#include "llvm/Support/CallSite.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Analysis/MemoryBuiltins.h"
+#include "llvm/Transforms/Utils/BuildLibCalls.h"
using namespace llvm;
/// getPromotedType - Return the specified type promoted as it would be to pass
// Treat this like a bitcast.
return EnforceKnownAlignment(U->getOperand(0), Align, PrefAlign);
}
- break;
+ return Align;
+ }
+ case Instruction::Alloca: {
+ AllocaInst *AI = cast<AllocaInst>(V);
+ // If there is a requested alignment and if this is an alloca, round up.
+ if (AI->getAlignment() >= PrefAlign)
+ return AI->getAlignment();
+ AI->setAlignment(PrefAlign);
+ return PrefAlign;
}
}
if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
// If there is a large requested alignment and we can, bump up the alignment
// of the global.
- if (!GV->isDeclaration()) {
- if (GV->getAlignment() >= PrefAlign)
- Align = GV->getAlignment();
- else {
- GV->setAlignment(PrefAlign);
- Align = PrefAlign;
- }
- }
- } else if (AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
- // If there is a requested alignment and if this is an alloca, round up.
- if (AI->getAlignment() >= PrefAlign)
- Align = AI->getAlignment();
- else {
- AI->setAlignment(PrefAlign);
- Align = PrefAlign;
- }
+ if (GV->isDeclaration()) return Align;
+
+ if (GV->getAlignment() >= PrefAlign)
+ return GV->getAlignment();
+ // We can only increase the alignment of the global if it has no alignment
+ // specified or if it is not assigned a section. If it is assigned a
+ // section, the global could be densely packed with other objects in the
+ // section, increasing the alignment could cause padding issues.
+ if (!GV->hasSection() || GV->getAlignment() == 0)
+ GV->setAlignment(PrefAlign);
+ return GV->getAlignment();
}
return Align;
return 0; // If not 1/2/4/8 bytes, exit.
// Use an integer load+store unless we can find something better.
- Type *NewPtrTy =
- PointerType::getUnqual(IntegerType::get(MI->getContext(), Size<<3));
+ unsigned SrcAddrSp =
+ cast<PointerType>(MI->getOperand(2)->getType())->getAddressSpace();
+ unsigned DstAddrSp =
+ cast<PointerType>(MI->getOperand(1)->getType())->getAddressSpace();
+
+ const IntegerType* IntType = IntegerType::get(MI->getContext(), Size<<3);
+ Type *NewSrcPtrTy = PointerType::get(IntType, SrcAddrSp);
+ Type *NewDstPtrTy = PointerType::get(IntType, DstAddrSp);
// Memcpy forces the use of i8* for the source and destination. That means
// that if you're using memcpy to move one double around, you'll get a cast
break;
}
- if (SrcETy->isSingleValueType())
- NewPtrTy = PointerType::getUnqual(SrcETy);
+ if (SrcETy->isSingleValueType()) {
+ NewSrcPtrTy = PointerType::get(SrcETy, SrcAddrSp);
+ NewDstPtrTy = PointerType::get(SrcETy, DstAddrSp);
+ }
}
}
SrcAlign = std::max(SrcAlign, CopyAlign);
DstAlign = std::max(DstAlign, CopyAlign);
- Value *Src = Builder->CreateBitCast(MI->getOperand(2), NewPtrTy);
- Value *Dest = Builder->CreateBitCast(MI->getOperand(1), NewPtrTy);
- Instruction *L = new LoadInst(Src, "tmp", false, SrcAlign);
+ Value *Src = Builder->CreateBitCast(MI->getOperand(2), NewSrcPtrTy);
+ Value *Dest = Builder->CreateBitCast(MI->getOperand(1), NewDstPtrTy);
+ Instruction *L = new LoadInst(Src, "tmp", MI->isVolatile(), SrcAlign);
InsertNewInstBefore(L, *MI);
- InsertNewInstBefore(new StoreInst(L, Dest, false, DstAlign), *MI);
+ InsertNewInstBefore(new StoreInst(L, Dest, MI->isVolatile(), DstAlign),
+ *MI);
// Set the size of the copy to 0, it will be deleted on the next iteration.
MI->setOperand(3, Constant::getNullValue(MemOpLength->getType()));
// Extract the length and alignment and fill if they are constant.
ConstantInt *LenC = dyn_cast<ConstantInt>(MI->getLength());
ConstantInt *FillC = dyn_cast<ConstantInt>(MI->getValue());
- if (!LenC || !FillC || !FillC->getType()->isInteger(8))
+ if (!LenC || !FillC || !FillC->getType()->isIntegerTy(8))
return 0;
uint64_t Len = LenC->getZExtValue();
Alignment = MI->getAlignment();
Instruction *InstCombiner::visitCallInst(CallInst &CI) {
if (isFreeCall(&CI))
return visitFree(CI);
+ if (isMalloc(&CI))
+ return visitMalloc(CI);
// If the caller function is nounwind, mark the call as nounwind, even if the
// callee isn't.
if (GVSrc->isConstant()) {
Module *M = CI.getParent()->getParent()->getParent();
Intrinsic::ID MemCpyID = Intrinsic::memcpy;
- const Type *Tys[1];
- Tys[0] = CI.getOperand(3)->getType();
- CI.setOperand(0,
- Intrinsic::getDeclaration(M, MemCpyID, Tys, 1));
+ const Type *Tys[3] = { CI.getOperand(1)->getType(),
+ CI.getOperand(2)->getType(),
+ CI.getOperand(3)->getType() };
+ CI.setCalledFunction(
+ Intrinsic::getDeclaration(M, MemCpyID, Tys, 3));
Changed = true;
}
}
switch (II->getIntrinsicID()) {
default: break;
case Intrinsic::objectsize: {
+ // We need target data for just about everything so depend on it.
+ if (!TD) break;
+
const Type *ReturnTy = CI.getType();
- Value *Op1 = II->getOperand(1);
bool Min = (cast<ConstantInt>(II->getOperand(2))->getZExtValue() == 1);
+
+ // Get to the real allocated thing and offset as fast as possible.
+ Value *Op1 = II->getOperand(1)->stripPointerCasts();
- if (!TD) break;
- Op1 = Op1->stripPointerCasts();
-
+ // If we've stripped down to a single global variable that we
+ // can know the size of then just return that.
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Op1)) {
if (GV->hasDefinitiveInitializer()) {
Constant *C = GV->getInitializer();
- size_t globalSize = TD->getTypeAllocSize(C->getType());
- return ReplaceInstUsesWith(CI, ConstantInt::get(ReturnTy, globalSize));
+ uint64_t GlobalSize = TD->getTypeAllocSize(C->getType());
+ return ReplaceInstUsesWith(CI, ConstantInt::get(ReturnTy, GlobalSize));
} else {
+ // Can't determine size of the GV.
Constant *RetVal = ConstantInt::get(ReturnTy, Min ? 0 : -1ULL);
return ReplaceInstUsesWith(CI, RetVal);
}
- }
+ } else if (AllocaInst *AI = dyn_cast<AllocaInst>(Op1)) {
+ // Get alloca size.
+ if (AI->getAllocatedType()->isSized()) {
+ uint64_t AllocaSize = TD->getTypeAllocSize(AI->getAllocatedType());
+ if (AI->isArrayAllocation()) {
+ const ConstantInt *C = dyn_cast<ConstantInt>(AI->getArraySize());
+ if (!C) break;
+ AllocaSize *= C->getZExtValue();
+ }
+ return ReplaceInstUsesWith(CI, ConstantInt::get(ReturnTy, AllocaSize));
+ }
+ } else if (CallInst *MI = extractMallocCall(Op1)) {
+ const Type* MallocType = getMallocAllocatedType(MI);
+ // Get alloca size.
+ if (MallocType && MallocType->isSized()) {
+ if (Value *NElems = getMallocArraySize(MI, TD, true)) {
+ if (ConstantInt *NElements = dyn_cast<ConstantInt>(NElems))
+ return ReplaceInstUsesWith(CI, ConstantInt::get(ReturnTy,
+ (NElements->getZExtValue() * TD->getTypeAllocSize(MallocType))));
+ }
+ }
+ } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Op1)) {
+ // Only handle constant GEPs here.
+ if (CE->getOpcode() != Instruction::GetElementPtr) break;
+ GEPOperator *GEP = cast<GEPOperator>(CE);
+
+ // Make sure we're not a constant offset from an external
+ // global.
+ Value *Operand = GEP->getPointerOperand();
+ Operand = Operand->stripPointerCasts();
+ if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Operand))
+ if (!GV->hasDefinitiveInitializer()) break;
+
+ // Get what we're pointing to and its size.
+ const PointerType *BaseType =
+ cast<PointerType>(Operand->getType());
+ uint64_t Size = TD->getTypeAllocSize(BaseType->getElementType());
+
+ // Get the current byte offset into the thing. Use the original
+ // operand in case we're looking through a bitcast.
+ SmallVector<Value*, 8> Ops(CE->op_begin()+1, CE->op_end());
+ const PointerType *OffsetType =
+ cast<PointerType>(GEP->getPointerOperand()->getType());
+ uint64_t Offset = TD->getIndexedOffset(OffsetType, &Ops[0], Ops.size());
+
+ if (Size < Offset) {
+ // Out of bound reference? Negative index normalized to large
+ // index? Just return "I don't know".
+ Constant *RetVal = ConstantInt::get(ReturnTy, Min ? 0 : -1ULL);
+ return ReplaceInstUsesWith(CI, RetVal);
+ }
+
+ Constant *RetVal = ConstantInt::get(ReturnTy, Size-Offset);
+ return ReplaceInstUsesWith(CI, RetVal);
+
+ }
+
+ // Do not return "I don't know" here. Later optimization passes could
+ // make it possible to evaluate objectsize to a constant.
+ break;
}
case Intrinsic::bswap:
// bswap(bswap(x)) -> x
// X + 0 -> {X, false}
if (RHS->isZero()) {
Constant *V[] = {
- UndefValue::get(II->getOperand(0)->getType()),
+ UndefValue::get(II->getCalledValue()->getType()),
ConstantInt::getFalse(II->getContext())
};
Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
return true;
}
+namespace {
+class InstCombineFortifiedLibCalls : public SimplifyFortifiedLibCalls {
+ InstCombiner *IC;
+protected:
+ void replaceCall(Value *With) {
+ NewInstruction = IC->ReplaceInstUsesWith(*CI, With);
+ }
+ bool isFoldable(unsigned SizeCIOp, unsigned SizeArgOp, bool isString) const {
+ if (ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(SizeCIOp))) {
+ if (SizeCI->isAllOnesValue())
+ return true;
+ if (isString)
+ return SizeCI->getZExtValue() >=
+ GetStringLength(CI->getOperand(SizeArgOp));
+ if (ConstantInt *Arg = dyn_cast<ConstantInt>(CI->getOperand(SizeArgOp)))
+ return SizeCI->getZExtValue() >= Arg->getZExtValue();
+ }
+ return false;
+ }
+public:
+ InstCombineFortifiedLibCalls(InstCombiner *IC) : IC(IC), NewInstruction(0) { }
+ Instruction *NewInstruction;
+};
+} // end anonymous namespace
+
+// Try to fold some different type of calls here.
+// Currently we're only working with the checking functions, memcpy_chk,
+// mempcpy_chk, memmove_chk, memset_chk, strcpy_chk, stpcpy_chk, strncpy_chk,
+// strcat_chk and strncat_chk.
+Instruction *InstCombiner::tryOptimizeCall(CallInst *CI, const TargetData *TD) {
+ if (CI->getCalledFunction() == 0) return 0;
+
+ InstCombineFortifiedLibCalls Simplifier(this);
+ Simplifier.fold(CI, TD);
+ return Simplifier.NewInstruction;
+}
+
// visitCallSite - Improvements for call and invoke instructions.
//
Instruction *InstCombiner::visitCallSite(CallSite CS) {
// We cannot remove an invoke, because it would change the CFG, just
// change the callee to a null pointer.
- cast<InvokeInst>(OldCall)->setOperand(0,
+ cast<InvokeInst>(OldCall)->setCalledFunction(
Constant::getNullValue(CalleeF->getType()));
return 0;
}
Changed = true;
}
+ // Try to optimize the call if possible, we require TargetData for most of
+ // this. None of these calls are seen as possibly dead so go ahead and
+ // delete the instruction now.
+ if (CallInst *CI = dyn_cast<CallInst>(CS.getInstruction())) {
+ Instruction *I = tryOptimizeCall(CI, TD);
+ // If we changed something return the result, etc. Otherwise let
+ // the fallthrough check.
+ if (I) return EraseInstFromFunction(*I);
+ }
+
return Changed ? CS.getInstruction() : 0;
}
const Type *OldRetTy = Caller->getType();
const Type *NewRetTy = FT->getReturnType();
- if (isa<StructType>(NewRetTy))
+ if (NewRetTy->isStructTy())
return false; // TODO: Handle multiple return values.
// Check to see if we are changing the return type...
if (Callee->isDeclaration() &&
// Conversion is ok if changing from one pointer type to another or from
// a pointer to an integer of the same size.
- !((isa<PointerType>(OldRetTy) || !TD ||
+ !((OldRetTy->isPointerTy() || !TD ||
OldRetTy == TD->getIntPtrType(Caller->getContext())) &&
- (isa<PointerType>(NewRetTy) || !TD ||
+ (NewRetTy->isPointerTy() || !TD ||
NewRetTy == TD->getIntPtrType(Caller->getContext()))))
return false; // Cannot transform this return value.
// Converting from one pointer type to another or between a pointer and an
// integer of the same size is safe even if we do not have a body.
bool isConvertible = ActTy == ParamTy ||
- (TD && ((isa<PointerType>(ParamTy) ||
+ (TD && ((ParamTy->isPointerTy() ||
ParamTy == TD->getIntPtrType(Caller->getContext())) &&
- (isa<PointerType>(ActTy) ||
+ (ActTy->isPointerTy() ||
ActTy == TD->getIntPtrType(Caller->getContext()))));
if (Callee->isDeclaration() && !isConvertible) return false;
}
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