diff options
| author | Saleem Abdulrasool <compnerd@compnerd.org> | 2017-08-17 02:42:24 +0000 |
|---|---|---|
| committer | Saleem Abdulrasool <compnerd@compnerd.org> | 2017-08-17 02:42:24 +0000 |
| commit | e042428b3e1d69205ff422e0c328e28f67b3e465 (patch) | |
| tree | 104f7cf67387fbc1b359a582edd800917b6d212d /lib | |
| parent | 23aac208ffe19cecba13dc463b0e634014a5202e (diff) | |
ARM: mark CPSR as clobbered for Windows VLAs
When lowering a VLA, we emit a __chstk call. However, this call can
internally clobber CPSR. We did not mark this register as an ImpDef,
which could potentially allow a comparison to be hoisted above the call
to `__chkstk`. In such a case, the CPSR could be clobbered, and the
check invalidated. When the support was initially added, it seemed that
the call would take care of preventing CPSR from being clobbered, but
this is not the case. Mark the register as clobbered to fix a possible
state corruption.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311061 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Target/ARM/ARMISelLowering.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp index 778ed3b26d2..ff8491d2e62 100644 --- a/lib/Target/ARM/ARMISelLowering.cpp +++ b/lib/Target/ARM/ARMISelLowering.cpp @@ -8790,6 +8790,8 @@ ARMTargetLowering::EmitLowered__chkstk(MachineInstr &MI, .addReg(ARM::R4, RegState::Implicit | RegState::Kill) .addReg(ARM::R4, RegState::Implicit | RegState::Define) .addReg(ARM::R12, + RegState::Implicit | RegState::Define | RegState::Dead) + .addReg(ARM::CPSR, RegState::Implicit | RegState::Define | RegState::Dead); break; case CodeModel::Large: { @@ -8804,6 +8806,8 @@ ARMTargetLowering::EmitLowered__chkstk(MachineInstr &MI, .addReg(ARM::R4, RegState::Implicit | RegState::Kill) .addReg(ARM::R4, RegState::Implicit | RegState::Define) .addReg(ARM::R12, + RegState::Implicit | RegState::Define | RegState::Dead) + .addReg(ARM::CPSR, RegState::Implicit | RegState::Define | RegState::Dead); break; } |