[llvm-commits] [llvm] r98338 - in /llvm/trunk: include/llvm/Transforms/Utils/BuildLibCalls.h lib/Transforms/InstCombine/InstCombineCalls.cpp lib/Transforms/Scalar/CodeGenPrepare.cpp lib/Transforms/Utils/BuildLibCalls.cpp
Benjamin Kramer
benny.kra at googlemail.com
Fri Mar 12 01:27:42 PST 2010
Author: d0k
Date: Fri Mar 12 03:27:41 2010
New Revision: 98338
URL: http://llvm.org/viewvc/llvm-project?rev=98338&view=rev
Log:
Factor checked library call optimization into a common helper class and use it
to unify the almost identical code in CodeGenPrepare and InstCombineCalls.
Modified:
llvm/trunk/include/llvm/Transforms/Utils/BuildLibCalls.h
llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp
llvm/trunk/lib/Transforms/Scalar/CodeGenPrepare.cpp
llvm/trunk/lib/Transforms/Utils/BuildLibCalls.cpp
Modified: llvm/trunk/include/llvm/Transforms/Utils/BuildLibCalls.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/BuildLibCalls.h?rev=98338&r1=98337&r2=98338&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/BuildLibCalls.h (original)
+++ llvm/trunk/include/llvm/Transforms/Utils/BuildLibCalls.h Fri Mar 12 03:27:41 2010
@@ -96,6 +96,18 @@
/// a pointer, Size is an 'intptr_t', and File is a pointer to FILE.
void EmitFWrite(Value *Ptr, Value *Size, Value *File, IRBuilder<> &B,
const TargetData *TD);
+
+ /// SimplifyFortifiedLibCalls - Helper class for folding checked library
+ /// calls (e.g. __strcpy_chk) into their unchecked counterparts.
+ class SimplifyFortifiedLibCalls {
+ protected:
+ CallInst *CI;
+ virtual void replaceCall(Value *With) = 0;
+ virtual bool isFoldable(unsigned SizeCIOp, unsigned SizeArgOp,
+ bool isString) const = 0;
+ public:
+ bool fold(CallInst *CI, const TargetData *TD);
+ };
}
#endif
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp?rev=98338&r1=98337&r2=98338&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp Fri Mar 12 03:27:41 2010
@@ -751,117 +751,41 @@
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;
-
- StringRef Name = CI->getCalledFunction()->getName();
- BasicBlock *BB = CI->getParent();
- IRBuilder<> B(CI->getParent()->getContext());
-
- // Set the builder to the instruction after the call.
- B.SetInsertPoint(BB, CI);
-
- if (Name == "__memcpy_chk") {
- ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(4));
- if (!SizeCI)
- return 0;
- ConstantInt *SizeArg = dyn_cast<ConstantInt>(CI->getOperand(3));
- if (!SizeArg)
- return 0;
- if (SizeCI->isAllOnesValue() ||
- SizeCI->getZExtValue() <= SizeArg->getZExtValue()) {
- EmitMemCpy(CI->getOperand(1), CI->getOperand(2), CI->getOperand(3),
- 1, B, TD);
- return ReplaceInstUsesWith(*CI, CI->getOperand(1));
- }
- return 0;
- }
-
- // Should be similar to memcpy.
- if (Name == "__mempcpy_chk") {
- return 0;
- }
-
- if (Name == "__memmove_chk") {
- ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(4));
- if (!SizeCI)
- return 0;
- ConstantInt *SizeArg = dyn_cast<ConstantInt>(CI->getOperand(3));
- if (!SizeArg)
- return 0;
- if (SizeCI->isAllOnesValue() ||
- SizeCI->getZExtValue() <= SizeArg->getZExtValue()) {
- EmitMemMove(CI->getOperand(1), CI->getOperand(2), CI->getOperand(3),
- 1, B, TD);
- return ReplaceInstUsesWith(*CI, CI->getOperand(1));
- }
- return 0;
- }
-
- if (Name == "__memset_chk") {
- ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(4));
- if (!SizeCI)
- return 0;
- ConstantInt *SizeArg = dyn_cast<ConstantInt>(CI->getOperand(3));
- if (!SizeArg)
- return 0;
- if (SizeCI->isAllOnesValue() ||
- SizeCI->getZExtValue() <= SizeArg->getZExtValue()) {
- Value *Val = B.CreateIntCast(CI->getOperand(2), B.getInt8Ty(),
- false);
- EmitMemSet(CI->getOperand(1), Val, CI->getOperand(3), B, TD);
- return ReplaceInstUsesWith(*CI, CI->getOperand(1));
- }
- return 0;
- }
-
- if (Name == "__strcpy_chk" || Name == "__stpcpy_chk") {
- ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(3));
- if (!SizeCI)
- return 0;
- // If a) we don't have any length information, or b) we know this will
- // fit then just lower to a plain st[rp]cpy. Otherwise we'll keep our
- // st[rp]cpy_chk call which may fail at runtime if the size is too long.
- // TODO: It might be nice to get a maximum length out of the possible
- // string lengths for varying.
- if (SizeCI->isAllOnesValue() ||
- SizeCI->getZExtValue() >= GetStringLength(CI->getOperand(2))) {
- Value *Ret = EmitStrCpy(CI->getOperand(1), CI->getOperand(2), B, TD,
- Name.substr(2, 6));
- return ReplaceInstUsesWith(*CI, Ret);
- }
- return 0;
- }
-
- if (Name == "__strncpy_chk") {
- ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(4));
- if (!SizeCI)
- return 0;
- ConstantInt *SizeArg = dyn_cast<ConstantInt>(CI->getOperand(3));
- if (!SizeArg)
- return 0;
- if (SizeCI->isAllOnesValue() ||
- SizeCI->getZExtValue() <= SizeArg->getZExtValue()) {
- Value *Ret = EmitStrNCpy(CI->getOperand(1), CI->getOperand(2),
- CI->getOperand(3), B, TD);
- return ReplaceInstUsesWith(*CI, Ret);
- }
- return 0;
- }
-
- if (Name == "__strcat_chk") {
- return 0;
- }
-
- if (Name == "__strncat_chk") {
- return 0;
- }
- return 0;
+ InstCombineFortifiedLibCalls Simplifier(this);
+ Simplifier.fold(CI, TD);
+ return Simplifier.NewInstruction;
}
// visitCallSite - Improvements for call and invoke instructions.
Modified: llvm/trunk/lib/Transforms/Scalar/CodeGenPrepare.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/CodeGenPrepare.cpp?rev=98338&r1=98337&r2=98338&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/CodeGenPrepare.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/CodeGenPrepare.cpp Fri Mar 12 03:27:41 2010
@@ -540,9 +540,22 @@
return MadeChange;
}
+namespace {
+class CodeGenPrepareFortifiedLibCalls : public SimplifyFortifiedLibCalls {
+protected:
+ void replaceCall(Value *With) {
+ CI->replaceAllUsesWith(With);
+ CI->eraseFromParent();
+ }
+ bool isFoldable(unsigned SizeCIOp, unsigned, bool) const {
+ if (ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(SizeCIOp)))
+ return SizeCI->isAllOnesValue();
+ return false;
+ }
+};
+} // end anonymous namespace
+
bool CodeGenPrepare::OptimizeCallInst(CallInst *CI) {
- bool MadeChange = false;
-
// Lower all uses of llvm.objectsize.*
IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI);
if (II && II->getIntrinsicID() == Intrinsic::objectsize) {
@@ -561,102 +574,12 @@
const TargetData *TD = TLI ? TLI->getTargetData() : 0;
if (!TD) return false;
- // Lower all default uses of _chk calls. This is code very similar
- // to the code in InstCombineCalls, but here we are only lowering calls
+ // Lower all default uses of _chk calls. This is very similar
+ // to what InstCombineCalls does, but here we are only lowering calls
// that have the default "don't know" as the objectsize. Anything else
// should be left alone.
- StringRef Name = CI->getCalledFunction()->getName();
- BasicBlock *BB = CI->getParent();
- IRBuilder<> B(CI->getParent()->getContext());
-
- // Set the builder to the instruction after the call.
- B.SetInsertPoint(BB, CI);
-
- if (Name == "__memcpy_chk") {
- ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(4));
- if (!SizeCI)
- return 0;
- if (SizeCI->isAllOnesValue()) {
- EmitMemCpy(CI->getOperand(1), CI->getOperand(2), CI->getOperand(3),
- 1, B, TD);
- CI->replaceAllUsesWith(CI->getOperand(1));
- CI->eraseFromParent();
- return true;
- }
- return 0;
- }
-
- // Should be similar to memcpy.
- if (Name == "__mempcpy_chk") {
- return 0;
- }
-
- if (Name == "__memmove_chk") {
- ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(4));
- if (!SizeCI)
- return 0;
- if (SizeCI->isAllOnesValue()) {
- EmitMemMove(CI->getOperand(1), CI->getOperand(2), CI->getOperand(3),
- 1, B, TD);
- CI->replaceAllUsesWith(CI->getOperand(1));
- CI->eraseFromParent();
- return true;
- }
- return 0;
- }
-
- if (Name == "__memset_chk") {
- ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(4));
- if (!SizeCI)
- return 0;
- if (SizeCI->isAllOnesValue()) {
- Value *Val = B.CreateIntCast(CI->getOperand(2), B.getInt8Ty(),
- false);
- EmitMemSet(CI->getOperand(1), Val, CI->getOperand(3), B, TD);
- CI->replaceAllUsesWith(CI->getOperand(1));
- CI->eraseFromParent();
- return true;
- }
- return 0;
- }
-
- if (Name == "__strcpy_chk" || Name == "__stpcpy_chk") {
- ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(3));
- if (!SizeCI)
- return 0;
- if (SizeCI->isAllOnesValue()) {
- Value *Ret = EmitStrCpy(CI->getOperand(1), CI->getOperand(2), B, TD,
- Name.substr(2, 6));
- CI->replaceAllUsesWith(Ret);
- CI->eraseFromParent();
- return true;
- }
- return 0;
- }
-
- if (Name == "__strncpy_chk") {
- ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(4));
- if (!SizeCI)
- return 0;
- if (SizeCI->isAllOnesValue()) {
- Value *Ret = EmitStrNCpy(CI->getOperand(1), CI->getOperand(2),
- CI->getOperand(3), B, TD);
- CI->replaceAllUsesWith(Ret);
- CI->eraseFromParent();
- return true;
- }
- return 0;
- }
-
- if (Name == "__strcat_chk") {
- return 0;
- }
-
- if (Name == "__strncat_chk") {
- return 0;
- }
-
- return MadeChange;
+ CodeGenPrepareFortifiedLibCalls Simplifier;
+ return Simplifier.fold(CI, TD);
}
//===----------------------------------------------------------------------===//
// Memory Optimization
Modified: llvm/trunk/lib/Transforms/Utils/BuildLibCalls.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/BuildLibCalls.cpp?rev=98338&r1=98337&r2=98338&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/BuildLibCalls.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/BuildLibCalls.cpp Fri Mar 12 03:27:41 2010
@@ -342,3 +342,84 @@
if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
CI->setCallingConv(Fn->getCallingConv());
}
+
+bool SimplifyFortifiedLibCalls::fold(CallInst *CI, const TargetData *TD) {
+ this->CI = CI;
+ StringRef Name = CI->getCalledFunction()->getName();
+ BasicBlock *BB = CI->getParent();
+ IRBuilder<> B(CI->getParent()->getContext());
+
+ // Set the builder to the instruction after the call.
+ B.SetInsertPoint(BB, CI);
+
+ if (Name == "__memcpy_chk") {
+ if (isFoldable(4, 3, false)) {
+ EmitMemCpy(CI->getOperand(1), CI->getOperand(2), CI->getOperand(3),
+ 1, B, TD);
+ replaceCall(CI->getOperand(1));
+ return true;
+ }
+ return false;
+ }
+
+ // Should be similar to memcpy.
+ if (Name == "__mempcpy_chk") {
+ return false;
+ }
+
+ if (Name == "__memmove_chk") {
+ if (isFoldable(4, 3, false)) {
+ EmitMemMove(CI->getOperand(1), CI->getOperand(2), CI->getOperand(3),
+ 1, B, TD);
+ replaceCall(CI->getOperand(1));
+ return true;
+ }
+ return false;
+ }
+
+ if (Name == "__memset_chk") {
+ if (isFoldable(4, 3, false)) {
+ Value *Val = B.CreateIntCast(CI->getOperand(2), B.getInt8Ty(),
+ false);
+ EmitMemSet(CI->getOperand(1), Val, CI->getOperand(3), B, TD);
+ replaceCall(CI->getOperand(1));
+ return true;
+ }
+ return false;
+ }
+
+ if (Name == "__strcpy_chk" || Name == "__stpcpy_chk") {
+ // If a) we don't have any length information, or b) we know this will
+ // fit then just lower to a plain st[rp]cpy. Otherwise we'll keep our
+ // st[rp]cpy_chk call which may fail at runtime if the size is too long.
+ // TODO: It might be nice to get a maximum length out of the possible
+ // string lengths for varying.
+ if (isFoldable(3, 2, true)) {
+ Value *Ret = EmitStrCpy(CI->getOperand(1), CI->getOperand(2), B, TD,
+ Name.substr(2, 6));
+ replaceCall(Ret);
+ return true;
+ }
+ return false;
+ }
+
+ if (Name == "__strncpy_chk") {
+ if (isFoldable(4, 3, false)) {
+ Value *Ret = EmitStrNCpy(CI->getOperand(1), CI->getOperand(2),
+ CI->getOperand(3), B, TD);
+ replaceCall(Ret);
+ return true;
+ }
+ return false;
+ }
+
+ if (Name == "__strcat_chk") {
+ return false;
+ }
+
+ if (Name == "__strncat_chk") {
+ return false;
+ }
+
+ return false;
+}
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