//
//===----------------------------------------------------------------------===//
+#include "llvm/Instruction.h"
#include "llvm/Type.h"
#include "llvm/Instructions.h"
-#include "llvm/Function.h"
+#include "llvm/Constants.h"
+#include "llvm/Module.h"
#include "llvm/Support/CallSite.h"
#include "llvm/Support/LeakDetector.h"
using namespace llvm;
// Out of line virtual method, so the vtable, etc has a home.
Instruction::~Instruction() {
assert(Parent == 0 && "Instruction still linked in the program!");
+ if (hasMetadataHashEntry())
+ clearMetadataHashEntries();
}
case Ret: return "ret";
case Br: return "br";
case Switch: return "switch";
+ case IndirectBr: return "indirectbr";
case Invoke: return "invoke";
case Unwind: return "unwind";
case Unreachable: return "unreachable";
case Xor: return "xor";
// Memory instructions...
- case Malloc: return "malloc";
- case Free: return "free";
case Alloca: return "alloca";
case Load: return "load";
case Store: return "store";
// Other instructions...
case ICmp: return "icmp";
case FCmp: return "fcmp";
- case VICmp: return "vicmp";
- case VFCmp: return "vfcmp";
case PHI: return "phi";
case Select: return "select";
case Call: return "call";
/// identical to the current one. This means that all operands match and any
/// extra information (e.g. load is volatile) agree.
bool Instruction::isIdenticalTo(const Instruction *I) const {
+ return isIdenticalToWhenDefined(I) &&
+ SubclassOptionalData == I->SubclassOptionalData;
+}
+
+/// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it
+/// ignores the SubclassOptionalData flags, which specify conditions
+/// under which the instruction's result is undefined.
+bool Instruction::isIdenticalToWhenDefined(const Instruction *I) const {
if (getOpcode() != I->getOpcode() ||
getNumOperands() != I->getNumOperands() ||
getType() != I->getType())
/// specified block. Note that PHI nodes are considered to evaluate their
/// operands in the corresponding predecessor block.
bool Instruction::isUsedOutsideOfBlock(const BasicBlock *BB) const {
- for (use_const_iterator UI = use_begin(), E = use_end(); UI != E; ++UI) {
+ for (const_use_iterator UI = use_begin(), E = use_end(); UI != E; ++UI) {
// PHI nodes uses values in the corresponding predecessor block. For other
// instructions, just check to see whether the parent of the use matches up.
- const PHINode *PN = dyn_cast<PHINode>(*UI);
+ const User *U = *UI;
+ const PHINode *PN = dyn_cast<PHINode>(U);
if (PN == 0) {
- if (cast<Instruction>(*UI)->getParent() != BB)
+ if (cast<Instruction>(U)->getParent() != BB)
return true;
continue;
}
-
+
if (PN->getIncomingBlock(UI) != BB)
return true;
}
- return false;
+ return false;
}
/// mayReadFromMemory - Return true if this instruction may read memory.
bool Instruction::mayReadFromMemory() const {
switch (getOpcode()) {
default: return false;
- case Instruction::Free:
case Instruction::VAArg:
case Instruction::Load:
return true;
bool Instruction::mayWriteToMemory() const {
switch (getOpcode()) {
default: return false;
- case Instruction::Free:
case Instruction::Store:
case Instruction::VAArg:
return true;
}
}
-/// isTrapping - Return true if the instruction may trap.
-///
-bool Instruction::isTrapping(unsigned op) {
- switch(op) {
+bool Instruction::isSafeToSpeculativelyExecute() const {
+ for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
+ if (Constant *C = dyn_cast<Constant>(getOperand(i)))
+ if (C->canTrap())
+ return false;
+
+ switch (getOpcode()) {
+ default:
+ return true;
case UDiv:
+ case URem: {
+ // x / y is undefined if y == 0, but calcuations like x / 3 are safe.
+ ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
+ return Op && !Op->isNullValue();
+ }
case SDiv:
- case FDiv:
- case URem:
- case SRem:
- case FRem:
- case Load:
- case Store:
+ case SRem: {
+ // x / y is undefined if y == 0, and might be undefined if y == -1,
+ // but calcuations like x / 3 are safe.
+ ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
+ return Op && !Op->isNullValue() && !Op->isAllOnesValue();
+ }
+ case Load: {
+ if (cast<LoadInst>(this)->isVolatile())
+ return false;
+ // Note that it is not safe to speculate into a malloc'd region because
+ // malloc may return null.
+ // It's also not safe to follow a bitcast, for example:
+ // bitcast i8* (alloca i8) to i32*
+ // would result in a 4-byte load from a 1-byte alloca.
+ Value *Op0 = getOperand(0);
+ if (GEPOperator *GEP = dyn_cast<GEPOperator>(Op0)) {
+ // TODO: it's safe to do this for any GEP with constant indices that
+ // compute inside the allocated type, but not for any inbounds gep.
+ if (GEP->hasAllZeroIndices())
+ Op0 = GEP->getPointerOperand();
+ }
+ if (isa<AllocaInst>(Op0))
+ return true;
+ if (GlobalVariable *GV = dyn_cast<GlobalVariable>(getOperand(0)))
+ return !GV->hasExternalWeakLinkage();
+ return false;
+ }
case Call:
- case Invoke:
+ return false; // The called function could have undefined behavior or
+ // side-effects.
+ // FIXME: We should special-case some intrinsics (bswap,
+ // overflow-checking arithmetic, etc.)
case VAArg:
- return true;
- default:
- return false;
+ case Alloca:
+ case Invoke:
+ case PHI:
+ case Store:
+ case Ret:
+ case Br:
+ case IndirectBr:
+ case Switch:
+ case Unwind:
+ case Unreachable:
+ return false; // Misc instructions which have effects
}
}
+
+Instruction *Instruction::clone() const {
+ Instruction *New = clone_impl();
+ New->SubclassOptionalData = SubclassOptionalData;
+ if (!hasMetadata())
+ return New;
+
+ // Otherwise, enumerate and copy over metadata from the old instruction to the
+ // new one.
+ SmallVector<std::pair<unsigned, MDNode*>, 4> TheMDs;
+ getAllMetadata(TheMDs);
+ for (unsigned i = 0, e = TheMDs.size(); i != e; ++i)
+ New->setMetadata(TheMDs[i].first, TheMDs[i].second);
+ return New;
+}
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