Simplify RegScavenger::FindUnusedReg.

- Drop the Candidates argument and fix all callers. Now that RegScavenger
  tracks available registers accurately, there is no need to restict the
  search.
- Make sure that no aliases of the found register are in use. This was a potential bug.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79369 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jakob Stoklund Olesen
2009-08-18 21:14:54 +00:00
parent 1123135dbf
commit c0823fe7c6
6 changed files with 13 additions and 51 deletions

View File

@ -941,12 +941,8 @@ bool ARMLoadStoreOpt::LoadStoreMultipleOpti(MachineBasicBlock &MBB) {
// Try to find a free register to use as a new base in case it's needed.
// First advance to the instruction just before the start of the chain.
AdvanceRS(MBB, MemOps);
// Find a scratch register. Make sure it's a call clobbered register or
// a spilled callee-saved register.
unsigned Scratch = RS->FindUnusedReg(&ARM::GPRRegClass, true);
if (!Scratch)
Scratch = RS->FindUnusedReg(&ARM::GPRRegClass,
AFI->getSpilledCSRegisters());
// Find a scratch register.
unsigned Scratch = RS->FindUnusedReg(&ARM::GPRRegClass);
// Process the load / store instructions.
RS->forward(prior(MBBI));