//
//===----------------------------------------------------------------------===//
+#include "LLVMContextImpl.h"
#include "llvm/Type.h"
#include "llvm/Instructions.h"
#include "llvm/Function.h"
+#include "llvm/Constants.h"
+#include "llvm/GlobalVariable.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 (hasMetadata()) {
+ LLVMContext &Context = getContext();
+ Context.pImpl->TheMetadata.ValueIsDeleted(this);
+ }
}
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";
/// 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())
return true;
continue;
}
-
+
if (PN->getIncomingBlock(UI) != BB)
return true;
}
- return false;
+ return false;
+}
+
+// Code here matches isFreeCall from MallocFreeHelper, which is not in VMCore.
+static bool isFreeCall(const Value* I) {
+ const CallInst *CI = dyn_cast<CallInst>(I);
+ if (!CI)
+ return false;
+
+ const Module* M = CI->getParent()->getParent()->getParent();
+ Function *FreeFunc = M->getFunction("free");
+
+ if (CI->getOperand(0) != FreeFunc)
+ return false;
+
+ // Check free prototype.
+ // FIXME: workaround for PR5130, this will be obsolete when a nobuiltin
+ // attribute will exist.
+ const FunctionType *FTy = FreeFunc->getFunctionType();
+ if (FTy->getReturnType() != Type::getVoidTy(M->getContext()))
+ return false;
+ if (FTy->getNumParams() != 1)
+ return false;
+ if (FTy->param_begin()->get() != Type::getInt8PtrTy(M->getContext()))
+ return false;
+
+ return true;
}
/// 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;
case Instruction::Call:
+ if (isFreeCall(this))
+ return true;
return !cast<CallInst>(this)->doesNotAccessMemory();
case Instruction::Invoke:
return !cast<InvokeInst>(this)->doesNotAccessMemory();
bool Instruction::mayWriteToMemory() const {
switch (getOpcode()) {
default: return false;
- case Instruction::Free:
case Instruction::Store:
case Instruction::VAArg:
return true;
case Instruction::Call:
+ if (isFreeCall(this))
+ return true;
return !cast<CallInst>(this)->onlyReadsMemory();
case Instruction::Invoke:
return !cast<InvokeInst>(this)->onlyReadsMemory();
}
}
-/// isTrapping - Return true if the instruction may trap.
-///
-bool Instruction::isTrapping(unsigned op) {
- switch(op) {
+// Code here matches isMalloc from MallocFreeHelper, which is not in VMCore.
+static bool isMalloc(const Value* I) {
+ const CallInst *CI = dyn_cast<CallInst>(I);
+ if (!CI) {
+ const BitCastInst *BCI = dyn_cast<BitCastInst>(I);
+ if (!BCI) return false;
+
+ CI = dyn_cast<CallInst>(BCI->getOperand(0));
+ }
+
+ if (!CI) return false;
+
+ const Module* M = CI->getParent()->getParent()->getParent();
+ Constant *MallocFunc = M->getFunction("malloc");
+
+ if (CI->getOperand(0) != MallocFunc)
+ return false;
+
+ // Check malloc prototype.
+ // FIXME: workaround for PR5130, this will be obsolete when a nobuiltin
+ // attribute will exist.
+ const FunctionType *FTy = cast<Function>(MallocFunc)->getFunctionType();
+ if (FTy->getNumParams() != 1)
+ return false;
+ if (IntegerType *ITy = dyn_cast<IntegerType>(FTy->param_begin()->get())) {
+ if (ITy->getBitWidth() != 32 && ITy->getBitWidth() != 64)
+ return false;
+ return true;
+ }
+
+ return false;
+}
+
+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;
+ if (isa<AllocaInst>(getOperand(0)) || isMalloc(getOperand(0)))
+ return true;
+ if (GlobalVariable *GV = dyn_cast<GlobalVariable>(getOperand(0)))
+ return !GV->hasExternalWeakLinkage();
+ // FIXME: Handle cases involving GEPs. We have to be careful because
+ // a load of a out-of-bounds GEP has undefined behavior.
+ 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 Switch:
+ case Unwind:
+ case Unreachable:
+ return false; // Misc instructions which have effects
}
}
projects / oota-llvm.git / blobdiff