From bb51ec8b62c2819882b82a2510bf4df6f459bd51 Mon Sep 17 00:00:00 2001 From: Meador Inge Date: Sun, 11 Nov 2012 05:11:20 +0000 Subject: [PATCH] instcombine: Migrate memcmp optimizations This patch migrates the memcmp optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167683 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/SimplifyLibCalls.cpp | 51 +----------------- lib/Transforms/Utils/SimplifyLibCalls.cpp | 55 ++++++++++++++++++- test/Transforms/InstCombine/memcmp-1.ll | 63 ++++++++++++++++++++++ test/Transforms/InstCombine/memcmp-2.ll | 17 ++++++ test/Transforms/InstCombine/strncmp-1.ll | 10 ++-- test/Transforms/SimplifyLibCalls/memcmp.ll | 35 ------------ 6 files changed, 140 insertions(+), 91 deletions(-) create mode 100644 test/Transforms/InstCombine/memcmp-1.ll create mode 100644 test/Transforms/InstCombine/memcmp-2.ll delete mode 100644 test/Transforms/SimplifyLibCalls/memcmp.ll diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp index 3f39df94560..4d54e13c771 100644 --- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp +++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp @@ -104,54 +104,6 @@ static bool CallHasFloatingPointArgument(const CallInst *CI) { //===----------------------------------------------------------------------===// namespace { -//===---------------------------------------===// -// 'memcmp' Optimizations - -struct MemCmpOpt : public LibCallOptimization { - virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) { - FunctionType *FT = Callee->getFunctionType(); - if (FT->getNumParams() != 3 || !FT->getParamType(0)->isPointerTy() || - !FT->getParamType(1)->isPointerTy() || - !FT->getReturnType()->isIntegerTy(32)) - return 0; - - Value *LHS = CI->getArgOperand(0), *RHS = CI->getArgOperand(1); - - if (LHS == RHS) // memcmp(s,s,x) -> 0 - return Constant::getNullValue(CI->getType()); - - // Make sure we have a constant length. - ConstantInt *LenC = dyn_cast(CI->getArgOperand(2)); - if (!LenC) return 0; - uint64_t Len = LenC->getZExtValue(); - - if (Len == 0) // memcmp(s1,s2,0) -> 0 - return Constant::getNullValue(CI->getType()); - - // memcmp(S1,S2,1) -> *(unsigned char*)LHS - *(unsigned char*)RHS - if (Len == 1) { - Value *LHSV = B.CreateZExt(B.CreateLoad(CastToCStr(LHS, B), "lhsc"), - CI->getType(), "lhsv"); - Value *RHSV = B.CreateZExt(B.CreateLoad(CastToCStr(RHS, B), "rhsc"), - CI->getType(), "rhsv"); - return B.CreateSub(LHSV, RHSV, "chardiff"); - } - - // Constant folding: memcmp(x, y, l) -> cnst (all arguments are constant) - StringRef LHSStr, RHSStr; - if (getConstantStringInfo(LHS, LHSStr) && - getConstantStringInfo(RHS, RHSStr)) { - // Make sure we're not reading out-of-bounds memory. - if (Len > LHSStr.size() || Len > RHSStr.size()) - return 0; - uint64_t Ret = memcmp(LHSStr.data(), RHSStr.data(), Len); - return ConstantInt::get(CI->getType(), Ret); - } - - return 0; - } -}; - //===---------------------------------------===// // 'memcpy' Optimizations @@ -887,7 +839,7 @@ namespace { StringMap Optimizations; // Memory LibCall Optimizations - MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet; + MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet; // Math Library Optimizations CosOpt Cos; PowOpt Pow; Exp2Opt Exp2; UnaryDoubleFPOpt UnaryDoubleFP, UnsafeUnaryDoubleFP; @@ -954,7 +906,6 @@ void SimplifyLibCalls::AddOpt(LibFunc::Func F1, LibFunc::Func F2, /// we know. void SimplifyLibCalls::InitOptimizations() { // Memory LibCall Optimizations - Optimizations["memcmp"] = &MemCmp; AddOpt(LibFunc::memcpy, &MemCpy); Optimizations["memmove"] = &MemMove; AddOpt(LibFunc::memset, &MemSet); diff --git a/lib/Transforms/Utils/SimplifyLibCalls.cpp b/lib/Transforms/Utils/SimplifyLibCalls.cpp index b5ea46dc0db..805fcbe3cb1 100644 --- a/lib/Transforms/Utils/SimplifyLibCalls.cpp +++ b/lib/Transforms/Utils/SimplifyLibCalls.cpp @@ -914,6 +914,51 @@ struct StrStrOpt : public LibCallOptimization { } }; +struct MemCmpOpt : public LibCallOptimization { + virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) { + FunctionType *FT = Callee->getFunctionType(); + if (FT->getNumParams() != 3 || !FT->getParamType(0)->isPointerTy() || + !FT->getParamType(1)->isPointerTy() || + !FT->getReturnType()->isIntegerTy(32)) + return 0; + + Value *LHS = CI->getArgOperand(0), *RHS = CI->getArgOperand(1); + + if (LHS == RHS) // memcmp(s,s,x) -> 0 + return Constant::getNullValue(CI->getType()); + + // Make sure we have a constant length. + ConstantInt *LenC = dyn_cast(CI->getArgOperand(2)); + if (!LenC) return 0; + uint64_t Len = LenC->getZExtValue(); + + if (Len == 0) // memcmp(s1,s2,0) -> 0 + return Constant::getNullValue(CI->getType()); + + // memcmp(S1,S2,1) -> *(unsigned char*)LHS - *(unsigned char*)RHS + if (Len == 1) { + Value *LHSV = B.CreateZExt(B.CreateLoad(CastToCStr(LHS, B), "lhsc"), + CI->getType(), "lhsv"); + Value *RHSV = B.CreateZExt(B.CreateLoad(CastToCStr(RHS, B), "rhsc"), + CI->getType(), "rhsv"); + return B.CreateSub(LHSV, RHSV, "chardiff"); + } + + // Constant folding: memcmp(x, y, l) -> cnst (all arguments are constant) + StringRef LHSStr, RHSStr; + if (getConstantStringInfo(LHS, LHSStr) && + getConstantStringInfo(RHS, RHSStr)) { + // Make sure we're not reading out-of-bounds memory. + if (Len > LHSStr.size() || Len > RHSStr.size()) + return 0; + uint64_t Ret = memcmp(LHSStr.data(), RHSStr.data(), Len); + return ConstantInt::get(CI->getType(), Ret); + } + + return 0; + } +}; + } // End anonymous namespace. namespace llvm { @@ -932,7 +977,7 @@ class LibCallSimplifierImpl { StpCpyChkOpt StpCpyChk; StrNCpyChkOpt StrNCpyChk; - // String and memory library call optimizations. + // String library call optimizations. StrCatOpt StrCat; StrNCatOpt StrNCat; StrChrOpt StrChr; @@ -949,6 +994,9 @@ class LibCallSimplifierImpl { StrCSpnOpt StrCSpn; StrStrOpt StrStr; + // Memory library call optimizations. + MemCmpOpt MemCmp; + void initOptimizations(); void addOpt(LibFunc::Func F, LibCallOptimization* Opt); public: @@ -972,7 +1020,7 @@ void LibCallSimplifierImpl::initOptimizations() { Optimizations["__strncpy_chk"] = &StrNCpyChk; Optimizations["__stpncpy_chk"] = &StrNCpyChk; - // String and memory library call optimizations. + // String library call optimizations. addOpt(LibFunc::strcat, &StrCat); addOpt(LibFunc::strncat, &StrNCat); addOpt(LibFunc::strchr, &StrChr); @@ -994,6 +1042,9 @@ void LibCallSimplifierImpl::initOptimizations() { addOpt(LibFunc::strspn, &StrSpn); addOpt(LibFunc::strcspn, &StrCSpn); addOpt(LibFunc::strstr, &StrStr); + + // Memory library call optimizations. + addOpt(LibFunc::memcmp, &MemCmp); } Value *LibCallSimplifierImpl::optimizeCall(CallInst *CI) { diff --git a/test/Transforms/InstCombine/memcmp-1.ll b/test/Transforms/InstCombine/memcmp-1.ll new file mode 100644 index 00000000000..862fd3a85ab --- /dev/null +++ b/test/Transforms/InstCombine/memcmp-1.ll @@ -0,0 +1,63 @@ +; Test that the memcmp 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" + +@foo = constant [4 x i8] c"foo\00" +@hel = constant [4 x i8] c"hel\00" +@hello_u = constant [8 x i8] c"hello_u\00" + +declare i32 @memcmp(i8*, i8*, i32) + +; Check memcmp(mem, mem, size) -> 0. + +define i32 @test_simplify1(i8* %mem, i32 %size) { +; CHECK: @test_simplify1 + %ret = call i32 @memcmp(i8* %mem, i8* %mem, i32 %size) + ret i32 %ret +; CHECK: ret i32 0 +} + +; Check memcmp(mem1, mem2, 0) -> 0. + +define i32 @test_simplify2(i8* %mem1, i8* %mem2) { +; CHECK: @test_simplify2 + %ret = call i32 @memcmp(i8* %mem1, i8* %mem2, i32 0) + ret i32 %ret +; CHECK: ret i32 0 +} + +;; Check memcmp(mem1, mem2, 1) -> *(unsigned char*)mem1 - *(unsigned char*)mem2. + +define i32 @test_simplify3(i8* %mem1, i8* %mem2) { +; CHECK: @test_simplify3 + %ret = call i32 @memcmp(i8* %mem1, i8* %mem2, i32 1) +; CHECK: [[LOAD1:%[a-z]+]] = load i8* %mem1, align 1 +; CHECK: [[ZEXT1:%[a-z]+]] = zext i8 [[LOAD1]] to i32 +; CHECK: [[LOAD2:%[a-z]+]] = load i8* %mem2, align 1 +; CHECK: [[ZEXT2:%[a-z]+]] = zext i8 [[LOAD2]] to i32 +; CHECK: [[RET:%[a-z]+]] = sub i32 [[ZEXT1]], [[ZEXT2]] + ret i32 %ret +; CHECK: ret i32 [[RET]] +} + +; Check memcmp(mem1, mem2, size) -> cnst, where all arguments are constants. + +define i32 @test_simplify4() { +; CHECK: @test_simplify4 + %mem1 = getelementptr [4 x i8]* @hel, i32 0, i32 0 + %mem2 = getelementptr [8 x i8]* @hello_u, i32 0, i32 0 + %ret = call i32 @memcmp(i8* %mem1, i8* %mem2, i32 3) + ret i32 %ret +; CHECK: ret i32 0 +} + +define i32 @test_simplify5() { +; CHECK: @test_simplify5 + %mem1 = getelementptr [4 x i8]* @hel, i32 0, i32 0 + %mem2 = getelementptr [4 x i8]* @foo, i32 0, i32 0 + %ret = call i32 @memcmp(i8* %mem1, i8* %mem2, i32 3) + ret i32 %ret +; CHECK: ret i32 2 +} diff --git a/test/Transforms/InstCombine/memcmp-2.ll b/test/Transforms/InstCombine/memcmp-2.ll new file mode 100644 index 00000000000..3796117bc24 --- /dev/null +++ b/test/Transforms/InstCombine/memcmp-2.ll @@ -0,0 +1,17 @@ +; Test that the memcmp 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" + +declare i32* @memcmp(i8*, i8*, i32) + +; Check that memcmp functions with the wrong prototype aren't simplified. + +define i32* @test_no_simplify1(i8* %mem, i32 %size) { +; CHECK: @test_no_simplify1 + %ret = call i32* @memcmp(i8* %mem, i8* %mem, i32 %size) +; CHECK-NEXT: call i32* @memcmp + ret i32* %ret +; CHECK-NEXT: ret i32* %ret +} diff --git a/test/Transforms/InstCombine/strncmp-1.ll b/test/Transforms/InstCombine/strncmp-1.ll index 48b26d1a5f3..187c2fa50e8 100644 --- a/test/Transforms/InstCombine/strncmp-1.ll +++ b/test/Transforms/InstCombine/strncmp-1.ll @@ -67,12 +67,14 @@ define i32 @test5() { } ; strncmp(x,y,1) -> memcmp(x,y,1) -; TODO: Once the memcmp simplifier gets moved into the instcombine pass -; the following memcmp will be folded into two loads and a subtract. define i32 @test6(i8* %str1, i8* %str2) { ; CHECK: @test6 -; CHECK: call i32 @memcmp -; CHECK: ret i32 %memcmp +; CHECK: [[LOAD1:%[a-z]+]] = load i8* %str1, align 1 +; CHECK: [[ZEXT1:%[a-z]+]] = zext i8 [[LOAD1]] to i32 +; CHECK: [[LOAD2:%[a-z]+]] = load i8* %str2, align 1 +; CHECK: [[ZEXT2:%[a-z]+]] = zext i8 [[LOAD2]] to i32 +; CHECK: [[RET:%[a-z]+]] = sub i32 [[ZEXT1]], [[ZEXT2]] +; CHECK: ret i32 [[RET]] %temp1 = call i32 @strncmp(i8* %str1, i8* %str2, i32 1) ret i32 %temp1 diff --git a/test/Transforms/SimplifyLibCalls/memcmp.ll b/test/Transforms/SimplifyLibCalls/memcmp.ll deleted file mode 100644 index 6ca4dc97a19..00000000000 --- a/test/Transforms/SimplifyLibCalls/memcmp.ll +++ /dev/null @@ -1,35 +0,0 @@ -; Test that the memcmpOptimizer works correctly -; RUN: opt < %s -simplify-libcalls -S | FileCheck %s - -@h = constant [2 x i8] c"h\00" ; <[2 x i8]*> [#uses=0] -@hel = constant [4 x i8] c"hel\00" ; <[4 x i8]*> [#uses=0] -@hello_u = constant [8 x i8] c"hello_u\00" ; <[8 x i8]*> [#uses=0] - -declare i32 @memcmp(i8*, i8*, i32) - -define void @test(i8* %P, i8* %Q, i32 %N, i32* %IP, i1* %BP) { - %A = call i32 @memcmp( i8* %P, i8* %P, i32 %N ) ; [#uses=1] -; CHECK-NOT: call {{.*}} memcmp -; CHECK: store volatile - store volatile i32 %A, i32* %IP - %B = call i32 @memcmp( i8* %P, i8* %Q, i32 0 ) ; [#uses=1] -; CHECK-NOT: call {{.*}} memcmp -; CHECK: store volatile - store volatile i32 %B, i32* %IP - %C = call i32 @memcmp( i8* %P, i8* %Q, i32 1 ) ; [#uses=1] -; CHECK: load -; CHECK: zext -; CHECK: load -; CHECK: zext -; CHECK: sub -; CHECK: store volatile - store volatile i32 %C, i32* %IP - %F = call i32 @memcmp(i8* getelementptr ([4 x i8]* @hel, i32 0, i32 0), - i8* getelementptr ([8 x i8]* @hello_u, i32 0, i32 0), - i32 3) -; CHECK-NOT: call {{.*}} memcmp -; CHECK: store volatile - store volatile i32 %F, i32* %IP - ret void -} -