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| author | Eric Christopher <echristo@apple.com> | 2010-02-02 22:10:43 +0000 |
|---|---|---|
| committer | Eric Christopher <echristo@apple.com> | 2010-02-02 22:10:43 +0000 |
| commit | a6a089cd244033109a232c99cb09ac424703afff (patch) | |
| tree | 00ebc1b3f91ed2385c814e9d706980b2a4563d34 /lib/Transforms/Scalar | |
| parent | 7f89fdae34a11f8b0b3e0ee1de3f2f6d317f38c4 (diff) | |
| download | external_llvm-a6a089cd244033109a232c99cb09ac424703afff.zip external_llvm-a6a089cd244033109a232c99cb09ac424703afff.tar.gz external_llvm-a6a089cd244033109a232c99cb09ac424703afff.tar.bz2 | |
Re-add strcmp and known size object size checking optimization.
Passed bootstrap and nightly test run here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95145 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Scalar')
| -rw-r--r-- | lib/Transforms/Scalar/SimplifyLibCalls.cpp | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp index db6ff29..4216e8f 100644 --- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp +++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp @@ -1213,8 +1213,13 @@ struct StrCpyChkOpt : public LibCallOptimization { if (!SizeCI) return 0; - // We don't have any length information, just lower to a plain strcpy. - if (SizeCI->isAllOnesValue()) + // If a) we don't have any length information, or b) we know this will + // fit then just lower to a plain strcpy. Otherwise we'll keep our + // strcpy_chk call which may fail at runtime if the size is too long. + // TODO: It might be nice to get a maximum length out of the possible + // string lengths for varying. + if (SizeCI->isAllOnesValue() || + SizeCI->getZExtValue() >= GetStringLength(CI->getOperand(2))) return EmitStrCpy(CI->getOperand(1), CI->getOperand(2), B); return 0; |