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/ARMBaseRegisterInfo.cpp b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
index 09ab87c..07164ff 100644
--- a/lib/Target/ARM/ARMBaseRegisterInfo.cpp
+++ b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
@@ -1006,12 +1006,8 @@
static
unsigned findScratchRegister(RegScavenger *RS, const TargetRegisterClass *RC,
ARMFunctionInfo *AFI) {
- unsigned Reg = RS ? RS->FindUnusedReg(RC, true) : (unsigned) ARM::R12;
+ unsigned Reg = RS ? RS->FindUnusedReg(RC) : (unsigned) ARM::R12;
assert(!AFI->isThumb1OnlyFunction());
- if (Reg == 0)
- // Try a already spilled CS register.
- Reg = RS->FindUnusedReg(RC, AFI->getSpilledCSRegisters());
-
return Reg;
}
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));
diff --git a/lib/Target/Blackfin/BlackfinRegisterInfo.cpp b/lib/Target/Blackfin/BlackfinRegisterInfo.cpp
index 7fcfd12..e820c3b 100644
--- a/lib/Target/Blackfin/BlackfinRegisterInfo.cpp
+++ b/lib/Target/Blackfin/BlackfinRegisterInfo.cpp
@@ -213,7 +213,7 @@
const TargetRegisterClass *RC,
int SPAdj) {
assert(RS && "Register scavenging must be on");
- unsigned Reg = RS->FindUnusedReg(RC, true);
+ unsigned Reg = RS->FindUnusedReg(RC);
if (Reg == 0)
Reg = RS->scavengeRegister(RC, II, SPAdj);
return Reg;
diff --git a/lib/Target/PowerPC/PPCRegisterInfo.cpp b/lib/Target/PowerPC/PPCRegisterInfo.cpp
index 2eb2abc..f120caa 100644
--- a/lib/Target/PowerPC/PPCRegisterInfo.cpp
+++ b/lib/Target/PowerPC/PPCRegisterInfo.cpp
@@ -527,7 +527,7 @@
unsigned findScratchRegister(MachineBasicBlock::iterator II, RegScavenger *RS,
const TargetRegisterClass *RC, int SPAdj) {
assert(RS && "Register scavenging must be on");
- unsigned Reg = RS->FindUnusedReg(RC, true);
+ unsigned Reg = RS->FindUnusedReg(RC);
// FIXME: move ARM callee-saved reg scan to target independent code, then
// search for already spilled CS register here.
if (Reg == 0)