From: David Bolvansky Date: Tue, 1 Oct 2019 13:19:04 +0000 (+0000) Subject: Revert [InstCombine] sprintf(dest, "%s", str) -> memccpy(dest, str, 0, MAX) X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d795c5c32c7430e0e6d189ef5a78e54dc2814bd2;p=llvm Revert [InstCombine] sprintf(dest, "%s", str) -> memccpy(dest, str, 0, MAX) Seems to be slower than memcpy + strlen. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@373335 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/Transforms/Utils/SimplifyLibCalls.cpp b/lib/Transforms/Utils/SimplifyLibCalls.cpp index c77daba4a95..3af754a3eb0 100644 --- a/lib/Transforms/Utils/SimplifyLibCalls.cpp +++ b/lib/Transforms/Utils/SimplifyLibCalls.cpp @@ -2415,11 +2415,9 @@ Value *LibCallSimplifier::optimizePrintF(CallInst *CI, IRBuilder<> &B) { } Value *LibCallSimplifier::optimizeSPrintFString(CallInst *CI, IRBuilder<> &B) { - Value *Dst = CI->getArgOperand(0); - Value *FmtStr = CI->getArgOperand(1); // Check for a fixed format string. StringRef FormatStr; - if (!getConstantStringInfo(FmtStr, FormatStr)) + if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr)) return nullptr; // If we just have a format string (nothing else crazy) transform it. @@ -2430,10 +2428,9 @@ Value *LibCallSimplifier::optimizeSPrintFString(CallInst *CI, IRBuilder<> &B) { return nullptr; // we found a format specifier, bail out. // sprintf(str, fmt) -> llvm.memcpy(align 1 str, align 1 fmt, strlen(fmt)+1) - B.CreateMemCpy( - Dst, 1, FmtStr, 1, - ConstantInt::get(DL.getIntPtrType(CI->getContext()), - FormatStr.size() + 1)); // Copy the null byte. + B.CreateMemCpy(CI->getArgOperand(0), 1, CI->getArgOperand(1), 1, + ConstantInt::get(DL.getIntPtrType(CI->getContext()), + FormatStr.size() + 1)); // Copy the null byte. return ConstantInt::get(CI->getType(), FormatStr.size()); } @@ -2443,14 +2440,13 @@ Value *LibCallSimplifier::optimizeSPrintFString(CallInst *CI, IRBuilder<> &B) { CI->getNumArgOperands() < 3) return nullptr; - Value *Str = CI->getArgOperand(2); // Decode the second character of the format string. if (FormatStr[1] == 'c') { // sprintf(dst, "%c", chr) --> *(i8*)dst = chr; *((i8*)dst+1) = 0 - if (!Str->getType()->isIntegerTy()) + if (!CI->getArgOperand(2)->getType()->isIntegerTy()) return nullptr; - Value *V = B.CreateTrunc(Str, B.getInt8Ty(), "char"); - Value *Ptr = castToCStr(Dst, B); + Value *V = B.CreateTrunc(CI->getArgOperand(2), B.getInt8Ty(), "char"); + Value *Ptr = castToCStr(CI->getArgOperand(0), B); B.CreateStore(V, Ptr); Ptr = B.CreateGEP(B.getInt8Ty(), Ptr, B.getInt32(1), "nul"); B.CreateStore(B.getInt8(0), Ptr); @@ -2459,30 +2455,17 @@ Value *LibCallSimplifier::optimizeSPrintFString(CallInst *CI, IRBuilder<> &B) { } if (FormatStr[1] == 's') { - if (!Str->getType()->isPointerTy()) - return nullptr; - - // sprintf(dest, "%s", str) -> memccpy(dest, str, 0, MAX) - if (CI->use_empty()) { - Value *S = (Dst->getType() == Str->getType()) - ? Str - : B.CreateBitCast(Str, Dst->getType()); - unsigned SizeTyBitwidth = - DL.getIntPtrType(CI->getContext())->getPrimitiveSizeInBits(); - Value *NewSize = ConstantInt::get(B.getIntNTy(SizeTyBitwidth), - APInt::getMaxValue(SizeTyBitwidth)); - emitMemCCpy(Dst, S, B.getInt32('\0'), NewSize, B, TLI); - return Dst; - } - // sprintf(dest, "%s", str) -> llvm.memcpy(align 1 dest, align 1 str, // strlen(str)+1) - Value *Len = emitStrLen(Str, B, DL, TLI); + if (!CI->getArgOperand(2)->getType()->isPointerTy()) + return nullptr; + + Value *Len = emitStrLen(CI->getArgOperand(2), B, DL, TLI); if (!Len) return nullptr; Value *IncLen = B.CreateAdd(Len, ConstantInt::get(Len->getType(), 1), "leninc"); - B.CreateMemCpy(Dst, 1, Str, 1, IncLen); + B.CreateMemCpy(CI->getArgOperand(0), 1, CI->getArgOperand(2), 1, IncLen); // The sprintf result is the unincremented number of bytes in the string. return B.CreateIntCast(Len, CI->getType(), false); diff --git a/test/Transforms/InstCombine/2010-05-30-memcpy-Struct.ll b/test/Transforms/InstCombine/2010-05-30-memcpy-Struct.ll index 55619f25075..51610698c24 100644 --- a/test/Transforms/InstCombine/2010-05-30-memcpy-Struct.ll +++ b/test/Transforms/InstCombine/2010-05-30-memcpy-Struct.ll @@ -1,4 +1,3 @@ -; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt -instcombine -S < %s | FileCheck %s ; PR7265 @@ -10,14 +9,10 @@ target triple = "x86_64-unknown-linux-gnu" @.str = private constant [3 x i8] c"%s\00" define void @CopyEventArg(%union.anon* %ev) nounwind { -; CHECK-LABEL: @CopyEventArg( -; CHECK-NEXT: entry: -; CHECK-NEXT: [[TMP0:%.*]] = bitcast %union.anon* [[EV:%.*]] to i8* -; CHECK-NEXT: [[MEMCCPY:%.*]] = call i8* @memccpy(i8* undef, i8* [[TMP0]], i32 0, i64 -1) -; CHECK-NEXT: ret void -; entry: %call = call i32 (i8*, i8*, ...) @sprintf(i8* undef, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), %union.anon* %ev) nounwind +; CHECK: bitcast %union.anon* %ev to i8* +; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64 ret void } diff --git a/test/Transforms/InstCombine/sprintf-1.ll b/test/Transforms/InstCombine/sprintf-1.ll index 6f92063d745..9dbfecaecb3 100644 --- a/test/Transforms/InstCombine/sprintf-1.ll +++ b/test/Transforms/InstCombine/sprintf-1.ll @@ -85,11 +85,15 @@ define void @test_simplify4(i8* %dst) { define void @test_simplify5(i8* %dst, i8* %str) { ; CHECK-LABEL: @test_simplify5( -; CHECK-NEXT: [[MEMCCPY:%.*]] = call i8* @memccpy(i8* [[DST:%.*]], i8* [[STR:%.*]], i32 0, i32 -1) +; CHECK-NEXT: [[STRLEN:%.*]] = call i32 @strlen(i8* nonnull dereferenceable(1) [[STR:%.*]]) +; CHECK-NEXT: [[LENINC:%.*]] = add i32 [[STRLEN]], 1 +; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 1 [[DST:%.*]], i8* align 1 [[STR]], i32 [[LENINC]], i1 false) ; CHECK-NEXT: ret void ; ; CHECK-IPRINTF-LABEL: @test_simplify5( -; CHECK-IPRINTF-NEXT: [[MEMCCPY:%.*]] = call i8* @memccpy(i8* [[DST:%.*]], i8* [[STR:%.*]], i32 0, i32 -1) +; CHECK-IPRINTF-NEXT: [[STRLEN:%.*]] = call i32 @strlen(i8* nonnull dereferenceable(1) [[STR:%.*]]) +; CHECK-IPRINTF-NEXT: [[LENINC:%.*]] = add i32 [[STRLEN]], 1 +; CHECK-IPRINTF-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 1 [[DST:%.*]], i8* align 1 [[STR]], i32 [[LENINC]], i1 false) ; CHECK-IPRINTF-NEXT: ret void ; %fmt = getelementptr [3 x i8], [3 x i8]* @percent_s, i32 0, i32 0