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

3 files changed, 1 insertions, 3 deletions

diff --git a/llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp b/llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp
index 587ea63d679..d23b92edef3 100644
--- a/llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp
@@ -53,7 +53,6 @@ SIMachineFunctionInfo::SpilledReg SIMachineFunctionInfo::getSpilledReg(
   if (!LaneVGPRs.count(LaneVGPRIdx)) {
     unsigned LaneVGPR = TRI->findUnusedRegister(MRI, &AMDGPU::VGPR_32RegClass);
     LaneVGPRs[LaneVGPRIdx] = LaneVGPR;
-    MRI.setPhysRegUsed(LaneVGPR);
 
     // Add this register as live-in to all blocks to avoid machine verifer
     // complaining about use of an undefined physical register.
diff --git a/llvm/lib/Target/AMDGPU/SIPrepareScratchRegs.cpp b/llvm/lib/Target/AMDGPU/SIPrepareScratchRegs.cpp
index 0a7f684552f..b086d2ed665 100644
--- a/llvm/lib/Target/AMDGPU/SIPrepareScratchRegs.cpp
+++ b/llvm/lib/Target/AMDGPU/SIPrepareScratchRegs.cpp
@@ -91,7 +91,6 @@ bool SIPrepareScratchRegs::runOnMachineFunction(MachineFunction &MF) {
 
   if (ScratchOffsetReg != AMDGPU::NoRegister) {
     // Found an SGPR to use
-    MRI.setPhysRegUsed(ScratchOffsetReg);
     BuildMI(*Entry, I, DL, TII->get(AMDGPU::S_MOV_B32), ScratchOffsetReg)
             .addReg(ScratchOffsetPreloadReg);
   } else {
diff --git a/llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp b/llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp
index db2ff0b1f95..ce4acafac9f 100644
--- a/llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp
@@ -499,7 +499,7 @@ unsigned SIRegisterInfo::findUnusedRegister(const MachineRegisterInfo &MRI,
 
   for (TargetRegisterClass::iterator I = RC->begin(), E = RC->end();
        I != E; ++I) {
-    if (!MRI.isPhysRegUsed(*I))
+    if (MRI.reg_nodbg_empty(*I))
       return *I;
   }
   return AMDGPU::NoRegister;