diff options
Diffstat (limited to 'llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp')
| -rw-r--r-- | llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp index 0bdfaf67c40..a1f036d68ec 100644 --- a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp +++ b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp @@ -354,6 +354,15 @@ void SystemZFrameLowering::emitPrologue(MachineFunction &MF, uint64_t StackSize = getAllocatedStackSize(MF); if (StackSize) { + // Determine if we want to store a backchain. + bool StoreBackchain = MF.getFunction()->hasFnAttribute("backchain"); + + // If we need backchain, save current stack pointer. R1 is free at this + // point. + if (StoreBackchain) + BuildMI(MBB, MBBI, DL, ZII->get(SystemZ::LGR)) + .addReg(SystemZ::R1D, RegState::Define).addReg(SystemZ::R15D); + // Allocate StackSize bytes. int64_t Delta = -int64_t(StackSize); emitIncrement(MBB, MBBI, DL, SystemZ::R15D, Delta, ZII); @@ -364,6 +373,10 @@ void SystemZFrameLowering::emitPrologue(MachineFunction &MF, BuildMI(MBB, MBBI, DL, ZII->get(TargetOpcode::CFI_INSTRUCTION)) .addCFIIndex(CFIIndex); SPOffsetFromCFA += Delta; + + if (StoreBackchain) + BuildMI(MBB, MBBI, DL, ZII->get(SystemZ::STG)) + .addReg(SystemZ::R1D, RegState::Kill).addReg(SystemZ::R15D).addImm(0).addReg(0); } if (HasFP) { |
