Changed the liveness tracking in the RegisterScavenger

to use register units instead of registers.

reviewed by Jakob Stoklund Olesen.

llvm-svn: 214798

1 files changed, 9 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/MachineRegisterInfo.cpp b/llvm/lib/CodeGen/MachineRegisterInfo.cpp
index 8be6d718098..6da1b685a91 100644
--- a/llvm/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/llvm/lib/CodeGen/MachineRegisterInfo.cpp
@@ -284,18 +284,25 @@ void MachineRegisterInfo::moveOperands(MachineOperand *Dst,
 /// replaceRegWith - Replace all instances of FromReg with ToReg in the
 /// machine function.  This is like llvm-level X->replaceAllUsesWith(Y),
 /// except that it also changes any definitions of the register as well.
+/// If ToReg is a physical register we apply the sub register to obtain the
+/// final/proper physical register.
 void MachineRegisterInfo::replaceRegWith(unsigned FromReg, unsigned ToReg) {
   assert(FromReg != ToReg && "Cannot replace a reg with itself");
 
+  const TargetRegisterInfo *TRI = getTargetRegisterInfo();
+  
   // TODO: This could be more efficient by bulk changing the operands.
   for (reg_iterator I = reg_begin(FromReg), E = reg_end(); I != E; ) {
     MachineOperand &O = *I;
     ++I;
-    O.setReg(ToReg);
+    if (TargetRegisterInfo::isPhysicalRegister(ToReg)) {
+      O.substPhysReg(ToReg, *TRI);
+    } else {
+      O.setReg(ToReg);
+    }
   }
 }
 
-
 /// getVRegDef - Return the machine instr that defines the specified virtual
 /// register or null if none is found.  This assumes that the code is in SSA
 /// form, so there should only be one definition.