Move into findValueFromDef

This now passes the type of the Reg required through to the ArtifactFinder and
includes #119850.

Most of the tests are just changing because they use IMPLICIT_DEF for the
input. Most look OK to me, in that they are just changing `<complex
legalization of implicitdef> + operations` to `implicitdef + operations`, as in
```
     ; VI-LABEL: name: test_ffloor_v3s16
-    ; VI: [[DEF:%[0-9]+]]:_(<4 x s16>) = G_IMPLICIT_DEF
-    ; VI-NEXT: [[UV:%[0-9]+]]:_(<2 x s16>), [[UV1:%[0-9]+]]:_(<2 x s16>) = G_UNMERGE_VALUES [[DEF]](<4 x s16>)
-    ; VI-NEXT: [[BITCAST:%[0-9]+]]:_(s32) = G_BITCAST [[UV]](<2 x s16>)
-    ; VI-NEXT: [[TRUNC:%[0-9]+]]:_(s16) = G_TRUNC [[BITCAST]](s32)
-    ; VI-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 16
-    ; VI-NEXT: [[LSHR:%[0-9]+]]:_(s32) = G_LSHR [[BITCAST]], [[C]](s32)
-    ; VI-NEXT: [[TRUNC1:%[0-9]+]]:_(s16) = G_TRUNC [[LSHR]](s32)
-    ; VI-NEXT: [[BITCAST1:%[0-9]+]]:_(s32) = G_BITCAST [[UV1]](<2 x s16>)
-    ; VI-NEXT: [[TRUNC2:%[0-9]+]]:_(s16) = G_TRUNC [[BITCAST1]](s32)
-    ; VI-NEXT: [[FFLOOR:%[0-9]+]]:_(s16) = G_FFLOOR [[TRUNC]]
-    ; VI-NEXT: [[FFLOOR1:%[0-9]+]]:_(s16) = G_FFLOOR [[TRUNC1]]
-    ; VI-NEXT: [[FFLOOR2:%[0-9]+]]:_(s16) = G_FFLOOR [[TRUNC2]]
+    ; VI: [[DEF:%[0-9]+]]:_(s16) = G_IMPLICIT_DEF
+    ; VI-NEXT: [[FFLOOR:%[0-9]+]]:_(s16) = G_FFLOOR [[DEF]]
+    ; VI-NEXT: [[FFLOOR1:%[0-9]+]]:_(s16) = G_FFLOOR [[DEF]]
+    ; VI-NEXT: [[FFLOOR2:%[0-9]+]]:_(s16) = G_FFLOOR [[DEF]]
```

If any of these do look like a problem then let me know. I can try and define
the inputs better if we can come up with a way to do that (many are
G_IMPLICIT_DEF presumably because of the types involved).

One Mips test has an extra mov in one of the tests from a COPY of undef. Some
of the tests are now folding ZExt(IMPLICIT_DEF) to 0 which loses information
about the undef bits but would likely have been done anyway.

Author: davemgreen

llvm/include/llvm/CodeGen/GlobalISel/LegalizationArtifactCombiner.h

@@ -70,7 +70,7 @@ class LegalizationArtifactCombiner {
     // aext(trunc x) - > aext/copy/trunc x
     Register TruncSrc;
     if (mi_match(SrcReg, MRI, m_GTrunc(m_Reg(TruncSrc)))) {
-      LLVM_DEBUG(dbgs() << ".. Combine MI: " << MI;);
+      LLVM_DEBUG(dbgs() << ".. Combine MI: " << MI);
       if (MRI.getType(DstReg) == MRI.getType(TruncSrc))
         replaceRegOrBuildCopy(DstReg, TruncSrc, MRI, Builder, UpdatedDefs,
                               Observer);
@@ -136,7 +136,7 @@ class LegalizationArtifactCombiner {
       if (isInstUnsupported({TargetOpcode::G_AND, {DstTy}}) ||
           isConstantUnsupported(DstTy))
         return false;
-      LLVM_DEBUG(dbgs() << ".. Combine MI: " << MI;);
+      LLVM_DEBUG(dbgs() << ".. Combine MI: " << MI);
       LLT SrcTy = MRI.getType(SrcReg);
       APInt MaskVal = APInt::getAllOnes(SrcTy.getScalarSizeInBits());
       if (SextSrc && (DstTy != MRI.getType(SextSrc)))
@@ -207,7 +207,7 @@ class LegalizationArtifactCombiner {
       LLT DstTy = MRI.getType(DstReg);
       if (isInstUnsupported({TargetOpcode::G_SEXT_INREG, {DstTy}}))
         return false;
-      LLVM_DEBUG(dbgs() << ".. Combine MI: " << MI;);
+      LLVM_DEBUG(dbgs() << ".. Combine MI: " << MI);
       LLT SrcTy = MRI.getType(SrcReg);
       uint64_t SizeInBits = SrcTy.getScalarSizeInBits();
       if (DstTy != MRI.getType(TruncSrc))
@@ -356,11 +356,11 @@ class LegalizationArtifactCombiner {
     // trunc(ext x) -> x
     ArtifactValueFinder Finder(MRI, Builder, LI);
     if (Register FoundReg =
-            Finder.findValueFromDef(DstReg, 0, DstTy.getSizeInBits())) {
+            Finder.findValueFromDef(DstReg, 0, DstTy.getSizeInBits(), DstTy)) {
       LLT FoundRegTy = MRI.getType(FoundReg);
       if (DstTy == FoundRegTy) {
         LLVM_DEBUG(dbgs() << ".. Combine G_TRUNC(G_[S,Z,ANY]EXT/G_TRUNC...): "
-                          << MI;);
+                          << MI);
 
         replaceRegOrBuildCopy(DstReg, FoundReg, MRI, Builder, UpdatedDefs,
                               Observer);
@@ -392,7 +392,7 @@ class LegalizationArtifactCombiner {
         // G_ANYEXT (G_IMPLICIT_DEF) -> G_IMPLICIT_DEF
         if (!isInstLegal({TargetOpcode::G_IMPLICIT_DEF, {DstTy}}))
           return false;
-        LLVM_DEBUG(dbgs() << ".. Combine G_ANYEXT(G_IMPLICIT_DEF): " << MI;);
+        LLVM_DEBUG(dbgs() << ".. Combine G_ANYEXT(G_IMPLICIT_DEF): " << MI);
         auto Impl = Builder.buildUndef(DstTy);
         replaceRegOrBuildCopy(DstReg, Impl.getReg(0), MRI, Builder, UpdatedDefs,
                               Observer);
@@ -402,7 +402,7 @@ class LegalizationArtifactCombiner {
         // bits will be 0 for G_ZEXT and 0/1 for the G_SEXT.
         if (isConstantUnsupported(DstTy))
           return false;
-        LLVM_DEBUG(dbgs() << ".. Combine G_[SZ]EXT(G_IMPLICIT_DEF): " << MI;);
+        LLVM_DEBUG(dbgs() << ".. Combine G_[SZ]EXT(G_IMPLICIT_DEF): " << MI);
         auto Cnst = Builder.buildConstant(DstTy, 0);
         replaceRegOrBuildCopy(DstReg, Cnst.getReg(0), MRI, Builder, UpdatedDefs,
                               Observer);
@@ -641,10 +641,11 @@ class LegalizationArtifactCombiner {
       Register SrcReg = Concat.getReg(StartSrcIdx);
       if (InRegOffset == 0 && Size == SrcSize) {
         CurrentBest = SrcReg;
-        return findValueFromDefImpl(SrcReg, 0, Size);
+        return findValueFromDefImpl(SrcReg, 0, Size, MRI.getType(SrcReg));
       }
 
-      return findValueFromDefImpl(SrcReg, InRegOffset, Size);
+      return findValueFromDefImpl(SrcReg, InRegOffset, Size,
+                                  MRI.getType(SrcReg));
     }
 
     /// Given an build_vector op \p BV and a start bit and size, try to find
@@ -759,15 +760,17 @@ class LegalizationArtifactCombiner {
       if (EndBit <= InsertOffset || InsertedEndBit <= StartBit) {
         SrcRegToUse = ContainerSrcReg;
         NewStartBit = StartBit;
-        return findValueFromDefImpl(SrcRegToUse, NewStartBit, Size);
+        return findValueFromDefImpl(SrcRegToUse, NewStartBit, Size,
+                                    MRI.getType(SrcRegToUse));
       }
       if (InsertOffset <= StartBit && EndBit <= InsertedEndBit) {
         SrcRegToUse = InsertedReg;
         NewStartBit = StartBit - InsertOffset;
         if (NewStartBit == 0 &&
             Size == MRI.getType(SrcRegToUse).getSizeInBits())
           CurrentBest = SrcRegToUse;
-        return findValueFromDefImpl(SrcRegToUse, NewStartBit, Size);
+        return findValueFromDefImpl(SrcRegToUse, NewStartBit, Size,
+                                    MRI.getType(SrcRegToUse));
       }
       // The bit range spans both the inserted and container regions.
       return Register();
@@ -799,7 +802,7 @@ class LegalizationArtifactCombiner {
 
       if (StartBit == 0 && SrcType.getSizeInBits() == Size)
         CurrentBest = SrcReg;
-      return findValueFromDefImpl(SrcReg, StartBit, Size);
+      return findValueFromDefImpl(SrcReg, StartBit, Size, SrcType);
     }
 
     /// Given an G_TRUNC op \p MI and a start bit and size, try to find
@@ -819,14 +822,14 @@ class LegalizationArtifactCombiner {
       if (!SrcType.isScalar())
         return CurrentBest;
 
-      return findValueFromDefImpl(SrcReg, StartBit, Size);
+      return findValueFromDefImpl(SrcReg, StartBit, Size, SrcType);
     }
 
     /// Internal implementation for findValueFromDef(). findValueFromDef()
     /// initializes some data like the CurrentBest register, which this method
     /// and its callees rely upon.
     Register findValueFromDefImpl(Register DefReg, unsigned StartBit,
-                                  unsigned Size) {
+                                  unsigned Size, LLT DstTy) {
       std::optional<DefinitionAndSourceRegister> DefSrcReg =
           getDefSrcRegIgnoringCopies(DefReg, MRI);
       MachineInstr *Def = DefSrcReg->MI;
@@ -847,7 +850,7 @@ class LegalizationArtifactCombiner {
         }
         Register SrcReg = Def->getOperand(Def->getNumOperands() - 1).getReg();
         Register SrcOriginReg =
-            findValueFromDefImpl(SrcReg, StartBit + DefStartBit, Size);
+            findValueFromDefImpl(SrcReg, StartBit + DefStartBit, Size, DstTy);
         if (SrcOriginReg)
           return SrcOriginReg;
         // Failed to find a further value. If the StartBit and Size perfectly
@@ -868,6 +871,12 @@ class LegalizationArtifactCombiner {
       case TargetOpcode::G_ZEXT:
       case TargetOpcode::G_ANYEXT:
         return findValueFromExt(*Def, StartBit, Size);
+      case TargetOpcode::G_IMPLICIT_DEF: {
+        if (MRI.getType(DefReg) == DstTy)
+          return DefReg;
+        MIB.setInstrAndDebugLoc(*Def);
+        return MIB.buildUndef(DstTy).getReg(0);
+      }
       default:
         return CurrentBest;
       }
@@ -882,10 +891,10 @@ class LegalizationArtifactCombiner {
     /// at position \p StartBit with size \p Size.
     /// \returns a register with the requested size, or an empty Register if no
     /// better value could be found.
-    Register findValueFromDef(Register DefReg, unsigned StartBit,
-                              unsigned Size) {
+    Register findValueFromDef(Register DefReg, unsigned StartBit, unsigned Size,
+                              LLT DstTy) {
       CurrentBest = Register();
-      Register FoundReg = findValueFromDefImpl(DefReg, StartBit, Size);
+      Register FoundReg = findValueFromDefImpl(DefReg, StartBit, Size, DstTy);
       return FoundReg != DefReg ? FoundReg : Register();
     }
 
@@ -904,7 +913,8 @@ class LegalizationArtifactCombiner {
           DeadDefs[DefIdx] = true;
           continue;
         }
-        Register FoundVal = findValueFromDef(DefReg, 0, DestTy.getSizeInBits());
+        Register FoundVal =
+            findValueFromDef(DefReg, 0, DestTy.getSizeInBits(), DestTy);
         if (!FoundVal)
           continue;
         if (MRI.getType(FoundVal) != DestTy)
@@ -923,7 +933,7 @@ class LegalizationArtifactCombiner {
 
     GUnmerge *findUnmergeThatDefinesReg(Register Reg, unsigned Size,
                                         unsigned &DefOperandIdx) {
-      if (Register Def = findValueFromDefImpl(Reg, 0, Size)) {
+      if (Register Def = findValueFromDefImpl(Reg, 0, Size, MRI.getType(Reg))) {
         if (auto *Unmerge = dyn_cast<GUnmerge>(MRI.getVRegDef(Def))) {
           DefOperandIdx =
               Unmerge->findRegisterDefOperandIdx(Def, /*TRI=*/nullptr);
@@ -1074,17 +1084,6 @@ class LegalizationArtifactCombiner {
 
     Builder.setInstrAndDebugLoc(MI);
 
-    if (SrcDef->getOpcode() == TargetOpcode::G_IMPLICIT_DEF) {
-      auto Undef = Builder.buildUndef(DestTy);
-      for (unsigned I = 0; I != NumDefs; ++I) {
-        Register Def = MI.getReg(I);
-        replaceRegOrBuildCopy(Def, Undef.getReg(0), MRI, Builder, UpdatedDefs,
-                              Observer);
-      }
-      markInstAndDefDead(MI, *SrcDef, DeadInsts, SrcDefIdx);
-      return true;
-    }
-
     ArtifactValueFinder Finder(MRI, Builder, LI);
     if (Finder.tryCombineUnmergeDefs(MI, Observer, UpdatedDefs)) {
       markInstAndDefDead(MI, *SrcDef, DeadInsts, SrcDefIdx);
@@ -1294,12 +1293,19 @@ class LegalizationArtifactCombiner {
     // for N >= %2.getSizeInBits() / 2
     //    %3 = G_EXTRACT %1, (N - %0.getSizeInBits()
 
+    Register DstReg = MI.getOperand(0).getReg();
     Register SrcReg = lookThroughCopyInstrs(MI.getOperand(1).getReg());
     MachineInstr *MergeI = MRI.getVRegDef(SrcReg);
+    if (MergeI && MergeI->getOpcode() == TargetOpcode::G_IMPLICIT_DEF) {
+      Builder.setInstrAndDebugLoc(MI);
+      Builder.buildUndef(DstReg);
+      UpdatedDefs.push_back(DstReg);
+      markInstAndDefDead(MI, *MergeI, DeadInsts);
+      return true;
+    }
     if (!MergeI || !isa<GMergeLikeInstr>(MergeI))
       return false;
 
-    Register DstReg = MI.getOperand(0).getReg();
     LLT DstTy = MRI.getType(DstReg);
     LLT SrcTy = MRI.getType(SrcReg);
 

llvm/test/CodeGen/AArch64/GlobalISel/legalize-extracts.mir

@@ -290,11 +290,8 @@ body: |
     ; CHECK-LABEL: name: s3_from_s35
     ; CHECK: liveins: $w0
     ; CHECK-NEXT: {{  $}}
-    ; CHECK-NEXT: [[DEF:%[0-9]+]]:_(s64) = G_IMPLICIT_DEF
-    ; CHECK-NEXT: [[TRUNC:%[0-9]+]]:_(s32) = G_TRUNC [[DEF]](s64)
-    ; CHECK-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 7
-    ; CHECK-NEXT: %ext:_(s32) = G_AND [[TRUNC]], [[C]]
-    ; CHECK-NEXT: $w0 = COPY %ext(s32)
+    ; CHECK-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CHECK-NEXT: $w0 = COPY [[C]](s32)
     ; CHECK-NEXT: RET_ReallyLR implicit $w0
     %val:_(s35) = G_IMPLICIT_DEF
     %extract:_(s3) = G_EXTRACT %val, 0

llvm/test/CodeGen/AArch64/GlobalISel/legalize-load-store.mir

@@ -545,15 +545,18 @@ body:             |
     ; CHECK-LABEL: name: store_6xs64
     ; CHECK: liveins: $x0
     ; CHECK-NEXT: {{  $}}
-    ; CHECK-NEXT: [[DEF:%[0-9]+]]:_(<2 x s64>) = G_IMPLICIT_DEF
+    ; CHECK-NEXT: [[DEF:%[0-9]+]]:_(s64) = G_IMPLICIT_DEF
+    ; CHECK-NEXT: [[BUILD_VECTOR:%[0-9]+]]:_(<2 x s64>) = G_BUILD_VECTOR [[DEF]](s64), [[DEF]](s64)
+    ; CHECK-NEXT: [[BUILD_VECTOR1:%[0-9]+]]:_(<2 x s64>) = G_BUILD_VECTOR [[DEF]](s64), [[DEF]](s64)
+    ; CHECK-NEXT: [[BUILD_VECTOR2:%[0-9]+]]:_(<2 x s64>) = G_BUILD_VECTOR [[DEF]](s64), [[DEF]](s64)
     ; CHECK-NEXT: %ptr:_(p0) = COPY $x0
-    ; CHECK-NEXT: G_STORE [[DEF]](<2 x s64>), %ptr(p0) :: (store (<2 x s64>))
+    ; CHECK-NEXT: G_STORE [[BUILD_VECTOR]](<2 x s64>), %ptr(p0) :: (store (<2 x s64>))
     ; CHECK-NEXT: [[C:%[0-9]+]]:_(s64) = G_CONSTANT i64 16
     ; CHECK-NEXT: [[PTR_ADD:%[0-9]+]]:_(p0) = G_PTR_ADD %ptr, [[C]](s64)
-    ; CHECK-NEXT: G_STORE [[DEF]](<2 x s64>), [[PTR_ADD]](p0) :: (store (<2 x s64>) into unknown-address + 16)
+    ; CHECK-NEXT: G_STORE [[BUILD_VECTOR1]](<2 x s64>), [[PTR_ADD]](p0) :: (store (<2 x s64>) into unknown-address + 16)
     ; CHECK-NEXT: [[C1:%[0-9]+]]:_(s64) = G_CONSTANT i64 32
     ; CHECK-NEXT: [[PTR_ADD1:%[0-9]+]]:_(p0) = G_PTR_ADD %ptr, [[C1]](s64)
-    ; CHECK-NEXT: G_STORE [[DEF]](<2 x s64>), [[PTR_ADD1]](p0) :: (store (<2 x s64>) into unknown-address + 32)
+    ; CHECK-NEXT: G_STORE [[BUILD_VECTOR2]](<2 x s64>), [[PTR_ADD1]](p0) :: (store (<2 x s64>) into unknown-address + 32)
     ; CHECK-NEXT: RET_ReallyLR
     %val:_(<6 x s64>) = G_IMPLICIT_DEF
     %ptr:_(p0) = COPY $x0

llvm/test/CodeGen/AArch64/GlobalISel/legalize-select.mir

@@ -289,28 +289,28 @@ body:             |
     ; CHECK-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 4100
     ; CHECK-NEXT: [[ICMP2:%[0-9]+]]:_(s32) = G_ICMP intpred(eq), %w0(s32), [[C]]
     ; CHECK-NEXT: [[SEXT_INREG:%[0-9]+]]:_(s32) = G_SEXT_INREG [[ICMP2]], 1
-    ; CHECK-NEXT: [[DEF:%[0-9]+]]:_(<4 x s16>) = G_IMPLICIT_DEF
+    ; CHECK-NEXT: [[DEF:%[0-9]+]]:_(s16) = G_IMPLICIT_DEF
+    ; CHECK-NEXT: [[DEF1:%[0-9]+]]:_(<4 x s16>) = G_IMPLICIT_DEF
     ; CHECK-NEXT: [[C1:%[0-9]+]]:_(s64) = G_CONSTANT i64 0
     ; CHECK-NEXT: [[TRUNC:%[0-9]+]]:_(s16) = G_TRUNC [[SEXT_INREG]](s32)
-    ; CHECK-NEXT: [[IVEC:%[0-9]+]]:_(<4 x s16>) = G_INSERT_VECTOR_ELT [[DEF]], [[TRUNC]](s16), [[C1]](s64)
+    ; CHECK-NEXT: [[IVEC:%[0-9]+]]:_(<4 x s16>) = G_INSERT_VECTOR_ELT [[DEF1]], [[TRUNC]](s16), [[C1]](s64)
     ; CHECK-NEXT: [[UV:%[0-9]+]]:_(s16), [[UV1:%[0-9]+]]:_(s16), [[UV2:%[0-9]+]]:_(s16), [[UV3:%[0-9]+]]:_(s16) = G_UNMERGE_VALUES [[IVEC]](<4 x s16>)
     ; CHECK-NEXT: [[TRUNC1:%[0-9]+]]:_(s8) = G_TRUNC [[UV]](s16)
     ; CHECK-NEXT: [[TRUNC2:%[0-9]+]]:_(s8) = G_TRUNC [[UV1]](s16)
     ; CHECK-NEXT: [[TRUNC3:%[0-9]+]]:_(s8) = G_TRUNC [[UV2]](s16)
     ; CHECK-NEXT: [[TRUNC4:%[0-9]+]]:_(s8) = G_TRUNC [[UV3]](s16)
-    ; CHECK-NEXT: [[DEF1:%[0-9]+]]:_(s8) = G_IMPLICIT_DEF
-    ; CHECK-NEXT: [[BUILD_VECTOR:%[0-9]+]]:_(<8 x s8>) = G_BUILD_VECTOR [[TRUNC1]](s8), [[TRUNC2]](s8), [[TRUNC3]](s8), [[TRUNC4]](s8), [[DEF1]](s8), [[DEF1]](s8), [[DEF1]](s8), [[DEF1]](s8)
-    ; CHECK-NEXT: [[DEF2:%[0-9]+]]:_(s16) = G_IMPLICIT_DEF
-    ; CHECK-NEXT: [[TRUNC5:%[0-9]+]]:_(s8) = G_TRUNC [[DEF2]](s16)
-    ; CHECK-NEXT: [[TRUNC6:%[0-9]+]]:_(s8) = G_TRUNC [[DEF2]](s16)
-    ; CHECK-NEXT: [[TRUNC7:%[0-9]+]]:_(s8) = G_TRUNC [[DEF2]](s16)
-    ; CHECK-NEXT: [[TRUNC8:%[0-9]+]]:_(s8) = G_TRUNC [[DEF2]](s16)
-    ; CHECK-NEXT: [[BUILD_VECTOR1:%[0-9]+]]:_(<8 x s8>) = G_BUILD_VECTOR [[TRUNC5]](s8), [[TRUNC6]](s8), [[TRUNC7]](s8), [[TRUNC8]](s8), [[DEF1]](s8), [[DEF1]](s8), [[DEF1]](s8), [[DEF1]](s8)
+    ; CHECK-NEXT: [[DEF2:%[0-9]+]]:_(s8) = G_IMPLICIT_DEF
+    ; CHECK-NEXT: [[BUILD_VECTOR:%[0-9]+]]:_(<8 x s8>) = G_BUILD_VECTOR [[TRUNC1]](s8), [[TRUNC2]](s8), [[TRUNC3]](s8), [[TRUNC4]](s8), [[DEF2]](s8), [[DEF2]](s8), [[DEF2]](s8), [[DEF2]](s8)
+    ; CHECK-NEXT: [[TRUNC5:%[0-9]+]]:_(s8) = G_TRUNC [[DEF]](s16)
+    ; CHECK-NEXT: [[TRUNC6:%[0-9]+]]:_(s8) = G_TRUNC [[DEF]](s16)
+    ; CHECK-NEXT: [[TRUNC7:%[0-9]+]]:_(s8) = G_TRUNC [[DEF]](s16)
+    ; CHECK-NEXT: [[TRUNC8:%[0-9]+]]:_(s8) = G_TRUNC [[DEF]](s16)
+    ; CHECK-NEXT: [[BUILD_VECTOR1:%[0-9]+]]:_(<8 x s8>) = G_BUILD_VECTOR [[TRUNC5]](s8), [[TRUNC6]](s8), [[TRUNC7]](s8), [[TRUNC8]](s8), [[DEF2]](s8), [[DEF2]](s8), [[DEF2]](s8), [[DEF2]](s8)
     ; CHECK-NEXT: [[SHUF:%[0-9]+]]:_(<8 x s8>) = G_SHUFFLE_VECTOR [[BUILD_VECTOR]](<8 x s8>), [[BUILD_VECTOR1]], shufflemask(0, 0, 0, 0, undef, undef, undef, undef)
     ; CHECK-NEXT: [[C2:%[0-9]+]]:_(s8) = G_CONSTANT i8 1
     ; CHECK-NEXT: [[ANYEXT:%[0-9]+]]:_(<8 x s16>) = G_ANYEXT [[SHUF]](<8 x s8>)
     ; CHECK-NEXT: [[UV4:%[0-9]+]]:_(<4 x s16>), [[UV5:%[0-9]+]]:_(<4 x s16>) = G_UNMERGE_VALUES [[ANYEXT]](<8 x s16>)
-    ; CHECK-NEXT: [[BUILD_VECTOR2:%[0-9]+]]:_(<8 x s8>) = G_BUILD_VECTOR [[C2]](s8), [[C2]](s8), [[C2]](s8), [[C2]](s8), [[DEF1]](s8), [[DEF1]](s8), [[DEF1]](s8), [[DEF1]](s8)
+    ; CHECK-NEXT: [[BUILD_VECTOR2:%[0-9]+]]:_(<8 x s8>) = G_BUILD_VECTOR [[C2]](s8), [[C2]](s8), [[C2]](s8), [[C2]](s8), [[DEF2]](s8), [[DEF2]](s8), [[DEF2]](s8), [[DEF2]](s8)
     ; CHECK-NEXT: [[ANYEXT1:%[0-9]+]]:_(<8 x s16>) = G_ANYEXT [[BUILD_VECTOR2]](<8 x s8>)
     ; CHECK-NEXT: [[UV6:%[0-9]+]]:_(<4 x s16>), [[UV7:%[0-9]+]]:_(<4 x s16>) = G_UNMERGE_VALUES [[ANYEXT1]](<8 x s16>)
     ; CHECK-NEXT: [[XOR:%[0-9]+]]:_(<4 x s16>) = G_XOR [[UV4]], [[UV6]]

llvm/test/CodeGen/AMDGPU/GlobalISel/artifact-combiner-trunc.mir

@@ -137,10 +137,10 @@ body: |
   bb.0:
     ; Test that trunc(trunc) is combined to a single trunc
     ; CHECK-LABEL: name: trunc_trunc
-    ; CHECK: [[DEF:%[0-9]+]]:_(s64) = G_IMPLICIT_DEF
-    ; CHECK-NEXT: [[TRUNC:%[0-9]+]]:_(s32) = G_TRUNC [[DEF]](s64)
+    ; CHECK: [[COPY:%[0-9]+]]:_(s64) = COPY $sgpr0_sgpr1
+    ; CHECK-NEXT: [[TRUNC:%[0-9]+]]:_(s32) = G_TRUNC [[COPY]](s64)
     ; CHECK-NEXT: $vgpr0 = COPY [[TRUNC]](s32)
-    %0:_(s64) = G_IMPLICIT_DEF
+    %0:_(s64) = COPY $sgpr0_sgpr1
     %1:_(s48) = G_TRUNC %0
     %2:_(s32) = G_TRUNC %1
     $vgpr0 = COPY %2

llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-fcmp.mir

@@ -241,8 +241,8 @@ body: |
     ; GFX7-LABEL: name: test_fcmp_v3s32
     ; GFX7: liveins: $vgpr0_vgpr1_vgpr2
     ; GFX7-NEXT: {{  $}}
-    ; GFX7-NEXT: [[COPY:%[0-9]+]]:_(<3 x s32>) = COPY $vgpr0_vgpr1_vgpr2
     ; GFX7-NEXT: [[DEF:%[0-9]+]]:_(s32) = G_IMPLICIT_DEF
+    ; GFX7-NEXT: [[COPY:%[0-9]+]]:_(<3 x s32>) = COPY $vgpr0_vgpr1_vgpr2
     ; GFX7-NEXT: [[UV:%[0-9]+]]:_(s32), [[UV1:%[0-9]+]]:_(s32), [[UV2:%[0-9]+]]:_(s32) = G_UNMERGE_VALUES [[COPY]](<3 x s32>)
     ; GFX7-NEXT: [[FCMP:%[0-9]+]]:_(s1) = G_FCMP floatpred(oeq), [[DEF]](s32), [[UV]]
     ; GFX7-NEXT: [[FCMP1:%[0-9]+]]:_(s1) = G_FCMP floatpred(oeq), [[DEF]](s32), [[UV1]]
@@ -256,8 +256,8 @@ body: |
     ; GFX8-LABEL: name: test_fcmp_v3s32
     ; GFX8: liveins: $vgpr0_vgpr1_vgpr2
     ; GFX8-NEXT: {{  $}}
-    ; GFX8-NEXT: [[COPY:%[0-9]+]]:_(<3 x s32>) = COPY $vgpr0_vgpr1_vgpr2
     ; GFX8-NEXT: [[DEF:%[0-9]+]]:_(s32) = G_IMPLICIT_DEF
+    ; GFX8-NEXT: [[COPY:%[0-9]+]]:_(<3 x s32>) = COPY $vgpr0_vgpr1_vgpr2
     ; GFX8-NEXT: [[UV:%[0-9]+]]:_(s32), [[UV1:%[0-9]+]]:_(s32), [[UV2:%[0-9]+]]:_(s32) = G_UNMERGE_VALUES [[COPY]](<3 x s32>)
     ; GFX8-NEXT: [[FCMP:%[0-9]+]]:_(s1) = G_FCMP floatpred(oeq), [[DEF]](s32), [[UV]]
     ; GFX8-NEXT: [[FCMP1:%[0-9]+]]:_(s1) = G_FCMP floatpred(oeq), [[DEF]](s32), [[UV1]]
@@ -271,8 +271,8 @@ body: |
     ; GFX9-LABEL: name: test_fcmp_v3s32
     ; GFX9: liveins: $vgpr0_vgpr1_vgpr2
     ; GFX9-NEXT: {{  $}}
-    ; GFX9-NEXT: [[COPY:%[0-9]+]]:_(<3 x s32>) = COPY $vgpr0_vgpr1_vgpr2
     ; GFX9-NEXT: [[DEF:%[0-9]+]]:_(s32) = G_IMPLICIT_DEF
+    ; GFX9-NEXT: [[COPY:%[0-9]+]]:_(<3 x s32>) = COPY $vgpr0_vgpr1_vgpr2
     ; GFX9-NEXT: [[UV:%[0-9]+]]:_(s32), [[UV1:%[0-9]+]]:_(s32), [[UV2:%[0-9]+]]:_(s32) = G_UNMERGE_VALUES [[COPY]](<3 x s32>)
     ; GFX9-NEXT: [[FCMP:%[0-9]+]]:_(s1) = G_FCMP floatpred(oeq), [[DEF]](s32), [[UV]]
     ; GFX9-NEXT: [[FCMP1:%[0-9]+]]:_(s1) = G_FCMP floatpred(oeq), [[DEF]](s32), [[UV1]]

llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-icmp.mir

@@ -300,8 +300,8 @@ body: |
     ; GFX7-LABEL: name: test_icmp_v3s32
     ; GFX7: liveins: $vgpr0_vgpr1_vgpr2
     ; GFX7-NEXT: {{  $}}
-    ; GFX7-NEXT: [[COPY:%[0-9]+]]:_(<3 x s32>) = COPY $vgpr0_vgpr1_vgpr2
     ; GFX7-NEXT: [[DEF:%[0-9]+]]:_(s32) = G_IMPLICIT_DEF
+    ; GFX7-NEXT: [[COPY:%[0-9]+]]:_(<3 x s32>) = COPY $vgpr0_vgpr1_vgpr2
     ; GFX7-NEXT: [[UV:%[0-9]+]]:_(s32), [[UV1:%[0-9]+]]:_(s32), [[UV2:%[0-9]+]]:_(s32) = G_UNMERGE_VALUES [[COPY]](<3 x s32>)
     ; GFX7-NEXT: [[ICMP:%[0-9]+]]:_(s1) = G_ICMP intpred(ne), [[DEF]](s32), [[UV]]
     ; GFX7-NEXT: [[ICMP1:%[0-9]+]]:_(s1) = G_ICMP intpred(ne), [[DEF]](s32), [[UV1]]
@@ -319,8 +319,8 @@ body: |
     ; GFX8-LABEL: name: test_icmp_v3s32
     ; GFX8: liveins: $vgpr0_vgpr1_vgpr2
     ; GFX8-NEXT: {{  $}}
-    ; GFX8-NEXT: [[COPY:%[0-9]+]]:_(<3 x s32>) = COPY $vgpr0_vgpr1_vgpr2
     ; GFX8-NEXT: [[DEF:%[0-9]+]]:_(s32) = G_IMPLICIT_DEF
+    ; GFX8-NEXT: [[COPY:%[0-9]+]]:_(<3 x s32>) = COPY $vgpr0_vgpr1_vgpr2
     ; GFX8-NEXT: [[UV:%[0-9]+]]:_(s32), [[UV1:%[0-9]+]]:_(s32), [[UV2:%[0-9]+]]:_(s32) = G_UNMERGE_VALUES [[COPY]](<3 x s32>)
     ; GFX8-NEXT: [[ICMP:%[0-9]+]]:_(s1) = G_ICMP intpred(ne), [[DEF]](s32), [[UV]]
     ; GFX8-NEXT: [[ICMP1:%[0-9]+]]:_(s1) = G_ICMP intpred(ne), [[DEF]](s32), [[UV1]]
@@ -338,8 +338,8 @@ body: |
     ; GFX9-LABEL: name: test_icmp_v3s32
     ; GFX9: liveins: $vgpr0_vgpr1_vgpr2
     ; GFX9-NEXT: {{  $}}
-    ; GFX9-NEXT: [[COPY:%[0-9]+]]:_(<3 x s32>) = COPY $vgpr0_vgpr1_vgpr2
     ; GFX9-NEXT: [[DEF:%[0-9]+]]:_(s32) = G_IMPLICIT_DEF
+    ; GFX9-NEXT: [[COPY:%[0-9]+]]:_(<3 x s32>) = COPY $vgpr0_vgpr1_vgpr2
     ; GFX9-NEXT: [[UV:%[0-9]+]]:_(s32), [[UV1:%[0-9]+]]:_(s32), [[UV2:%[0-9]+]]:_(s32) = G_UNMERGE_VALUES [[COPY]](<3 x s32>)
     ; GFX9-NEXT: [[ICMP:%[0-9]+]]:_(s1) = G_ICMP intpred(ne), [[DEF]](s32), [[UV]]
     ; GFX9-NEXT: [[ICMP1:%[0-9]+]]:_(s1) = G_ICMP intpred(ne), [[DEF]](s32), [[UV1]]