From a0885fb8825ed362041b5cf291a007a9f9301ff8 Mon Sep 17 00:00:00 2001 From: Meador Inge Date: Wed, 31 Oct 2012 03:33:00 +0000 Subject: [PATCH] instcombine: Migrate strncpy optimizations This patch migrates the strncpy optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167102 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/SimplifyLibCalls.cpp | 52 --------------- lib/Transforms/Utils/SimplifyLibCalls.cpp | 49 ++++++++++++++ test/Transforms/InstCombine/strncpy-1.ll | 95 ++++++++++++++++++++++++++++ test/Transforms/InstCombine/strncpy-2.ll | 22 +++++++ test/Transforms/InstCombine/strncpy_chk-1.ll | 18 +++--- test/Transforms/SimplifyLibCalls/StrNCpy.ll | 29 --------- 6 files changed, 175 insertions(+), 90 deletions(-) create mode 100644 test/Transforms/InstCombine/strncpy-1.ll create mode 100644 test/Transforms/InstCombine/strncpy-2.ll delete mode 100644 test/Transforms/SimplifyLibCalls/StrNCpy.ll diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp index f7593e7ea89..4251e60a916 100644 --- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp +++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp @@ -135,56 +135,6 @@ static bool IsOnlyUsedInEqualityComparison(Value *V, Value *With) { namespace { //===---------------------------------------===// -// 'strncpy' Optimizations - -struct StrNCpyOpt : public LibCallOptimization { - virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) { - FunctionType *FT = Callee->getFunctionType(); - if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) || - FT->getParamType(0) != FT->getParamType(1) || - FT->getParamType(0) != B.getInt8PtrTy() || - !FT->getParamType(2)->isIntegerTy()) - return 0; - - Value *Dst = CI->getArgOperand(0); - Value *Src = CI->getArgOperand(1); - Value *LenOp = CI->getArgOperand(2); - - // See if we can get the length of the input string. - uint64_t SrcLen = GetStringLength(Src); - if (SrcLen == 0) return 0; - --SrcLen; - - if (SrcLen == 0) { - // strncpy(x, "", y) -> memset(x, '\0', y, 1) - B.CreateMemSet(Dst, B.getInt8('\0'), LenOp, 1); - return Dst; - } - - uint64_t Len; - if (ConstantInt *LengthArg = dyn_cast(LenOp)) - Len = LengthArg->getZExtValue(); - else - return 0; - - if (Len == 0) return Dst; // strncpy(x, y, 0) -> x - - // These optimizations require DataLayout. - if (!TD) return 0; - - // Let strncpy handle the zero padding - if (Len > SrcLen+1) return 0; - - Type *PT = FT->getParamType(0); - // strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant] - B.CreateMemCpy(Dst, Src, - ConstantInt::get(TD->getIntPtrType(PT), Len), 1); - - return Dst; - } -}; - -//===---------------------------------------===// // 'strlen' Optimizations struct StrLenOpt : public LibCallOptimization { @@ -1196,7 +1146,6 @@ namespace { StringMap Optimizations; // String and Memory LibCall Optimizations - StrNCpyOpt StrNCpy; StrLenOpt StrLen; StrPBrkOpt StrPBrk; StrToOpt StrTo; StrSpnOpt StrSpn; StrCSpnOpt StrCSpn; StrStrOpt StrStr; MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet; @@ -1266,7 +1215,6 @@ void SimplifyLibCalls::AddOpt(LibFunc::Func F1, LibFunc::Func F2, /// we know. void SimplifyLibCalls::InitOptimizations() { // String and Memory LibCall Optimizations - Optimizations["strncpy"] = &StrNCpy; Optimizations["strlen"] = &StrLen; Optimizations["strpbrk"] = &StrPBrk; Optimizations["strtol"] = &StrTo; diff --git a/lib/Transforms/Utils/SimplifyLibCalls.cpp b/lib/Transforms/Utils/SimplifyLibCalls.cpp index bc360010de4..cc03573326e 100644 --- a/lib/Transforms/Utils/SimplifyLibCalls.cpp +++ b/lib/Transforms/Utils/SimplifyLibCalls.cpp @@ -628,6 +628,53 @@ struct StpCpyOpt: public LibCallOptimization { } }; +struct StrNCpyOpt : public LibCallOptimization { + virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) { + FunctionType *FT = Callee->getFunctionType(); + if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) || + FT->getParamType(0) != FT->getParamType(1) || + FT->getParamType(0) != B.getInt8PtrTy() || + !FT->getParamType(2)->isIntegerTy()) + return 0; + + Value *Dst = CI->getArgOperand(0); + Value *Src = CI->getArgOperand(1); + Value *LenOp = CI->getArgOperand(2); + + // See if we can get the length of the input string. + uint64_t SrcLen = GetStringLength(Src); + if (SrcLen == 0) return 0; + --SrcLen; + + if (SrcLen == 0) { + // strncpy(x, "", y) -> memset(x, '\0', y, 1) + B.CreateMemSet(Dst, B.getInt8('\0'), LenOp, 1); + return Dst; + } + + uint64_t Len; + if (ConstantInt *LengthArg = dyn_cast(LenOp)) + Len = LengthArg->getZExtValue(); + else + return 0; + + if (Len == 0) return Dst; // strncpy(x, y, 0) -> x + + // These optimizations require DataLayout. + if (!TD) return 0; + + // Let strncpy handle the zero padding + if (Len > SrcLen+1) return 0; + + Type *PT = FT->getParamType(0); + // strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant] + B.CreateMemCpy(Dst, Src, + ConstantInt::get(TD->getIntPtrType(PT), Len), 1); + + return Dst; + } +}; + } // End anonymous namespace. namespace llvm { @@ -654,6 +701,7 @@ class LibCallSimplifierImpl { StrNCmpOpt StrNCmp; StrCpyOpt StrCpy; StpCpyOpt StpCpy; + StrNCpyOpt StrNCpy; void initOptimizations(); public: @@ -684,6 +732,7 @@ void LibCallSimplifierImpl::initOptimizations() { Optimizations["strncmp"] = &StrNCmp; Optimizations["strcpy"] = &StrCpy; Optimizations["stpcpy"] = &StpCpy; + Optimizations["strncpy"] = &StrNCpy; } Value *LibCallSimplifierImpl::optimizeCall(CallInst *CI) { diff --git a/test/Transforms/InstCombine/strncpy-1.ll b/test/Transforms/InstCombine/strncpy-1.ll new file mode 100644 index 00000000000..3ce2b9b5eec --- /dev/null +++ b/test/Transforms/InstCombine/strncpy-1.ll @@ -0,0 +1,95 @@ +; Test that the strncpy library call simplifier works correctly. +; +; RUN: opt < %s -instcombine -S | FileCheck %s + +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" + +@hello = constant [6 x i8] c"hello\00" +@null = constant [1 x i8] zeroinitializer +@null_hello = constant [7 x i8] c"\00hello\00" +@a = common global [32 x i8] zeroinitializer, align 1 +@b = common global [32 x i8] zeroinitializer, align 1 + +declare i8* @strncpy(i8*, i8*, i32) +declare i32 @puts(i8*) + +; Check a bunch of strncpy invocations together. + +define i32 @test_simplify1() { +; CHECK: @test_simplify1 +; CHECK-NOT: call i8* @strncpy +; CHECK: call i32 @puts + %target = alloca [1024 x i8] + %arg1 = getelementptr [1024 x i8]* %target, i32 0, i32 0 + store i8 0, i8* %arg1 + + %arg2 = getelementptr [6 x i8]* @hello, i32 0, i32 0 + %rslt1 = call i8* @strncpy(i8* %arg1, i8* %arg2, i32 6) + + %arg3 = getelementptr [1 x i8]* @null, i32 0, i32 0 + %rslt2 = call i8* @strncpy(i8* %rslt1, i8* %arg3, i32 42) + + %arg4 = getelementptr [7 x i8]* @null_hello, i32 0, i32 0 + %rslt3 = call i8* @strncpy(i8* %rslt2, i8* %arg4, i32 42) + + call i32 @puts( i8* %rslt3 ) + ret i32 0 +} + +; Check strncpy(x, "", y) -> memset(x, '\0', y, 1). + +define void @test_simplify2() { +; CHECK: @test_simplify2 + %dst = getelementptr [32 x i8]* @a, i32 0, i32 0 + %src = getelementptr [1 x i8]* @null, i32 0, i32 0 + + call i8* @strncpy(i8* %dst, i8* %src, i32 32) +; CHECK: call void @llvm.memset.p0i8.i32 + ret void +} + +; Check strncpy(x, y, 0) -> x. + +define i8* @test_simplify3() { +; CHECK: @test_simplify3 + %dst = getelementptr [32 x i8]* @a, i32 0, i32 0 + %src = getelementptr [6 x i8]* @hello, i32 0, i32 0 + + %ret = call i8* @strncpy(i8* %dst, i8* %src, i32 0) + ret i8* %ret +; CHECK: ret i8* getelementptr inbounds ([32 x i8]* @a, i32 0, i32 0) +} + +; Check strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant]. + +define void @test_simplify4() { +; CHECK: @test_simplify4 + %dst = getelementptr [32 x i8]* @a, i32 0, i32 0 + %src = getelementptr [6 x i8]* @hello, i32 0, i32 0 + + call i8* @strncpy(i8* %dst, i8* %src, i32 6) +; CHECK: call void @llvm.memcpy.p0i8.p0i8.i32 + ret void +} + +; Check cases that shouldn't be simplified. + +define void @test_no_simplify1() { +; CHECK: @test_no_simplify1 + %dst = getelementptr [32 x i8]* @a, i32 0, i32 0 + %src = getelementptr [32 x i8]* @b, i32 0, i32 0 + + call i8* @strncpy(i8* %dst, i8* %src, i32 32) +; CHECK: call i8* @strncpy + ret void +} + +define void @test_no_simplify2() { +; CHECK: @test_no_simplify2 + %dst = getelementptr [32 x i8]* @a, i32 0, i32 0 + %src = getelementptr [6 x i8]* @hello, i32 0, i32 0 + + call i8* @strncpy(i8* %dst, i8* %src, i32 8) +; CHECK: call i8* @strncpy + ret void +} diff --git a/test/Transforms/InstCombine/strncpy-2.ll b/test/Transforms/InstCombine/strncpy-2.ll new file mode 100644 index 00000000000..ac28ea65500 --- /dev/null +++ b/test/Transforms/InstCombine/strncpy-2.ll @@ -0,0 +1,22 @@ +; Test that the strncpy library call simplifier works correctly. +; +; RUN: opt < %s -instcombine -S | FileCheck %s + +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" + +@hello = constant [6 x i8] c"hello\00" +@a = common global [32 x i8] zeroinitializer, align 1 + +declare i16* @strncpy(i8*, i8*, i32) + +; Check that 'strncpy' functions with the wrong prototype aren't simplified. + +define void @test_no_simplify1() { +; CHECK: @test_no_simplify1 + %dst = getelementptr [32 x i8]* @a, i32 0, i32 0 + %src = getelementptr [6 x i8]* @hello, i32 0, i32 0 + + call i16* @strncpy(i8* %dst, i8* %src, i32 6) +; CHECK: call i16* @strncpy + ret void +} diff --git a/test/Transforms/InstCombine/strncpy_chk-1.ll b/test/Transforms/InstCombine/strncpy_chk-1.ll index ae7e2fb5f18..aadff4268ec 100644 --- a/test/Transforms/InstCombine/strncpy_chk-1.ll +++ b/test/Transforms/InstCombine/strncpy_chk-1.ll @@ -7,27 +7,27 @@ target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f3 @a = common global [60 x i8] zeroinitializer, align 1 @b = common global [60 x i8] zeroinitializer, align 1 -@.str = private constant [8 x i8] c"abcdefg\00" +@.str = private constant [12 x i8] c"abcdefghijk\00" ; Check cases where dstlen >= len define void @test_simplify1() { ; CHECK: @test_simplify1 %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0 - %src = getelementptr inbounds [8 x i8]* @.str, i32 0, i32 0 + %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0 -; CHECK-NEXT: call i8* @strncpy - call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 8, i32 60) +; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32 + call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 12, i32 60) ret void } define void @test_simplify2() { ; CHECK: @test_simplify2 %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0 - %src = getelementptr inbounds [8 x i8]* @.str, i32 0, i32 0 + %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0 -; CHECK-NEXT: call i8* @strncpy - call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 8, i32 8) +; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32 + call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 12, i32 12) ret void } @@ -37,7 +37,7 @@ define void @test_simplify3() { %src = getelementptr inbounds [60 x i8]* @b, i32 0, i32 0 ; CHECK-NEXT: call i8* @strncpy - call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 8, i32 60) + call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 12, i32 60) ret void } @@ -46,7 +46,7 @@ define void @test_simplify3() { define void @test_no_simplify1() { ; CHECK: @test_no_simplify1 %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0 - %src = getelementptr inbounds [8 x i8]* @.str, i32 0, i32 0 + %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0 ; CHECK-NEXT: call i8* @__strncpy_chk call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 8, i32 4) diff --git a/test/Transforms/SimplifyLibCalls/StrNCpy.ll b/test/Transforms/SimplifyLibCalls/StrNCpy.ll deleted file mode 100644 index 4e47b31a6af..00000000000 --- a/test/Transforms/SimplifyLibCalls/StrNCpy.ll +++ /dev/null @@ -1,29 +0,0 @@ -; Test that the StrNCpyOptimizer works correctly -; RUN: opt < %s -simplify-libcalls -S | \ -; RUN: not grep "call.*strncpy" - -; This transformation requires the pointer size, as it assumes that size_t is -; the size of a pointer. -target datalayout = "-p:64:64:64" - -@hello = constant [6 x i8] c"hello\00" ; <[6 x i8]*> [#uses=1] -@null = constant [1 x i8] zeroinitializer ; <[1 x i8]*> [#uses=1] -@null_hello = constant [7 x i8] c"\00hello\00" ; <[7 x i8]*> [#uses=1] - -declare i8* @strncpy(i8*, i8*, i32) - -declare i32 @puts(i8*) - -define i32 @main() { - %target = alloca [1024 x i8] ; <[1024 x i8]*> [#uses=1] - %arg1 = getelementptr [1024 x i8]* %target, i32 0, i32 0 ; [#uses=2] - store i8 0, i8* %arg1 - %arg2 = getelementptr [6 x i8]* @hello, i32 0, i32 0 ; [#uses=1] - %rslt1 = call i8* @strncpy( i8* %arg1, i8* %arg2, i32 6 ) ; [#uses=1] - %arg3 = getelementptr [1 x i8]* @null, i32 0, i32 0 ; [#uses=1] - %rslt2 = call i8* @strncpy( i8* %rslt1, i8* %arg3, i32 42 ) ; [#uses=1] - %arg4 = getelementptr [7 x i8]* @null_hello, i32 0, i32 0 ; [#uses=1] - %rslt3 = call i8* @strncpy( i8* %rslt2, i8* %arg4, i32 42 ) ; [#uses=1] - call i32 @puts( i8* %rslt3 ) ; :1 [#uses=0] - ret i32 0 -} -- 2.11.0