From: Matt Arsenault <Matthew.Arsenault@amd.com>
Date: Wed, 23 Nov 2016 21:00:10 +0000 (+0000)
Subject: AMDGPU: Fix adding extra implicit def of register
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e834ce5976567575621901fb967b8018b9916d71;p=llvm

AMDGPU: Fix adding extra implicit def of register

In the scalar case, there's no reason to add an additional
def of the same register.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287807 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/AMDGPU/SIRegisterInfo.cpp b/lib/Target/AMDGPU/SIRegisterInfo.cpp
index 759df16e6d3..71c1ac7ffbc 100644
--- a/lib/Target/AMDGPU/SIRegisterInfo.cpp
+++ b/lib/Target/AMDGPU/SIRegisterInfo.cpp
@@ -476,7 +476,7 @@ void SIRegisterInfo::buildSpillLoadStore(MachineBasicBlock::iterator MI,
       = MF->getMachineMemOperand(PInfo, MMO->getFlags(),
                                  EltSize, MinAlign(Align, EltSize * i));
 
-    BuildMI(*MBB, MI, DL, Desc)
+    auto MIB = BuildMI(*MBB, MI, DL, Desc)
       .addReg(SubReg, getDefRegState(!IsStore))
       .addReg(ScratchRsrcReg)
       .addReg(SOffset, SOffsetRegState)
@@ -484,8 +484,10 @@ void SIRegisterInfo::buildSpillLoadStore(MachineBasicBlock::iterator MI,
       .addImm(0) // glc
       .addImm(0) // slc
       .addImm(0) // tfe
-      .addMemOperand(NewMMO)
-      .addReg(ValueReg, RegState::Implicit | SrcDstRegState);
+      .addMemOperand(NewMMO);
+
+    if (NumSubRegs > 1)
+      MIB.addReg(ValueReg, RegState::Implicit | SrcDstRegState);
   }
 
   if (RanOutOfSGPRs) {
@@ -689,12 +691,15 @@ void SIRegisterInfo::restoreSGPR(MachineBasicBlock::iterator MI,
           .addReg(MFI->getScratchWaveOffsetReg());
       }
 
-      BuildMI(*MBB, MI, DL, TII->get(AMDGPU::S_BUFFER_LOAD_DWORD_SGPR), SubReg)
+      auto MIB =
+        BuildMI(*MBB, MI, DL, TII->get(AMDGPU::S_BUFFER_LOAD_DWORD_SGPR), SubReg)
         .addReg(MFI->getScratchRSrcReg()) // sbase
         .addReg(OffsetReg)                // soff
         .addImm(0)                        // glc
-        .addMemOperand(MMO)
-        .addReg(MI->getOperand(0).getReg(), RegState::ImplicitDefine);
+        .addMemOperand(MMO);
+
+      if (NumSubRegs > 1)
+        MIB.addReg(MI->getOperand(0).getReg(), RegState::ImplicitDefine);
 
       continue;
     }
@@ -703,12 +708,14 @@ void SIRegisterInfo::restoreSGPR(MachineBasicBlock::iterator MI,
       = MFI->getSpilledReg(MF, Index, i);
 
     if (Spill.hasReg()) {
-      BuildMI(*MBB, MI, DL,
-              TII->getMCOpcodeFromPseudo(AMDGPU::V_READLANE_B32),
-              SubReg)
+      auto MIB =
+        BuildMI(*MBB, MI, DL, TII->getMCOpcodeFromPseudo(AMDGPU::V_READLANE_B32),
+                SubReg)
         .addReg(Spill.VGPR)
-        .addImm(Spill.Lane)
-        .addReg(MI->getOperand(0).getReg(), RegState::ImplicitDefine);
+        .addImm(Spill.Lane);
+
+      if (NumSubRegs > 1)
+        MIB.addReg(MI->getOperand(0).getReg(), RegState::ImplicitDefine);
     } else {
       // Restore SGPR from a stack slot.
       // FIXME: We should use S_LOAD_DWORD here for VI.
@@ -728,9 +735,13 @@ void SIRegisterInfo::restoreSGPR(MachineBasicBlock::iterator MI,
         .addReg(MFI->getScratchWaveOffsetReg()) // soffset
         .addImm(i * 4)                          // offset
         .addMemOperand(MMO);
-      BuildMI(*MBB, MI, DL, TII->get(AMDGPU::V_READFIRSTLANE_B32), SubReg)
-        .addReg(TmpReg, RegState::Kill)
-        .addReg(MI->getOperand(0).getReg(), RegState::ImplicitDefine);
+
+      auto MIB =
+        BuildMI(*MBB, MI, DL, TII->get(AMDGPU::V_READFIRSTLANE_B32), SubReg)
+        .addReg(TmpReg, RegState::Kill);
+
+      if (NumSubRegs > 1)
+        MIB.addReg(MI->getOperand(0).getReg(), RegState::ImplicitDefine);
     }
   }