AMDGPU: Stop adding m0 implicit def to SGPR spills

r375293 removed the SGPR spilling with scalar stores path, so this is
no longer necessary. This also always had the defect of adding the def
even when this path wasn't in use.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@375448 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 12 insertions, 23 deletions

diff --git a/lib/Target/AMDGPU/SIInstrInfo.cpp b/lib/Target/AMDGPU/SIInstrInfo.cpp
index 57c271a1a6d..d97e6a62971 100644
--- a/lib/Target/AMDGPU/SIInstrInfo.cpp
+++ b/lib/Target/AMDGPU/SIInstrInfo.cpp
@@ -1074,7 +1074,7 @@ void SIInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
       MRI.constrainRegClass(SrcReg, &AMDGPU::SReg_32_XM0RegClass);
     }
 
-    MachineInstrBuilder Spill = BuildMI(MBB, MI, DL, OpDesc)
+    BuildMI(MBB, MI, DL, OpDesc)
       .addReg(SrcReg, getKillRegState(isKill)) // data
       .addFrameIndex(FrameIndex)               // addr
       .addMemOperand(MMO)
@@ -1085,11 +1085,6 @@ void SIInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
     // correctly handled.
     if (RI.spillSGPRToVGPR())
       FrameInfo.setStackID(FrameIndex, TargetStackID::SGPRSpill);
-    if (ST.hasScalarStores()) {
-      // m0 is used for offset to scalar stores if used to spill.
-      Spill.addReg(AMDGPU::M0, RegState::ImplicitDefine | RegState::Dead);
-    }
-
     return;
   }
 
@@ -1206,17 +1201,11 @@ void SIInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
 
     if (RI.spillSGPRToVGPR())
       FrameInfo.setStackID(FrameIndex, TargetStackID::SGPRSpill);
-    MachineInstrBuilder Spill = BuildMI(MBB, MI, DL, OpDesc, DestReg)
+    BuildMI(MBB, MI, DL, OpDesc, DestReg)
       .addFrameIndex(FrameIndex) // addr
       .addMemOperand(MMO)
       .addReg(MFI->getScratchRSrcReg(), RegState::Implicit)
       .addReg(MFI->getStackPtrOffsetReg(), RegState::Implicit);
-
-    if (ST.hasScalarStores()) {
-      // m0 is used for offset to scalar stores if used to spill.
-      Spill.addReg(AMDGPU::M0, RegState::ImplicitDefine | RegState::Dead);
-    }
-
     return;
   }
 
diff --git a/test/CodeGen/AMDGPU/indirect-addressing-term.ll b/test/CodeGen/AMDGPU/indirect-addressing-term.ll
index 40722ce4374..563e38cfe53 100644
--- a/test/CodeGen/AMDGPU/indirect-addressing-term.ll
+++ b/test/CodeGen/AMDGPU/indirect-addressing-term.ll
@@ -73,14 +73,14 @@ define amdgpu_kernel void @extract_w_offset_vgpr(i32 addrspace(1)* %out) {
   ; GCN:   renamable $vgpr1 = IMPLICIT_DEF
   ; GCN:   renamable $sgpr24_sgpr25 = IMPLICIT_DEF
   ; GCN:   SI_SPILL_V32_SAVE killed $vgpr0, %stack.0, $sgpr96_sgpr97_sgpr98_sgpr99, $sgpr3, 0, implicit $exec :: (store 4 into %stack.0, addrspace 5)
-  ; GCN:   SI_SPILL_S128_SAVE killed $sgpr8_sgpr9_sgpr10_sgpr11, %stack.1, implicit $exec, implicit $sgpr96_sgpr97_sgpr98_sgpr99, implicit $sgpr3, implicit-def dead $m0 :: (store 16 into %stack.1, align 4, addrspace 5)
+  ; GCN:   SI_SPILL_S128_SAVE killed $sgpr8_sgpr9_sgpr10_sgpr11, %stack.1, implicit $exec, implicit $sgpr96_sgpr97_sgpr98_sgpr99, implicit $sgpr3 :: (store 16 into %stack.1, align 4, addrspace 5)
   ; GCN:   SI_SPILL_V512_SAVE killed $vgpr17_vgpr18_vgpr19_vgpr20_vgpr21_vgpr22_vgpr23_vgpr24_vgpr25_vgpr26_vgpr27_vgpr28_vgpr29_vgpr30_vgpr31_vgpr32, %stack.2, $sgpr96_sgpr97_sgpr98_sgpr99, $sgpr3, 0, implicit $exec :: (store 64 into %stack.2, align 4, addrspace 5)
-  ; GCN:   SI_SPILL_S64_SAVE killed $sgpr22_sgpr23, %stack.3, implicit $exec, implicit $sgpr96_sgpr97_sgpr98_sgpr99, implicit $sgpr3, implicit-def dead $m0 :: (store 8 into %stack.3, align 4, addrspace 5)
+  ; GCN:   SI_SPILL_S64_SAVE killed $sgpr22_sgpr23, %stack.3, implicit $exec, implicit $sgpr96_sgpr97_sgpr98_sgpr99, implicit $sgpr3 :: (store 8 into %stack.3, align 4, addrspace 5)
   ; GCN:   SI_SPILL_V32_SAVE killed $vgpr1, %stack.4, $sgpr96_sgpr97_sgpr98_sgpr99, $sgpr3, 0, implicit $exec :: (store 4 into %stack.4, addrspace 5)
-  ; GCN:   SI_SPILL_S64_SAVE killed $sgpr24_sgpr25, %stack.5, implicit $exec, implicit $sgpr96_sgpr97_sgpr98_sgpr99, implicit $sgpr3, implicit-def dead $m0 :: (store 8 into %stack.5, align 4, addrspace 5)
+  ; GCN:   SI_SPILL_S64_SAVE killed $sgpr24_sgpr25, %stack.5, implicit $exec, implicit $sgpr96_sgpr97_sgpr98_sgpr99, implicit $sgpr3 :: (store 8 into %stack.5, align 4, addrspace 5)
   ; GCN: bb.1:
   ; GCN:   successors: %bb.1(0x40000000), %bb.2(0x40000000)
-  ; GCN:   $sgpr0_sgpr1 = SI_SPILL_S64_RESTORE %stack.5, implicit $exec, implicit $sgpr96_sgpr97_sgpr98_sgpr99, implicit $sgpr3, implicit-def dead $m0 :: (load 8 from %stack.5, align 4, addrspace 5)
+  ; GCN:   $sgpr0_sgpr1 = SI_SPILL_S64_RESTORE %stack.5, implicit $exec, implicit $sgpr96_sgpr97_sgpr98_sgpr99, implicit $sgpr3 :: (load 8 from %stack.5, align 4, addrspace 5)
   ; GCN:   $vgpr0 = SI_SPILL_V32_RESTORE %stack.4, $sgpr96_sgpr97_sgpr98_sgpr99, $sgpr3, 0, implicit $exec :: (load 4 from %stack.4, addrspace 5)
   ; GCN:   $vgpr1 = SI_SPILL_V32_RESTORE %stack.0, $sgpr96_sgpr97_sgpr98_sgpr99, $sgpr3, 0, implicit $exec :: (load 4 from %stack.0, addrspace 5)
   ; GCN:   renamable $sgpr2 = V_READFIRSTLANE_B32 $vgpr1, implicit $exec
@@ -92,18 +92,18 @@ define amdgpu_kernel void @extract_w_offset_vgpr(i32 addrspace(1)* %out) {
   ; GCN:   S_SET_GPR_IDX_OFF
   ; GCN:   renamable $vgpr19 = COPY renamable $vgpr18
   ; GCN:   renamable $sgpr6_sgpr7 = COPY renamable $sgpr4_sgpr5
-  ; GCN:   SI_SPILL_S64_SAVE killed $sgpr6_sgpr7, %stack.5, implicit $exec, implicit $sgpr96_sgpr97_sgpr98_sgpr99, implicit $sgpr3, implicit-def dead $m0 :: (store 8 into %stack.5, align 4, addrspace 5)
-  ; GCN:   SI_SPILL_S64_SAVE killed $sgpr0_sgpr1, %stack.6, implicit $exec, implicit $sgpr96_sgpr97_sgpr98_sgpr99, implicit $sgpr3, implicit-def dead $m0 :: (store 8 into %stack.6, align 4, addrspace 5)
+  ; GCN:   SI_SPILL_S64_SAVE killed $sgpr6_sgpr7, %stack.5, implicit $exec, implicit $sgpr96_sgpr97_sgpr98_sgpr99, implicit $sgpr3 :: (store 8 into %stack.5, align 4, addrspace 5)
+  ; GCN:   SI_SPILL_S64_SAVE killed $sgpr0_sgpr1, %stack.6, implicit $exec, implicit $sgpr96_sgpr97_sgpr98_sgpr99, implicit $sgpr3 :: (store 8 into %stack.6, align 4, addrspace 5)
   ; GCN:   SI_SPILL_V32_SAVE killed $vgpr19, %stack.4, $sgpr96_sgpr97_sgpr98_sgpr99, $sgpr3, 0, implicit $exec :: (store 4 into %stack.4, addrspace 5)
   ; GCN:   SI_SPILL_V32_SAVE killed $vgpr0, %stack.7, $sgpr96_sgpr97_sgpr98_sgpr99, $sgpr3, 0, implicit $exec :: (store 4 into %stack.7, addrspace 5)
   ; GCN:   SI_SPILL_V32_SAVE killed $vgpr18, %stack.8, $sgpr96_sgpr97_sgpr98_sgpr99, $sgpr3, 0, implicit $exec :: (store 4 into %stack.8, addrspace 5)
   ; GCN:   $exec = S_XOR_B64_term $exec, killed renamable $sgpr4_sgpr5, implicit-def $scc
   ; GCN:   S_CBRANCH_EXECNZ %bb.1, implicit $exec
   ; GCN: bb.2:
-  ; GCN:   $sgpr0_sgpr1 = SI_SPILL_S64_RESTORE %stack.3, implicit $exec, implicit $sgpr96_sgpr97_sgpr98_sgpr99, implicit $sgpr3, implicit-def dead $m0 :: (load 8 from %stack.3, align 4, addrspace 5)
+  ; GCN:   $sgpr0_sgpr1 = SI_SPILL_S64_RESTORE %stack.3, implicit $exec, implicit $sgpr96_sgpr97_sgpr98_sgpr99, implicit $sgpr3 :: (load 8 from %stack.3, align 4, addrspace 5)
   ; GCN:   $exec = S_MOV_B64 renamable $sgpr0_sgpr1
   ; GCN:   $vgpr0 = SI_SPILL_V32_RESTORE %stack.8, $sgpr96_sgpr97_sgpr98_sgpr99, $sgpr3, 0, implicit $exec :: (load 4 from %stack.8, addrspace 5)
-  ; GCN:   $sgpr4_sgpr5_sgpr6_sgpr7 = SI_SPILL_S128_RESTORE %stack.1, implicit $exec, implicit $sgpr96_sgpr97_sgpr98_sgpr99, implicit $sgpr3, implicit-def dead $m0 :: (load 16 from %stack.1, align 4, addrspace 5)
+  ; GCN:   $sgpr4_sgpr5_sgpr6_sgpr7 = SI_SPILL_S128_RESTORE %stack.1, implicit $exec, implicit $sgpr96_sgpr97_sgpr98_sgpr99, implicit $sgpr3 :: (load 16 from %stack.1, align 4, addrspace 5)
   ; GCN:   BUFFER_STORE_DWORD_OFFSET renamable $vgpr0, renamable $sgpr4_sgpr5_sgpr6_sgpr7, 0, 0, 0, 0, 0, 0, 0, implicit $exec :: (store 4 into %ir.out.load, addrspace 1)
   ; GCN:   S_ENDPGM 0
 entry:
diff --git a/test/CodeGen/AMDGPU/stack-slot-color-sgpr-vgpr-spills.mir b/test/CodeGen/AMDGPU/stack-slot-color-sgpr-vgpr-spills.mir
index c051b61f52b..77010834cc3 100644
--- a/test/CodeGen/AMDGPU/stack-slot-color-sgpr-vgpr-spills.mir
+++ b/test/CodeGen/AMDGPU/stack-slot-color-sgpr-vgpr-spills.mir
@@ -12,8 +12,8 @@
 # CHECK: SI_SPILL_V32_SAVE killed $vgpr0, %stack.0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr32, 0, implicit $exec :: (store 4 into %stack.0, addrspace 5)
 # CHECK: $vgpr0 = SI_SPILL_V32_RESTORE %stack.0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr32, 0, implicit $exec :: (load 4 from %stack.0, addrspace 5)
 
-# CHECK: SI_SPILL_S32_SAVE killed renamable $sgpr6, %stack.1, implicit $exec, implicit $sgpr0_sgpr1_sgpr2_sgpr3, implicit $sgpr32, implicit-def dead $m0 :: (store 4 into %stack.1, addrspace 5)
-# CHECK: $sgpr6 = SI_SPILL_S32_RESTORE %stack.1, implicit $exec, implicit $sgpr0_sgpr1_sgpr2_sgpr3, implicit $sgpr32, implicit-def dead $m0 :: (load 4 from %stack.1, addrspace 5)
+# CHECK: SI_SPILL_S32_SAVE killed renamable $sgpr6, %stack.1, implicit $exec, implicit $sgpr0_sgpr1_sgpr2_sgpr3, implicit $sgpr32 :: (store 4 into %stack.1, addrspace 5)
+# CHECK: $sgpr6 = SI_SPILL_S32_RESTORE %stack.1, implicit $exec, implicit $sgpr0_sgpr1_sgpr2_sgpr3, implicit $sgpr32 :: (load 4 from %stack.1, addrspace 5)
 
 name: no_merge_sgpr_vgpr_spill_slot
 tracksRegLiveness: true