diff options
| -rw-r--r-- | lib/Transforms/Scalar/SimplifyLibCalls.cpp | 9 | ||||
| -rw-r--r-- | test/Transforms/SimplifyLibCalls/memcmp.ll | 14 |
2 files changed, 19 insertions, 4 deletions
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp index b053cfc3b4..0f3ab7d8b5 100644 --- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp +++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp @@ -558,9 +558,12 @@ struct MemCmpOpt : public LibCallOptimization { if (Len == 0) // memcmp(s1,s2,0) -> 0 return Constant::getNullValue(CI->getType()); - if (Len == 1) { // memcmp(S1,S2,1) -> *LHS - *RHS - Value *LHSV = B.CreateLoad(CastToCStr(LHS, B), "lhsv"); - Value *RHSV = B.CreateLoad(CastToCStr(RHS, B), "rhsv"); + // 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.CreateSExt(B.CreateSub(LHSV, RHSV, "chardiff"), CI->getType()); } diff --git a/test/Transforms/SimplifyLibCalls/memcmp.ll b/test/Transforms/SimplifyLibCalls/memcmp.ll index 640d232a7f..ee99501bc0 100644 --- a/test/Transforms/SimplifyLibCalls/memcmp.ll +++ b/test/Transforms/SimplifyLibCalls/memcmp.ll @@ -1,5 +1,5 @@ ; Test that the memcmpOptimizer works correctly -; RUN: opt < %s -simplify-libcalls -S | not grep {call.*memcmp} +; 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] @@ -9,14 +9,26 @@ 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 ) ; <i32> [#uses=1] +; CHECK-NOT: call {{.*}} memcmp +; CHECK: volatile store volatile store i32 %A, i32* %IP %B = call i32 @memcmp( i8* %P, i8* %Q, i32 0 ) ; <i32> [#uses=1] +; CHECK-NOT: call {{.*}} memcmp +; CHECK: volatile store volatile store i32 %B, i32* %IP %C = call i32 @memcmp( i8* %P, i8* %Q, i32 1 ) ; <i32> [#uses=1] +; CHECK: load +; CHECK: zext +; CHECK: load +; CHECK: zext +; CHECK: sub +; CHECK: volatile store volatile store 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: volatile store volatile store i32 %F, i32* %IP ret void } |