diff options
Diffstat (limited to 'lib/Transforms/Scalar/SimplifyLibCalls.cpp')
| -rw-r--r-- | lib/Transforms/Scalar/SimplifyLibCalls.cpp | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp index b053cfc..7414be7 100644 --- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp +++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp @@ -558,10 +558,13 @@ 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"); - return B.CreateSExt(B.CreateSub(LHSV, RHSV, "chardiff"), CI->getType()); + // 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.CreateSub(LHSV, RHSV, "chardiff"); } // Constant folding: memcmp(x, y, l) -> cnst (all arguments are constant) |
