From 42a84b54bf4061ba6d404a876ed2cc36f994d14a Mon Sep 17 00:00:00 2001 From: Benjamin Kramer Date: Sat, 21 Mar 2015 22:04:26 +0000 Subject: [PATCH] [SimplifyLibCalls] Fix negative shifts being produced by the memchr -> bitfield transform. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232903 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Utils/SimplifyLibCalls.cpp | 4 +++- test/Transforms/InstCombine/memchr.ll | 12 ++++++++++++ 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/lib/Transforms/Utils/SimplifyLibCalls.cpp b/lib/Transforms/Utils/SimplifyLibCalls.cpp index f6cc431656b..5867d65e7e4 100644 --- a/lib/Transforms/Utils/SimplifyLibCalls.cpp +++ b/lib/Transforms/Utils/SimplifyLibCalls.cpp @@ -782,7 +782,9 @@ Value *LibCallSimplifier::optimizeMemChr(CallInst *CI, IRBuilder<> &B) { // memchr("\r\n", C, 2) != nullptr -> (C & ((1 << '\r') | (1 << '\n'))) != 0 // after bounds check. if (!CharC && !Str.empty() && isOnlyUsedInZeroEqualityComparison(CI)) { - unsigned char Max = *std::max_element(Str.begin(), Str.end()); + unsigned char Max = + *std::max_element(reinterpret_cast(Str.begin()), + reinterpret_cast(Str.end())); // Make sure the bit field we're about to create fits in a register on the // target. diff --git a/test/Transforms/InstCombine/memchr.ll b/test/Transforms/InstCombine/memchr.ll index 6783249877d..216dba874cc 100644 --- a/test/Transforms/InstCombine/memchr.ll +++ b/test/Transforms/InstCombine/memchr.ll @@ -9,6 +9,7 @@ target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f3 @newlines = constant [3 x i8] c"\0D\0A\00" @single = constant [2 x i8] c"\1F\00" @spaces = constant [4 x i8] c" \0D\0A\00" +@negative = constant [3 x i8] c"\FF\FE\00" @chp = global i8* zeroinitializer declare i8* @memchr(i8*, i32, i32) @@ -186,3 +187,14 @@ define i1 @test14(i32 %C) { %cmp = icmp ne i8* %dst, null ret i1 %cmp } + +define i1 @test15(i32 %C) { +; CHECK-LABEL: @test15 +; CHECK-NEXT: %dst = call i8* @memchr(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @negative, i32 0, i32 0), i32 %C, i32 3) +; CHECK-NEXT: %cmp = icmp ne i8* %dst, null +; CHECK-NEXT: ret i1 %cmp + + %dst = call i8* @memchr(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @negative, i64 0, i64 0), i32 %C, i32 3) + %cmp = icmp ne i8* %dst, null + ret i1 %cmp +} -- 2.34.1