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| author | Benjamin Kramer <benny.kra@googlemail.com> | 2010-05-25 22:53:43 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2010-05-25 22:53:43 +0000 |
| commit | 9439084cea7452256832f137cc9eaf79a1c7e45b (patch) | |
| tree | 73714f15bd2c4819ed98fc8fd9543d5f4527db2d /llvm/lib/Transforms | |
| parent | 388f6385113b6d25cfd5c5950f6c2176526a4e3b (diff) | |
| download | bcm5719-llvm-9439084cea7452256832f137cc9eaf79a1c7e45b.tar.gz bcm5719-llvm-9439084cea7452256832f137cc9eaf79a1c7e45b.zip | |
Properly promote operands when optimizing a single-character memcmp.
llvm-svn: 104648
Diffstat (limited to 'llvm/lib/Transforms')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp index b053cfc3b46..0f3ab7d8b53 100644 --- a/llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp +++ b/llvm/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()); } |
