Fix a bug where we were counting the alias sets as completely used

registers for fast allocation a different way. This has us updating
used registers only when we're using that exact register.

Fixes rdar://9207598

llvm-svn: 129711

1 files changed, 0 insertions, 5 deletions

diff --git a/llvm/lib/CodeGen/RegAllocFast.cpp b/llvm/lib/CodeGen/RegAllocFast.cpp
index 7bb849ef546..93e3adc3c78 100644
--- a/llvm/lib/CodeGen/RegAllocFast.cpp
+++ b/llvm/lib/CodeGen/RegAllocFast.cpp
@@ -396,7 +396,6 @@ void RAFast::definePhysReg(MachineInstr *MI, unsigned PhysReg,
   PhysRegState[PhysReg] = NewState;
   for (const unsigned *AS = TRI->getAliasSet(PhysReg);
        unsigned Alias = *AS; ++AS) {
-    UsedInInstr.set(Alias);
     switch (unsigned VirtReg = PhysRegState[Alias]) {
     case regDisabled:
       break;
@@ -734,10 +733,6 @@ void RAFast::handleThroughOperands(MachineInstr *MI,
     if (!Reg || !TargetRegisterInfo::isPhysicalRegister(Reg)) continue;
     DEBUG(dbgs() << "\tSetting reg " << Reg << " as used in instr\n");
     UsedInInstr.set(Reg);
-    for (const unsigned *AS = TRI->getAliasSet(Reg); *AS; ++AS) {
-      DEBUG(dbgs() << "\tSetting alias reg " << *AS << " as used in instr\n");
-      UsedInInstr.set(*AS);
-    }
   }
 
   // Also mark PartialDefs as used to avoid reallocation.