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author | Michael Liao <michael.liao@intel.com> | 2013-10-23 18:32:43 +0000 |
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committer | Michael Liao <michael.liao@intel.com> | 2013-10-23 18:32:43 +0000 |
commit | 531f025361555e7a695eb559ec02645c054ee146 (patch) | |
tree | 4b363afb627fe1266a9c96bad74b8581f694f4dd /lib/Target/X86/X86VZeroUpper.cpp | |
parent | df5ed1b08acf0f278275bce15ffc6d2cf953816d (diff) | |
download | llvm-531f025361555e7a695eb559ec02645c054ee146.tar.gz llvm-531f025361555e7a695eb559ec02645c054ee146.tar.bz2 llvm-531f025361555e7a695eb559ec02645c054ee146.tar.xz |
Fix PR17631
- Skip instructions added in prolog. For specific targets, prolog may
insert helper function calls (e.g. _chkstk will be called when
there're more than 4K bytes allocated on stack). However, these
helpers don't use/def YMM/XMM registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193261 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86/X86VZeroUpper.cpp')
-rw-r--r-- | lib/Target/X86/X86VZeroUpper.cpp | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/lib/Target/X86/X86VZeroUpper.cpp b/lib/Target/X86/X86VZeroUpper.cpp index 477f75afef..0d37a7d0e6 100644 --- a/lib/Target/X86/X86VZeroUpper.cpp +++ b/lib/Target/X86/X86VZeroUpper.cpp @@ -231,8 +231,17 @@ bool VZeroUpperInserter::processBasicBlock(MachineFunction &MF, bool BBHasCall = false; for (MachineBasicBlock::iterator I = BB.begin(); I != BB.end(); ++I) { - MachineInstr *MI = I; DebugLoc dl = I->getDebugLoc(); + MachineInstr *MI = I; + + // Don't need to check instructions added in prolog. + // In prolog, special function calls may be added for specific targets + // (e.g. on Windows, a prolog helper '_chkstk' is called when the local + // variables exceed 4K bytes on stack.) These helpers won't use/def YMM/XMM + // registers. + if (MI->getFlag(MachineInstr::FrameSetup)) + continue; + bool isControlFlow = MI->isCall() || MI->isReturn(); // Shortcut: don't need to check regular instructions in dirty state. |