diff options
| author | Dan Gohman <gohman@apple.com> | 2010-12-17 01:09:43 +0000 |
|---|---|---|
| committer | Dan Gohman <gohman@apple.com> | 2010-12-17 01:09:43 +0000 |
| commit | c32046e6eaffba890897da94ab8900d51bf9d18f (patch) | |
| tree | 8220b7d279b1e43f6051fc11df9dc6f6c4cf5add | |
| parent | 2d8e3e741f49baadfc72403de9c4b362a07af8d9 (diff) | |
Revert r64460. strtol and friends cannot be marked readonly, even with
a null endptr argument, because they may write to errno.
This fixes a seflhost miscompile observed on Linux targets when TBAA
was enabled.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122014 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/Scalar/SimplifyLibCalls.cpp | 3 | ||||
| -rw-r--r-- | test/Transforms/SimplifyLibCalls/2009-02-12-StrTo.ll | 2 |
2 files changed, 3 insertions, 2 deletions
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp index 43c6f6dda2..3edc447cec 100644 --- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp +++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp @@ -577,7 +577,8 @@ struct StrToOpt : public LibCallOptimization { Value *EndPtr = CI->getArgOperand(1); if (isa<ConstantPointerNull>(EndPtr)) { - CI->setOnlyReadsMemory(); + // With a null EndPtr, this function won't capture the main argument. + // It would be readonly too, except that it still may write to errno. CI->addAttribute(1, Attribute::NoCapture); } diff --git a/test/Transforms/SimplifyLibCalls/2009-02-12-StrTo.ll b/test/Transforms/SimplifyLibCalls/2009-02-12-StrTo.ll index cb9819cace..f8a0c88d2f 100644 --- a/test/Transforms/SimplifyLibCalls/2009-02-12-StrTo.ll +++ b/test/Transforms/SimplifyLibCalls/2009-02-12-StrTo.ll @@ -1,7 +1,7 @@ ; RUN: opt < %s -simplify-libcalls -S > %t ; RUN: grep nocapture %t | count 2 ; RUN: grep null %t | grep nocapture | count 1 -; RUN: grep null %t | grep call | grep readonly | count 1 +; RUN: grep null %t | grep call | not grep readonly ; Test that we add nocapture to the declaration, and to the second call only. |