#include "llvm/Function.h"
#include "llvm/Instructions.h"
#include "llvm/IntrinsicInst.h"
-#include "llvm/LLVMContext.h"
#include "llvm/Pass.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/Support/CFG.h"
/// LowerNegateToMultiply - Replace 0-X with X*-1.
///
static Instruction *LowerNegateToMultiply(Instruction *Neg,
- std::map<AssertingVH<>, unsigned> &ValueRankMap,
- LLVMContext &Context) {
+ std::map<AssertingVH<>, unsigned> &ValueRankMap) {
Constant *Cst = Constant::getAllOnesValue(Neg->getType());
Instruction *Res = BinaryOperator::CreateMul(Neg->getOperand(1), Cst, "",Neg);
std::vector<ValueEntry> &Ops) {
Value *LHS = I->getOperand(0), *RHS = I->getOperand(1);
unsigned Opcode = I->getOpcode();
- LLVMContext &Context = I->getContext();
// First step, linearize the expression if it is in ((A+B)+(C+D)) form.
BinaryOperator *LHSBO = isReassociableOp(LHS, Opcode);
// transform them into multiplies by -1 so they can be reassociated.
if (I->getOpcode() == Instruction::Mul) {
if (!LHSBO && LHS->hasOneUse() && BinaryOperator::isNeg(LHS)) {
- LHS = LowerNegateToMultiply(cast<Instruction>(LHS),
- ValueRankMap, Context);
+ LHS = LowerNegateToMultiply(cast<Instruction>(LHS), ValueRankMap);
LHSBO = isReassociableOp(LHS, Opcode);
}
if (!RHSBO && RHS->hasOneUse() && BinaryOperator::isNeg(RHS)) {
- RHS = LowerNegateToMultiply(cast<Instruction>(RHS),
- ValueRankMap, Context);
+ RHS = LowerNegateToMultiply(cast<Instruction>(RHS), ValueRankMap);
RHSBO = isReassociableOp(RHS, Opcode);
}
}
// version of the value is returned, and BI is left pointing at the instruction
// that should be processed next by the reassociation pass.
//
-static Value *NegateValue(LLVMContext &Context, Value *V, Instruction *BI) {
+static Value *NegateValue(Value *V, Instruction *BI) {
// We are trying to expose opportunity for reassociation. One of the things
// that we want to do to achieve this is to push a negation as deep into an
// expression chain as possible, to expose the add instructions. In practice,
if (Instruction *I = dyn_cast<Instruction>(V))
if (I->getOpcode() == Instruction::Add && I->hasOneUse()) {
// Push the negates through the add.
- I->setOperand(0, NegateValue(Context, I->getOperand(0), BI));
- I->setOperand(1, NegateValue(Context, I->getOperand(1), BI));
+ I->setOperand(0, NegateValue(I->getOperand(0), BI));
+ I->setOperand(1, NegateValue(I->getOperand(1), BI));
// We must move the add instruction here, because the neg instructions do
// not dominate the old add instruction in general. By moving it, we are
/// ShouldBreakUpSubtract - Return true if we should break up this subtract of
/// X-Y into (X + -Y).
-static bool ShouldBreakUpSubtract(LLVMContext &Context, Instruction *Sub) {
+static bool ShouldBreakUpSubtract(Instruction *Sub) {
// If this is a negation, we can't split it up!
if (BinaryOperator::isNeg(Sub))
return false;
/// BreakUpSubtract - If we have (X-Y), and if either X is an add, or if this is
/// only used by an add, transform this into (X+(0-Y)) to promote better
/// reassociation.
-static Instruction *BreakUpSubtract(LLVMContext &Context, Instruction *Sub,
+static Instruction *BreakUpSubtract(Instruction *Sub,
std::map<AssertingVH<>, unsigned> &ValueRankMap) {
// Convert a subtract into an add and a neg instruction... so that sub
// instructions can be commuted with other add instructions...
// Calculate the negative value of Operand 1 of the sub instruction...
// and set it as the RHS of the add instruction we just made...
//
- Value *NegVal = NegateValue(Context, Sub->getOperand(1), Sub);
+ Value *NegVal = NegateValue(Sub->getOperand(1), Sub);
Instruction *New =
BinaryOperator::CreateAdd(Sub->getOperand(0), NegVal, "", Sub);
New->takeName(Sub);
/// by one, change this into a multiply by a constant to assist with further
/// reassociation.
static Instruction *ConvertShiftToMul(Instruction *Shl,
- std::map<AssertingVH<>, unsigned> &ValueRankMap,
- LLVMContext &Context) {
+ std::map<AssertingVH<>, unsigned> &ValueRankMap) {
// If an operand of this shift is a reassociable multiply, or if the shift
// is used by a reassociable multiply or add, turn into a multiply.
if (isReassociableOp(Shl->getOperand(0), Instruction::Mul) ||
/// ReassociateBB - Inspect all of the instructions in this basic block,
/// reassociating them as we go.
void Reassociate::ReassociateBB(BasicBlock *BB) {
- LLVMContext &Context = BB->getContext();
-
for (BasicBlock::iterator BBI = BB->begin(); BBI != BB->end(); ) {
Instruction *BI = BBI++;
if (BI->getOpcode() == Instruction::Shl &&
isa<ConstantInt>(BI->getOperand(1)))
- if (Instruction *NI = ConvertShiftToMul(BI, ValueRankMap, Context)) {
+ if (Instruction *NI = ConvertShiftToMul(BI, ValueRankMap)) {
MadeChange = true;
BI = NI;
}
// If this is a subtract instruction which is not already in negate form,
// see if we can convert it to X+-Y.
if (BI->getOpcode() == Instruction::Sub) {
- if (ShouldBreakUpSubtract(Context, BI)) {
- BI = BreakUpSubtract(Context, BI, ValueRankMap);
+ if (ShouldBreakUpSubtract(BI)) {
+ BI = BreakUpSubtract(BI, ValueRankMap);
MadeChange = true;
} else if (BinaryOperator::isNeg(BI)) {
// Otherwise, this is a negation. See if the operand is a multiply tree
if (isReassociableOp(BI->getOperand(1), Instruction::Mul) &&
(!BI->hasOneUse() ||
!isReassociableOp(BI->use_back(), Instruction::Mul))) {
- BI = LowerNegateToMultiply(BI, ValueRankMap, Context);
+ BI = LowerNegateToMultiply(BI, ValueRankMap);
MadeChange = true;
}
}