherwise returns null.
static Value *ThreadCmpOverPHI(CmpInst::Predicate Pred, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
- return 0;
+ return nullptr;
// Make sure the phi is on the LHS.
if (!isa<PHINode>(LHS)) {
PHINode *PI = cast<PHINode>(LHS);
// Bail out if RHS and the phi may be mutually interdependent due to a loop.
- if (!ValueDominatesPHI(RHS, PI, DT))
- return 0;
+ if (!ValueDominatesPHI(RHS, PI, Q.DT))
+ return nullptr;
// Evaluate the BinOp on the incoming phi values.
- Value *CommonValue = 0;
+ Value *CommonValue = nullptr;
for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) {
Value *Incoming = PI->getIncomingValue(i);
// If the incoming value is the phi node itself, it can safely be skipped.
if (Incoming == PI) continue;
- Value *V = SimplifyCmpInst(Pred, Incoming, RHS, TD, DT, MaxRecurse);
+ Value *V = SimplifyCmpInst(Pred, Incoming, RHS, Q, MaxRecurse);
// If the operation failed to simplify, or simplified to a different value
// to previously, then give up.
if (!V || (CommonValue && V != CommonValue))
- return 0;
+ return nullptr;
CommonValue = V;
}
/// SimplifyAddInst - Given operands for an Add, see if we can
/// fold the result. If not, this returns null.
static Value *SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
Constant *Ops[] = { CLHS, CRHS };
- return ConstantFoldInstOperands(Instruction::Add, CLHS->getType(),
- Ops, 2, TD);
+ return ConstantFoldInstOperands(Instruction::Add, CLHS->getType(), Ops,
+ Q.DL, Q.TLI);
}
// Canonicalize the constant to the RHS.
// X + (Y - X) -> Y
// (Y - X) + X -> Y
// Eg: X + -X -> 0
- Value *Y = 0;
+ Value *Y = nullptr;
if (match(Op1, m_Sub(m_Value(Y), m_Specific(Op0))) ||
match(Op0, m_Sub(m_Value(Y), m_Specific(Op1))))
return Y;
/// i1 add -> xor.
if (MaxRecurse && Op0->getType()->isIntegerTy(1))
- if (Value *V = SimplifyXorInst(Op0, Op1, TD, DT, MaxRecurse-1))
+ if (Value *V = SimplifyXorInst(Op0, Op1, Q, MaxRecurse-1))
return V;
// Try some generic simplifications for associative operations.
- if (Value *V = SimplifyAssociativeBinOp(Instruction::Add, Op0, Op1, TD, DT,
+ if (Value *V = SimplifyAssociativeBinOp(Instruction::Add, Op0, Op1, Q,
MaxRecurse))
return V;
- // Mul distributes over Add. Try some generic simplifications based on this.
- if (Value *V = FactorizeBinOp(Instruction::Add, Op0, Op1, Instruction::Mul,
- TD, DT, MaxRecurse))
- return V;
-
// Threading Add over selects and phi nodes is pointless, so don't bother.
// Threading over the select in "A + select(cond, B, C)" means evaluating
// "A+B" and "A+C" and seeing if they are equal; but they are equal if and
// "A+B" and "A+C" thus gains nothing, but costs compile time. Similarly
// for threading over phi nodes.
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
- const TargetData *TD, const DominatorTree *DT) {
- return ::SimplifyAddInst(Op0, Op1, isNSW, isNUW, TD, DT, RecursionLimit);
+ const DataLayout *DL, const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyAddInst(Op0, Op1, isNSW, isNUW, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
+}
+
+/// \brief Compute the base pointer and cumulative constant offsets for V.
+///
+/// This strips all constant offsets off of V, leaving it the base pointer, and
+/// accumulates the total constant offset applied in the returned constant. It
+/// returns 0 if V is not a pointer, and returns the constant '0' if there are
+/// no constant offsets applied.
+///
+/// This is very similar to GetPointerBaseWithConstantOffset except it doesn't
+/// follow non-inbounds geps. This allows it to remain usable for icmp ult/etc.
+/// folding.
+static Constant *stripAndComputeConstantOffsets(const DataLayout *DL,
+ Value *&V,
+ bool AllowNonInbounds = false) {
+ assert(V->getType()->getScalarType()->isPointerTy());
+
+ // Without DataLayout, just be conservative for now. Theoretically, more could
+ // be done in this case.
+ if (!DL)
+ return ConstantInt::get(IntegerType::get(V->getContext(), 64), 0);
+
+ Type *IntPtrTy = DL->getIntPtrType(V->getType())->getScalarType();
+ APInt Offset = APInt::getNullValue(IntPtrTy->getIntegerBitWidth());
+
+ // Even though we don't look through PHI nodes, we could be called on an
+ // instruction in an unreachable block, which may be on a cycle.
+ SmallPtrSet<Value *, 4> Visited;
+ Visited.insert(V);
+ do {
+ if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
+ if ((!AllowNonInbounds && !GEP->isInBounds()) ||
+ !GEP->accumulateConstantOffset(*DL, Offset))
+ break;
+ V = GEP->getPointerOperand();
+ } else if (Operator::getOpcode(V) == Instruction::BitCast) {
+ V = cast<Operator>(V)->getOperand(0);
+ } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
+ if (GA->mayBeOverridden())
+ break;
+ V = GA->getAliasee();
+ } else {
+ break;
+ }
+ assert(V->getType()->getScalarType()->isPointerTy() &&
+ "Unexpected operand type!");
+ } while (Visited.insert(V).second);
+
+ Constant *OffsetIntPtr = ConstantInt::get(IntPtrTy, Offset);
+ if (V->getType()->isVectorTy())
+ return ConstantVector::getSplat(V->getType()->getVectorNumElements(),
+ OffsetIntPtr);
+ return OffsetIntPtr;
+}
+
+/// \brief Compute the constant difference between two pointer values.
+/// If the difference is not a constant, returns zero.
+static Constant *computePointerDifference(const DataLayout *DL,
+ Value *LHS, Value *RHS) {
+ Constant *LHSOffset = stripAndComputeConstantOffsets(DL, LHS);
+ Constant *RHSOffset = stripAndComputeConstantOffsets(DL, RHS);
+
+ // If LHS and RHS are not related via constant offsets to the same base
+ // value, there is nothing we can do here.
+ if (LHS != RHS)
+ return nullptr;
+
+ // Otherwise, the difference of LHS - RHS can be computed as:
+ // LHS - RHS
+ // = (LHSOffset + Base) - (RHSOffset + Base)
+ // = LHSOffset - RHSOffset
+ return ConstantExpr::getSub(LHSOffset, RHSOffset);
}
/// SimplifySubInst - Given operands for a Sub, see if we can
/// fold the result. If not, this returns null.
static Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
if (Constant *CLHS = dyn_cast<Constant>(Op0))
if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
Constant *Ops[] = { CLHS, CRHS };
return ConstantFoldInstOperands(Instruction::Sub, CLHS->getType(),
- Ops, 2, TD);
+ Ops, Q.DL, Q.TLI);
}
// X - undef -> undef
if (Op0 == Op1)
return Constant::getNullValue(Op0->getType());
- // (X*2) - X -> X
- // (X<<1) - X -> X
- Value *X = 0;
- if (match(Op0, m_Mul(m_Specific(Op1), m_ConstantInt<2>())) ||
- match(Op0, m_Shl(m_Specific(Op1), m_One())))
- return Op1;
+ // 0 - X -> 0 if the sub is NUW.
+ if (isNUW && match(Op0, m_Zero()))
+ return Op0;
// (X + Y) - Z -> X + (Y - Z) or Y + (X - Z) if everything simplifies.
// For example, (X + Y) - Y -> X; (Y + X) - Y -> X
- Value *Y = 0, *Z = Op1;
+ Value *X = nullptr, *Y = nullptr, *Z = Op1;
if (MaxRecurse && match(Op0, m_Add(m_Value(X), m_Value(Y)))) { // (X + Y) - Z
// See if "V === Y - Z" simplifies.
- if (Value *V = SimplifyBinOp(Instruction::Sub, Y, Z, TD, DT, MaxRecurse-1))
+ if (Value *V = SimplifyBinOp(Instruction::Sub, Y, Z, Q, MaxRecurse-1))
// It does! Now see if "X + V" simplifies.
- if (Value *W = SimplifyBinOp(Instruction::Add, X, V, TD, DT,
- MaxRecurse-1)) {
+ if (Value *W = SimplifyBinOp(Instruction::Add, X, V, Q, MaxRecurse-1)) {
// It does, we successfully reassociated!
++NumReassoc;
return W;
}
// See if "V === X - Z" simplifies.
- if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, TD, DT, MaxRecurse-1))
+ if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, Q, MaxRecurse-1))
// It does! Now see if "Y + V" simplifies.
- if (Value *W = SimplifyBinOp(Instruction::Add, Y, V, TD, DT,
- MaxRecurse-1)) {
+ if (Value *W = SimplifyBinOp(Instruction::Add, Y, V, Q, MaxRecurse-1)) {
// It does, we successfully reassociated!
++NumReassoc;
return W;
X = Op0;
if (MaxRecurse && match(Op1, m_Add(m_Value(Y), m_Value(Z)))) { // X - (Y + Z)
// See if "V === X - Y" simplifies.
- if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, TD, DT, MaxRecurse-1))
+ if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, Q, MaxRecurse-1))
// It does! Now see if "V - Z" simplifies.
- if (Value *W = SimplifyBinOp(Instruction::Sub, V, Z, TD, DT,
- MaxRecurse-1)) {
+ if (Value *W = SimplifyBinOp(Instruction::Sub, V, Z, Q, MaxRecurse-1)) {
// It does, we successfully reassociated!
++NumReassoc;
return W;
}
// See if "V === X - Z" simplifies.
- if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, TD, DT, MaxRecurse-1))
+ if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, Q, MaxRecurse-1))
// It does! Now see if "V - Y" simplifies.
- if (Value *W = SimplifyBinOp(Instruction::Sub, V, Y, TD, DT,
- MaxRecurse-1)) {
+ if (Value *W = SimplifyBinOp(Instruction::Sub, V, Y, Q, MaxRecurse-1)) {
// It does, we successfully reassociated!
++NumReassoc;
return W;
Z = Op0;
if (MaxRecurse && match(Op1, m_Sub(m_Value(X), m_Value(Y)))) // Z - (X - Y)
// See if "V === Z - X" simplifies.
- if (Value *V = SimplifyBinOp(Instruction::Sub, Z, X, TD, DT, MaxRecurse-1))
+ if (Value *V = SimplifyBinOp(Instruction::Sub, Z, X, Q, MaxRecurse-1))
// It does! Now see if "V + Y" simplifies.
- if (Value *W = SimplifyBinOp(Instruction::Add, V, Y, TD, DT,
- MaxRecurse-1)) {
+ if (Value *W = SimplifyBinOp(Instruction::Add, V, Y, Q, MaxRecurse-1)) {
// It does, we successfully reassociated!
++NumReassoc;
return W;
}
- // Mul distributes over Sub. Try some generic simplifications based on this.
- if (Value *V = FactorizeBinOp(Instruction::Sub, Op0, Op1, Instruction::Mul,
- TD, DT, MaxRecurse))
- return V;
+ // trunc(X) - trunc(Y) -> trunc(X - Y) if everything simplifies.
+ if (MaxRecurse && match(Op0, m_Trunc(m_Value(X))) &&
+ match(Op1, m_Trunc(m_Value(Y))))
+ if (X->getType() == Y->getType())
+ // See if "V === X - Y" simplifies.
+ if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, Q, MaxRecurse-1))
+ // It does! Now see if "trunc V" simplifies.
+ if (Value *W = SimplifyTruncInst(V, Op0->getType(), Q, MaxRecurse-1))
+ // It does, return the simplified "trunc V".
+ return W;
+
+ // Variations on GEP(base, I, ...) - GEP(base, i, ...) -> GEP(null, I-i, ...).
+ if (match(Op0, m_PtrToInt(m_Value(X))) &&
+ match(Op1, m_PtrToInt(m_Value(Y))))
+ if (Constant *Result = computePointerDifference(Q.DL, X, Y))
+ return ConstantExpr::getIntegerCast(Result, Op0->getType(), true);
// i1 sub -> xor.
if (MaxRecurse && Op0->getType()->isIntegerTy(1))
- if (Value *V = SimplifyXorInst(Op0, Op1, TD, DT, MaxRecurse-1))
+ if (Value *V = SimplifyXorInst(Op0, Op1, Q, MaxRecurse-1))
return V;
// Threading Sub over selects and phi nodes is pointless, so don't bother.
// "A-B" and "A-C" thus gains nothing, but costs compile time. Similarly
// for threading over phi nodes.
- return 0;
+ return nullptr;
}
Value *llvm::SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
- const TargetData *TD, const DominatorTree *DT) {
- return ::SimplifySubInst(Op0, Op1, isNSW, isNUW, TD, DT, RecursionLimit);
+ const DataLayout *DL, const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifySubInst(Op0, Op1, isNSW, isNUW, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
+}
+
+/// Given operands for an FAdd, see if we can fold the result. If not, this
+/// returns null.
+static Value *SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF,
+ const Query &Q, unsigned MaxRecurse) {
+ if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
+ if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
+ Constant *Ops[] = { CLHS, CRHS };
+ return ConstantFoldInstOperands(Instruction::FAdd, CLHS->getType(),
+ Ops, Q.DL, Q.TLI);
+ }
+
+ // Canonicalize the constant to the RHS.
+ std::swap(Op0, Op1);
+ }
+
+ // fadd X, -0 ==> X
+ if (match(Op1, m_NegZero()))
+ return Op0;
+
+ // fadd X, 0 ==> X, when we know X is not -0
+ if (match(Op1, m_Zero()) &&
+ (FMF.noSignedZeros() || CannotBeNegativeZero(Op0)))
+ return Op0;
+
+ // fadd [nnan ninf] X, (fsub [nnan ninf] 0, X) ==> 0
+ // where nnan and ninf have to occur at least once somewhere in this
+ // expression
+ Value *SubOp = nullptr;
+ if (match(Op1, m_FSub(m_AnyZero(), m_Specific(Op0))))
+ SubOp = Op1;
+ else if (match(Op0, m_FSub(m_AnyZero(), m_Specific(Op1))))
+ SubOp = Op0;
+ if (SubOp) {
+ Instruction *FSub = cast<Instruction>(SubOp);
+ if ((FMF.noNaNs() || FSub->hasNoNaNs()) &&
+ (FMF.noInfs() || FSub->hasNoInfs()))
+ return Constant::getNullValue(Op0->getType());
+ }
+
+ return nullptr;
+}
+
+/// Given operands for an FSub, see if we can fold the result. If not, this
+/// returns null.
+static Value *SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF,
+ const Query &Q, unsigned MaxRecurse) {
+ if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
+ if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
+ Constant *Ops[] = { CLHS, CRHS };
+ return ConstantFoldInstOperands(Instruction::FSub, CLHS->getType(),
+ Ops, Q.DL, Q.TLI);
+ }
+ }
+
+ // fsub X, 0 ==> X
+ if (match(Op1, m_Zero()))
+ return Op0;
+
+ // fsub X, -0 ==> X, when we know X is not -0
+ if (match(Op1, m_NegZero()) &&
+ (FMF.noSignedZeros() || CannotBeNegativeZero(Op0)))
+ return Op0;
+
+ // fsub 0, (fsub -0.0, X) ==> X
+ Value *X;
+ if (match(Op0, m_AnyZero())) {
+ if (match(Op1, m_FSub(m_NegZero(), m_Value(X))))
+ return X;
+ if (FMF.noSignedZeros() && match(Op1, m_FSub(m_AnyZero(), m_Value(X))))
+ return X;
+ }
+
+ // fsub nnan ninf x, x ==> 0.0
+ if (FMF.noNaNs() && FMF.noInfs() && Op0 == Op1)
+ return Constant::getNullValue(Op0->getType());
+
+ return nullptr;
+}
+
+/// Given the operands for an FMul, see if we can fold the result
+static Value *SimplifyFMulInst(Value *Op0, Value *Op1,
+ FastMathFlags FMF,
+ const Query &Q,
+ unsigned MaxRecurse) {
+ if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
+ if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
+ Constant *Ops[] = { CLHS, CRHS };
+ return ConstantFoldInstOperands(Instruction::FMul, CLHS->getType(),
+ Ops, Q.DL, Q.TLI);
+ }
+
+ // Canonicalize the constant to the RHS.
+ std::swap(Op0, Op1);
+ }
+
+ // fmul X, 1.0 ==> X
+ if (match(Op1, m_FPOne()))
+ return Op0;
+
+ // fmul nnan nsz X, 0 ==> 0
+ if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op1, m_AnyZero()))
+ return Op1;
+
+ return nullptr;
}
/// SimplifyMulInst - Given operands for a Mul, see if we can
/// fold the result. If not, this returns null.
-static Value *SimplifyMulInst(Value *Op0, Value *Op1, const TargetData *TD,
- const DominatorTree *DT, unsigned MaxRecurse) {
+static Value *SimplifyMulInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned MaxRecurse) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
Constant *Ops[] = { CLHS, CRHS };
return ConstantFoldInstOperands(Instruction::Mul, CLHS->getType(),
- Ops, 2, TD);
+ Ops, Q.DL, Q.TLI);
}
// Canonicalize the constant to the RHS.
return Op0;
// (X / Y) * Y -> X if the division is exact.
- Value *X = 0, *Y = 0;
- if ((match(Op0, m_IDiv(m_Value(X), m_Value(Y))) && Y == Op1) || // (X / Y) * Y
- (match(Op1, m_IDiv(m_Value(X), m_Value(Y))) && Y == Op0)) { // Y * (X / Y)
- BinaryOperator *Div = cast<BinaryOperator>(Y == Op1 ? Op0 : Op1);
- if (Div->isExact())
- return X;
- }
+ Value *X = nullptr;
+ if (match(Op0, m_Exact(m_IDiv(m_Value(X), m_Specific(Op1)))) || // (X / Y) * Y
+ match(Op1, m_Exact(m_IDiv(m_Value(X), m_Specific(Op0))))) // Y * (X / Y)
+ return X;
// i1 mul -> and.
if (MaxRecurse && Op0->getType()->isIntegerTy(1))
- if (Value *V = SimplifyAndInst(Op0, Op1, TD, DT, MaxRecurse-1))
+ if (Value *V = SimplifyAndInst(Op0, Op1, Q, MaxRecurse-1))
return V;
// Try some generic simplifications for associative operations.
- if (Value *V = SimplifyAssociativeBinOp(Instruction::Mul, Op0, Op1, TD, DT,
+ if (Value *V = SimplifyAssociativeBinOp(Instruction::Mul, Op0, Op1, Q,
MaxRecurse))
return V;
// Mul distributes over Add. Try some generic simplifications based on this.
if (Value *V = ExpandBinOp(Instruction::Mul, Op0, Op1, Instruction::Add,
- TD, DT, MaxRecurse))
+ Q, MaxRecurse))
return V;
// If the operation is with the result of a select instruction, check whether
// operating on either branch of the select always yields the same value.
if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
- if (Value *V = ThreadBinOpOverSelect(Instruction::Mul, Op0, Op1, TD, DT,
+ if (Value *V = ThreadBinOpOverSelect(Instruction::Mul, Op0, Op1, Q,
MaxRecurse))
return V;
// If the operation is with the result of a phi instruction, check whether
// operating on all incoming values of the phi always yields the same value.
if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
- if (Value *V = ThreadBinOpOverPHI(Instruction::Mul, Op0, Op1, TD, DT,
+ if (Value *V = ThreadBinOpOverPHI(Instruction::Mul, Op0, Op1, Q,
MaxRecurse))
return V;
- return 0;
+ return nullptr;
+}
+
+Value *llvm::SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF,
+ const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyFAddInst(Op0, Op1, FMF, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
+}
+
+Value *llvm::SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF,
+ const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyFSubInst(Op0, Op1, FMF, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
}
-Value *llvm::SimplifyMulInst(Value *Op0, Value *Op1, const TargetData *TD,
- const DominatorTree *DT) {
- return ::SimplifyMulInst(Op0, Op1, TD, DT, RecursionLimit);
+Value *llvm::SimplifyFMulInst(Value *Op0, Value *Op1, FastMathFlags FMF,
+ const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyFMulInst(Op0, Op1, FMF, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
+}
+
+Value *llvm::SimplifyMulInst(Value *Op0, Value *Op1, const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyMulInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
}
/// SimplifyDiv - Given operands for an SDiv or UDiv, see if we can
/// fold the result. If not, this returns null.
static Value *SimplifyDiv(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
if (Constant *C0 = dyn_cast<Constant>(Op0)) {
if (Constant *C1 = dyn_cast<Constant>(Op1)) {
Constant *Ops[] = { C0, C1 };
- return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, 2, TD);
+ return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.DL, Q.TLI);
}
}
if (match(Op1, m_Undef()))
return Op1;
+ // X / 0 -> undef, we don't need to preserve faults!
+ if (match(Op1, m_Zero()))
+ return UndefValue::get(Op1->getType());
+
// undef / X -> 0
if (match(Op0, m_Undef()))
return Constant::getNullValue(Op0->getType());
return ConstantInt::get(Op0->getType(), 1);
// (X * Y) / Y -> X if the multiplication does not overflow.
- Value *X = 0, *Y = 0;
+ Value *X = nullptr, *Y = nullptr;
if (match(Op0, m_Mul(m_Value(X), m_Value(Y))) && (X == Op1 || Y == Op1)) {
if (Y != Op1) std::swap(X, Y); // Ensure expression is (X * Y) / Y, Y = Op1
- BinaryOperator *Mul = cast<BinaryOperator>(Op0);
+ OverflowingBinaryOperator *Mul = cast<OverflowingBinaryOperator>(Op0);
// If the Mul knows it does not overflow, then we are good to go.
if ((isSigned && Mul->hasNoSignedWrap()) ||
(!isSigned && Mul->hasNoUnsignedWrap()))
(!isSigned && match(Op0, m_URem(m_Value(), m_Specific(Op1)))))
return Constant::getNullValue(Op0->getType());
+ // (X /u C1) /u C2 -> 0 if C1 * C2 overflow
+ ConstantInt *C1, *C2;
+ if (!isSigned && match(Op0, m_UDiv(m_Value(X), m_ConstantInt(C1))) &&
+ match(Op1, m_ConstantInt(C2))) {
+ bool Overflow;
+ C1->getValue().umul_ov(C2->getValue(), Overflow);
+ if (Overflow)
+ return Constant::getNullValue(Op0->getType());
+ }
+
// If the operation is with the result of a select instruction, check whether
// operating on either branch of the select always yields the same value.
if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
- if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, TD, DT, MaxRecurse))
+ if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
return V;
// If the operation is with the result of a phi instruction, check whether
// operating on all incoming values of the phi always yields the same value.
if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
- if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, TD, DT, MaxRecurse))
+ if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
/// SimplifySDivInst - Given operands for an SDiv, see if we can
/// fold the result. If not, this returns null.
-static Value *SimplifySDivInst(Value *Op0, Value *Op1, const TargetData *TD,
- const DominatorTree *DT, unsigned MaxRecurse) {
- if (Value *V = SimplifyDiv(Instruction::SDiv, Op0, Op1, TD, DT, MaxRecurse))
+static Value *SimplifySDivInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned MaxRecurse) {
+ if (Value *V = SimplifyDiv(Instruction::SDiv, Op0, Op1, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
-Value *llvm::SimplifySDivInst(Value *Op0, Value *Op1, const TargetData *TD,
- const DominatorTree *DT) {
- return ::SimplifySDivInst(Op0, Op1, TD, DT, RecursionLimit);
+Value *llvm::SimplifySDivInst(Value *Op0, Value *Op1, const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifySDivInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
}
/// SimplifyUDivInst - Given operands for a UDiv, see if we can
/// fold the result. If not, this returns null.
-static Value *SimplifyUDivInst(Value *Op0, Value *Op1, const TargetData *TD,
- const DominatorTree *DT, unsigned MaxRecurse) {
- if (Value *V = SimplifyDiv(Instruction::UDiv, Op0, Op1, TD, DT, MaxRecurse))
+static Value *SimplifyUDivInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned MaxRecurse) {
+ if (Value *V = SimplifyDiv(Instruction::UDiv, Op0, Op1, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
-Value *llvm::SimplifyUDivInst(Value *Op0, Value *Op1, const TargetData *TD,
- const DominatorTree *DT) {
- return ::SimplifyUDivInst(Op0, Op1, TD, DT, RecursionLimit);
+Value *llvm::SimplifyUDivInst(Value *Op0, Value *Op1, const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyUDivInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
}
-static Value *SimplifyFDivInst(Value *Op0, Value *Op1, const TargetData *,
- const DominatorTree *, unsigned) {
+static Value *SimplifyFDivInst(Value *Op0, Value *Op1, FastMathFlags FMF,
+ const Query &Q, unsigned) {
// undef / X -> undef (the undef could be a snan).
if (match(Op0, m_Undef()))
return Op0;
if (match(Op1, m_Undef()))
return Op1;
- return 0;
+ // 0 / X -> 0
+ // Requires that NaNs are off (X could be zero) and signed zeroes are
+ // ignored (X could be positive or negative, so the output sign is unknown).
+ if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op0, m_AnyZero()))
+ return Op0;
+
+ return nullptr;
}
-Value *llvm::SimplifyFDivInst(Value *Op0, Value *Op1, const TargetData *TD,
- const DominatorTree *DT) {
- return ::SimplifyFDivInst(Op0, Op1, TD, DT, RecursionLimit);
+Value *llvm::SimplifyFDivInst(Value *Op0, Value *Op1, FastMathFlags FMF,
+ const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyFDivInst(Op0, Op1, FMF, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
}
-/// SimplifyShift - Given operands for an Shl, LShr or AShr, see if we can
+/// SimplifyRem - Given operands for an SRem or URem, see if we can
/// fold the result. If not, this returns null.
-static Value *SimplifyShift(unsigned Opcode, Value *Op0, Value *Op1,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+static Value *SimplifyRem(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
+ const Query &Q, unsigned MaxRecurse) {
if (Constant *C0 = dyn_cast<Constant>(Op0)) {
if (Constant *C1 = dyn_cast<Constant>(Op1)) {
Constant *Ops[] = { C0, C1 };
- return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, 2, TD);
+ return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.DL, Q.TLI);
}
}
- // 0 shift by X -> 0
+ // X % undef -> undef
+ if (match(Op1, m_Undef()))
+ return Op1;
+
+ // undef % X -> 0
+ if (match(Op0, m_Undef()))
+ return Constant::getNullValue(Op0->getType());
+
+ // 0 % X -> 0, we don't need to preserve faults!
if (match(Op0, m_Zero()))
return Op0;
- // X shift by 0 -> X
+ // X % 0 -> undef, we don't need to preserve faults!
if (match(Op1, m_Zero()))
+ return UndefValue::get(Op0->getType());
+
+ // X % 1 -> 0
+ if (match(Op1, m_One()))
+ return Constant::getNullValue(Op0->getType());
+
+ if (Op0->getType()->isIntegerTy(1))
+ // It can't be remainder by zero, hence it must be remainder by one.
+ return Constant::getNullValue(Op0->getType());
+
+ // X % X -> 0
+ if (Op0 == Op1)
+ return Constant::getNullValue(Op0->getType());
+
+ // (X % Y) % Y -> X % Y
+ if ((Opcode == Instruction::SRem &&
+ match(Op0, m_SRem(m_Value(), m_Specific(Op1)))) ||
+ (Opcode == Instruction::URem &&
+ match(Op0, m_URem(m_Value(), m_Specific(Op1)))))
return Op0;
- // X shift by undef -> undef because it may shift by the bitwidth.
+ // If the operation is with the result of a select instruction, check whether
+ // operating on either branch of the select always yields the same value.
+ if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
+ if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ // If the operation is with the result of a phi instruction, check whether
+ // operating on all incoming values of the phi always yields the same value.
+ if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
+ if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ return nullptr;
+}
+
+/// SimplifySRemInst - Given operands for an SRem, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifySRemInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned MaxRecurse) {
+ if (Value *V = SimplifyRem(Instruction::SRem, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ return nullptr;
+}
+
+Value *llvm::SimplifySRemInst(Value *Op0, Value *Op1, const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifySRemInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
+}
+
+/// SimplifyURemInst - Given operands for a URem, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyURemInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned MaxRecurse) {
+ if (Value *V = SimplifyRem(Instruction::URem, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ return nullptr;
+}
+
+Value *llvm::SimplifyURemInst(Value *Op0, Value *Op1, const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyURemInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
+}
+
+static Value *SimplifyFRemInst(Value *Op0, Value *Op1, FastMathFlags FMF,
+ const Query &, unsigned) {
+ // undef % X -> undef (the undef could be a snan).
+ if (match(Op0, m_Undef()))
+ return Op0;
+
+ // X % undef -> undef
if (match(Op1, m_Undef()))
return Op1;
+ // 0 % X -> 0
+ // Requires that NaNs are off (X could be zero) and signed zeroes are
+ // ignored (X could be positive or negative, so the output sign is unknown).
+ if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op0, m_AnyZero()))
+ return Op0;
+
+ return nullptr;
+}
+
+Value *llvm::SimplifyFRemInst(Value *Op0, Value *Op1, FastMathFlags FMF,
+ const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyFRemInst(Op0, Op1, FMF, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
+}
+
+/// isUndefShift - Returns true if a shift by \c Amount always yields undef.
+static bool isUndefShift(Value *Amount) {
+ Constant *C = dyn_cast<Constant>(Amount);
+ if (!C)
+ return false;
+
+ // X shift by undef -> undef because it may shift by the bitwidth.
+ if (isa<UndefValue>(C))
+ return true;
+
// Shifting by the bitwidth or more is undefined.
- if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1))
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(C))
if (CI->getValue().getLimitedValue() >=
- Op0->getType()->getScalarSizeInBits())
- return UndefValue::get(Op0->getType());
+ CI->getType()->getScalarSizeInBits())
+ return true;
+
+ // If all lanes of a vector shift are undefined the whole shift is.
+ if (isa<ConstantVector>(C) || isa<ConstantDataVector>(C)) {
+ for (unsigned I = 0, E = C->getType()->getVectorNumElements(); I != E; ++I)
+ if (!isUndefShift(C->getAggregateElement(I)))
+ return false;
+ return true;
+ }
+
+ return false;
+}
+
+/// SimplifyShift - Given operands for an Shl, LShr or AShr, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyShift(unsigned Opcode, Value *Op0, Value *Op1,
+ const Query &Q, unsigned MaxRecurse) {
+ if (Constant *C0 = dyn_cast<Constant>(Op0)) {
+ if (Constant *C1 = dyn_cast<Constant>(Op1)) {
+ Constant *Ops[] = { C0, C1 };
+ return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.DL, Q.TLI);
+ }
+ }
+
+ // 0 shift by X -> 0
+ if (match(Op0, m_Zero()))
+ return Op0;
+
+ // X shift by 0 -> X
+ if (match(Op1, m_Zero()))
+ return Op0;
+
+ // Fold undefined shifts.
+ if (isUndefShift(Op1))
+ return UndefValue::get(Op0->getType());
// If the operation is with the result of a select instruction, check whether
// operating on either branch of the select always yields the same value.
if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
- if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, TD, DT, MaxRecurse))
+ if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
return V;
// If the operation is with the result of a phi instruction, check whether
// operating on all incoming values of the phi always yields the same value.
if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
- if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, TD, DT, MaxRecurse))
+ if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
+}
+
+/// \brief Given operands for an Shl, LShr or AShr, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyRightShift(unsigned Opcode, Value *Op0, Value *Op1,
+ bool isExact, const Query &Q,
+ unsigned MaxRecurse) {
+ if (Value *V = SimplifyShift(Opcode, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ // X >> X -> 0
+ if (Op0 == Op1)
+ return Constant::getNullValue(Op0->getType());
+
+ // undef >> X -> 0
+ // undef >> X -> undef (if it's exact)
+ if (match(Op0, m_Undef()))
+ return isExact ? Op0 : Constant::getNullValue(Op0->getType());
+
+ // The low bit cannot be shifted out of an exact shift if it is set.
+ if (isExact) {
+ unsigned BitWidth = Op0->getType()->getScalarSizeInBits();
+ APInt Op0KnownZero(BitWidth, 0);
+ APInt Op0KnownOne(BitWidth, 0);
+ computeKnownBits(Op0, Op0KnownZero, Op0KnownOne, Q.DL, /*Depth=*/0, Q.AC,
+ Q.CxtI, Q.DT);
+ if (Op0KnownOne[0])
+ return Op0;
+ }
+
+ return nullptr;
}
/// SimplifyShlInst - Given operands for an Shl, see if we can
/// fold the result. If not, this returns null.
static Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
- if (Value *V = SimplifyShift(Instruction::Shl, Op0, Op1, TD, DT, MaxRecurse))
+ const Query &Q, unsigned MaxRecurse) {
+ if (Value *V = SimplifyShift(Instruction::Shl, Op0, Op1, Q, MaxRecurse))
return V;
// undef << X -> 0
+ // undef << X -> undef if (if it's NSW/NUW)
if (match(Op0, m_Undef()))
- return Constant::getNullValue(Op0->getType());
+ return isNSW || isNUW ? Op0 : Constant::getNullValue(Op0->getType());
// (X >> A) << A -> X
Value *X;
- if (match(Op0, m_Shr(m_Value(X), m_Specific(Op1))) &&
- cast<PossiblyExactOperator>(Op0)->isExact())
+ if (match(Op0, m_Exact(m_Shr(m_Value(X), m_Specific(Op1)))))
return X;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
- const TargetData *TD, const DominatorTree *DT) {
- return ::SimplifyShlInst(Op0, Op1, isNSW, isNUW, TD, DT, RecursionLimit);
+ const DataLayout *DL, const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyShlInst(Op0, Op1, isNSW, isNUW, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
}
/// SimplifyLShrInst - Given operands for an LShr, see if we can
/// fold the result. If not, this returns null.
static Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
- if (Value *V = SimplifyShift(Instruction::LShr, Op0, Op1, TD, DT, MaxRecurse))
- return V;
-
- // undef >>l X -> 0
- if (match(Op0, m_Undef()))
- return Constant::getNullValue(Op0->getType());
+ const Query &Q, unsigned MaxRecurse) {
+ if (Value *V = SimplifyRightShift(Instruction::LShr, Op0, Op1, isExact, Q,
+ MaxRecurse))
+ return V;
// (X << A) >> A -> X
Value *X;
- if (match(Op0, m_Shl(m_Value(X), m_Specific(Op1))) &&
- cast<OverflowingBinaryOperator>(Op0)->hasNoUnsignedWrap())
+ if (match(Op0, m_NUWShl(m_Value(X), m_Specific(Op1))))
return X;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
- const TargetData *TD, const DominatorTree *DT) {
- return ::SimplifyLShrInst(Op0, Op1, isExact, TD, DT, RecursionLimit);
+ const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyLShrInst(Op0, Op1, isExact, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
}
/// SimplifyAShrInst - Given operands for an AShr, see if we can
/// fold the result. If not, this returns null.
static Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
- if (Value *V = SimplifyShift(Instruction::AShr, Op0, Op1, TD, DT, MaxRecurse))
+ const Query &Q, unsigned MaxRecurse) {
+ if (Value *V = SimplifyRightShift(Instruction::AShr, Op0, Op1, isExact, Q,
+ MaxRecurse))
return V;
// all ones >>a X -> all ones
if (match(Op0, m_AllOnes()))
return Op0;
- // undef >>a X -> all ones
- if (match(Op0, m_Undef()))
- return Constant::getAllOnesValue(Op0->getType());
-
// (X << A) >> A -> X
Value *X;
- if (match(Op0, m_Shl(m_Value(X), m_Specific(Op1))) &&
- cast<OverflowingBinaryOperator>(Op0)->hasNoSignedWrap())
+ if (match(Op0, m_NSWShl(m_Value(X), m_Specific(Op1))))
return X;
- return 0;
+ // Arithmetic shifting an all-sign-bit value is a no-op.
+ unsigned NumSignBits = ComputeNumSignBits(Op0, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
+ if (NumSignBits == Op0->getType()->getScalarSizeInBits())
+ return Op0;
+
+ return nullptr;
}
Value *llvm::SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
- const TargetData *TD, const DominatorTree *DT) {
- return ::SimplifyAShrInst(Op0, Op1, isExact, TD, DT, RecursionLimit);
+ const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyAShrInst(Op0, Op1, isExact, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
}
-/// SimplifyAndInst - Given operands for an And, see if we can
-/// fold the result. If not, this returns null.
-static Value *SimplifyAndInst(Value *Op0, Value *Op1, const TargetData *TD,
- const DominatorTree *DT, unsigned MaxRecurse) {
- if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
- if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
- Constant *Ops[] = { CLHS, CRHS };
- return ConstantFoldInstOperands(Instruction::And, CLHS->getType(),
- Ops, 2, TD);
- }
-
- // Canonicalize the constant to the RHS.
- std::swap(Op0, Op1);
+static Value *simplifyUnsignedRangeCheck(ICmpInst *ZeroICmp,
+ ICmpInst *UnsignedICmp, bool IsAnd) {
+ Value *X, *Y;
+
+ ICmpInst::Predicate EqPred;
+ if (!match(ZeroICmp, m_ICmp(EqPred, m_Value(Y), m_Zero())) ||
+ !ICmpInst::isEquality(EqPred))
+ return nullptr;
+
+ ICmpInst::Predicate UnsignedPred;
+ if (match(UnsignedICmp, m_ICmp(UnsignedPred, m_Value(X), m_Specific(Y))) &&
+ ICmpInst::isUnsigned(UnsignedPred))
+ ;
+ else if (match(UnsignedICmp,
+ m_ICmp(UnsignedPred, m_Value(Y), m_Specific(X))) &&
+ ICmpInst::isUnsigned(UnsignedPred))
+ UnsignedPred = ICmpInst::getSwappedPredicate(UnsignedPred);
+ else
+ return nullptr;
+
+ // X < Y && Y != 0 --> X < Y
+ // X < Y || Y != 0 --> Y != 0
+ if (UnsignedPred == ICmpInst::ICMP_ULT && EqPred == ICmpInst::ICMP_NE)
+ return IsAnd ? UnsignedICmp : ZeroICmp;
+
+ // X >= Y || Y != 0 --> true
+ // X >= Y || Y == 0 --> X >= Y
+ if (UnsignedPred == ICmpInst::ICMP_UGE && !IsAnd) {
+ if (EqPred == ICmpInst::ICMP_NE)
+ return getTrue(UnsignedICmp->getType());
+ return UnsignedICmp;
}
- // X & undef -> 0
- if (match(Op1, m_Undef()))
+ // X < Y && Y == 0 --> false
+ if (UnsignedPred == ICmpInst::ICMP_ULT && EqPred == ICmpInst::ICMP_EQ &&
+ IsAnd)
+ return getFalse(UnsignedICmp->getType());
+
+ return nullptr;
+}
+
+// Simplify (and (icmp ...) (icmp ...)) to true when we can tell that the range
+// of possible values cannot be satisfied.
+static Value *SimplifyAndOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
+ ICmpInst::Predicate Pred0, Pred1;
+ ConstantInt *CI1, *CI2;
+ Value *V;
+
+ if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/true))
+ return X;
+
+ if (!match(Op0, m_ICmp(Pred0, m_Add(m_Value(V), m_ConstantInt(CI1)),
+ m_ConstantInt(CI2))))
+ return nullptr;
+
+ if (!match(Op1, m_ICmp(Pred1, m_Specific(V), m_Specific(CI1))))
+ return nullptr;
+
+ Type *ITy = Op0->getType();
+
+ auto *AddInst = cast<BinaryOperator>(Op0->getOperand(0));
+ bool isNSW = AddInst->hasNoSignedWrap();
+ bool isNUW = AddInst->hasNoUnsignedWrap();
+
+ const APInt &CI1V = CI1->getValue();
+ const APInt &CI2V = CI2->getValue();
+ const APInt Delta = CI2V - CI1V;
+ if (CI1V.isStrictlyPositive()) {
+ if (Delta == 2) {
+ if (Pred0 == ICmpInst::ICMP_ULT && Pred1 == ICmpInst::ICMP_SGT)
+ return getFalse(ITy);
+ if (Pred0 == ICmpInst::ICMP_SLT && Pred1 == ICmpInst::ICMP_SGT && isNSW)
+ return getFalse(ITy);
+ }
+ if (Delta == 1) {
+ if (Pred0 == ICmpInst::ICMP_ULE && Pred1 == ICmpInst::ICMP_SGT)
+ return getFalse(ITy);
+ if (Pred0 == ICmpInst::ICMP_SLE && Pred1 == ICmpInst::ICMP_SGT && isNSW)
+ return getFalse(ITy);
+ }
+ }
+ if (CI1V.getBoolValue() && isNUW) {
+ if (Delta == 2)
+ if (Pred0 == ICmpInst::ICMP_ULT && Pred1 == ICmpInst::ICMP_UGT)
+ return getFalse(ITy);
+ if (Delta == 1)
+ if (Pred0 == ICmpInst::ICMP_ULE && Pred1 == ICmpInst::ICMP_UGT)
+ return getFalse(ITy);
+ }
+
+ return nullptr;
+}
+
+/// SimplifyAndInst - Given operands for an And, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyAndInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned MaxRecurse) {
+ if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
+ if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
+ Constant *Ops[] = { CLHS, CRHS };
+ return ConstantFoldInstOperands(Instruction::And, CLHS->getType(),
+ Ops, Q.DL, Q.TLI);
+ }
+
+ // Canonicalize the constant to the RHS.
+ std::swap(Op0, Op1);
+ }
+
+ // X & undef -> 0
+ if (match(Op1, m_Undef()))
return Constant::getNullValue(Op0->getType());
// X & X = X
return Constant::getNullValue(Op0->getType());
// (A | ?) & A = A
- Value *A = 0, *B = 0;
+ Value *A = nullptr, *B = nullptr;
if (match(Op0, m_Or(m_Value(A), m_Value(B))) &&
(A == Op1 || B == Op1))
return Op1;
(A == Op0 || B == Op0))
return Op0;
+ // A & (-A) = A if A is a power of two or zero.
+ if (match(Op0, m_Neg(m_Specific(Op1))) ||
+ match(Op1, m_Neg(m_Specific(Op0)))) {
+ if (isKnownToBeAPowerOfTwo(Op0, /*OrZero*/ true, 0, Q.AC, Q.CxtI, Q.DT))
+ return Op0;
+ if (isKnownToBeAPowerOfTwo(Op1, /*OrZero*/ true, 0, Q.AC, Q.CxtI, Q.DT))
+ return Op1;
+ }
+
+ if (auto *ICILHS = dyn_cast<ICmpInst>(Op0)) {
+ if (auto *ICIRHS = dyn_cast<ICmpInst>(Op1)) {
+ if (Value *V = SimplifyAndOfICmps(ICILHS, ICIRHS))
+ return V;
+ if (Value *V = SimplifyAndOfICmps(ICIRHS, ICILHS))
+ return V;
+ }
+ }
+
// Try some generic simplifications for associative operations.
- if (Value *V = SimplifyAssociativeBinOp(Instruction::And, Op0, Op1, TD, DT,
+ if (Value *V = SimplifyAssociativeBinOp(Instruction::And, Op0, Op1, Q,
MaxRecurse))
return V;
// And distributes over Or. Try some generic simplifications based on this.
if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Or,
- TD, DT, MaxRecurse))
+ Q, MaxRecurse))
return V;
// And distributes over Xor. Try some generic simplifications based on this.
if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Xor,
- TD, DT, MaxRecurse))
- return V;
-
- // Or distributes over And. Try some generic simplifications based on this.
- if (Value *V = FactorizeBinOp(Instruction::And, Op0, Op1, Instruction::Or,
- TD, DT, MaxRecurse))
+ Q, MaxRecurse))
return V;
// If the operation is with the result of a select instruction, check whether
// operating on either branch of the select always yields the same value.
if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
- if (Value *V = ThreadBinOpOverSelect(Instruction::And, Op0, Op1, TD, DT,
+ if (Value *V = ThreadBinOpOverSelect(Instruction::And, Op0, Op1, Q,
MaxRecurse))
return V;
// If the operation is with the result of a phi instruction, check whether
// operating on all incoming values of the phi always yields the same value.
if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
- if (Value *V = ThreadBinOpOverPHI(Instruction::And, Op0, Op1, TD, DT,
+ if (Value *V = ThreadBinOpOverPHI(Instruction::And, Op0, Op1, Q,
MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
-Value *llvm::SimplifyAndInst(Value *Op0, Value *Op1, const TargetData *TD,
- const DominatorTree *DT) {
- return ::SimplifyAndInst(Op0, Op1, TD, DT, RecursionLimit);
+Value *llvm::SimplifyAndInst(Value *Op0, Value *Op1, const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyAndInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
+}
+
+// Simplify (or (icmp ...) (icmp ...)) to true when we can tell that the union
+// contains all possible values.
+static Value *SimplifyOrOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
+ ICmpInst::Predicate Pred0, Pred1;
+ ConstantInt *CI1, *CI2;
+ Value *V;
+
+ if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/false))
+ return X;
+
+ if (!match(Op0, m_ICmp(Pred0, m_Add(m_Value(V), m_ConstantInt(CI1)),
+ m_ConstantInt(CI2))))
+ return nullptr;
+
+ if (!match(Op1, m_ICmp(Pred1, m_Specific(V), m_Specific(CI1))))
+ return nullptr;
+
+ Type *ITy = Op0->getType();
+
+ auto *AddInst = cast<BinaryOperator>(Op0->getOperand(0));
+ bool isNSW = AddInst->hasNoSignedWrap();
+ bool isNUW = AddInst->hasNoUnsignedWrap();
+
+ const APInt &CI1V = CI1->getValue();
+ const APInt &CI2V = CI2->getValue();
+ const APInt Delta = CI2V - CI1V;
+ if (CI1V.isStrictlyPositive()) {
+ if (Delta == 2) {
+ if (Pred0 == ICmpInst::ICMP_UGE && Pred1 == ICmpInst::ICMP_SLE)
+ return getTrue(ITy);
+ if (Pred0 == ICmpInst::ICMP_SGE && Pred1 == ICmpInst::ICMP_SLE && isNSW)
+ return getTrue(ITy);
+ }
+ if (Delta == 1) {
+ if (Pred0 == ICmpInst::ICMP_UGT && Pred1 == ICmpInst::ICMP_SLE)
+ return getTrue(ITy);
+ if (Pred0 == ICmpInst::ICMP_SGT && Pred1 == ICmpInst::ICMP_SLE && isNSW)
+ return getTrue(ITy);
+ }
+ }
+ if (CI1V.getBoolValue() && isNUW) {
+ if (Delta == 2)
+ if (Pred0 == ICmpInst::ICMP_UGE && Pred1 == ICmpInst::ICMP_ULE)
+ return getTrue(ITy);
+ if (Delta == 1)
+ if (Pred0 == ICmpInst::ICMP_UGT && Pred1 == ICmpInst::ICMP_ULE)
+ return getTrue(ITy);
+ }
+
+ return nullptr;
}
/// SimplifyOrInst - Given operands for an Or, see if we can
/// fold the result. If not, this returns null.
-static Value *SimplifyOrInst(Value *Op0, Value *Op1, const TargetData *TD,
- const DominatorTree *DT, unsigned MaxRecurse) {
+static Value *SimplifyOrInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned MaxRecurse) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
Constant *Ops[] = { CLHS, CRHS };
return ConstantFoldInstOperands(Instruction::Or, CLHS->getType(),
- Ops, 2, TD);
+ Ops, Q.DL, Q.TLI);
}
// Canonicalize the constant to the RHS.
return Constant::getAllOnesValue(Op0->getType());
// (A & ?) | A = A
- Value *A = 0, *B = 0;
+ Value *A = nullptr, *B = nullptr;
if (match(Op0, m_And(m_Value(A), m_Value(B))) &&
(A == Op1 || B == Op1))
return Op1;
(A == Op0 || B == Op0))
return Op0;
+ // ~(A & ?) | A = -1
+ if (match(Op0, m_Not(m_And(m_Value(A), m_Value(B)))) &&
+ (A == Op1 || B == Op1))
+ return Constant::getAllOnesValue(Op1->getType());
+
+ // A | ~(A & ?) = -1
+ if (match(Op1, m_Not(m_And(m_Value(A), m_Value(B)))) &&
+ (A == Op0 || B == Op0))
+ return Constant::getAllOnesValue(Op0->getType());
+
+ if (auto *ICILHS = dyn_cast<ICmpInst>(Op0)) {
+ if (auto *ICIRHS = dyn_cast<ICmpInst>(Op1)) {
+ if (Value *V = SimplifyOrOfICmps(ICILHS, ICIRHS))
+ return V;
+ if (Value *V = SimplifyOrOfICmps(ICIRHS, ICILHS))
+ return V;
+ }
+ }
+
// Try some generic simplifications for associative operations.
- if (Value *V = SimplifyAssociativeBinOp(Instruction::Or, Op0, Op1, TD, DT,
+ if (Value *V = SimplifyAssociativeBinOp(Instruction::Or, Op0, Op1, Q,
MaxRecurse))
return V;
// Or distributes over And. Try some generic simplifications based on this.
- if (Value *V = ExpandBinOp(Instruction::Or, Op0, Op1, Instruction::And,
- TD, DT, MaxRecurse))
- return V;
-
- // And distributes over Or. Try some generic simplifications based on this.
- if (Value *V = FactorizeBinOp(Instruction::Or, Op0, Op1, Instruction::And,
- TD, DT, MaxRecurse))
+ if (Value *V = ExpandBinOp(Instruction::Or, Op0, Op1, Instruction::And, Q,
+ MaxRecurse))
return V;
// If the operation is with the result of a select instruction, check whether
// operating on either branch of the select always yields the same value.
if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
- if (Value *V = ThreadBinOpOverSelect(Instruction::Or, Op0, Op1, TD, DT,
+ if (Value *V = ThreadBinOpOverSelect(Instruction::Or, Op0, Op1, Q,
MaxRecurse))
return V;
+ // (A & C)|(B & D)
+ Value *C = nullptr, *D = nullptr;
+ if (match(Op0, m_And(m_Value(A), m_Value(C))) &&
+ match(Op1, m_And(m_Value(B), m_Value(D)))) {
+ ConstantInt *C1 = dyn_cast<ConstantInt>(C);
+ ConstantInt *C2 = dyn_cast<ConstantInt>(D);
+ if (C1 && C2 && (C1->getValue() == ~C2->getValue())) {
+ // (A & C1)|(B & C2)
+ // If we have: ((V + N) & C1) | (V & C2)
+ // .. and C2 = ~C1 and C2 is 0+1+ and (N & C2) == 0
+ // replace with V+N.
+ Value *V1, *V2;
+ if ((C2->getValue() & (C2->getValue() + 1)) == 0 && // C2 == 0+1+
+ match(A, m_Add(m_Value(V1), m_Value(V2)))) {
+ // Add commutes, try both ways.
+ if (V1 == B &&
+ MaskedValueIsZero(V2, C2->getValue(), Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
+ return A;
+ if (V2 == B &&
+ MaskedValueIsZero(V1, C2->getValue(), Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
+ return A;
+ }
+ // Or commutes, try both ways.
+ if ((C1->getValue() & (C1->getValue() + 1)) == 0 &&
+ match(B, m_Add(m_Value(V1), m_Value(V2)))) {
+ // Add commutes, try both ways.
+ if (V1 == A &&
+ MaskedValueIsZero(V2, C1->getValue(), Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
+ return B;
+ if (V2 == A &&
+ MaskedValueIsZero(V1, C1->getValue(), Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
+ return B;
+ }
+ }
+ }
+
// If the operation is with the result of a phi instruction, check whether
// operating on all incoming values of the phi always yields the same value.
if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
- if (Value *V = ThreadBinOpOverPHI(Instruction::Or, Op0, Op1, TD, DT,
- MaxRecurse))
+ if (Value *V = ThreadBinOpOverPHI(Instruction::Or, Op0, Op1, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
-Value *llvm::SimplifyOrInst(Value *Op0, Value *Op1, const TargetData *TD,
- const DominatorTree *DT) {
- return ::SimplifyOrInst(Op0, Op1, TD, DT, RecursionLimit);
+Value *llvm::SimplifyOrInst(Value *Op0, Value *Op1, const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyOrInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
}
/// SimplifyXorInst - Given operands for a Xor, see if we can
/// fold the result. If not, this returns null.
-static Value *SimplifyXorInst(Value *Op0, Value *Op1, const TargetData *TD,
- const DominatorTree *DT, unsigned MaxRecurse) {
+static Value *SimplifyXorInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned MaxRecurse) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
Constant *Ops[] = { CLHS, CRHS };
return ConstantFoldInstOperands(Instruction::Xor, CLHS->getType(),
- Ops, 2, TD);
+ Ops, Q.DL, Q.TLI);
}
// Canonicalize the constant to the RHS.
return Constant::getAllOnesValue(Op0->getType());
// Try some generic simplifications for associative operations.
- if (Value *V = SimplifyAssociativeBinOp(Instruction::Xor, Op0, Op1, TD, DT,
+ if (Value *V = SimplifyAssociativeBinOp(Instruction::Xor, Op0, Op1, Q,
MaxRecurse))
return V;
- // And distributes over Xor. Try some generic simplifications based on this.
- if (Value *V = FactorizeBinOp(Instruction::Xor, Op0, Op1, Instruction::And,
- TD, DT, MaxRecurse))
- return V;
-
// Threading Xor over selects and phi nodes is pointless, so don't bother.
// Threading over the select in "A ^ select(cond, B, C)" means evaluating
// "A^B" and "A^C" and seeing if they are equal; but they are equal if and
// "A^B" and "A^C" thus gains nothing, but costs compile time. Similarly
// for threading over phi nodes.
- return 0;
+ return nullptr;
}
-Value *llvm::SimplifyXorInst(Value *Op0, Value *Op1, const TargetData *TD,
- const DominatorTree *DT) {
- return ::SimplifyXorInst(Op0, Op1, TD, DT, RecursionLimit);
+Value *llvm::SimplifyXorInst(Value *Op0, Value *Op1, const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyXorInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
}
-static const Type *GetCompareTy(Value *Op) {
+static Type *GetCompareTy(Value *Op) {
return CmpInst::makeCmpResultType(Op->getType());
}
+/// ExtractEquivalentCondition - Rummage around inside V looking for something
+/// equivalent to the comparison "LHS Pred RHS". Return such a value if found,
+/// otherwise return null. Helper function for analyzing max/min idioms.
+static Value *ExtractEquivalentCondition(Value *V, CmpInst::Predicate Pred,
+ Value *LHS, Value *RHS) {
+ SelectInst *SI = dyn_cast<SelectInst>(V);
+ if (!SI)
+ return nullptr;
+ CmpInst *Cmp = dyn_cast<CmpInst>(SI->getCondition());
+ if (!Cmp)
+ return nullptr;
+ Value *CmpLHS = Cmp->getOperand(0), *CmpRHS = Cmp->getOperand(1);
+ if (Pred == Cmp->getPredicate() && LHS == CmpLHS && RHS == CmpRHS)
+ return Cmp;
+ if (Pred == CmpInst::getSwappedPredicate(Cmp->getPredicate()) &&
+ LHS == CmpRHS && RHS == CmpLHS)
+ return Cmp;
+ return nullptr;
+}
+
+// A significant optimization not implemented here is assuming that alloca
+// addresses are not equal to incoming argument values. They don't *alias*,
+// as we say, but that doesn't mean they aren't equal, so we take a
+// conservative approach.
+//
+// This is inspired in part by C++11 5.10p1:
+// "Two pointers of the same type compare equal if and only if they are both
+// null, both point to the same function, or both represent the same
+// address."
+//
+// This is pretty permissive.
+//
+// It's also partly due to C11 6.5.9p6:
+// "Two pointers compare equal if and only if both are null pointers, both are
+// pointers to the same object (including a pointer to an object and a
+// subobject at its beginning) or function, both are pointers to one past the
+// last element of the same array object, or one is a pointer to one past the
+// end of one array object and the other is a pointer to the start of a
+// different array object that happens to immediately follow the first array
+// object in the address space.)
+//
+// C11's version is more restrictive, however there's no reason why an argument
+// couldn't be a one-past-the-end value for a stack object in the caller and be
+// equal to the beginning of a stack object in the callee.
+//
+// If the C and C++ standards are ever made sufficiently restrictive in this
+// area, it may be possible to update LLVM's semantics accordingly and reinstate
+// this optimization.
+static Constant *computePointerICmp(const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ CmpInst::Predicate Pred,
+ Value *LHS, Value *RHS) {
+ // First, skip past any trivial no-ops.
+ LHS = LHS->stripPointerCasts();
+ RHS = RHS->stripPointerCasts();
+
+ // A non-null pointer is not equal to a null pointer.
+ if (llvm::isKnownNonNull(LHS, TLI) && isa<ConstantPointerNull>(RHS) &&
+ (Pred == CmpInst::ICMP_EQ || Pred == CmpInst::ICMP_NE))
+ return ConstantInt::get(GetCompareTy(LHS),
+ !CmpInst::isTrueWhenEqual(Pred));
+
+ // We can only fold certain predicates on pointer comparisons.
+ switch (Pred) {
+ default:
+ return nullptr;
+
+ // Equality comaprisons are easy to fold.
+ case CmpInst::ICMP_EQ:
+ case CmpInst::ICMP_NE:
+ break;
+
+ // We can only handle unsigned relational comparisons because 'inbounds' on
+ // a GEP only protects against unsigned wrapping.
+ case CmpInst::ICMP_UGT:
+ case CmpInst::ICMP_UGE:
+ case CmpInst::ICMP_ULT:
+ case CmpInst::ICMP_ULE:
+ // However, we have to switch them to their signed variants to handle
+ // negative indices from the base pointer.
+ Pred = ICmpInst::getSignedPredicate(Pred);
+ break;
+ }
+
+ // Strip off any constant offsets so that we can reason about them.
+ // It's tempting to use getUnderlyingObject or even just stripInBoundsOffsets
+ // here and compare base addresses like AliasAnalysis does, however there are
+ // numerous hazards. AliasAnalysis and its utilities rely on special rules
+ // governing loads and stores which don't apply to icmps. Also, AliasAnalysis
+ // doesn't need to guarantee pointer inequality when it says NoAlias.
+ Constant *LHSOffset = stripAndComputeConstantOffsets(DL, LHS);
+ Constant *RHSOffset = stripAndComputeConstantOffsets(DL, RHS);
+
+ // If LHS and RHS are related via constant offsets to the same base
+ // value, we can replace it with an icmp which just compares the offsets.
+ if (LHS == RHS)
+ return ConstantExpr::getICmp(Pred, LHSOffset, RHSOffset);
+
+ // Various optimizations for (in)equality comparisons.
+ if (Pred == CmpInst::ICMP_EQ || Pred == CmpInst::ICMP_NE) {
+ // Different non-empty allocations that exist at the same time have
+ // different addresses (if the program can tell). Global variables always
+ // exist, so they always exist during the lifetime of each other and all
+ // allocas. Two different allocas usually have different addresses...
+ //
+ // However, if there's an @llvm.stackrestore dynamically in between two
+ // allocas, they may have the same address. It's tempting to reduce the
+ // scope of the problem by only looking at *static* allocas here. That would
+ // cover the majority of allocas while significantly reducing the likelihood
+ // of having an @llvm.stackrestore pop up in the middle. However, it's not
+ // actually impossible for an @llvm.stackrestore to pop up in the middle of
+ // an entry block. Also, if we have a block that's not attached to a
+ // function, we can't tell if it's "static" under the current definition.
+ // Theoretically, this problem could be fixed by creating a new kind of
+ // instruction kind specifically for static allocas. Such a new instruction
+ // could be required to be at the top of the entry block, thus preventing it
+ // from being subject to a @llvm.stackrestore. Instcombine could even
+ // convert regular allocas into these special allocas. It'd be nifty.
+ // However, until then, this problem remains open.
+ //
+ // So, we'll assume that two non-empty allocas have different addresses
+ // for now.
+ //
+ // With all that, if the offsets are within the bounds of their allocations
+ // (and not one-past-the-end! so we can't use inbounds!), and their
+ // allocations aren't the same, the pointers are not equal.
+ //
+ // Note that it's not necessary to check for LHS being a global variable
+ // address, due to canonicalization and constant folding.
+ if (isa<AllocaInst>(LHS) &&
+ (isa<AllocaInst>(RHS) || isa<GlobalVariable>(RHS))) {
+ ConstantInt *LHSOffsetCI = dyn_cast<ConstantInt>(LHSOffset);
+ ConstantInt *RHSOffsetCI = dyn_cast<ConstantInt>(RHSOffset);
+ uint64_t LHSSize, RHSSize;
+ if (LHSOffsetCI && RHSOffsetCI &&
+ getObjectSize(LHS, LHSSize, DL, TLI) &&
+ getObjectSize(RHS, RHSSize, DL, TLI)) {
+ const APInt &LHSOffsetValue = LHSOffsetCI->getValue();
+ const APInt &RHSOffsetValue = RHSOffsetCI->getValue();
+ if (!LHSOffsetValue.isNegative() &&
+ !RHSOffsetValue.isNegative() &&
+ LHSOffsetValue.ult(LHSSize) &&
+ RHSOffsetValue.ult(RHSSize)) {
+ return ConstantInt::get(GetCompareTy(LHS),
+ !CmpInst::isTrueWhenEqual(Pred));
+ }
+ }
+
+ // Repeat the above check but this time without depending on DataLayout
+ // or being able to compute a precise size.
+ if (!cast<PointerType>(LHS->getType())->isEmptyTy() &&
+ !cast<PointerType>(RHS->getType())->isEmptyTy() &&
+ LHSOffset->isNullValue() &&
+ RHSOffset->isNullValue())
+ return ConstantInt::get(GetCompareTy(LHS),
+ !CmpInst::isTrueWhenEqual(Pred));
+ }
+
+ // Even if an non-inbounds GEP occurs along the path we can still optimize
+ // equality comparisons concerning the result. We avoid walking the whole
+ // chain again by starting where the last calls to
+ // stripAndComputeConstantOffsets left off and accumulate the offsets.
+ Constant *LHSNoBound = stripAndComputeConstantOffsets(DL, LHS, true);
+ Constant *RHSNoBound = stripAndComputeConstantOffsets(DL, RHS, true);
+ if (LHS == RHS)
+ return ConstantExpr::getICmp(Pred,
+ ConstantExpr::getAdd(LHSOffset, LHSNoBound),
+ ConstantExpr::getAdd(RHSOffset, RHSNoBound));
+
+ // If one side of the equality comparison must come from a noalias call
+ // (meaning a system memory allocation function), and the other side must
+ // come from a pointer that cannot overlap with dynamically-allocated
+ // memory within the lifetime of the current function (allocas, byval
+ // arguments, globals), then determine the comparison result here.
+ SmallVector<Value *, 8> LHSUObjs, RHSUObjs;
+ GetUnderlyingObjects(LHS, LHSUObjs, DL);
+ GetUnderlyingObjects(RHS, RHSUObjs, DL);
+
+ // Is the set of underlying objects all noalias calls?
+ auto IsNAC = [](SmallVectorImpl<Value *> &Objects) {
+ return std::all_of(Objects.begin(), Objects.end(),
+ [](Value *V){ return isNoAliasCall(V); });
+ };
+
+ // Is the set of underlying objects all things which must be disjoint from
+ // noalias calls. For allocas, we consider only static ones (dynamic
+ // allocas might be transformed into calls to malloc not simultaneously
+ // live with the compared-to allocation). For globals, we exclude symbols
+ // that might be resolve lazily to symbols in another dynamically-loaded
+ // library (and, thus, could be malloc'ed by the implementation).
+ auto IsAllocDisjoint = [](SmallVectorImpl<Value *> &Objects) {
+ return std::all_of(Objects.begin(), Objects.end(),
+ [](Value *V){
+ if (const AllocaInst *AI = dyn_cast<AllocaInst>(V))
+ return AI->getParent() && AI->getParent()->getParent() &&
+ AI->isStaticAlloca();
+ if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
+ return (GV->hasLocalLinkage() ||
+ GV->hasHiddenVisibility() ||
+ GV->hasProtectedVisibility() ||
+ GV->hasUnnamedAddr()) &&
+ !GV->isThreadLocal();
+ if (const Argument *A = dyn_cast<Argument>(V))
+ return A->hasByValAttr();
+ return false;
+ });
+ };
+
+ if ((IsNAC(LHSUObjs) && IsAllocDisjoint(RHSUObjs)) ||
+ (IsNAC(RHSUObjs) && IsAllocDisjoint(LHSUObjs)))
+ return ConstantInt::get(GetCompareTy(LHS),
+ !CmpInst::isTrueWhenEqual(Pred));
+ }
+
+ // Otherwise, fail.
+ return nullptr;
+}
+
/// SimplifyICmpInst - Given operands for an ICmpInst, see if we can
/// fold the result. If not, this returns null.
static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
assert(CmpInst::isIntPredicate(Pred) && "Not an integer compare!");
if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
if (Constant *CRHS = dyn_cast<Constant>(RHS))
- return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, TD);
+ return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.DL, Q.TLI);
// If we have a constant, make sure it is on the RHS.
std::swap(LHS, RHS);
Pred = CmpInst::getSwappedPredicate(Pred);
}
- const Type *ITy = GetCompareTy(LHS); // The return type.
- const Type *OpTy = LHS->getType(); // The operand type.
+ Type *ITy = GetCompareTy(LHS); // The return type.
+ Type *OpTy = LHS->getType(); // The operand type.
// icmp X, X -> true/false
// X icmp undef -> true/false. For example, icmp ugt %X, undef -> false
return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred));
// Special case logic when the operands have i1 type.
- if (OpTy->isIntegerTy(1) || (OpTy->isVectorTy() &&
- cast<VectorType>(OpTy)->getElementType()->isIntegerTy(1))) {
+ if (OpTy->getScalarType()->isIntegerTy(1)) {
switch (Pred) {
default: break;
case ICmpInst::ICMP_EQ:
}
}
- // icmp <alloca*>, <global/alloca*/null> - Different stack variables have
- // different addresses, and what's more the address of a stack variable is
- // never null or equal to the address of a global. Note that generalizing
- // to the case where LHS is a global variable address or null is pointless,
- // since if both LHS and RHS are constants then we already constant folded
- // the compare, and if only one of them is then we moved it to RHS already.
- if (isa<AllocaInst>(LHS) && (isa<GlobalValue>(RHS) || isa<AllocaInst>(RHS) ||
- isa<ConstantPointerNull>(RHS)))
- // We already know that LHS != LHS.
- return ConstantInt::get(ITy, CmpInst::isFalseWhenEqual(Pred));
-
// If we are comparing with zero then try hard since this is a common case.
if (match(RHS, m_Zero())) {
bool LHSKnownNonNegative, LHSKnownNegative;
switch (Pred) {
- default:
- assert(false && "Unknown ICmp predicate!");
+ default: llvm_unreachable("Unknown ICmp predicate!");
case ICmpInst::ICMP_ULT:
- return ConstantInt::getFalse(LHS->getContext());
+ return getFalse(ITy);
case ICmpInst::ICMP_UGE:
- return ConstantInt::getTrue(LHS->getContext());
+ return getTrue(ITy);
case ICmpInst::ICMP_EQ:
case ICmpInst::ICMP_ULE:
- if (isKnownNonZero(LHS, TD))
- return ConstantInt::getFalse(LHS->getContext());
+ if (isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
+ return getFalse(ITy);
break;
case ICmpInst::ICMP_NE:
case ICmpInst::ICMP_UGT:
- if (isKnownNonZero(LHS, TD))
- return ConstantInt::getTrue(LHS->getContext());
+ if (isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
+ return getTrue(ITy);
break;
case ICmpInst::ICMP_SLT:
- ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, TD);
+ ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC,
+ Q.CxtI, Q.DT);
if (LHSKnownNegative)
- return ConstantInt::getTrue(LHS->getContext());
+ return getTrue(ITy);
if (LHSKnownNonNegative)
- return ConstantInt::getFalse(LHS->getContext());
+ return getFalse(ITy);
break;
case ICmpInst::ICMP_SLE:
- ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, TD);
+ ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC,
+ Q.CxtI, Q.DT);
if (LHSKnownNegative)
- return ConstantInt::getTrue(LHS->getContext());
- if (LHSKnownNonNegative && isKnownNonZero(LHS, TD))
- return ConstantInt::getFalse(LHS->getContext());
+ return getTrue(ITy);
+ if (LHSKnownNonNegative &&
+ isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
+ return getFalse(ITy);
break;
case ICmpInst::ICMP_SGE:
- ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, TD);
+ ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC,
+ Q.CxtI, Q.DT);
if (LHSKnownNegative)
- return ConstantInt::getFalse(LHS->getContext());
+ return getFalse(ITy);
if (LHSKnownNonNegative)
- return ConstantInt::getTrue(LHS->getContext());
+ return getTrue(ITy);
break;
case ICmpInst::ICMP_SGT:
- ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, TD);
+ ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC,
+ Q.CxtI, Q.DT);
if (LHSKnownNegative)
- return ConstantInt::getFalse(LHS->getContext());
- if (LHSKnownNonNegative && isKnownNonZero(LHS, TD))
- return ConstantInt::getTrue(LHS->getContext());
+ return getFalse(ITy);
+ if (LHSKnownNonNegative &&
+ isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
+ return getTrue(ITy);
break;
}
}
// See if we are doing a comparison with a constant integer.
if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
- switch (Pred) {
- default: break;
- case ICmpInst::ICMP_UGT:
- if (CI->isMaxValue(false)) // A >u MAX -> FALSE
- return ConstantInt::getFalse(CI->getContext());
- break;
- case ICmpInst::ICMP_UGE:
- if (CI->isMinValue(false)) // A >=u MIN -> TRUE
- return ConstantInt::getTrue(CI->getContext());
- break;
- case ICmpInst::ICMP_ULT:
- if (CI->isMinValue(false)) // A <u MIN -> FALSE
- return ConstantInt::getFalse(CI->getContext());
- break;
- case ICmpInst::ICMP_ULE:
- if (CI->isMaxValue(false)) // A <=u MAX -> TRUE
- return ConstantInt::getTrue(CI->getContext());
- break;
- case ICmpInst::ICMP_SGT:
- if (CI->isMaxValue(true)) // A >s MAX -> FALSE
- return ConstantInt::getFalse(CI->getContext());
- break;
- case ICmpInst::ICMP_SGE:
- if (CI->isMinValue(true)) // A >=s MIN -> TRUE
- return ConstantInt::getTrue(CI->getContext());
- break;
- case ICmpInst::ICMP_SLT:
- if (CI->isMinValue(true)) // A <s MIN -> FALSE
- return ConstantInt::getFalse(CI->getContext());
- break;
- case ICmpInst::ICMP_SLE:
- if (CI->isMaxValue(true)) // A <=s MAX -> TRUE
- return ConstantInt::getTrue(CI->getContext());
- break;
+ // Rule out tautological comparisons (eg., ult 0 or uge 0).
+ ConstantRange RHS_CR = ICmpInst::makeConstantRange(Pred, CI->getValue());
+ if (RHS_CR.isEmptySet())
+ return ConstantInt::getFalse(CI->getContext());
+ if (RHS_CR.isFullSet())
+ return ConstantInt::getTrue(CI->getContext());
+
+ // Many binary operators with constant RHS have easy to compute constant
+ // range. Use them to check whether the comparison is a tautology.
+ unsigned Width = CI->getBitWidth();
+ APInt Lower = APInt(Width, 0);
+ APInt Upper = APInt(Width, 0);
+ ConstantInt *CI2;
+ if (match(LHS, m_URem(m_Value(), m_ConstantInt(CI2)))) {
+ // 'urem x, CI2' produces [0, CI2).
+ Upper = CI2->getValue();
+ } else if (match(LHS, m_SRem(m_Value(), m_ConstantInt(CI2)))) {
+ // 'srem x, CI2' produces (-|CI2|, |CI2|).
+ Upper = CI2->getValue().abs();
+ Lower = (-Upper) + 1;
+ } else if (match(LHS, m_UDiv(m_ConstantInt(CI2), m_Value()))) {
+ // 'udiv CI2, x' produces [0, CI2].
+ Upper = CI2->getValue() + 1;
+ } else if (match(LHS, m_UDiv(m_Value(), m_ConstantInt(CI2)))) {
+ // 'udiv x, CI2' produces [0, UINT_MAX / CI2].
+ APInt NegOne = APInt::getAllOnesValue(Width);
+ if (!CI2->isZero())
+ Upper = NegOne.udiv(CI2->getValue()) + 1;
+ } else if (match(LHS, m_SDiv(m_ConstantInt(CI2), m_Value()))) {
+ if (CI2->isMinSignedValue()) {
+ // 'sdiv INT_MIN, x' produces [INT_MIN, INT_MIN / -2].
+ Lower = CI2->getValue();
+ Upper = Lower.lshr(1) + 1;
+ } else {
+ // 'sdiv CI2, x' produces [-|CI2|, |CI2|].
+ Upper = CI2->getValue().abs() + 1;
+ Lower = (-Upper) + 1;
+ }
+ } else if (match(LHS, m_SDiv(m_Value(), m_ConstantInt(CI2)))) {
+ APInt IntMin = APInt::getSignedMinValue(Width);
+ APInt IntMax = APInt::getSignedMaxValue(Width);
+ APInt Val = CI2->getValue();
+ if (Val.isAllOnesValue()) {
+ // 'sdiv x, -1' produces [INT_MIN + 1, INT_MAX]
+ // where CI2 != -1 and CI2 != 0 and CI2 != 1
+ Lower = IntMin + 1;
+ Upper = IntMax + 1;
+ } else if (Val.countLeadingZeros() < Width - 1) {
+ // 'sdiv x, CI2' produces [INT_MIN / CI2, INT_MAX / CI2]
+ // where CI2 != -1 and CI2 != 0 and CI2 != 1
+ Lower = IntMin.sdiv(Val);
+ Upper = IntMax.sdiv(Val);
+ if (Lower.sgt(Upper))
+ std::swap(Lower, Upper);
+ Upper = Upper + 1;
+ assert(Upper != Lower && "Upper part of range has wrapped!");
+ }
+ } else if (match(LHS, m_NUWShl(m_ConstantInt(CI2), m_Value()))) {
+ // 'shl nuw CI2, x' produces [CI2, CI2 << CLZ(CI2)]
+ Lower = CI2->getValue();
+ Upper = Lower.shl(Lower.countLeadingZeros()) + 1;
+ } else if (match(LHS, m_NSWShl(m_ConstantInt(CI2), m_Value()))) {
+ if (CI2->isNegative()) {
+ // 'shl nsw CI2, x' produces [CI2 << CLO(CI2)-1, CI2]
+ unsigned ShiftAmount = CI2->getValue().countLeadingOnes() - 1;
+ Lower = CI2->getValue().shl(ShiftAmount);
+ Upper = CI2->getValue() + 1;
+ } else {
+ // 'shl nsw CI2, x' produces [CI2, CI2 << CLZ(CI2)-1]
+ unsigned ShiftAmount = CI2->getValue().countLeadingZeros() - 1;
+ Lower = CI2->getValue();
+ Upper = CI2->getValue().shl(ShiftAmount) + 1;
+ }
+ } else if (match(LHS, m_LShr(m_Value(), m_ConstantInt(CI2)))) {
+ // 'lshr x, CI2' produces [0, UINT_MAX >> CI2].
+ APInt NegOne = APInt::getAllOnesValue(Width);
+ if (CI2->getValue().ult(Width))
+ Upper = NegOne.lshr(CI2->getValue()) + 1;
+ } else if (match(LHS, m_LShr(m_ConstantInt(CI2), m_Value()))) {
+ // 'lshr CI2, x' produces [CI2 >> (Width-1), CI2].
+ unsigned ShiftAmount = Width - 1;
+ if (!CI2->isZero() && cast<BinaryOperator>(LHS)->isExact())
+ ShiftAmount = CI2->getValue().countTrailingZeros();
+ Lower = CI2->getValue().lshr(ShiftAmount);
+ Upper = CI2->getValue() + 1;
+ } else if (match(LHS, m_AShr(m_Value(), m_ConstantInt(CI2)))) {
+ // 'ashr x, CI2' produces [INT_MIN >> CI2, INT_MAX >> CI2].
+ APInt IntMin = APInt::getSignedMinValue(Width);
+ APInt IntMax = APInt::getSignedMaxValue(Width);
+ if (CI2->getValue().ult(Width)) {
+ Lower = IntMin.ashr(CI2->getValue());
+ Upper = IntMax.ashr(CI2->getValue()) + 1;
+ }
+ } else if (match(LHS, m_AShr(m_ConstantInt(CI2), m_Value()))) {
+ unsigned ShiftAmount = Width - 1;
+ if (!CI2->isZero() && cast<BinaryOperator>(LHS)->isExact())
+ ShiftAmount = CI2->getValue().countTrailingZeros();
+ if (CI2->isNegative()) {
+ // 'ashr CI2, x' produces [CI2, CI2 >> (Width-1)]
+ Lower = CI2->getValue();
+ Upper = CI2->getValue().ashr(ShiftAmount) + 1;
+ } else {
+ // 'ashr CI2, x' produces [CI2 >> (Width-1), CI2]
+ Lower = CI2->getValue().ashr(ShiftAmount);
+ Upper = CI2->getValue() + 1;
+ }
+ } else if (match(LHS, m_Or(m_Value(), m_ConstantInt(CI2)))) {
+ // 'or x, CI2' produces [CI2, UINT_MAX].
+ Lower = CI2->getValue();
+ } else if (match(LHS, m_And(m_Value(), m_ConstantInt(CI2)))) {
+ // 'and x, CI2' produces [0, CI2].
+ Upper = CI2->getValue() + 1;
+ }
+ if (Lower != Upper) {
+ ConstantRange LHS_CR = ConstantRange(Lower, Upper);
+ if (RHS_CR.contains(LHS_CR))
+ return ConstantInt::getTrue(RHS->getContext());
+ if (RHS_CR.inverse().contains(LHS_CR))
+ return ConstantInt::getFalse(RHS->getContext());
}
}
if (isa<CastInst>(LHS) && (isa<Constant>(RHS) || isa<CastInst>(RHS))) {
Instruction *LI = cast<CastInst>(LHS);
Value *SrcOp = LI->getOperand(0);
- const Type *SrcTy = SrcOp->getType();
- const Type *DstTy = LI->getType();
+ Type *SrcTy = SrcOp->getType();
+ Type *DstTy = LI->getType();
// Turn icmp (ptrtoint x), (ptrtoint/constant) into a compare of the input
// if the integer type is the same size as the pointer type.
- if (MaxRecurse &&
TD && isa<PtrToIntInst>(LI) &&
- TD->getPointerSizeInBits() == DstTy->getPrimitiveSizeInBits()) {
+ if (MaxRecurse &&
Q.DL && isa<PtrToIntInst>(LI) &&
+ Q.DL->getTypeSizeInBits(SrcTy) == DstTy->getPrimitiveSizeInBits()) {
if (Constant *RHSC = dyn_cast<Constant>(RHS)) {
// Transfer the cast to the constant.
if (Value *V = SimplifyICmpInst(Pred, SrcOp,
ConstantExpr::getIntToPtr(RHSC, SrcTy),
- TD, DT, MaxRecurse-1))
+ Q, MaxRecurse-1))
return V;
} else if (PtrToIntInst *RI = dyn_cast<PtrToIntInst>(RHS)) {
if (RI->getOperand(0)->getType() == SrcTy)
// Compare without the cast.
if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0),
- TD, DT, MaxRecurse-1))
+ Q, MaxRecurse-1))
return V;
}
}
if (MaxRecurse && SrcTy == RI->getOperand(0)->getType())
// Compare X and Y. Note that signed predicates become unsigned.
if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred),
- SrcOp, RI->getOperand(0), TD, DT,
+ SrcOp, RI->getOperand(0), Q,
MaxRecurse-1))
return V;
}
// also a case of comparing two zero-extended values.
if (RExt == CI && MaxRecurse)
if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred),
- SrcOp, Trunc, TD, DT, MaxRecurse-1))
+ SrcOp, Trunc, Q, MaxRecurse-1))
return V;
// Otherwise the upper bits of LHS are zero while RHS has a non-zero bit
// there. Use this to work out the result of the comparison.
if (RExt != CI) {
switch (Pred) {
- default:
- assert(false && "Unknown ICmp predicate!");
+ default: llvm_unreachable("Unknown ICmp predicate!");
// LHS <u RHS.
case ICmpInst::ICMP_EQ:
case ICmpInst::ICMP_UGT:
if (MaxRecurse && SrcTy == RI->getOperand(0)->getType())
// Compare X and Y. Note that the predicate does not change.
if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0),
- TD, DT, MaxRecurse-1))
+ Q, MaxRecurse-1))
return V;
}
// Turn icmp (sext X), Cst into a compare of X and Cst if Cst is extended
// If the re-extended constant didn't change then this is effectively
// also a case of comparing two sign-extended values.
if (RExt == CI && MaxRecurse)
- if (Value *V = SimplifyICmpInst(Pred, SrcOp, Trunc, TD, DT,
- MaxRecurse-1))
+ if (Value *V = SimplifyICmpInst(Pred, SrcOp, Trunc, Q, MaxRecurse-1))
return V;
// Otherwise the upper bits of LHS are all equal, while RHS has varying
// bits there. Use this to work out the result of the comparison.
if (RExt != CI) {
switch (Pred) {
- default:
- assert(false && "Unknown ICmp predicate!");
+ default: llvm_unreachable("Unknown ICmp predicate!");
case ICmpInst::ICMP_EQ:
return ConstantInt::getFalse(CI->getContext());
case ICmpInst::ICMP_NE:
if (MaxRecurse)
if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SLT, SrcOp,
Constant::getNullValue(SrcTy),
- TD, DT, MaxRecurse-1))
+ Q, MaxRecurse-1))
return V;
break;
case ICmpInst::ICMP_ULT:
if (MaxRecurse)
if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SGE, SrcOp,
Constant::getNullValue(SrcTy),
- TD, DT, MaxRecurse-1))
+ Q, MaxRecurse-1))
return V;
break;
}
BinaryOperator *RBO = dyn_cast<BinaryOperator>(RHS);
if (MaxRecurse && (LBO || RBO)) {
// Analyze the case when either LHS or RHS is an add instruction.
- Value *A = 0, *B = 0, *C = 0, *D = 0;
+ Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr;
// LHS = A + B (or A and B are null); RHS = C + D (or C and D are null).
bool NoLHSWrapProblem = false, NoRHSWrapProblem = false;
if (LBO && LBO->getOpcode() == Instruction::Add) {
if ((A == RHS || B == RHS) && NoLHSWrapProblem)
if (Value *V = SimplifyICmpInst(Pred, A == RHS ? B : A,
Constant::getNullValue(RHS->getType()),
- TD, DT, MaxRecurse-1))
+ Q, MaxRecurse-1))
return V;
// icmp X, (X+Y) -> icmp 0, Y for equalities or if there is no overflow.
if ((C == LHS || D == LHS) && NoRHSWrapProblem)
if (Value *V = SimplifyICmpInst(Pred,
Constant::getNullValue(LHS->getType()),
- C == LHS ? D : C, TD, DT, MaxRecurse-1))
+ C == LHS ? D : C, Q, MaxRecurse-1))
return V;
// icmp (X+Y), (X+Z) -> icmp Y,Z for equalities or if there is no overflow.
if (A && C && (A == C || A == D || B == C || B == D) &&
NoLHSWrapProblem && NoRHSWrapProblem) {
// Determine Y and Z in the form icmp (X+Y), (X+Z).
- Value *Y = (A == C || A == D) ? B : A;
- Value *Z = (C == A || C == B) ? D : C;
- if (Value *V = SimplifyICmpInst(Pred, Y, Z, TD, DT, MaxRecurse-1))
+ Value *Y, *Z;
+ if (A == C) {
+ // C + B == C + D -> B == D
+ Y = B;
+ Z = D;
+ } else if (A == D) {
+ // D + B == C + D -> B == C
+ Y = B;
+ Z = C;
+ } else if (B == C) {
+ // A + C == C + D -> A == D
+ Y = A;
+ Z = D;
+ } else {
+ assert(B == D);
+ // A + D == C + D -> A == C
+ Y = A;
+ Z = C;
+ }
+ if (Value *V = SimplifyICmpInst(Pred, Y, Z, Q, MaxRecurse-1))
return V;
}
}
+ // icmp pred (or X, Y), X
+ if (LBO && match(LBO, m_CombineOr(m_Or(m_Value(), m_Specific(RHS)),
+ m_Or(m_Specific(RHS), m_Value())))) {
+ if (Pred == ICmpInst::ICMP_ULT)
+ return getFalse(ITy);
+ if (Pred == ICmpInst::ICMP_UGE)
+ return getTrue(ITy);
+ }
+ // icmp pred X, (or X, Y)
+ if (RBO && match(RBO, m_CombineOr(m_Or(m_Value(), m_Specific(LHS)),
+ m_Or(m_Specific(LHS), m_Value())))) {
+ if (Pred == ICmpInst::ICMP_ULE)
+ return getTrue(ITy);
+ if (Pred == ICmpInst::ICMP_UGT)
+ return getFalse(ITy);
+ }
+
+ // icmp pred (and X, Y), X
+ if (LBO && match(LBO, m_CombineOr(m_And(m_Value(), m_Specific(RHS)),
+ m_And(m_Specific(RHS), m_Value())))) {
+ if (Pred == ICmpInst::ICMP_UGT)
+ return getFalse(ITy);
+ if (Pred == ICmpInst::ICMP_ULE)
+ return getTrue(ITy);
+ }
+ // icmp pred X, (and X, Y)
+ if (RBO && match(RBO, m_CombineOr(m_And(m_Value(), m_Specific(LHS)),
+ m_And(m_Specific(LHS), m_Value())))) {
+ if (Pred == ICmpInst::ICMP_UGE)
+ return getTrue(ITy);
+ if (Pred == ICmpInst::ICMP_ULT)
+ return getFalse(ITy);
+ }
+
+ // 0 - (zext X) pred C
+ if (!CmpInst::isUnsigned(Pred) && match(LHS, m_Neg(m_ZExt(m_Value())))) {
+ if (ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS)) {
+ if (RHSC->getValue().isStrictlyPositive()) {
+ if (Pred == ICmpInst::ICMP_SLT)
+ return ConstantInt::getTrue(RHSC->getContext());
+ if (Pred == ICmpInst::ICMP_SGE)
+ return ConstantInt::getFalse(RHSC->getContext());
+ if (Pred == ICmpInst::ICMP_EQ)
+ return ConstantInt::getFalse(RHSC->getContext());
+ if (Pred == ICmpInst::ICMP_NE)
+ return ConstantInt::getTrue(RHSC->getContext());
+ }
+ if (RHSC->getValue().isNonNegative()) {
+ if (Pred == ICmpInst::ICMP_SLE)
+ return ConstantInt::getTrue(RHSC->getContext());
+ if (Pred == ICmpInst::ICMP_SGT)
+ return ConstantInt::getFalse(RHSC->getContext());
+ }
+ }
+ }
+
+ // icmp pred (urem X, Y), Y
+ if (LBO && match(LBO, m_URem(m_Value(), m_Specific(RHS)))) {
+ bool KnownNonNegative, KnownNegative;
+ switch (Pred) {
+ default:
+ break;
+ case ICmpInst::ICMP_SGT:
+ case ICmpInst::ICMP_SGE:
+ ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC,
+ Q.CxtI, Q.DT);
+ if (!KnownNonNegative)
+ break;
+ // fall-through
+ case ICmpInst::ICMP_EQ:
+ case ICmpInst::ICMP_UGT:
+ case ICmpInst::ICMP_UGE:
+ return getFalse(ITy);
+ case ICmpInst::ICMP_SLT:
+ case ICmpInst::ICMP_SLE:
+ ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC,
+ Q.CxtI, Q.DT);
+ if (!KnownNonNegative)
+ break;
+ // fall-through
+ case ICmpInst::ICMP_NE:
+ case ICmpInst::ICMP_ULT:
+ case ICmpInst::ICMP_ULE:
+ return getTrue(ITy);
+ }
+ }
+
+ // icmp pred X, (urem Y, X)
+ if (RBO && match(RBO, m_URem(m_Value(), m_Specific(LHS)))) {
+ bool KnownNonNegative, KnownNegative;
+ switch (Pred) {
+ default:
+ break;
+ case ICmpInst::ICMP_SGT:
+ case ICmpInst::ICMP_SGE:
+ ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC,
+ Q.CxtI, Q.DT);
+ if (!KnownNonNegative)
+ break;
+ // fall-through
+ case ICmpInst::ICMP_NE:
+ case ICmpInst::ICMP_UGT:
+ case ICmpInst::ICMP_UGE:
+ return getTrue(ITy);
+ case ICmpInst::ICMP_SLT:
+ case ICmpInst::ICMP_SLE:
+ ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC,
+ Q.CxtI, Q.DT);
+ if (!KnownNonNegative)
+ break;
+ // fall-through
+ case ICmpInst::ICMP_EQ:
+ case ICmpInst::ICMP_ULT:
+ case ICmpInst::ICMP_ULE:
+ return getFalse(ITy);
+ }
+ }
+
+ // x udiv y <=u x.
+ if (LBO && match(LBO, m_UDiv(m_Specific(RHS), m_Value()))) {
+ // icmp pred (X /u Y), X
+ if (Pred == ICmpInst::ICMP_UGT)
+ return getFalse(ITy);
+ if (Pred == ICmpInst::ICMP_ULE)
+ return getTrue(ITy);
+ }
+
+ // handle:
+ // CI2 << X == CI
+ // CI2 << X != CI
+ //
+ // where CI2 is a power of 2 and CI isn't
+ if (auto *CI = dyn_cast<ConstantInt>(RHS)) {
+ const APInt *CI2Val, *CIVal = &CI->getValue();
+ if (LBO && match(LBO, m_Shl(m_APInt(CI2Val), m_Value())) &&
+ CI2Val->isPowerOf2()) {
+ if (!CIVal->isPowerOf2()) {
+ // CI2 << X can equal zero in some circumstances,
+ // this simplification is unsafe if CI is zero.
+ //
+ // We know it is safe if:
+ // - The shift is nsw, we can't shift out the one bit.
+ // - The shift is nuw, we can't shift out the one bit.
+ // - CI2 is one
+ // - CI isn't zero
+ if (LBO->hasNoSignedWrap() || LBO->hasNoUnsignedWrap() ||
+ *CI2Val == 1 || !CI->isZero()) {
+ if (Pred == ICmpInst::ICMP_EQ)
+ return ConstantInt::getFalse(RHS->getContext());
+ if (Pred == ICmpInst::ICMP_NE)
+ return ConstantInt::getTrue(RHS->getContext());
+ }
+ }
+ if (CIVal->isSignBit() && *CI2Val == 1) {
+ if (Pred == ICmpInst::ICMP_UGT)
+ return ConstantInt::getFalse(RHS->getContext());
+ if (Pred == ICmpInst::ICMP_ULE)
+ return ConstantInt::getTrue(RHS->getContext());
+ }
+ }
+ }
+
+ if (MaxRecurse && LBO && RBO && LBO->getOpcode() == RBO->getOpcode() &&
+ LBO->getOperand(1) == RBO->getOperand(1)) {
+ switch (LBO->getOpcode()) {
+ default: break;
+ case Instruction::UDiv:
+ case Instruction::LShr:
+ if (ICmpInst::isSigned(Pred))
+ break;
+ // fall-through
+ case Instruction::SDiv:
+ case Instruction::AShr:
+ if (!LBO->isExact() || !RBO->isExact())
+ break;
+ if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
+ RBO->getOperand(0), Q, MaxRecurse-1))
+ return V;
+ break;
+ case Instruction::Shl: {
+ bool NUW = LBO->hasNoUnsignedWrap() && RBO->hasNoUnsignedWrap();
+ bool NSW = LBO->hasNoSignedWrap() && RBO->hasNoSignedWrap();
+ if (!NUW && !NSW)
+ break;
+ if (!NSW && ICmpInst::isSigned(Pred))
+ break;
+ if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
+ RBO->getOperand(0), Q, MaxRecurse-1))
+ return V;
+ break;
+ }
+ }
+ }
+
+ // Simplify comparisons involving max/min.
+ Value *A, *B;
+ CmpInst::Predicate P = CmpInst::BAD_ICMP_PREDICATE;
+ CmpInst::Predicate EqP; // Chosen so that "A == max/min(A,B)" iff "A EqP B".
+
+ // Signed variants on "max(a,b)>=a -> true".
+ if (match(LHS, m_SMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) {
+ if (A != RHS) std::swap(A, B); // smax(A, B) pred A.
+ EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B".
+ // We analyze this as smax(A, B) pred A.
+ P = Pred;
+ } else if (match(RHS, m_SMax(m_Value(A), m_Value(B))) &&
+ (A == LHS || B == LHS)) {
+ if (A != LHS) std::swap(A, B); // A pred smax(A, B).
+ EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B".
+ // We analyze this as smax(A, B) swapped-pred A.
+ P = CmpInst::getSwappedPredicate(Pred);
+ } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) &&
+ (A == RHS || B == RHS)) {
+ if (A != RHS) std::swap(A, B); // smin(A, B) pred A.
+ EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B".
+ // We analyze this as smax(-A, -B) swapped-pred -A.
+ // Note that we do not need to actually form -A or -B thanks to EqP.
+ P = CmpInst::getSwappedPredicate(Pred);
+ } else if (match(RHS, m_SMin(m_Value(A), m_Value(B))) &&
+ (A == LHS || B == LHS)) {
+ if (A != LHS) std::swap(A, B); // A pred smin(A, B).
+ EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B".
+ // We analyze this as smax(-A, -B) pred -A.
+ // Note that we do not need to actually form -A or -B thanks to EqP.
+ P = Pred;
+ }
+ if (P != CmpInst::BAD_ICMP_PREDICATE) {
+ // Cases correspond to "max(A, B) p A".
+ switch (P) {
+ default:
+ break;
+ case CmpInst::ICMP_EQ:
+ case CmpInst::ICMP_SLE:
+ // Equivalent to "A EqP B". This may be the same as the condition tested
+ // in the max/min; if so, we can just return that.
+ if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B))
+ return V;
+ if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B))
+ return V;
+ // Otherwise, see if "A EqP B" simplifies.
+ if (MaxRecurse)
+ if (Value *V = SimplifyICmpInst(EqP, A, B, Q, MaxRecurse-1))
+ return V;
+ break;
+ case CmpInst::ICMP_NE:
+ case CmpInst::ICMP_SGT: {
+ CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP);
+ // Equivalent to "A InvEqP B". This may be the same as the condition
+ // tested in the max/min; if so, we can just return that.
+ if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B))
+ return V;
+ if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B))
+ return V;
+ // Otherwise, see if "A InvEqP B" simplifies.
+ if (MaxRecurse)
+ if (Value *V = SimplifyICmpInst(InvEqP, A, B, Q, MaxRecurse-1))
+ return V;
+ break;
+ }
+ case CmpInst::ICMP_SGE:
+ // Always true.
+ return getTrue(ITy);
+ case CmpInst::ICMP_SLT:
+ // Always false.
+ return getFalse(ITy);
+ }
+ }
+
+ // Unsigned variants on "max(a,b)>=a -> true".
+ P = CmpInst::BAD_ICMP_PREDICATE;
+ if (match(LHS, m_UMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) {
+ if (A != RHS) std::swap(A, B); // umax(A, B) pred A.
+ EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B".
+ // We analyze this as umax(A, B) pred A.
+ P = Pred;
+ } else if (match(RHS, m_UMax(m_Value(A), m_Value(B))) &&
+ (A == LHS || B == LHS)) {
+ if (A != LHS) std::swap(A, B); // A pred umax(A, B).
+ EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B".
+ // We analyze this as umax(A, B) swapped-pred A.
+ P = CmpInst::getSwappedPredicate(Pred);
+ } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) &&
+ (A == RHS || B == RHS)) {
+ if (A != RHS) std::swap(A, B); // umin(A, B) pred A.
+ EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B".
+ // We analyze this as umax(-A, -B) swapped-pred -A.
+ // Note that we do not need to actually form -A or -B thanks to EqP.
+ P = CmpInst::getSwappedPredicate(Pred);
+ } else if (match(RHS, m_UMin(m_Value(A), m_Value(B))) &&
+ (A == LHS || B == LHS)) {
+ if (A != LHS) std::swap(A, B); // A pred umin(A, B).
+ EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B".
+ // We analyze this as umax(-A, -B) pred -A.
+ // Note that we do not need to actually form -A or -B thanks to EqP.
+ P = Pred;
+ }
+ if (P != CmpInst::BAD_ICMP_PREDICATE) {
+ // Cases correspond to "max(A, B) p A".
+ switch (P) {
+ default:
+ break;
+ case CmpInst::ICMP_EQ:
+ case CmpInst::ICMP_ULE:
+ // Equivalent to "A EqP B". This may be the same as the condition tested
+ // in the max/min; if so, we can just return that.
+ if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B))
+ return V;
+ if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B))
+ return V;
+ // Otherwise, see if "A EqP B" simplifies.
+ if (MaxRecurse)
+ if (Value *V = SimplifyICmpInst(EqP, A, B, Q, MaxRecurse-1))
+ return V;
+ break;
+ case CmpInst::ICMP_NE:
+ case CmpInst::ICMP_UGT: {
+ CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP);
+ // Equivalent to "A InvEqP B". This may be the same as the condition
+ // tested in the max/min; if so, we can just return that.
+ if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B))
+ return V;
+ if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B))
+ return V;
+ // Otherwise, see if "A InvEqP B" simplifies.
+ if (MaxRecurse)
+ if (Value *V = SimplifyICmpInst(InvEqP, A, B, Q, MaxRecurse-1))
+ return V;
+ break;
+ }
+ case CmpInst::ICMP_UGE:
+ // Always true.
+ return getTrue(ITy);
+ case CmpInst::ICMP_ULT:
+ // Always false.
+ return getFalse(ITy);
+ }
+ }
+
+ // Variants on "max(x,y) >= min(x,z)".
+ Value *C, *D;
+ if (match(LHS, m_SMax(m_Value(A), m_Value(B))) &&
+ match(RHS, m_SMin(m_Value(C), m_Value(D))) &&
+ (A == C || A == D || B == C || B == D)) {
+ // max(x, ?) pred min(x, ?).
+ if (Pred == CmpInst::ICMP_SGE)
+ // Always true.
+ return getTrue(ITy);
+ if (Pred == CmpInst::ICMP_SLT)
+ // Always false.
+ return getFalse(ITy);
+ } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) &&
+ match(RHS, m_SMax(m_Value(C), m_Value(D))) &&
+ (A == C || A == D || B == C || B == D)) {
+ // min(x, ?) pred max(x, ?).
+ if (Pred == CmpInst::ICMP_SLE)
+ // Always true.
+ return getTrue(ITy);
+ if (Pred == CmpInst::ICMP_SGT)
+ // Always false.
+ return getFalse(ITy);
+ } else if (match(LHS, m_UMax(m_Value(A), m_Value(B))) &&
+ match(RHS, m_UMin(m_Value(C), m_Value(D))) &&
+ (A == C || A == D || B == C || B == D)) {
+ // max(x, ?) pred min(x, ?).
+ if (Pred == CmpInst::ICMP_UGE)
+ // Always true.
+ return getTrue(ITy);
+ if (Pred == CmpInst::ICMP_ULT)
+ // Always false.
+ return getFalse(ITy);
+ } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) &&
+ match(RHS, m_UMax(m_Value(C), m_Value(D))) &&
+ (A == C || A == D || B == C || B == D)) {
+ // min(x, ?) pred max(x, ?).
+ if (Pred == CmpInst::ICMP_ULE)
+ // Always true.
+ return getTrue(ITy);
+ if (Pred == CmpInst::ICMP_UGT)
+ // Always false.
+ return getFalse(ITy);
+ }
+
+ // Simplify comparisons of related pointers using a powerful, recursive
+ // GEP-walk when we have target data available..
+ if (LHS->getType()->isPointerTy())
+ if (Constant *C = computePointerICmp(Q.DL, Q.TLI, Pred, LHS, RHS))
+ return C;
+
+ if (GetElementPtrInst *GLHS = dyn_cast<GetElementPtrInst>(LHS)) {
+ if (GEPOperator *GRHS = dyn_cast<GEPOperator>(RHS)) {
+ if (GLHS->getPointerOperand() == GRHS->getPointerOperand() &&
+ GLHS->hasAllConstantIndices() && GRHS->hasAllConstantIndices() &&
+ (ICmpInst::isEquality(Pred) ||
+ (GLHS->isInBounds() && GRHS->isInBounds() &&
+ Pred == ICmpInst::getSignedPredicate(Pred)))) {
+ // The bases are equal and the indices are constant. Build a constant
+ // expression GEP with the same indices and a null base pointer to see
+ // what constant folding can make out of it.
+ Constant *Null = Constant::getNullValue(GLHS->getPointerOperandType());
+ SmallVector<Value *, 4> IndicesLHS(GLHS->idx_begin(), GLHS->idx_end());
+ Constant *NewLHS = ConstantExpr::getGetElementPtr(Null, IndicesLHS);
+
+ SmallVector<Value *, 4> IndicesRHS(GRHS->idx_begin(), GRHS->idx_end());
+ Constant *NewRHS = ConstantExpr::getGetElementPtr(Null, IndicesRHS);
+ return ConstantExpr::getICmp(Pred, NewLHS, NewRHS);
+ }
+ }
+ }
+
+ // If a bit is known to be zero for A and known to be one for B,
+ // then A and B cannot be equal.
+ if (ICmpInst::isEquality(Pred)) {
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
+ uint32_t BitWidth = CI->getBitWidth();
+ APInt LHSKnownZero(BitWidth, 0);
+ APInt LHSKnownOne(BitWidth, 0);
+ computeKnownBits(LHS, LHSKnownZero, LHSKnownOne, Q.DL, /*Depth=*/0, Q.AC,
+ Q.CxtI, Q.DT);
+ const APInt &RHSVal = CI->getValue();
+ if (((LHSKnownZero & RHSVal) != 0) || ((LHSKnownOne & ~RHSVal) != 0))
+ return Pred == ICmpInst::ICMP_EQ
+ ? ConstantInt::getFalse(CI->getContext())
+ : ConstantInt::getTrue(CI->getContext());
+ }
+ }
+
// If the comparison is with the result of a select instruction, check whether
// comparing with either branch of the select always yields the same value.
if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
- if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, TD, DT, MaxRecurse))
+ if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, Q, MaxRecurse))
return V;
// If the comparison is with the result of a phi instruction, check whether
// doing the compare with each incoming phi value yields a common result.
if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
- if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, TD, DT, MaxRecurse))
+ if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT) {
- return ::SimplifyICmpInst(Predicate, LHS, RHS, TD, DT, RecursionLimit);
+ const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ Instruction *CxtI) {
+ return ::SimplifyICmpInst(Predicate, LHS, RHS, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
}
/// SimplifyFCmpInst - Given operands for an FCmpInst, see if we can
/// fold the result. If not, this returns null.
static Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
assert(CmpInst::isFPPredicate(Pred) && "Not an FP compare!");
if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
if (Constant *CRHS = dyn_cast<Constant>(RHS))
- return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, TD);
+ return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.DL, Q.TLI);
// If we have a constant, make sure it is on the RHS.
std::swap(LHS, RHS);
if (Pred == FCmpInst::FCMP_TRUE)
return ConstantInt::get(GetCompareTy(LHS), 1);
- if (isa<UndefValue>(RHS)) // fcmp pred X, undef -> undef
- return UndefValue::get(GetCompareTy(LHS));
+ // fcmp pred x, undef and fcmp pred undef, x
+ // fold to true if unordered, false if ordered
+ if (isa<UndefValue>(LHS) || isa<UndefValue>(RHS)) {
+ // Choosing NaN for the undef will always make unordered comparison succeed
+ // and ordered comparison fail.
+ return ConstantInt::get(GetCompareTy(LHS), CmpInst::isUnordered(Pred));
+ }
// fcmp x,x -> true/false. Not all compares are foldable.
if (LHS == RHS) {
}
// Handle fcmp with constant RHS
- if (Constant *RHSC = dyn_cast<Constant>(RHS)) {
+ if (ConstantFP *CFP = dyn_cast<ConstantFP>(RHS)) {
// If the constant is a nan, see if we can fold the comparison based on it.
- if (ConstantFP *CFP = dyn_cast<ConstantFP>(RHSC)) {
- if (CFP->getValueAPF().isNaN()) {
- if (FCmpInst::isOrdered(Pred)) // True "if ordered and foo"
+ if (CFP->getValueAPF().isNaN()) {
+ if (FCmpInst::isOrdered(Pred)) // True "if ordered and foo"
+ return ConstantInt::getFalse(CFP->getContext());
+ assert(FCmpInst::isUnordered(Pred) &&
+ "Comparison must be either ordered or unordered!");
+ // True if unordered.
+ return ConstantInt::getTrue(CFP->getContext());
+ }
+ // Check whether the constant is an infinity.
+ if (CFP->getValueAPF().isInfinity()) {
+ if (CFP->getValueAPF().isNegative()) {
+ switch (Pred) {
+ case FCmpInst::FCMP_OLT:
+ // No value is ordered and less than negative infinity.
return ConstantInt::getFalse(CFP->getContext());
- assert(FCmpInst::isUnordered(Pred) &&
- "Comparison must be either ordered or unordered!");
- // True if unordered.
- return ConstantInt::getTrue(CFP->getContext());
- }
- // Check whether the constant is an infinity.
- if (CFP->getValueAPF().isInfinity()) {
- if (CFP->getValueAPF().isNegative()) {
- switch (Pred) {
- case FCmpInst::FCMP_OLT:
- // No value is ordered and less than negative infinity.
- return ConstantInt::getFalse(CFP->getContext());
- case FCmpInst::FCMP_UGE:
- // All values are unordered with or at least negative infinity.
- return ConstantInt::getTrue(CFP->getContext());
- default:
- break;
- }
- } else {
- switch (Pred) {
- case FCmpInst::FCMP_OGT:
- // No value is ordered and greater than infinity.
- return ConstantInt::getFalse(CFP->getContext());
- case FCmpInst::FCMP_ULE:
- // All values are unordered with and at most infinity.
- return ConstantInt::getTrue(CFP->getContext());
- default:
- break;
- }
+ case FCmpInst::FCMP_UGE:
+ // All values are unordered with or at least negative infinity.
+ return ConstantInt::getTrue(CFP->getContext());
+ default:
+ break;
+ }
+ } else {
+ switch (Pred) {
+ case FCmpInst::FCMP_OGT:
+ // No value is ordered and greater than infinity.
+ return ConstantInt::getFalse(CFP->getContext());
+ case FCmpInst::FCMP_ULE:
+ // All values are unordered with and at most infinity.
+ return ConstantInt::getTrue(CFP->getContext());
+ default:
+ break;
}
}
}
+ if (CFP->getValueAPF().isZero()) {
+ switch (Pred) {
+ case FCmpInst::FCMP_UGE:
+ if (CannotBeOrderedLessThanZero(LHS))
+ return ConstantInt::getTrue(CFP->getContext());
+ break;
+ case FCmpInst::FCMP_OLT:
+ // X < 0
+ if (CannotBeOrderedLessThanZero(LHS))
+ return ConstantInt::getFalse(CFP->getContext());
+ break;
+ default:
+ break;
+ }
+ }
}
// If the comparison is with the result of a select instruction, check whether
// comparing with either branch of the select always yields the same value.
if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
- if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, TD, DT, MaxRecurse))
+ if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, Q, MaxRecurse))
return V;
// If the comparison is with the result of a phi instruction, check whether
// doing the compare with each incoming phi value yields a common result.
if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
- if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, TD, DT, MaxRecurse))
+ if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT) {
- return ::SimplifyFCmpInst(Predicate, LHS, RHS, TD, DT, RecursionLimit);
+ const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyFCmpInst(Predicate, LHS, RHS, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
}
/// SimplifySelectInst - Given operands for a SelectInst, see if we can fold
/// the result. If not, this returns null.
-Value *llvm::SimplifySelectInst(Value *CondVal, Value *TrueVal, Value *FalseVal,
- const TargetData *TD, const DominatorTree *) {
+static Value *SimplifySelectInst(Value *CondVal, Value *TrueVal,
+ Value *FalseVal, const Query &Q,
+ unsigned MaxRecurse) {
// select true, X, Y -> X
// select false, X, Y -> Y
- if (ConstantInt *CB = dyn_cast<ConstantInt>(CondVal))
- return CB->getZExtValue() ? TrueVal : FalseVal;
+ if (Constant *CB = dyn_cast<Constant>(CondVal)) {
+ if (CB->isAllOnesValue())
+ return TrueVal;
+ if (CB->isNullValue())
+ return FalseVal;
+ }
// select C, X, X -> X
if (TrueVal == FalseVal)
return TrueVal;
- if (isa<UndefValue>(TrueVal)) // select C, undef, X -> X
- return FalseVal;
- if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X
- return TrueVal;
if (isa<UndefValue>(CondVal)) { // select undef, X, Y -> X or Y
if (isa<Constant>(TrueVal))
return TrueVal;
return FalseVal;
}
+ if (isa<UndefValue>(TrueVal)) // select C, undef, X -> X
+ return FalseVal;
+ if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X
+ return TrueVal;
- return 0;
+ const auto *ICI = dyn_cast<ICmpInst>(CondVal);
+ unsigned BitWidth = TrueVal->getType()->getScalarSizeInBits();
+ if (ICI && BitWidth) {
+ ICmpInst::Predicate Pred = ICI->getPredicate();
+ APInt MinSignedValue = APInt::getSignBit(BitWidth);
+ Value *X;
+ const APInt *Y;
+ bool TrueWhenUnset;
+ bool IsBitTest = false;
+ if (ICmpInst::isEquality(Pred) &&
+ match(ICI->getOperand(0), m_And(m_Value(X), m_APInt(Y))) &&
+ match(ICI->getOperand(1), m_Zero())) {
+ IsBitTest = true;
+ TrueWhenUnset = Pred == ICmpInst::ICMP_EQ;
+ } else if (Pred == ICmpInst::ICMP_SLT &&
+ match(ICI->getOperand(1), m_Zero())) {
+ X = ICI->getOperand(0);
+ Y = &MinSignedValue;
+ IsBitTest = true;
+ TrueWhenUnset = false;
+ } else if (Pred == ICmpInst::ICMP_SGT &&
+ match(ICI->getOperand(1), m_AllOnes())) {
+ X = ICI->getOperand(0);
+ Y = &MinSignedValue;
+ IsBitTest = true;
+ TrueWhenUnset = true;
+ }
+ if (IsBitTest) {
+ const APInt *C;
+ // (X & Y) == 0 ? X & ~Y : X --> X
+ // (X & Y) != 0 ? X & ~Y : X --> X & ~Y
+ if (FalseVal == X && match(TrueVal, m_And(m_Specific(X), m_APInt(C))) &&
+ *Y == ~*C)
+ return TrueWhenUnset ? FalseVal : TrueVal;
+ // (X & Y) == 0 ? X : X & ~Y --> X & ~Y
+ // (X & Y) != 0 ? X : X & ~Y --> X
+ if (TrueVal == X && match(FalseVal, m_And(m_Specific(X), m_APInt(C))) &&
+ *Y == ~*C)
+ return TrueWhenUnset ? FalseVal : TrueVal;
+
+ if (Y->isPowerOf2()) {
+ // (X & Y) == 0 ? X | Y : X --> X | Y
+ // (X & Y) != 0 ? X | Y : X --> X
+ if (FalseVal == X && match(TrueVal, m_Or(m_Specific(X), m_APInt(C))) &&
+ *Y == *C)
+ return TrueWhenUnset ? TrueVal : FalseVal;
+ // (X & Y) == 0 ? X : X | Y --> X
+ // (X & Y) != 0 ? X : X | Y --> X | Y
+ if (TrueVal == X && match(FalseVal, m_Or(m_Specific(X), m_APInt(C))) &&
+ *Y == *C)
+ return TrueWhenUnset ? TrueVal : FalseVal;
+ }
+ }
+ }
+
+ return nullptr;
+}
+
+Value *llvm::SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
+ const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifySelectInst(Cond, TrueVal, FalseVal,
+ Query(DL, TLI, DT, AC, CxtI), RecursionLimit);
}
/// SimplifyGEPInst - Given operands for an GetElementPtrInst, see if we can
/// fold the result. If not, this returns null.
-Value *llvm::SimplifyGEPInst(Value *const *Ops, unsigned NumOps,
- const TargetData *TD, const DominatorTree *) {
+static Value *SimplifyGEPInst(ArrayRef<Value *> Ops, const Query &Q, unsigned) {
// The type of the GEP pointer operand.
- const PointerType *PtrTy = cast<PointerType>(Ops[0]->getType());
+ PointerType *PtrTy = cast<PointerType>(Ops[0]->getType()->getScalarType());
+ unsigned AS = PtrTy->getAddressSpace();
// getelementptr P -> P.
- if (NumOps == 1)
+ if (Ops.size() == 1)
return Ops[0];
- if (isa<UndefValue>(Ops[0])) {
- // Compute the (pointer) type returned by the GEP instruction.
- const Type *LastType = GetElementPtrInst::getIndexedType(PtrTy, &Ops[1],
- NumOps-1);
- const Type *GEPTy = PointerType::get(LastType, PtrTy->getAddressSpace());
+ // Compute the (pointer) type returned by the GEP instruction.
+ Type *LastType = GetElementPtrInst::getIndexedType(PtrTy, Ops.slice(1));
+ Type *GEPTy = PointerType::get(LastType, AS);
+ if (VectorType *VT = dyn_cast<VectorType>(Ops[0]->getType()))
+ GEPTy = VectorType::get(GEPTy, VT->getNumElements());
+
+ if (isa<UndefValue>(Ops[0]))
return UndefValue::get(GEPTy);
- }
- if (NumOps == 2) {
+ if (Ops.size() == 2) {
// getelementptr P, 0 -> P.
- if (ConstantInt *C = dyn_cast<ConstantInt>(Ops[1]))
- if (C->isZero())
- return Ops[0];
- // getelementptr P, N -> P if P points to a type of zero size.
- if (TD) {
- const Type *Ty = PtrTy->getElementType();
- if (Ty->isSized() && TD->getTypeAllocSize(Ty) == 0)
+ if (match(Ops[1], m_Zero()))
+ return Ops[0];
+
+ Type *Ty = PtrTy->getElementType();
+ if (Q.DL && Ty->isSized()) {
+ Value *P;
+ uint64_t C;
+ uint64_t TyAllocSize = Q.DL->getTypeAllocSize(Ty);
+ // getelementptr P, N -> P if P points to a type of zero size.
+ if (TyAllocSize == 0)
return Ops[0];
+
+ // The following transforms are only safe if the ptrtoint cast
+ // doesn't truncate the pointers.
+ if (Ops[1]->getType()->getScalarSizeInBits() ==
+ Q.DL->getPointerSizeInBits(AS)) {
+ auto PtrToIntOrZero = [GEPTy](Value *P) -> Value * {
+ if (match(P, m_Zero()))
+ return Constant::getNullValue(GEPTy);
+ Value *Temp;
+ if (match(P, m_PtrToInt(m_Value(Temp))))
+ if (Temp->getType() == GEPTy)
+ return Temp;
+ return nullptr;
+ };
+
+ // getelementptr V, (sub P, V) -> P if P points to a type of size 1.
+ if (TyAllocSize == 1 &&
+ match(Ops[1], m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0])))))
+ if (Value *R = PtrToIntOrZero(P))
+ return R;
+
+ // getelementptr V, (ashr (sub P, V), C) -> Q
+ // if P points to a type of size 1 << C.
+ if (match(Ops[1],
+ m_AShr(m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0]))),
+ m_ConstantInt(C))) &&
+ TyAllocSize == 1ULL << C)
+ if (Value *R = PtrToIntOrZero(P))
+ return R;
+
+ // getelementptr V, (sdiv (sub P, V), C) -> Q
+ // if P points to a type of size C.
+ if (match(Ops[1],
+ m_SDiv(m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0]))),
+ m_SpecificInt(TyAllocSize))))
+ if (Value *R = PtrToIntOrZero(P))
+ return R;
+ }
}
}
// Check to see if this is constant foldable.
- for (unsigned i = 0; i != NumOps; ++i)
+ for (unsigned i = 0, e = Ops.size(); i != e; ++i)
if (!isa<Constant>(Ops[i]))
- return 0;
+ return nullptr;
- return ConstantExpr::getGetElementPtr(cast<Constant>(Ops[0]),
- (Constant *const*)Ops+1, NumOps-1);
+ return ConstantExpr::getGetElementPtr(cast<Constant>(Ops[0]), Ops.slice(1));
+}
+
+Value *llvm::SimplifyGEPInst(ArrayRef<Value *> Ops, const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyGEPInst(Ops, Query(DL, TLI, DT, AC, CxtI), RecursionLimit);
+}
+
+/// SimplifyInsertValueInst - Given operands for an InsertValueInst, see if we
+/// can fold the result. If not, this returns null.
+static Value *SimplifyInsertValueInst(Value *Agg, Value *Val,
+ ArrayRef<unsigned> Idxs, const Query &Q,
+ unsigned) {
+ if (Constant *CAgg = dyn_cast<Constant>(Agg))
+ if (Constant *CVal = dyn_cast<Constant>(Val))
+ return ConstantFoldInsertValueInstruction(CAgg, CVal, Idxs);
+
+ // insertvalue x, undef, n -> x
+ if (match(Val, m_Undef()))
+ return Agg;
+
+ // insertvalue x, (extractvalue y, n), n
+ if (ExtractValueInst *EV = dyn_cast<ExtractValueInst>(Val))
+ if (EV->getAggregateOperand()->getType() == Agg->getType() &&
+ EV->getIndices() == Idxs) {
+ // insertvalue undef, (extractvalue y, n), n -> y
+ if (match(Agg, m_Undef()))
+ return EV->getAggregateOperand();
+
+ // insertvalue y, (extractvalue y, n), n -> y
+ if (Agg == EV->getAggregateOperand())
+ return Agg;
+ }
+
+ return nullptr;
+}
+
+Value *llvm::SimplifyInsertValueInst(
+ Value *Agg, Value *Val, ArrayRef<unsigned> Idxs, const DataLayout *DL,
+ const TargetLibraryInfo *TLI, const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyInsertValueInst(Agg, Val, Idxs, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
}
/// SimplifyPHINode - See if we can fold the given phi. If not, returns null.
-static Value *SimplifyPHINode(PHINode *PN, const DominatorTree *DT) {
+static Value *SimplifyPHINode(PHINode *PN, const Query &Q) {
// If all of the PHI's incoming values are the same then replace the PHI node
// with the common value.
- Value *CommonValue = 0;
+ Value *CommonValue = nullptr;
bool HasUndefInput = false;
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
Value *Incoming = PN->getIncomingValue(i);
continue;
}
if (CommonValue && Incoming != CommonValue)
- return 0; // Not the same, bail out.
+ return nullptr; // Not the same, bail out.
CommonValue = Incoming;
}
// instruction, we cannot return X as the result of the PHI node unless it
// dominates the PHI block.
if (HasUndefInput)
- return ValueDominatesPHI(CommonValue, PN, DT) ? CommonValue : 0;
+ return ValueDominatesPHI(CommonValue, PN, Q.DT) ? CommonValue : nullptr;
return CommonValue;
}
+static Value *SimplifyTruncInst(Value *Op, Type *Ty, const Query &Q, unsigned) {
+ if (Constant *C = dyn_cast<Constant>(Op))
+ return ConstantFoldInstOperands(Instruction::Trunc, Ty, C, Q.DL, Q.TLI);
+
+ return nullptr;
+}
+
+Value *llvm::SimplifyTruncInst(Value *Op, Type *Ty, const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyTruncInst(Op, Ty, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
+}
//=== Helper functions for higher up the class hierarchy.
/// SimplifyBinOp - Given operands for a BinaryOperator, see if we can
/// fold the result. If not, this returns null.
static Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
switch (Opcode) {
case Instruction::Add:
return SimplifyAddInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
- TD, DT, MaxRecurse);
+ Q, MaxRecurse);
+ case Instruction::FAdd:
+ return SimplifyFAddInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
+
case Instruction::Sub:
return SimplifySubInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
- TD, DT, MaxRecurse);
- case Instruction::Mul: return SimplifyMulInst (LHS, RHS, TD, DT, MaxRecurse);
- case Instruction::SDiv: return SimplifySDivInst(LHS, RHS, TD, DT, MaxRecurse);
- case Instruction::UDiv: return SimplifyUDivInst(LHS, RHS, TD, DT, MaxRecurse);
- case Instruction::FDiv: return SimplifyFDivInst(LHS, RHS, TD, DT, MaxRecurse);
+ Q, MaxRecurse);
+ case Instruction::FSub:
+ return SimplifyFSubInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
+
+ case Instruction::Mul: return SimplifyMulInst (LHS, RHS, Q, MaxRecurse);
+ case Instruction::FMul:
+ return SimplifyFMulInst (LHS, RHS, FastMathFlags(), Q, MaxRecurse);
+ case Instruction::SDiv: return SimplifySDivInst(LHS, RHS, Q, MaxRecurse);
+ case Instruction::UDiv: return SimplifyUDivInst(LHS, RHS, Q, MaxRecurse);
+ case Instruction::FDiv:
+ return SimplifyFDivInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
+ case Instruction::SRem: return SimplifySRemInst(LHS, RHS, Q, MaxRecurse);
+ case Instruction::URem: return SimplifyURemInst(LHS, RHS, Q, MaxRecurse);
+ case Instruction::FRem:
+ return SimplifyFRemInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
case Instruction::Shl:
return SimplifyShlInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
- TD, DT, MaxRecurse);
+ Q, MaxRecurse);
case Instruction::LShr:
- return SimplifyLShrInst(LHS, RHS, /*isExact*/false, TD, DT, MaxRecurse);
+ return SimplifyLShrInst(LHS, RHS, /*isExact*/false, Q, MaxRecurse);
case Instruction::AShr:
- return SimplifyAShrInst(LHS, RHS, /*isExact*/false, TD, DT, MaxRecurse);
- case Instruction::And: return SimplifyAndInst(LHS, RHS, TD, DT, MaxRecurse);
- case Instruction::Or: return SimplifyOrInst (LHS, RHS, TD, DT, MaxRecurse);
- case Instruction::Xor: return SimplifyXorInst(LHS, RHS, TD, DT, MaxRecurse);
+ return SimplifyAShrInst(LHS, RHS, /*isExact*/false, Q, MaxRecurse);
+ case Instruction::And: return SimplifyAndInst(LHS, RHS, Q, MaxRecurse);
+ case Instruction::Or: return SimplifyOrInst (LHS, RHS, Q, MaxRecurse);
+ case Instruction::Xor: return SimplifyXorInst(LHS, RHS, Q, MaxRecurse);
default:
if (Constant *CLHS = dyn_cast<Constant>(LHS))
if (Constant *CRHS = dyn_cast<Constant>(RHS)) {
Constant *COps[] = {CLHS, CRHS};
- return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, 2, TD);
+ return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, Q.DL,
+ Q.TLI);
}
// If the operation is associative, try some generic simplifications.
if (Instruction::isAssociative(Opcode))
- if (Value *V = SimplifyAssociativeBinOp(Opcode, LHS, RHS, TD, DT,
- MaxRecurse))
+ if (Value *V = SimplifyAssociativeBinOp(Opcode, LHS, RHS, Q, MaxRecurse))
return V;
- // If the operation is with the result of a select instruction, check whether
+ // If the operation is with the result of a select instruction check whether
// operating on either branch of the select always yields the same value.
if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
- if (Value *V = ThreadBinOpOverSelect(Opcode, LHS, RHS, TD, DT,
- MaxRecurse))
+ if (Value *V = ThreadBinOpOverSelect(Opcode, LHS, RHS, Q, MaxRecurse))
return V;
// If the operation is with the result of a phi instruction, check whether
// operating on all incoming values of the phi always yields the same value.
if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
- if (Value *V = ThreadBinOpOverPHI(Opcode, LHS, RHS, TD, DT, MaxRecurse))
+ if (Value *V = ThreadBinOpOverPHI(Opcode, LHS, RHS, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
+ }
+}
+
+/// SimplifyFPBinOp - Given operands for a BinaryOperator, see if we can
+/// fold the result. If not, this returns null.
+/// In contrast to SimplifyBinOp, try to use FastMathFlag when folding the
+/// result. In case we don't need FastMathFlags, simply fall to SimplifyBinOp.
+static Value *SimplifyFPBinOp(unsigned Opcode, Value *LHS, Value *RHS,
+ const FastMathFlags &FMF, const Query &Q,
+ unsigned MaxRecurse) {
+ switch (Opcode) {
+ case Instruction::FAdd:
+ return SimplifyFAddInst(LHS, RHS, FMF, Q, MaxRecurse);
+ case Instruction::FSub:
+ return SimplifyFSubInst(LHS, RHS, FMF, Q, MaxRecurse);
+ case Instruction::FMul:
+ return SimplifyFMulInst(LHS, RHS, FMF, Q, MaxRecurse);
+ default:
+ return SimplifyBinOp(Opcode, LHS, RHS, Q, MaxRecurse);
}
}
Value *llvm::SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT) {
- return ::SimplifyBinOp(Opcode, LHS, RHS, TD, DT, RecursionLimit);
+ const DataLayout *DL, const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyBinOp(Opcode, LHS, RHS, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
+}
+
+Value *llvm::SimplifyFPBinOp(unsigned Opcode, Value *LHS, Value *RHS,
+ const FastMathFlags &FMF, const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyFPBinOp(Opcode, LHS, RHS, FMF, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
}
/// SimplifyCmpInst - Given operands for a CmpInst, see if we can
/// fold the result.
static Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
if (CmpInst::isIntPredicate((CmpInst::Predicate)Predicate))
- return SimplifyICmpInst(Predicate, LHS, RHS, TD, DT, MaxRecurse);
- return SimplifyFCmpInst(Predicate, LHS, RHS, TD, DT, MaxRecurse);
+ return SimplifyICmpInst(Predicate, LHS, RHS, Q, MaxRecurse);
+ return SimplifyFCmpInst(Predicate, LHS, RHS, Q, MaxRecurse);
}
Value *llvm::SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT) {
- return ::SimplifyCmpInst(Predicate, LHS, RHS, TD, DT, RecursionLimit);
+ const DataLayout *DL, const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyCmpInst(Predicate, LHS, RHS, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
+}
+
+static bool IsIdempotent(Intrinsic::ID ID) {
+ switch (ID) {
+ default: return false;
+
+ // Unary idempotent: f(f(x)) = f(x)
+ case Intrinsic::fabs:
+ case Intrinsic::floor:
+ case Intrinsic::ceil:
+ case Intrinsic::trunc:
+ case Intrinsic::rint:
+ case Intrinsic::nearbyint:
+ case Intrinsic::round:
+ return true;
+ }
+}
+
+template <typename IterTy>
+static Value *SimplifyIntrinsic(Intrinsic::ID IID, IterTy ArgBegin, IterTy ArgEnd,
+ const Query &Q, unsigned MaxRecurse) {
+ // Perform idempotent optimizations
+ if (!IsIdempotent(IID))
+ return nullptr;
+
+ // Unary Ops
+ if (std::distance(ArgBegin, ArgEnd) == 1)
+ if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(*ArgBegin))
+ if (II->getIntrinsicID() == IID)
+ return II;
+
+ return nullptr;
+}
+
+template <typename IterTy>
+static Value *SimplifyCall(Value *V, IterTy ArgBegin, IterTy ArgEnd,
+ const Query &Q, unsigned MaxRecurse) {
+ Type *Ty = V->getType();
+ if (PointerType *PTy = dyn_cast<PointerType>(Ty))
+ Ty = PTy->getElementType();
+ FunctionType *FTy = cast<FunctionType>(Ty);
+
+ // call undef -> undef
+ if (isa<UndefValue>(V))
+ return UndefValue::get(FTy->getReturnType());
+
+ Function *F = dyn_cast<Function>(V);
+ if (!F)
+ return nullptr;
+
+ if (unsigned IID = F->getIntrinsicID())
+ if (Value *Ret =
+ SimplifyIntrinsic((Intrinsic::ID) IID, ArgBegin, ArgEnd, Q, MaxRecurse))
+ return Ret;
+
+ if (!canConstantFoldCallTo(F))
+ return nullptr;
+
+ SmallVector<Constant *, 4> ConstantArgs;
+ ConstantArgs.reserve(ArgEnd - ArgBegin);
+ for (IterTy I = ArgBegin, E = ArgEnd; I != E; ++I) {
+ Constant *C = dyn_cast<Constant>(*I);
+ if (!C)
+ return nullptr;
+ ConstantArgs.push_back(C);
+ }
+
+ return ConstantFoldCall(F, ConstantArgs, Q.TLI);
+}
+
+Value *llvm::SimplifyCall(Value *V, User::op_iterator ArgBegin,
+ User::op_iterator ArgEnd, const DataLayout *DL,
+ const TargetLibraryInfo *TLI, const DominatorTree *DT,
+ AssumptionCache *AC, const Instruction *CxtI) {
+ return ::SimplifyCall(V, ArgBegin, ArgEnd, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
+}
+
+Value *llvm::SimplifyCall(Value *V, ArrayRef<Value *> Args,
+ const DataLayout *DL, const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyCall(V, Args.begin(), Args.end(),
+ Query(DL, TLI, DT, AC, CxtI), RecursionLimit);
}
/// SimplifyInstruction - See if we can compute a simplified version of this
/// instruction. If not, this returns null.
-Value *llvm::SimplifyInstruction(Instruction *I, const TargetData *TD,
- const DominatorTree *DT) {
+Value *llvm::SimplifyInstruction(Instruction *I, const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC) {
Value *Result;
switch (I->getOpcode()) {
default:
- Result = ConstantFoldInstruction(I, TD);
+ Result = ConstantFoldInstruction(I, DL, TLI);
+ break;
+ case Instruction::FAdd:
+ Result = SimplifyFAddInst(I->getOperand(0), I->getOperand(1),
+ I->getFastMathFlags(), DL, TLI, DT, AC, I);
break;
case Instruction::Add:
Result = SimplifyAddInst(I->getOperand(0), I->getOperand(1),
cast<BinaryOperator>(I)->hasNoSignedWrap(),
- cast<BinaryOperator>(I)->hasNoUnsignedWrap(),
- TD, DT);
+ cast<BinaryOperator>(I)->hasNoUnsignedWrap(), DL,
+ TLI, DT, AC, I);
+ break;
+ case Instruction::FSub:
+ Result = SimplifyFSubInst(I->getOperand(0), I->getOperand(1),
+ I->getFastMathFlags(), DL, TLI, DT, AC, I);
break;
case Instruction::Sub:
Result = SimplifySubInst(I->getOperand(0), I->getOperand(1),
cast<BinaryOperator>(I)->hasNoSignedWrap(),
- cast<BinaryOperator>(I)->hasNoUnsignedWrap(),
- TD, DT);
+ cast<BinaryOperator>(I)->hasNoUnsignedWrap(), DL,
+ TLI, DT, AC, I);
+ break;
+ case Instruction::FMul:
+ Result = SimplifyFMulInst(I->getOperand(0), I->getOperand(1),
+ I->getFastMathFlags(), DL, TLI, DT, AC, I);
break;
case Instruction::Mul:
- Result = SimplifyMulInst(I->getOperand(0), I->getOperand(1), TD, DT);
+ Result =
+ SimplifyMulInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, AC, I);
break;
case Instruction::SDiv:
- Result = SimplifySDivInst(I->getOperand(0), I->getOperand(1), TD, DT);
+ Result = SimplifySDivInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT,
+ AC, I);
break;
case Instruction::UDiv:
- Result = SimplifyUDivInst(I->getOperand(0), I->getOperand(1), TD, DT);
+ Result = SimplifyUDivInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT,
+ AC, I);
break;
case Instruction::FDiv:
- Result = SimplifyFDivInst(I->getOperand(0), I->getOperand(1), TD, DT);
+ Result = SimplifyFDivInst(I->getOperand(0), I->getOperand(1),
+ I->getFastMathFlags(), DL, TLI, DT, AC, I);
+ break;
+ case Instruction::SRem:
+ Result = SimplifySRemInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT,
+ AC, I);
+ break;
+ case Instruction::URem:
+ Result = SimplifyURemInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT,
+ AC, I);
+ break;
+ case Instruction::FRem:
+ Result = SimplifyFRemInst(I->getOperand(0), I->getOperand(1),
+ I->getFastMathFlags(), DL, TLI, DT, AC, I);
break;
case Instruction::Shl:
Result = SimplifyShlInst(I->getOperand(0), I->getOperand(1),
cast<BinaryOperator>(I)->hasNoSignedWrap(),
- cast<BinaryOperator>(I)->hasNoUnsignedWrap(),
- TD, DT);
+ cast<BinaryOperator>(I)->hasNoUnsignedWrap(), DL,
+ TLI, DT, AC, I);
break;
case Instruction::LShr:
Result = SimplifyLShrInst(I->getOperand(0), I->getOperand(1),
- cast<BinaryOperator>(I)->isExact(),
- TD, DT);
+ cast<BinaryOperator>(I)->isExact(), DL, TLI, DT,
+ AC, I);
break;
case Instruction::AShr:
Result = SimplifyAShrInst(I->getOperand(0), I->getOperand(1),
- cast<BinaryOperator>(I)->isExact(),
- TD, DT);
+ cast<BinaryOperator>(I)->isExact(), DL, TLI, DT,
+ AC, I);
break;
case Instruction::And:
- Result = SimplifyAndInst(I->getOperand(0), I->getOperand(1), TD, DT);
+ Result =
+ SimplifyAndInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, AC, I);
break;
case Instruction::Or:
- Result = SimplifyOrInst(I->getOperand(0), I->getOperand(1), TD, DT);
+ Result =
+ SimplifyOrInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, AC, I);
break;
case Instruction::Xor:
- Result = SimplifyXorInst(I->getOperand(0), I->getOperand(1), TD, DT);
+ Result =
+ SimplifyXorInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, AC, I);
break;
case Instruction::ICmp:
- Result = SimplifyICmpInst(cast<ICmpInst>(I)->getPredicate(),
- I->getOperand(0), I->getOperand(1), TD, DT);
+ Result =
+ SimplifyICmpInst(cast<ICmpInst>(I)->getPredicate(), I->getOperand(0),
+ I->getOperand(1), DL, TLI, DT, AC, I);
break;
case Instruction::FCmp:
- Result = SimplifyFCmpInst(cast<FCmpInst>(I)->getPredicate(),
- I->getOperand(0), I->getOperand(1), TD, DT);
+ Result =
+ SimplifyFCmpInst(cast<FCmpInst>(I)->getPredicate(), I->getOperand(0),
+ I->getOperand(1), DL, TLI, DT, AC, I);
break;
case Instruction::Select:
Result = SimplifySelectInst(I->getOperand(0), I->getOperand(1),
- I->getOperand(2), TD, DT);
+ I->getOperand(2), DL, TLI, DT, AC, I);
break;
case Instruction::GetElementPtr: {
SmallVector<Value*, 8> Ops(I->op_begin(), I->op_end());
- Result = SimplifyGEPInst(&Ops[0], Ops.size(), TD, DT);
+ Result = SimplifyGEPInst(Ops, DL, TLI, DT, AC, I);
+ break;
+ }
+ case Instruction::InsertValue: {
+ InsertValueInst *IV = cast<InsertValueInst>(I);
+ Result = SimplifyInsertValueInst(IV->getAggregateOperand(),
+ IV->getInsertedValueOperand(),
+ IV->getIndices(), DL, TLI, DT, AC, I);
break;
}
case Instruction::PHI:
- Result = SimplifyPHINode(cast<PHINode>(I), DT);
+ Result = SimplifyPHINode(cast<PHINode>(I), Query(DL, TLI, DT, AC, I));
+ break;
+ case Instruction::Call: {
+ CallSite CS(cast<CallInst>(I));
+ Result = SimplifyCall(CS.getCalledValue(), CS.arg_begin(), CS.arg_end(), DL,
+ TLI, DT, AC, I);
+ break;
+ }
+ case Instruction::Trunc:
+ Result =
+ SimplifyTruncInst(I->getOperand(0), I->getType(), DL, TLI, DT, AC, I);
break;
}
return Result == I ? UndefValue::get(I->getType()) : Result;
}
-/// ReplaceAndSimplifyAllUses - Perform From->replaceAllUsesWith(To) and then
-/// delete the From instruction. In addition to a basic RAUW, this does a
-/// recursive simplification of the newly formed instructions. This catches
-/// things where one simplification exposes other opportunities. This only
-/// simplifies and deletes scalar operations, it does not change the CFG.
+/// \brief Implementation of recursive simplification through an instructions
+/// uses.
///
-void llvm::ReplaceAndSimplifyAllUses(Instruction *From, Value *To,
- const TargetData *TD,
- const DominatorTree *DT) {
- assert(From != To && "ReplaceAndSimplifyAllUses(X,X) is not valid!");
-
- // FromHandle/ToHandle - This keeps a WeakVH on the from/to values so that
- // we can know if it gets deleted out from under us or replaced in a
- // recursive simplification.
- WeakVH FromHandle(From);
- WeakVH ToHandle(To);
-
- while (!From->use_empty()) {
- // Update the instruction to use the new value.
- Use &TheUse = From->use_begin().getUse();
- Instruction *User = cast<Instruction>(TheUse.getUser());
- TheUse = To;
-
- // Check to see if the instruction can be folded due to the operand
- // replacement. For example changing (or X, Y) into (or X, -1) can replace
- // the 'or' with -1.
- Value *SimplifiedVal;
- {
- // Sanity check to make sure 'User' doesn't dangle across
- // SimplifyInstruction.
- AssertingVH<> UserHandle(User);
-
- SimplifiedVal = SimplifyInstruction(User, TD, DT);
- if (SimplifiedVal == 0) continue;
- }
+/// This is the common implementation of the recursive simplification routines.
+/// If we have a pre-simplified value in 'SimpleV', that is forcibly used to
+/// replace the instruction 'I'. Otherwise, we simply add 'I' to the list of
+/// instructions to process and attempt to simplify it using
+/// InstructionSimplify.
+///
+/// This routine returns 'true' only when *it* simplifies something. The passed
+/// in simplified value does not count toward this.
+static bool replaceAndRecursivelySimplifyImpl(Instruction *I, Value *SimpleV,
+ const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT,
+ AssumptionCache *AC) {
+ bool Simplified = false;
+ SmallSetVector<Instruction *, 8> Worklist;
+
+ // If we have an explicit value to collapse to, do that round of the
+ // simplification loop by hand initially.
+ if (SimpleV) {
+ for (User *U : I->users())
+ if (U != I)
+ Worklist.insert(cast<Instruction>(U));
+
+ // Replace the instruction with its simplified value.
+ I->replaceAllUsesWith(SimpleV);
+
+ // Gracefully handle edge cases where the instruction is not wired into any
+ // parent block.
+ if (I->getParent())
+ I->eraseFromParent();
+ } else {
+ Worklist.insert(I);
+ }
+
+ // Note that we must test the size on each iteration, the worklist can grow.
+ for (unsigned Idx = 0; Idx != Worklist.size(); ++Idx) {
+ I = Worklist[Idx];
- // Recursively simplify this user to the new value.
- ReplaceAndSimplifyAllUses(User, SimplifiedVal, TD, DT);
- From = dyn_cast_or_null<Instruction>((Value*)FromHandle);
- To = ToHandle;
+ // See if this instruction simplifies.
+ SimpleV = SimplifyInstruction(I, DL, TLI, DT, AC);
+ if (!SimpleV)
+ continue;
+
+ Simplified = true;
+
+ // Stash away all the uses of the old instruction so we can check them for
+ // recursive simplifications after a RAUW. This is cheaper than checking all
+ // uses of To on the recursive step in most cases.
+ for (User *U : I->users())
+ Worklist.insert(cast<Instruction>(U));
- assert(ToHandle && "To value deleted by recursive simplification?");
+ // Replace the instruction with its simplified value.
+ I->replaceAllUsesWith(SimpleV);
- // If the recursive simplification ended up revisiting and deleting
- // 'From' then we're done.
- if (From == 0)
- return;
+ // Gracefully handle edge cases where the instruction is not wired into any
+ // parent block.
+ if (I->getParent())
+ I->eraseFromParent();
}
+ return Simplified;
+}
- // If 'From' has value handles referring to it, do a real RAUW to update them.
- From->replaceAllUsesWith(To);
+bool llvm::recursivelySimplifyInstruction(Instruction *I, const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT,
+ AssumptionCache *AC) {
+ return replaceAndRecursivelySimplifyImpl(I, nullptr, DL, TLI, DT, AC);
+}
- From->eraseFromParent();
+bool llvm::replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV,
+ const DataLayout *DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT,
+ AssumptionCache *AC) {
+ assert(I != SimpleV && "replaceAndRecursivelySimplify(X,X) is not valid!");
+ assert(SimpleV && "Must provide a simplified value.");
+ return replaceAndRecursivelySimplifyImpl(I, SimpleV, DL, TLI, DT, AC);
}
projects / oota-llvm.git / blobdiff