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[ARM] Back up R4 and LR if calling the stack probe function 

Differential Revision: https://reviews.llvm.org/D46777

llvm-svn: 332298
This commit is contained in:
Martin Storsjo 2018-05-14 21:32:52 +00:00
parent 5556841cd3
commit ace7ae935f
2 changed files with 12 additions and 1 deletions
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11
llvm/lib/Target/ARM/ARMFrameLowering.cpp
View File

@ -1620,6 +1620,17 @@ void ARMFrameLowering::determineCalleeSaves(MachineFunction &MF,
(MFI.hasVarSizedObjects() || RegInfo->needsStackRealignment(MF)))
SavedRegs.set(ARM::R4);
// If a stack probe will be emitted, spill R4 and LR, since they are
// clobbered by the stack probe call.
// This estimate should be a safe, conservative estimate. The actual
// stack probe is enabled based on the size of the local objects;
// this estimate also includes the varargs store size.
if (STI.isTargetWindows() &&
WindowsRequiresStackProbe(MF, MFI.estimateStackSize(MF))) {
SavedRegs.set(ARM::R4);
SavedRegs.set(ARM::LR);
}
if (AFI->isThumb1OnlyFunction()) {
// Spill LR if Thumb1 function uses variable length argument lists.
if (AFI->getArgRegsSaveSize() > 0)

2
llvm/test/CodeGen/ARM/Windows/chkstk-movw-movt-isel.ll
View File

@ -18,7 +18,7 @@ entry:
}
; CHECK-LABEL: isel
; CHECK: push {r4, r5}
; CHECK: push {r4, r5, r6, lr}
; CHECK: movw r12, #0
; CHECK: movt r12, #0
; CHECK: movw r4, #{{\d*}}