MachineRegisterInfo: Remove UsedPhysReg infrastructure

We have a detailed def/use lists for every physical register in
MachineRegisterInfo anyway, so there is little use in maintaining an
additional bitset of which ones are used.

Removing it frees us from extra book keeping. This simplifies
VirtRegMap.

Differential Revision: http://reviews.llvm.org/D10911

llvm-svn: 242173

1 files changed, 0 insertions, 14 deletions

diff --git a/llvm/lib/CodeGen/RegAllocFast.cpp b/llvm/lib/CodeGen/RegAllocFast.cpp
index fd3d4d78968..660bb4f0e34 100644
--- a/llvm/lib/CodeGen/RegAllocFast.cpp
+++ b/llvm/lib/CodeGen/RegAllocFast.cpp
@@ -986,10 +986,6 @@ void RAFast::AllocateBasicBlock() {
       }
     }
 
-    for (UsedInInstrSet::iterator
-         I = UsedInInstr.begin(), E = UsedInInstr.end(); I != E; ++I)
-      MRI->setRegUnitUsed(*I);
-
     // Track registers defined by instruction - early clobbers and tied uses at
     // this point.
     UsedInInstr.clear();
@@ -1050,10 +1046,6 @@ void RAFast::AllocateBasicBlock() {
       killVirtReg(VirtDead[i]);
     VirtDead.clear();
 
-    for (UsedInInstrSet::iterator
-         I = UsedInInstr.begin(), E = UsedInInstr.end(); I != E; ++I)
-      MRI->setRegUnitUsed(*I);
-
     if (CopyDst && CopyDst == CopySrc && CopyDstSub == CopySrcSub) {
       DEBUG(dbgs() << "-- coalescing: " << *MI);
       Coalesced.push_back(MI);
@@ -1103,12 +1095,6 @@ bool RAFast::runOnMachineFunction(MachineFunction &Fn) {
     AllocateBasicBlock();
   }
 
-  // Add the clobber lists for all the instructions we skipped earlier.
-  for (const MCInstrDesc *Desc : SkippedInstrs)
-    if (const uint16_t *Defs = Desc->getImplicitDefs())
-      while (*Defs)
-        MRI->setPhysRegUsed(*Defs++);
-
   // All machine operands and other references to virtual registers have been
   // replaced. Remove the virtual registers.
   MRI->clearVirtRegs();