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| author | Chris Lattner <sabre@nondot.org> | 2009-06-19 04:17:36 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2009-06-19 04:17:36 +0000 |
| commit | 3791f13472ce676dd6d8a14abe76b8815c6986f3 (patch) | |
| tree | f2b648db29f164ed6365a3a316baa7de17063eb9 /lib/Transforms/Scalar | |
| parent | 7c3765da747832befd9a57fa96c6f56ac2838c2a (diff) | |
| download | external_llvm-3791f13472ce676dd6d8a14abe76b8815c6986f3.zip external_llvm-3791f13472ce676dd6d8a14abe76b8815c6986f3.tar.gz external_llvm-3791f13472ce676dd6d8a14abe76b8815c6986f3.tar.bz2 | |
part of PR4405: disable a contentious optimization for
strcmp -> memcmp when the lengths of the strings are unknown.
Patch by Nick Lewycky!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73751 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Scalar')
| -rw-r--r-- | lib/Transforms/Scalar/SimplifyLibCalls.cpp | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp index 7d0c35e..bbcb792 100644 --- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp +++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp @@ -709,12 +709,10 @@ struct VISIBILITY_HIDDEN StrCmpOpt : public LibCallOptimization { // strcmp(P, "x") -> memcmp(P, "x", 2) uint64_t Len1 = GetStringLength(Str1P); uint64_t Len2 = GetStringLength(Str2P); - if (Len1 || Len2) { - // Choose the smallest Len excluding 0 which means 'unknown'. - if (!Len1 || (Len2 && Len2 < Len1)) - Len1 = Len2; + if (Len1 && Len2) { return EmitMemCmp(Str1P, Str2P, - ConstantInt::get(TD->getIntPtrType(), Len1), B); + ConstantInt::get(TD->getIntPtrType(), + std::min(Len1, Len2)), B); } return 0; |