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| author | Amjad Aboud <amjad.aboud@intel.com> | 2016-03-01 11:32:03 +0000 |
|---|---|---|
| committer | Amjad Aboud <amjad.aboud@intel.com> | 2016-03-01 11:32:03 +0000 |
| commit | 719325fe11fcbf3177f588e5e7927625cafa7781 (patch) | |
| tree | 938f41be46b634e0ea9ebf06f40ab03294f423b3 /llvm/lib/Target/X86 | |
| parent | 016c024ca4798796480af7ecae6758e95600550f (diff) | |
| download | bcm5719-llvm-719325fe11fcbf3177f588e5e7927625cafa7781.tar.gz bcm5719-llvm-719325fe11fcbf3177f588e5e7927625cafa7781.zip | |
Disallow generating vzeroupper before return instruction (iret) in interrupt handler function.
This resolves https://llvm.org/bugs/show_bug.cgi?id=26412
Differential Revision: http://reviews.llvm.org/D17542
llvm-svn: 262319
Diffstat (limited to 'llvm/lib/Target/X86')
| -rw-r--r-- | llvm/lib/Target/X86/X86VZeroUpper.cpp | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/llvm/lib/Target/X86/X86VZeroUpper.cpp b/llvm/lib/Target/X86/X86VZeroUpper.cpp index cd822b08361..172f8665fad 100644 --- a/llvm/lib/Target/X86/X86VZeroUpper.cpp +++ b/llvm/lib/Target/X86/X86VZeroUpper.cpp @@ -80,6 +80,7 @@ namespace { BlockStateMap BlockStates; DirtySuccessorsWorkList DirtySuccessors; bool EverMadeChange; + bool IsX86INTR; const TargetInstrInfo *TII; static char ID; @@ -181,10 +182,13 @@ void VZeroUpperInserter::processBasicBlock(MachineBasicBlock &MBB) { for (MachineBasicBlock::iterator I = MBB.begin(); I != MBB.end(); ++I) { MachineInstr *MI = I; - bool isControlFlow = MI->isCall() || MI->isReturn(); + // No need for vzeroupper before iret in interrupt handler function, + // epilogue will restore YMM registers if needed. + bool IsReturnFromX86INTR = IsX86INTR && MI->isReturn(); + bool IsControlFlow = MI->isCall() || MI->isReturn(); // Shortcut: don't need to check regular instructions in dirty state. - if (!isControlFlow && CurState == EXITS_DIRTY) + if ((!IsControlFlow || IsReturnFromX86INTR) && CurState == EXITS_DIRTY) continue; if (hasYmmReg(MI)) { @@ -196,7 +200,7 @@ void VZeroUpperInserter::processBasicBlock(MachineBasicBlock &MBB) { // Check for control-flow out of the current function (which might // indirectly execute SSE instructions). - if (!isControlFlow) + if (!IsControlFlow || IsReturnFromX86INTR) continue; // If the call won't clobber any YMM register, skip it as well. It usually @@ -253,6 +257,7 @@ bool VZeroUpperInserter::runOnMachineFunction(MachineFunction &MF) { TII = ST.getInstrInfo(); MachineRegisterInfo &MRI = MF.getRegInfo(); EverMadeChange = false; + IsX86INTR = MF.getFunction()->getCallingConv() == CallingConv::X86_INTR; bool FnHasLiveInYmm = checkFnHasLiveInYmm(MRI); |
