[llvm-commits] [llvm] r99282 - in /llvm/trunk: lib/Transforms/Scalar/SimplifyLibCalls.cpp lib/Transforms/Utils/BuildLibCalls.cpp test/Transforms/SimplifyLibCalls/StrCpy.ll
Evan Cheng
evan.cheng at apple.com
Tue Mar 23 20:10:08 PDT 2010
On Mar 23, 2010, at 2:42 PM, Chris Lattner wrote:
>
> On Mar 23, 2010, at 8:48 AM, Evan Cheng wrote:
>
>> Author: evancheng
>> Date: Tue Mar 23 10:48:04 2010
>> New Revision: 99282
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=99282&view=rev
>> Log:
>> Teach simplify libcall to transform __strcpy_chk to __memcpy_chk to enable optimizations down stream.
>
> Hi Evan,
>
>> +++ llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp Tue Mar 23 10:48:04 2010
>> @@ -49,10 +49,13 @@
>> Function *Caller;
>> const TargetData *TD;
>> LLVMContext* Context;
>> + bool OptChkCall; // True if it's optimizing a *_chk libcall.
>
> This is state is not appropriate to add to LibCallOptimization. If you want to do this, it should be added as a constructor option to StrCpyOpt.
Why is it inappropriate? I can't add it to the constructor option because optimization objects are ivars. I can't construct it with "StrCpyOpt StrCpyChk(true);". And I don't want to heap allocate them.
Evan
>
> -Chris
>
>> public:
>> - LibCallOptimization() { }
>> + LibCallOptimization() : OptChkCall(false) { }
>> virtual ~LibCallOptimization() {}
>>
>> + void setOptChkCall(bool c) { OptChkCall = c; }
>> +
>> /// CallOptimizer - This pure virtual method is implemented by base classes to
>> /// do various optimizations. If this returns null then no transformation was
>> /// performed. If it returns CI, then it transformed the call and CI is to be
>> @@ -352,8 +355,10 @@
>> struct StrCpyOpt : public LibCallOptimization {
>> virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
>> // Verify the "strcpy" function prototype.
>> + unsigned NumParams = OptChkCall ? 3 : 2;
>> const FunctionType *FT = Callee->getFunctionType();
>> - if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
>> + if (FT->getNumParams() != NumParams ||
>> + FT->getReturnType() != FT->getParamType(0) ||
>> FT->getParamType(0) != FT->getParamType(1) ||
>> FT->getParamType(0) != Type::getInt8PtrTy(*Context))
>> return 0;
>> @@ -371,8 +376,13 @@
>>
>> // We have enough information to now generate the memcpy call to do the
>> // concatenation for us. Make a memcpy to copy the nul byte with align = 1.
>> - EmitMemCpy(Dst, Src,
>> - ConstantInt::get(TD->getIntPtrType(*Context), Len), 1, B, TD);
>> + if (OptChkCall)
>> + EmitMemCpyChk(Dst, Src,
>> + ConstantInt::get(TD->getIntPtrType(*Context), Len),
>> + CI->getOperand(3), B, TD);
>> + else
>> + EmitMemCpy(Dst, Src,
>> + ConstantInt::get(TD->getIntPtrType(*Context), Len), 1, B, TD);
>> return Dst;
>> }
>> };
>> @@ -1162,7 +1172,8 @@
>> StringMap<LibCallOptimization*> Optimizations;
>> // String and Memory LibCall Optimizations
>> StrCatOpt StrCat; StrNCatOpt StrNCat; StrChrOpt StrChr; StrCmpOpt StrCmp;
>> - StrNCmpOpt StrNCmp; StrCpyOpt StrCpy; StrNCpyOpt StrNCpy; StrLenOpt StrLen;
>> + StrNCmpOpt StrNCmp; StrCpyOpt StrCpy; StrCpyOpt StrCpyChk;
>> + StrNCpyOpt StrNCpy; StrLenOpt StrLen;
>> StrToOpt StrTo; StrStrOpt StrStr;
>> MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet;
>> // Math Library Optimizations
>> @@ -1228,6 +1239,10 @@
>> Optimizations["memmove"] = &MemMove;
>> Optimizations["memset"] = &MemSet;
>>
>> + // _chk variants of String and Memory LibCall Optimizations.
>> + StrCpyChk.setOptChkCall(true);
>> + Optimizations["__strcpy_chk"] = &StrCpyChk;
>> +
>> // Math Library Optimizations
>> Optimizations["powf"] = &Pow;
>> Optimizations["pow"] = &Pow;
>>
>> Modified: llvm/trunk/lib/Transforms/Utils/BuildLibCalls.cpp
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/BuildLibCalls.cpp?rev=99282&r1=99281&r2=99282&view=diff
>> ==============================================================================
>> --- llvm/trunk/lib/Transforms/Utils/BuildLibCalls.cpp (original)
>> +++ llvm/trunk/lib/Transforms/Utils/BuildLibCalls.cpp Tue Mar 23 10:48:04 2010
>> @@ -108,7 +108,7 @@
>>
>>
>> /// EmitMemCpy - Emit a call to the memcpy function to the builder. This always
>> -/// expects that the size has type 'intptr_t' and Dst/Src are pointers.
>> +/// expects that Len has type 'intptr_t' and Dst/Src are pointers.
>> Value *llvm::EmitMemCpy(Value *Dst, Value *Src, Value *Len,
>> unsigned Align, IRBuilder<> &B, const TargetData *TD) {
>> Module *M = B.GetInsertBlock()->getParent()->getParent();
>> @@ -120,6 +120,30 @@
>> ConstantInt::get(B.getInt32Ty(), Align));
>> }
>>
>> +/// EmitMemCpyChk - Emit a call to the __memcpy_chk function to the builder.
>> +/// This expects that the Len and ObjSize have type 'intptr_t' and Dst/Src
>> +/// are pointers.
>> +Value *llvm::EmitMemCpyChk(Value *Dst, Value *Src, Value *Len, Value *ObjSize,
>> + IRBuilder<> &B, const TargetData *TD) {
>> + Module *M = B.GetInsertBlock()->getParent()->getParent();
>> + AttributeWithIndex AWI;
>> + AWI = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
>> + LLVMContext &Context = B.GetInsertBlock()->getContext();
>> + Value *MemCpy = M->getOrInsertFunction("__memcpy_chk",
>> + AttrListPtr::get(&AWI, 1),
>> + B.getInt8PtrTy(),
>> + B.getInt8PtrTy(),
>> + B.getInt8PtrTy(),
>> + TD->getIntPtrType(Context),
>> + TD->getIntPtrType(Context), NULL);
>> + Dst = CastToCStr(Dst, B);
>> + Src = CastToCStr(Src, B);
>> + CallInst *CI = B.CreateCall4(MemCpy, Dst, Src, Len, ObjSize);
>> + if (const Function *F = dyn_cast<Function>(MemCpy->stripPointerCasts()))
>> + CI->setCallingConv(F->getCallingConv());
>> + return CI;
>> +}
>> +
>> /// EmitMemMove - Emit a call to the memmove function to the builder. This
>> /// always expects that the size has type 'intptr_t' and Dst/Src are pointers.
>> Value *llvm::EmitMemMove(Value *Dst, Value *Src, Value *Len,
>>
>> Modified: llvm/trunk/test/Transforms/SimplifyLibCalls/StrCpy.ll
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SimplifyLibCalls/StrCpy.ll?rev=99282&r1=99281&r2=99282&view=diff
>> ==============================================================================
>> --- llvm/trunk/test/Transforms/SimplifyLibCalls/StrCpy.ll (original)
>> +++ llvm/trunk/test/Transforms/SimplifyLibCalls/StrCpy.ll Tue Mar 23 10:48:04 2010
>> @@ -1,30 +1,37 @@
>> ; Test that the StrCpyOptimizer works correctly
>> -; RUN: opt < %s -simplify-libcalls -S | \
>> -; RUN: not grep {call.*strcpy}
>> +; RUN: opt < %s -simplify-libcalls -S | FileCheck %s
>>
>> ; This transformation requires the pointer size, as it assumes that size_t is
>> ; the size of a pointer.
>> -target datalayout = "-p:64:64:64"
>> +target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32"
>>
>> - at hello = constant [6 x i8] c"hello\00" ; <[6 x i8]*> [#uses=1]
>> - at null = constant [1 x i8] zeroinitializer ; <[1 x i8]*> [#uses=1]
>> - at null_hello = constant [7 x i8] c"\00hello\00" ; <[7 x i8]*> [#uses=1]
>> + at hello = constant [6 x i8] c"hello\00"
>>
>> declare i8* @strcpy(i8*, i8*)
>>
>> -declare i32 @puts(i8*)
>> +declare i8* @__strcpy_chk(i8*, i8*, i32) nounwind
>>
>> -define i32 @main() {
>> - %target = alloca [1024 x i8] ; <[1024 x i8]*> [#uses=1]
>> - %arg1 = getelementptr [1024 x i8]* %target, i32 0, i32 0 ; <i8*> [#uses=2]
>> - store i8 0, i8* %arg1
>> - %arg2 = getelementptr [6 x i8]* @hello, i32 0, i32 0 ; <i8*> [#uses=1]
>> - %rslt1 = call i8* @strcpy( i8* %arg1, i8* %arg2 ) ; <i8*> [#uses=1]
>> - %arg3 = getelementptr [1 x i8]* @null, i32 0, i32 0 ; <i8*> [#uses=1]
>> - %rslt2 = call i8* @strcpy( i8* %rslt1, i8* %arg3 ) ; <i8*> [#uses=1]
>> - %arg4 = getelementptr [7 x i8]* @null_hello, i32 0, i32 0 ; <i8*> [#uses=1]
>> - %rslt3 = call i8* @strcpy( i8* %rslt2, i8* %arg4 ) ; <i8*> [#uses=1]
>> - call i32 @puts( i8* %rslt3 ) ; <i32>:1 [#uses=0]
>> - ret i32 0
>> +declare i32 @llvm.objectsize.i32(i8*, i1) nounwind readonly
>> +
>> +; rdar://6839935
>> +
>> +define i32 @t1() {
>> +; CHECK: @t1
>> + %target = alloca [1024 x i8]
>> + %arg1 = getelementptr [1024 x i8]* %target, i32 0, i32 0
>> + %arg2 = getelementptr [6 x i8]* @hello, i32 0, i32 0
>> + %rslt1 = call i8* @strcpy( i8* %arg1, i8* %arg2 )
>> +; CHECK: @llvm.memcpy.i32
>> + ret i32 0
>> }
>>
>> +define i32 @t2() {
>> +; CHECK: @t2
>> + %target = alloca [1024 x i8]
>> + %arg1 = getelementptr [1024 x i8]* %target, i32 0, i32 0
>> + %arg2 = getelementptr [6 x i8]* @hello, i32 0, i32 0
>> + %tmp1 = call i32 @llvm.objectsize.i32(i8* %arg1, i1 false)
>> + %rslt1 = call i8* @__strcpy_chk(i8* %arg1, i8* %arg2, i32 %tmp1)
>> +; CHECK: @__memcpy_chk
>> + ret i32 0
>> +}
>>
>>
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