diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp --- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp @@ -2375,18 +2375,26 @@ if (FormatStr.size() == 1 || FormatStr == "%%") return emitPutChar(B.getInt32(FormatStr[0]), B, TLI); - // printf("%s", "a") --> putchar('a') + // Try to emit putchar or puts. if (FormatStr == "%s" && CI->getNumArgOperands() > 1) { - StringRef ChrStr; - if (!getConstantStringInfo(CI->getOperand(1), ChrStr)) + StringRef OperandStr; + if (!getConstantStringInfo(CI->getOperand(1), OperandStr) || + OperandStr.empty()) return nullptr; - if (ChrStr.size() != 1) - return nullptr; - return emitPutChar(B.getInt32(ChrStr[0]), B, TLI); + // printf("%s", "a") --> putchar('a') + if (OperandStr.size() == 1) + return emitPutChar(B.getInt32(OperandStr[0]), B, TLI); + // printf("%s", str"\n") --> puts(str) + else if (OperandStr.back() == '\n') { + OperandStr = OperandStr.drop_back(); + Value *GV = B.CreateGlobalString(OperandStr, "str"); + return emitPutS(GV, B, TLI); + } + return nullptr; } // printf("foo\n") --> puts("foo") - if (FormatStr[FormatStr.size() - 1] == '\n' && + if (FormatStr.back() == '\n' && FormatStr.find('%') == StringRef::npos) { // No format characters. // Create a string literal with no \n on it. We expect the constant merge // pass to be run after this pass, to merge duplicate strings. diff --git a/llvm/test/Transforms/InstCombine/printf-2.ll b/llvm/test/Transforms/InstCombine/printf-2.ll --- a/llvm/test/Transforms/InstCombine/printf-2.ll +++ b/llvm/test/Transforms/InstCombine/printf-2.ll @@ -1,4 +1,4 @@ -; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals ; Test that the printf library call simplifier works correctly. ; ; RUN: opt < %s -instcombine -S | FileCheck %s @@ -15,6 +15,15 @@ ; Check simplification of printf with void return type. +;. +; CHECK: @[[HELLO_WORLD:[a-zA-Z0-9_$"\\.-]+]] = constant [13 x i8] c"hello world\0A\00" +; CHECK: @[[H:[a-zA-Z0-9_$"\\.-]+]] = constant [2 x i8] c"h\00" +; CHECK: @[[PERCENT_S:[a-zA-Z0-9_$"\\.-]+]] = constant [4 x i8] c"%s\0A\00" +; CHECK: @[[FORMAT_STR:[a-zA-Z0-9_$"\\.-]+]] = constant [3 x i8] c"%s\00" +; CHECK: @[[CHARSTR:[a-zA-Z0-9_$"\\.-]+]] = constant [2 x i8] c"a\00" +; CHECK: @[[STR:[a-zA-Z0-9_$"\\.-]+]] = private unnamed_addr constant [12 x i8] c"hello world\00", align 1 +; CHECK: @[[STR_1:[a-zA-Z0-9_$"\\.-]+]] = private unnamed_addr constant [12 x i8] c"hello world\00", align 1 +;. define void @test_simplify1() { ; CHECK-LABEL: @test_simplify1( ; CHECK-NEXT: [[PUTCHAR:%.*]] = call i32 @putchar(i32 104) @@ -56,3 +65,17 @@ call void (i8*, ...) @printf(i8* %fmt, i8* %str) ret void } + +define void @test_simplify8() { +; CHECK-LABEL: @test_simplify8( +; CHECK-NEXT: [[PUTS:%.*]] = call i32 @puts(i8* nonnull dereferenceable(1) getelementptr inbounds ([12 x i8], [12 x i8]* @str.1, i32 0, i32 0)) +; CHECK-NEXT: ret void +; + %fmt = getelementptr [3 x i8], [3 x i8]* @format_str, i32 0, i32 0 + %str = getelementptr [13 x i8], [13 x i8]* @hello_world, i32 0, i32 0 + call void (i8*, ...) @printf(i8* %fmt, i8* %str) + ret void +} +;. +; CHECK: attributes #[[ATTR0:[0-9]+]] = { nofree nounwind } +;.