The scavenger should just use getAllocatableSet() rather than reinventing it

locally.

llvm-svn: 112845

1 files changed, 3 insertions, 13 deletions

diff --git a/llvm/lib/CodeGen/RegisterScavenging.cpp b/llvm/lib/CodeGen/RegisterScavenging.cpp
index 9e9b48df551..a2580b85bcc 100644
--- a/llvm/lib/CodeGen/RegisterScavenging.cpp
+++ b/llvm/lib/CodeGen/RegisterScavenging.cpp
@@ -228,14 +228,6 @@ void RegScavenger::getRegsUsed(BitVector &used, bool includeReserved) {
     used = ~RegsAvailable & ~ReservedRegs;
 }
 
-/// CreateRegClassMask - Set the bits that represent the registers in the
-/// TargetRegisterClass.
-static void CreateRegClassMask(const TargetRegisterClass *RC, BitVector &Mask) {
-  for (TargetRegisterClass::iterator I = RC->begin(), E = RC->end(); I != E;
-       ++I)
-    Mask.set(*I);
-}
-
 unsigned RegScavenger::FindUnusedReg(const TargetRegisterClass *RC) const {
   for (TargetRegisterClass::iterator I = RC->begin(), E = RC->end();
        I != E; ++I)
@@ -330,11 +322,9 @@ unsigned RegScavenger::findSurvivorReg(MachineBasicBlock::iterator StartMI,
 unsigned RegScavenger::scavengeRegister(const TargetRegisterClass *RC,
                                         MachineBasicBlock::iterator I,
                                         int SPAdj) {
-  // Mask off the registers which are not in the TargetRegisterClass.
-  BitVector Candidates(NumPhysRegs, false);
-  CreateRegClassMask(RC, Candidates);
-  // Do not include reserved registers.
-  Candidates ^= ReservedRegs & Candidates;
+  // Consider all allocatable registers in the register class initially
+  BitVector Candidates =
+    TRI->getAllocatableSet(*I->getParent()->getParent(), RC);
 
   // Exclude all the registers being used by the instruction.
   for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {