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
diff --git a/lib/Target/ARM/ARMLoadStoreOptimizer.cpp b/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
index 3c6778f..d927dd2 100644
--- a/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
+++ b/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
@@ -941,12 +941,8 @@
// 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));