LivePhysRegs: Automatically determine presence of pristine regs.

Remove the AddPristinesAndCSRs parameters from
addLiveIns()/addLiveOuts().

We need to respect pristine registers after prologue epilogue insertion,
Seeing that we got this wrong in at least two commits already, we should
rather pay the small price to query MachineFrameInfo for it.

There are three cases that did not set AddPristineAndCSRs to true even
after register allocation:
- ExecutionDepsFix: live-out registers are used as a hint that the
  register is used soon. This is not true for pristine registers so
  use the new addLiveOutsNoPristines() to maintain this behaviour.
- SystemZShortenInst: Not setting AddPristineAndCSRs to true looks like
  a bug, should do the right thing automatically now.
- StackMapLivenessAnalysis: Not adding pristine registers looks like a
  bug to me. Added a FIXME comment but maintain the current behaviour
  as a change may need to get coordinated with GC runtimes.

llvm-svn: 268336

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Target/ARM/Thumb1FrameLowering.cpp b/llvm/lib/Target/ARM/Thumb1FrameLowering.cpp
index ef225f34..ed74d20 100644
--- a/llvm/lib/Target/ARM/Thumb1FrameLowering.cpp
+++ b/llvm/lib/Target/ARM/Thumb1FrameLowering.cpp
@@ -467,7 +467,7 @@ bool Thumb1FrameLowering::emitPopSpecialFixUp(MachineBasicBlock &MBB,
   // Look for a temporary register to use.
   // First, compute the liveness information.
   LivePhysRegs UsedRegs(STI.getRegisterInfo());
-  UsedRegs.addLiveOuts(&MBB, /*AddPristines*/ true);
+  UsedRegs.addLiveOuts(&MBB);
   // The semantic of pristines changed recently and now,
   // the callee-saved registers that are touched in the function
   // are not part of the pristines set anymore.