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| author | Hal Finkel <hfinkel@anl.gov> | 2013-03-21 19:03:19 +0000 |
|---|---|---|
| committer | Hal Finkel <hfinkel@anl.gov> | 2013-03-21 19:03:19 +0000 |
| commit | e9cc0a09ae38c87b1b26a44f5e32222ede4f84e6 (patch) | |
| tree | 42e21d6c6941660042c344100602c339cb80b3bf /lib/Target/PowerPC/PPCISelLowering.cpp | |
| parent | 3382a840747c42c4a98eac802ee7b347a8ded1e4 (diff) | |
| download | llvm-e9cc0a09ae38c87b1b26a44f5e32222ede4f84e6.tar.gz llvm-e9cc0a09ae38c87b1b26a44f5e32222ede4f84e6.tar.bz2 llvm-e9cc0a09ae38c87b1b26a44f5e32222ede4f84e6.tar.xz | |
Correct PPC FRAMEADDR lowering using a pseudo-register
The old code used to lower FRAMEADDR tried to replicate the logic in the real
frame-lowering code that determines whether or not the frame pointer (r31) will
be used. When it seemed as through the frame pointer would not be used, the
stack pointer (r1) was used instead. Unfortunately, because the stack size is
not yet known, this does not work. Instead, this change introduces new
always-reserved pseudo-registers (FP and FP8) that are replaced during prologue
insertion with the real frame-pointer register (either r1 or r31).
It is important that this intrinsic always return a valid frame address because
it is used by Clang to store the frame address as part of code generation for
__builtin_setjmp.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177653 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/PowerPC/PPCISelLowering.cpp')
| -rw-r--r-- | lib/Target/PowerPC/PPCISelLowering.cpp | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp index c50811d52b..72cb6f535a 100644 --- a/lib/Target/PowerPC/PPCISelLowering.cpp +++ b/lib/Target/PowerPC/PPCISelLowering.cpp @@ -6815,13 +6815,16 @@ SDValue PPCTargetLowering::LowerFRAMEADDR(SDValue Op, MachineFunction &MF = DAG.getMachineFunction(); MachineFrameInfo *MFI = MF.getFrameInfo(); MFI->setFrameAddressIsTaken(true); - bool is31 = (getTargetMachine().Options.DisableFramePointerElim(MF) || - MFI->hasVarSizedObjects()) && - MFI->getStackSize() && - !MF.getFunction()->getAttributes(). - hasAttribute(AttributeSet::FunctionIndex, Attribute::Naked); - unsigned FrameReg = isPPC64 ? (is31 ? PPC::X31 : PPC::X1) : - (is31 ? PPC::R31 : PPC::R1); + + // Naked functions never have a frame pointer, and so we use r1. For all + // other functions, this decision must be delayed until during PEI. + unsigned FrameReg; + if (MF.getFunction()->getAttributes().hasAttribute( + AttributeSet::FunctionIndex, Attribute::Naked)) + FrameReg = isPPC64 ? PPC::X1 : PPC::R1; + else + FrameReg = isPPC64 ? PPC::FP8 : PPC::FP; + SDValue FrameAddr = DAG.getCopyFromReg(DAG.getEntryNode(), dl, FrameReg, PtrVT); while (Depth--) |