Commit Graph

3 Commits

Author SHA1 Message Date
Hans Wennborg
2f471c83a0 Check for dynamic allocas and inline asm that clobbers sp before building
selection dag (PR19012)

In X86SelectionDagInfo::EmitTargetCodeForMemcpy we check with MachineFrameInfo
to make sure that ESI isn't used as a base pointer register before we choose to
emit rep movs (which clobbers esi).

The problem is that MachineFrameInfo wouldn't know about dynamic allocas or
inline asm that clobbers the stack pointer until SelectionDAGBuilder has
encountered them.

This patch fixes the problem by checking for such things when building the
FunctionLoweringInfo.

Differential Revision: http://llvm-reviews.chandlerc.com/D2954

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202930 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-05 02:43:26 +00:00
Stephen Lin
b4dc0233c9 Convert CodeGen/*/*.ll tests to use the new CHECK-LABEL for easier debugging. No functionality change and all tests pass after conversion.
This was done with the following sed invocation to catch label lines demarking function boundaries:
    sed -i '' "s/^;\( *\)\([A-Z0-9_]*\):\( *\)test\([A-Za-z0-9_-]*\):\( *\)$/;\1\2-LABEL:\3test\4:\5/g" test/CodeGen/*/*.ll
which was written conservatively to avoid false positives rather than false negatives. I scanned through all the changes and everything looks correct.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186258 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-13 20:38:47 +00:00
Benjamin Kramer
f09e02f01a X86: Disable generation of rep;movsl when %esi is used as a base pointer.
This happens when there is both stack realignment and a dynamic alloca in the
function. If we overwrite %esi (rep;movsl uses fixed registers) we'll lose the
base pointer and the next register spill will write into oblivion.

Fixes PR15249 and unbreaks firefox on i386/freebsd. Mozilla uses dynamic allocas
and freebsd a 4 byte stack alignment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175057 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-13 13:40:35 +00:00