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-rw-r--r--llvm/lib/Target/X86/X86VZeroUpper.cpp11
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);
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