GlobalISel: Handle widenScalar of arbitrary G_MERGE_VALUES sources

Extract the sources to the GCD of the original size and target size,
padding with implicit_def as necessary.

Also fix the case where the requested source type is wider than the
original result type. This was ignoring the type, and just using the
destination. Do the operation in the requested type and truncate back.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366367 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/Support/MathExtras.h b/include/llvm/Support/MathExtras.h
index 85d5a5ae4b90316006feb671e8ba46383e56426c..249139e824b550db8d8fd1ac15ec06adbdf41624 100644 (file)
--- a/include/llvm/Support/MathExtras.h
+++ b/include/llvm/Support/MathExtras.h
@@ -559,15 +559,20 @@ inline unsigned Log2_64_Ceil(uint64_t Value) {
 }
 
 /// Return the greatest common divisor of the values using Euclid's algorithm.
-inline uint64_t GreatestCommonDivisor64(uint64_t A, uint64_t B) {
+template <typename T>
+inline T greatestCommonDivisor(T A, T B) {
   while (B) {
-    uint64_t T = B;
+    T Tmp = B;
     B = A % B;
-    A = T;
+    A = Tmp;
   }
   return A;
 }
 
+inline uint64_t GreatestCommonDivisor64(uint64_t A, uint64_t B) {
+  return greatestCommonDivisor<uint64_t>(A, B);
+}
+
 /// This function takes a 64-bit integer and returns the bit equivalent double.
 inline double BitsToDouble(uint64_t Bits) {
   double D;

diff --git a/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index caa49cf2cf771d8c9290b95401c9d634d4722431..f5cf7fc9bd9ba0fbed053127edeb1c4a9d6ad5e4 100644 (file)
--- a/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -871,71 +871,107 @@ LegalizerHelper::widenScalarMergeValues(MachineInstr &MI, unsigned TypeIdx,
 
   Register Src1 = MI.getOperand(1).getReg();
   LLT SrcTy = MRI.getType(Src1);
-  int NumMerge = DstTy.getSizeInBits() / WideTy.getSizeInBits();
+  const int DstSize = DstTy.getSizeInBits();
+  const int SrcSize = SrcTy.getSizeInBits();
+  const int WideSize = WideTy.getSizeInBits();
+  const int NumMerge = (DstSize + WideSize - 1) / WideSize;
 
-  // Try to turn this into a merge of merges if we can use the requested type as
-  // the source.
-  if (NumMerge > 1) {
-    int PartsPerMerge = WideTy.getSizeInBits() / SrcTy.getSizeInBits();
-    if (WideTy.getSizeInBits() % SrcTy.getSizeInBits() != 0)
-      return UnableToLegalize;
-
-    int RemainderBits = DstTy.getSizeInBits() % WideTy.getSizeInBits();
-    int RemainderParts = RemainderBits / SrcTy.getSizeInBits();
+  unsigned NumOps = MI.getNumOperands();
+  unsigned NumSrc = MI.getNumOperands() - 1;
+  unsigned PartSize = DstTy.getSizeInBits() / NumSrc;
 
-    SmallVector<Register, 4> Parts;
-    SmallVector<Register, 4> SubMerges;
+  if (WideSize >= DstSize) {
+    // Directly pack the bits in the target type.
+    Register ResultReg = MIRBuilder.buildZExt(WideTy, Src1).getReg(0);
 
-    for (int I = 0; I != NumMerge; ++I) {
-      for (int J = 0; J != PartsPerMerge; ++J)
-        Parts.push_back(MI.getOperand(I * PartsPerMerge + J + 1).getReg());
+    for (unsigned I = 2; I != NumOps; ++I) {
+      const unsigned Offset = (I - 1) * PartSize;
 
-      auto SubMerge = MIRBuilder.buildMerge(WideTy, Parts);
-      SubMerges.push_back(SubMerge.getReg(0));
-      Parts.clear();
-    }
+      Register SrcReg = MI.getOperand(I).getReg();
+      assert(MRI.getType(SrcReg) == LLT::scalar(PartSize));
 
-    if (RemainderParts == 0) {
-      MIRBuilder.buildMerge(DstReg, SubMerges);
-      MI.eraseFromParent();
-      return Legalized;
-    }
+      auto ZextInput = MIRBuilder.buildZExt(WideTy, SrcReg);
 
-    assert(RemainderParts == 1);
+      Register NextResult = I + 1 == NumOps && WideSize == DstSize ? DstReg :
+        MRI.createGenericVirtualRegister(WideTy);
 
-    auto AnyExt = MIRBuilder.buildAnyExt(
-      WideTy, MI.getOperand(MI.getNumOperands() - 1).getReg());
-    SubMerges.push_back(AnyExt.getReg(0));
+      auto ShiftAmt = MIRBuilder.buildConstant(WideTy, Offset);
+      auto Shl = MIRBuilder.buildShl(WideTy, ZextInput, ShiftAmt);
+      MIRBuilder.buildOr(NextResult, ResultReg, Shl);
+      ResultReg = NextResult;
+    }
 
-    LLT WiderDstTy = LLT::scalar(SubMerges.size() * WideTy.getSizeInBits());
-    auto Merge = MIRBuilder.buildMerge(WiderDstTy, SubMerges);
-    MIRBuilder.buildTrunc(DstReg, Merge);
+    if (WideSize > DstSize)
+      MIRBuilder.buildTrunc(DstReg, ResultReg);
 
     MI.eraseFromParent();
     return Legalized;
   }
 
-  unsigned NumOps = MI.getNumOperands();
-  unsigned NumSrc = MI.getNumOperands() - 1;
-  unsigned PartSize = DstTy.getSizeInBits() / NumSrc;
-
-  Register ResultReg = MIRBuilder.buildZExt(DstTy, Src1).getReg(0);
-
-  for (unsigned I = 2; I != NumOps; ++I) {
-    const unsigned Offset = (I - 1) * PartSize;
-
+  // Unmerge the original values to the GCD type, and recombine to the next
+  // multiple greater than the original type.
+  //
+  // %3:_(s12) = G_MERGE_VALUES %0:_(s4), %1:_(s4), %2:_(s4) -> s6
+  // %4:_(s2), %5:_(s2) = G_UNMERGE_VALUES %0
+  // %6:_(s2), %7:_(s2) = G_UNMERGE_VALUES %1
+  // %8:_(s2), %9:_(s2) = G_UNMERGE_VALUES %2
+  // %10:_(s6) = G_MERGE_VALUES %4, %5, %6
+  // %11:_(s6) = G_MERGE_VALUES %7, %8, %9
+  // %12:_(s12) = G_MERGE_VALUES %10, %11
+  //
+  // Padding with undef if necessary:
+  //
+  // %2:_(s8) = G_MERGE_VALUES %0:_(s4), %1:_(s4) -> s6
+  // %3:_(s2), %4:_(s2) = G_UNMERGE_VALUES %0
+  // %5:_(s2), %6:_(s2) = G_UNMERGE_VALUES %1
+  // %7:_(s2) = G_IMPLICIT_DEF
+  // %8:_(s6) = G_MERGE_VALUES %3, %4, %5
+  // %9:_(s6) = G_MERGE_VALUES %6, %7, %7
+  // %10:_(s12) = G_MERGE_VALUES %8, %9
+
+  const int GCD = greatestCommonDivisor(SrcSize, WideSize);
+  LLT GCDTy = LLT::scalar(GCD);
+
+  SmallVector<Register, 8> Parts;
+  SmallVector<Register, 8> NewMergeRegs;
+  SmallVector<Register, 8> Unmerges;
+  LLT WideDstTy = LLT::scalar(NumMerge * WideSize);
+
+  // Decompose the original operands if they don't evenly divide.
+  for (int I = 1, E = MI.getNumOperands(); I != E; ++I) {
     Register SrcReg = MI.getOperand(I).getReg();
-    assert(MRI.getType(SrcReg) == LLT::scalar(PartSize));
+    if (GCD == SrcSize) {
+      Unmerges.push_back(SrcReg);
+    } else {
+      auto Unmerge = MIRBuilder.buildUnmerge(GCDTy, SrcReg);
+      for (int J = 0, JE = Unmerge->getNumOperands() - 1; J != JE; ++J)
+        Unmerges.push_back(Unmerge.getReg(J));
+    }
+  }
 
-    auto ZextInput = MIRBuilder.buildZExt(DstTy, SrcReg);
+  // Pad with undef to the next size that is a multiple of the requested size.
+  if (static_cast<int>(Unmerges.size()) != NumMerge * WideSize) {
+    Register UndefReg = MIRBuilder.buildUndef(GCDTy).getReg(0);
+    for (int I = Unmerges.size(); I != NumMerge * WideSize; ++I)
+      Unmerges.push_back(UndefReg);
+  }
 
-    Register NextResult = I + 1 == NumOps ? DstReg :
-      MRI.createGenericVirtualRegister(DstTy);
+  const int PartsPerGCD = WideSize / GCD;
 
-    auto ShiftAmt = MIRBuilder.buildConstant(DstTy, Offset);
-    auto Shl = MIRBuilder.buildShl(DstTy, ZextInput, ShiftAmt);
-    MIRBuilder.buildOr(NextResult, ResultReg, Shl);
-    ResultReg = NextResult;
+  // Build merges of each piece.
+  ArrayRef<Register> Slicer(Unmerges);
+  for (int I = 0; I != NumMerge; ++I, Slicer = Slicer.drop_front(PartsPerGCD)) {
+    auto Merge = MIRBuilder.buildMerge(WideTy, Slicer.take_front(PartsPerGCD));
+    NewMergeRegs.push_back(Merge.getReg(0));
+  }
+
+  // A truncate may be necessary if the requested type doesn't evenly divide the
+  // original result type.
+  if (DstTy.getSizeInBits() == WideDstTy.getSizeInBits()) {
+    MIRBuilder.buildMerge(DstReg, NewMergeRegs);
+  } else {
+    auto FinalMerge = MIRBuilder.buildMerge(WideDstTy, NewMergeRegs);
+    MIRBuilder.buildTrunc(DstReg, FinalMerge.getReg(0));
   }
 
   MI.eraseFromParent();

diff --git a/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp b/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
index 8d94454b092a465dca1ab0bdacc71b584eec0052..b7a73326b85c6b07eddf626c280c8b86636a8cdf 100644 (file)
--- a/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
+++ b/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
@@ -568,6 +568,7 @@ MachineInstrBuilder MachineIRBuilder::buildMerge(const DstOp &Res,
   // we need some temporary storage for the DstOp objects. Here we use a
   // sufficiently large SmallVector to not go through the heap.
   SmallVector<SrcOp, 8> TmpVec(Ops.begin(), Ops.end());
+  assert(TmpVec.size() > 1);
   return buildInstr(TargetOpcode::G_MERGE_VALUES, Res, TmpVec);
 }
 
@@ -577,6 +578,7 @@ MachineInstrBuilder MachineIRBuilder::buildUnmerge(ArrayRef<LLT> Res,
   // we need some temporary storage for the DstOp objects. Here we use a
   // sufficiently large SmallVector to not go through the heap.
   SmallVector<DstOp, 8> TmpVec(Res.begin(), Res.end());
+  assert(TmpVec.size() > 1);
   return buildInstr(TargetOpcode::G_UNMERGE_VALUES, TmpVec, Op);
 }
 
@@ -595,6 +597,7 @@ MachineInstrBuilder MachineIRBuilder::buildUnmerge(ArrayRef<Register> Res,
   // we need some temporary storage for the DstOp objects. Here we use a
   // sufficiently large SmallVector to not go through the heap.
   SmallVector<DstOp, 8> TmpVec(Res.begin(), Res.end());
+  assert(TmpVec.size() > 1);
   return buildInstr(TargetOpcode::G_UNMERGE_VALUES, TmpVec, Op);
 }
 

diff --git a/test/CodeGen/AMDGPU/GlobalISel/legalize-merge-values.mir b/test/CodeGen/AMDGPU/GlobalISel/legalize-merge-values.mir
index 20b65021b31031bebfe28e335626de67412ea6c8..7c5f9e7566cb17c3d79298096bd57e6051daa8c2 100644 (file)
--- a/test/CodeGen/AMDGPU/GlobalISel/legalize-merge-values.mir
+++ b/test/CodeGen/AMDGPU/GlobalISel/legalize-merge-values.mir
@@ -1,5 +1,11 @@
 # NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
-# RUN: llc -mtriple=amdgcn-mesa-mesa3d -mcpu=tahiti -O0 -run-pass=legalizer %s -o - | FileCheck %s
+# RUN: llc -mtriple=amdgcn-mesa-mesa3d -mcpu=tahiti -O0 -run-pass=legalizer -global-isel-abort=2 -pass-remarks-missed='gisel*' -o - %s 2> %t  | FileCheck %s
+# FileCheck -check-prefix=ERR %s < %t
+
+# ERR-NOT: remark:
+# ERR: remark: <unknown>:0:0: unable to legalize instruction: %197:_(s136) = G_INSERT %209:_, %206:_(s8), 128 (in function: test_merge_s68_s17_s17_s17_s17)
+# ERR-NOT: remark:
+
 
 ---
 name: test_merge_p1_s8
@@ -120,29 +126,34 @@ body: |
     ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
     ; CHECK: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
     ; CHECK: [[C2:%[0-9]+]]:_(s32) = G_CONSTANT i32 2
-    ; CHECK: [[C3:%[0-9]+]]:_(s32) = G_CONSTANT i32 8
-    ; CHECK: [[C4:%[0-9]+]]:_(s32) = G_CONSTANT i32 16777215
-    ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY [[C3]](s32)
-    ; CHECK: [[AND:%[0-9]+]]:_(s32) = G_AND [[COPY]], [[C4]]
-    ; CHECK: [[C5:%[0-9]+]]:_(s32) = G_CONSTANT i32 255
+    ; CHECK: [[DEF:%[0-9]+]]:_(s32) = G_IMPLICIT_DEF
+    ; CHECK: [[C3:%[0-9]+]]:_(s32) = G_CONSTANT i32 255
+    ; CHECK: [[TRUNC:%[0-9]+]]:_(s16) = G_TRUNC [[C3]](s32)
+    ; CHECK: [[TRUNC1:%[0-9]+]]:_(s16) = G_TRUNC [[C]](s32)
+    ; CHECK: [[AND:%[0-9]+]]:_(s16) = G_AND [[TRUNC1]], [[TRUNC]]
+    ; CHECK: [[C4:%[0-9]+]]:_(s32) = G_CONSTANT i32 8
+    ; CHECK: [[C5:%[0-9]+]]:_(s32) = G_CONSTANT i32 65535
+    ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY [[C4]](s32)
+    ; CHECK: [[AND1:%[0-9]+]]:_(s32) = G_AND [[COPY]], [[C5]]
+    ; CHECK: [[C6:%[0-9]+]]:_(s32) = G_CONSTANT i32 255
     ; CHECK: [[COPY1:%[0-9]+]]:_(s32) = COPY [[C1]](s32)
-    ; CHECK: [[AND1:%[0-9]+]]:_(s32) = G_AND [[COPY1]], [[C5]]
-    ; CHECK: [[SHL:%[0-9]+]]:_(s32) = G_SHL [[AND1]], [[AND]](s32)
-    ; CHECK: [[COPY2:%[0-9]+]]:_(s32) = COPY [[C]](s32)
-    ; CHECK: [[AND2:%[0-9]+]]:_(s32) = G_AND [[COPY2]], [[C5]]
-    ; CHECK: [[COPY3:%[0-9]+]]:_(s32) = COPY [[SHL]](s32)
-    ; CHECK: [[OR:%[0-9]+]]:_(s32) = G_OR [[AND2]], [[COPY3]]
-    ; CHECK: [[C6:%[0-9]+]]:_(s32) = G_CONSTANT i32 16
-    ; CHECK: [[COPY4:%[0-9]+]]:_(s32) = COPY [[C6]](s32)
-    ; CHECK: [[AND3:%[0-9]+]]:_(s32) = G_AND [[COPY4]], [[C4]]
-    ; CHECK: [[COPY5:%[0-9]+]]:_(s32) = COPY [[C2]](s32)
-    ; CHECK: [[AND4:%[0-9]+]]:_(s32) = G_AND [[COPY5]], [[C5]]
-    ; CHECK: [[SHL1:%[0-9]+]]:_(s32) = G_SHL [[AND4]], [[AND3]](s32)
-    ; CHECK: [[COPY6:%[0-9]+]]:_(s32) = COPY [[OR]](s32)
-    ; CHECK: [[COPY7:%[0-9]+]]:_(s32) = COPY [[SHL1]](s32)
-    ; CHECK: [[OR1:%[0-9]+]]:_(s32) = G_OR [[COPY6]], [[COPY7]]
-    ; CHECK: [[COPY8:%[0-9]+]]:_(s32) = COPY [[OR1]](s32)
-    ; CHECK: $vgpr0 = COPY [[COPY8]](s32)
+    ; CHECK: [[AND2:%[0-9]+]]:_(s32) = G_AND [[COPY1]], [[C6]]
+    ; CHECK: [[SHL:%[0-9]+]]:_(s32) = G_SHL [[AND2]], [[AND1]](s32)
+    ; CHECK: [[TRUNC2:%[0-9]+]]:_(s16) = G_TRUNC [[SHL]](s32)
+    ; CHECK: [[OR:%[0-9]+]]:_(s16) = G_OR [[AND]], [[TRUNC2]]
+    ; CHECK: [[TRUNC3:%[0-9]+]]:_(s16) = G_TRUNC [[C2]](s32)
+    ; CHECK: [[AND3:%[0-9]+]]:_(s16) = G_AND [[TRUNC3]], [[TRUNC]]
+    ; CHECK: [[C7:%[0-9]+]]:_(s32) = G_CONSTANT i32 8
+    ; CHECK: [[COPY2:%[0-9]+]]:_(s32) = COPY [[C7]](s32)
+    ; CHECK: [[AND4:%[0-9]+]]:_(s32) = G_AND [[COPY2]], [[C5]]
+    ; CHECK: [[COPY3:%[0-9]+]]:_(s32) = COPY [[DEF]](s32)
+    ; CHECK: [[AND5:%[0-9]+]]:_(s32) = G_AND [[COPY3]], [[C6]]
+    ; CHECK: [[SHL1:%[0-9]+]]:_(s32) = G_SHL [[AND5]], [[AND4]](s32)
+    ; CHECK: [[TRUNC4:%[0-9]+]]:_(s16) = G_TRUNC [[SHL1]](s32)
+    ; CHECK: [[OR1:%[0-9]+]]:_(s16) = G_OR [[AND3]], [[TRUNC4]]
+    ; CHECK: [[MV:%[0-9]+]]:_(s32) = G_MERGE_VALUES [[OR]](s16), [[OR1]](s16)
+    ; CHECK: [[COPY4:%[0-9]+]]:_(s32) = COPY [[MV]](s32)
+    ; CHECK: $vgpr0 = COPY [[COPY4]](s32)
     %0:_(s8) = G_CONSTANT i8 0
     %1:_(s8) = G_CONSTANT i8 1
     %2:_(s8) = G_CONSTANT i8 2
@@ -250,56 +261,66 @@ body: |
     ; CHECK: [[C3:%[0-9]+]]:_(s32) = G_CONSTANT i32 3
     ; CHECK: [[C4:%[0-9]+]]:_(s32) = G_CONSTANT i32 4
     ; CHECK: [[C5:%[0-9]+]]:_(s32) = G_CONSTANT i32 5
-    ; CHECK: [[C6:%[0-9]+]]:_(s32) = G_CONSTANT i32 4
-    ; CHECK: [[C7:%[0-9]+]]:_(s32) = G_CONSTANT i32 16777215
-    ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY [[C6]](s32)
-    ; CHECK: [[AND:%[0-9]+]]:_(s32) = G_AND [[COPY]], [[C7]]
-    ; CHECK: [[C8:%[0-9]+]]:_(s32) = G_CONSTANT i32 15
+    ; CHECK: [[DEF:%[0-9]+]]:_(s32) = G_IMPLICIT_DEF
+    ; CHECK: [[C6:%[0-9]+]]:_(s32) = G_CONSTANT i32 15
+    ; CHECK: [[TRUNC:%[0-9]+]]:_(s16) = G_TRUNC [[C6]](s32)
+    ; CHECK: [[TRUNC1:%[0-9]+]]:_(s16) = G_TRUNC [[C]](s32)
+    ; CHECK: [[AND:%[0-9]+]]:_(s16) = G_AND [[TRUNC1]], [[TRUNC]]
+    ; CHECK: [[C7:%[0-9]+]]:_(s32) = G_CONSTANT i32 4
+    ; CHECK: [[C8:%[0-9]+]]:_(s32) = G_CONSTANT i32 65535
+    ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY [[C7]](s32)
+    ; CHECK: [[AND1:%[0-9]+]]:_(s32) = G_AND [[COPY]], [[C8]]
+    ; CHECK: [[C9:%[0-9]+]]:_(s32) = G_CONSTANT i32 15
     ; CHECK: [[COPY1:%[0-9]+]]:_(s32) = COPY [[C1]](s32)
-    ; CHECK: [[AND1:%[0-9]+]]:_(s32) = G_AND [[COPY1]], [[C8]]
-    ; CHECK: [[SHL:%[0-9]+]]:_(s32) = G_SHL [[AND1]], [[AND]](s32)
-    ; CHECK: [[COPY2:%[0-9]+]]:_(s32) = COPY [[C]](s32)
-    ; CHECK: [[AND2:%[0-9]+]]:_(s32) = G_AND [[COPY2]], [[C8]]
-    ; CHECK: [[COPY3:%[0-9]+]]:_(s32) = COPY [[SHL]](s32)
-    ; CHECK: [[OR:%[0-9]+]]:_(s32) = G_OR [[AND2]], [[COPY3]]
-    ; CHECK: [[C9:%[0-9]+]]:_(s32) = G_CONSTANT i32 8
-    ; CHECK: [[COPY4:%[0-9]+]]:_(s32) = COPY [[C9]](s32)
-    ; CHECK: [[AND3:%[0-9]+]]:_(s32) = G_AND [[COPY4]], [[C7]]
-    ; CHECK: [[COPY5:%[0-9]+]]:_(s32) = COPY [[C2]](s32)
-    ; CHECK: [[AND4:%[0-9]+]]:_(s32) = G_AND [[COPY5]], [[C8]]
+    ; CHECK: [[AND2:%[0-9]+]]:_(s32) = G_AND [[COPY1]], [[C9]]
+    ; CHECK: [[SHL:%[0-9]+]]:_(s32) = G_SHL [[AND2]], [[AND1]](s32)
+    ; CHECK: [[TRUNC2:%[0-9]+]]:_(s16) = G_TRUNC [[SHL]](s32)
+    ; CHECK: [[OR:%[0-9]+]]:_(s16) = G_OR [[AND]], [[TRUNC2]]
+    ; CHECK: [[C10:%[0-9]+]]:_(s32) = G_CONSTANT i32 8
+    ; CHECK: [[COPY2:%[0-9]+]]:_(s32) = COPY [[C10]](s32)
+    ; CHECK: [[AND3:%[0-9]+]]:_(s32) = G_AND [[COPY2]], [[C8]]
+    ; CHECK: [[COPY3:%[0-9]+]]:_(s32) = COPY [[C2]](s32)
+    ; CHECK: [[AND4:%[0-9]+]]:_(s32) = G_AND [[COPY3]], [[C9]]
     ; CHECK: [[SHL1:%[0-9]+]]:_(s32) = G_SHL [[AND4]], [[AND3]](s32)
-    ; CHECK: [[COPY6:%[0-9]+]]:_(s32) = COPY [[OR]](s32)
-    ; CHECK: [[COPY7:%[0-9]+]]:_(s32) = COPY [[SHL1]](s32)
-    ; CHECK: [[OR1:%[0-9]+]]:_(s32) = G_OR [[COPY6]], [[COPY7]]
-    ; CHECK: [[C10:%[0-9]+]]:_(s32) = G_CONSTANT i32 12
-    ; CHECK: [[COPY8:%[0-9]+]]:_(s32) = COPY [[C10]](s32)
-    ; CHECK: [[AND5:%[0-9]+]]:_(s32) = G_AND [[COPY8]], [[C7]]
-    ; CHECK: [[COPY9:%[0-9]+]]:_(s32) = COPY [[C3]](s32)
-    ; CHECK: [[AND6:%[0-9]+]]:_(s32) = G_AND [[COPY9]], [[C8]]
+    ; CHECK: [[TRUNC3:%[0-9]+]]:_(s16) = G_TRUNC [[SHL1]](s32)
+    ; CHECK: [[OR1:%[0-9]+]]:_(s16) = G_OR [[OR]], [[TRUNC3]]
+    ; CHECK: [[C11:%[0-9]+]]:_(s32) = G_CONSTANT i32 12
+    ; CHECK: [[COPY4:%[0-9]+]]:_(s32) = COPY [[C11]](s32)
+    ; CHECK: [[AND5:%[0-9]+]]:_(s32) = G_AND [[COPY4]], [[C8]]
+    ; CHECK: [[COPY5:%[0-9]+]]:_(s32) = COPY [[C3]](s32)
+    ; CHECK: [[AND6:%[0-9]+]]:_(s32) = G_AND [[COPY5]], [[C9]]
     ; CHECK: [[SHL2:%[0-9]+]]:_(s32) = G_SHL [[AND6]], [[AND5]](s32)
-    ; CHECK: [[COPY10:%[0-9]+]]:_(s32) = COPY [[OR1]](s32)
-    ; CHECK: [[COPY11:%[0-9]+]]:_(s32) = COPY [[SHL2]](s32)
-    ; CHECK: [[OR2:%[0-9]+]]:_(s32) = G_OR [[COPY10]], [[COPY11]]
-    ; CHECK: [[C11:%[0-9]+]]:_(s32) = G_CONSTANT i32 16
-    ; CHECK: [[COPY12:%[0-9]+]]:_(s32) = COPY [[C11]](s32)
-    ; CHECK: [[AND7:%[0-9]+]]:_(s32) = G_AND [[COPY12]], [[C7]]
-    ; CHECK: [[COPY13:%[0-9]+]]:_(s32) = COPY [[C4]](s32)
-    ; CHECK: [[AND8:%[0-9]+]]:_(s32) = G_AND [[COPY13]], [[C8]]
-    ; CHECK: [[SHL3:%[0-9]+]]:_(s32) = G_SHL [[AND8]], [[AND7]](s32)
-    ; CHECK: [[COPY14:%[0-9]+]]:_(s32) = COPY [[OR2]](s32)
-    ; CHECK: [[COPY15:%[0-9]+]]:_(s32) = COPY [[SHL3]](s32)
-    ; CHECK: [[OR3:%[0-9]+]]:_(s32) = G_OR [[COPY14]], [[COPY15]]
-    ; CHECK: [[C12:%[0-9]+]]:_(s32) = G_CONSTANT i32 20
-    ; CHECK: [[COPY16:%[0-9]+]]:_(s32) = COPY [[C12]](s32)
-    ; CHECK: [[AND9:%[0-9]+]]:_(s32) = G_AND [[COPY16]], [[C7]]
-    ; CHECK: [[COPY17:%[0-9]+]]:_(s32) = COPY [[C5]](s32)
-    ; CHECK: [[AND10:%[0-9]+]]:_(s32) = G_AND [[COPY17]], [[C8]]
-    ; CHECK: [[SHL4:%[0-9]+]]:_(s32) = G_SHL [[AND10]], [[AND9]](s32)
-    ; CHECK: [[COPY18:%[0-9]+]]:_(s32) = COPY [[OR3]](s32)
-    ; CHECK: [[COPY19:%[0-9]+]]:_(s32) = COPY [[SHL4]](s32)
-    ; CHECK: [[OR4:%[0-9]+]]:_(s32) = G_OR [[COPY18]], [[COPY19]]
-    ; CHECK: [[TRUNC:%[0-9]+]]:_(s24) = G_TRUNC [[OR4]](s32)
-    ; CHECK: S_NOP 0, implicit [[TRUNC]](s24)
+    ; CHECK: [[TRUNC4:%[0-9]+]]:_(s16) = G_TRUNC [[SHL2]](s32)
+    ; CHECK: [[OR2:%[0-9]+]]:_(s16) = G_OR [[OR1]], [[TRUNC4]]
+    ; CHECK: [[TRUNC5:%[0-9]+]]:_(s16) = G_TRUNC [[C4]](s32)
+    ; CHECK: [[AND7:%[0-9]+]]:_(s16) = G_AND [[TRUNC5]], [[TRUNC]]
+    ; CHECK: [[C12:%[0-9]+]]:_(s32) = G_CONSTANT i32 4
+    ; CHECK: [[COPY6:%[0-9]+]]:_(s32) = COPY [[C12]](s32)
+    ; CHECK: [[AND8:%[0-9]+]]:_(s32) = G_AND [[COPY6]], [[C8]]
+    ; CHECK: [[COPY7:%[0-9]+]]:_(s32) = COPY [[C5]](s32)
+    ; CHECK: [[AND9:%[0-9]+]]:_(s32) = G_AND [[COPY7]], [[C9]]
+    ; CHECK: [[SHL3:%[0-9]+]]:_(s32) = G_SHL [[AND9]], [[AND8]](s32)
+    ; CHECK: [[TRUNC6:%[0-9]+]]:_(s16) = G_TRUNC [[SHL3]](s32)
+    ; CHECK: [[OR3:%[0-9]+]]:_(s16) = G_OR [[AND7]], [[TRUNC6]]
+    ; CHECK: [[C13:%[0-9]+]]:_(s32) = G_CONSTANT i32 8
+    ; CHECK: [[COPY8:%[0-9]+]]:_(s32) = COPY [[C13]](s32)
+    ; CHECK: [[AND10:%[0-9]+]]:_(s32) = G_AND [[COPY8]], [[C8]]
+    ; CHECK: [[COPY9:%[0-9]+]]:_(s32) = COPY [[DEF]](s32)
+    ; CHECK: [[AND11:%[0-9]+]]:_(s32) = G_AND [[COPY9]], [[C9]]
+    ; CHECK: [[SHL4:%[0-9]+]]:_(s32) = G_SHL [[AND11]], [[AND10]](s32)
+    ; CHECK: [[TRUNC7:%[0-9]+]]:_(s16) = G_TRUNC [[SHL4]](s32)
+    ; CHECK: [[OR4:%[0-9]+]]:_(s16) = G_OR [[OR3]], [[TRUNC7]]
+    ; CHECK: [[C14:%[0-9]+]]:_(s32) = G_CONSTANT i32 12
+    ; CHECK: [[COPY10:%[0-9]+]]:_(s32) = COPY [[C14]](s32)
+    ; CHECK: [[AND12:%[0-9]+]]:_(s32) = G_AND [[COPY10]], [[C8]]
+    ; CHECK: [[COPY11:%[0-9]+]]:_(s32) = COPY [[DEF]](s32)
+    ; CHECK: [[AND13:%[0-9]+]]:_(s32) = G_AND [[COPY11]], [[C9]]
+    ; CHECK: [[SHL5:%[0-9]+]]:_(s32) = G_SHL [[AND13]], [[AND12]](s32)
+    ; CHECK: [[TRUNC8:%[0-9]+]]:_(s16) = G_TRUNC [[SHL5]](s32)
+    ; CHECK: [[OR5:%[0-9]+]]:_(s16) = G_OR [[OR4]], [[TRUNC8]]
+    ; CHECK: [[MV:%[0-9]+]]:_(s32) = G_MERGE_VALUES [[OR2]](s16), [[OR5]](s16)
+    ; CHECK: [[TRUNC9:%[0-9]+]]:_(s24) = G_TRUNC [[MV]](s32)
+    ; CHECK: S_NOP 0, implicit [[TRUNC9]](s24)
     %0:_(s4) = G_CONSTANT i4 0
     %1:_(s4) = G_CONSTANT i4 1
     %2:_(s4) = G_CONSTANT i4 2
@@ -322,65 +343,66 @@ body: |
     ; CHECK: [[C4:%[0-9]+]]:_(s32) = G_CONSTANT i32 4
     ; CHECK: [[C5:%[0-9]+]]:_(s32) = G_CONSTANT i32 5
     ; CHECK: [[C6:%[0-9]+]]:_(s32) = G_CONSTANT i32 6
-    ; CHECK: [[C7:%[0-9]+]]:_(s32) = G_CONSTANT i32 4
-    ; CHECK: [[C8:%[0-9]+]]:_(s32) = G_CONSTANT i32 268435455
-    ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY [[C7]](s32)
-    ; CHECK: [[AND:%[0-9]+]]:_(s32) = G_AND [[COPY]], [[C8]]
-    ; CHECK: [[C9:%[0-9]+]]:_(s32) = G_CONSTANT i32 15
+    ; CHECK: [[DEF:%[0-9]+]]:_(s32) = G_IMPLICIT_DEF
+    ; CHECK: [[C7:%[0-9]+]]:_(s32) = G_CONSTANT i32 15
+    ; CHECK: [[TRUNC:%[0-9]+]]:_(s16) = G_TRUNC [[C7]](s32)
+    ; CHECK: [[TRUNC1:%[0-9]+]]:_(s16) = G_TRUNC [[C]](s32)
+    ; CHECK: [[AND:%[0-9]+]]:_(s16) = G_AND [[TRUNC1]], [[TRUNC]]
+    ; CHECK: [[C8:%[0-9]+]]:_(s32) = G_CONSTANT i32 4
+    ; CHECK: [[C9:%[0-9]+]]:_(s32) = G_CONSTANT i32 65535
+    ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY [[C8]](s32)
+    ; CHECK: [[AND1:%[0-9]+]]:_(s32) = G_AND [[COPY]], [[C9]]
+    ; CHECK: [[C10:%[0-9]+]]:_(s32) = G_CONSTANT i32 15
     ; CHECK: [[COPY1:%[0-9]+]]:_(s32) = COPY [[C1]](s32)
-    ; CHECK: [[AND1:%[0-9]+]]:_(s32) = G_AND [[COPY1]], [[C9]]
-    ; CHECK: [[SHL:%[0-9]+]]:_(s32) = G_SHL [[AND1]], [[AND]](s32)
-    ; CHECK: [[COPY2:%[0-9]+]]:_(s32) = COPY [[C]](s32)
-    ; CHECK: [[AND2:%[0-9]+]]:_(s32) = G_AND [[COPY2]], [[C9]]
-    ; CHECK: [[COPY3:%[0-9]+]]:_(s32) = COPY [[SHL]](s32)
-    ; CHECK: [[OR:%[0-9]+]]:_(s32) = G_OR [[AND2]], [[COPY3]]
-    ; CHECK: [[C10:%[0-9]+]]:_(s32) = G_CONSTANT i32 8
-    ; CHECK: [[COPY4:%[0-9]+]]:_(s32) = COPY [[C10]](s32)
-    ; CHECK: [[AND3:%[0-9]+]]:_(s32) = G_AND [[COPY4]], [[C8]]
-    ; CHECK: [[COPY5:%[0-9]+]]:_(s32) = COPY [[C2]](s32)
-    ; CHECK: [[AND4:%[0-9]+]]:_(s32) = G_AND [[COPY5]], [[C9]]
+    ; CHECK: [[AND2:%[0-9]+]]:_(s32) = G_AND [[COPY1]], [[C10]]
+    ; CHECK: [[SHL:%[0-9]+]]:_(s32) = G_SHL [[AND2]], [[AND1]](s32)
+    ; CHECK: [[TRUNC2:%[0-9]+]]:_(s16) = G_TRUNC [[SHL]](s32)
+    ; CHECK: [[OR:%[0-9]+]]:_(s16) = G_OR [[AND]], [[TRUNC2]]
+    ; CHECK: [[C11:%[0-9]+]]:_(s32) = G_CONSTANT i32 8
+    ; CHECK: [[COPY2:%[0-9]+]]:_(s32) = COPY [[C11]](s32)
+    ; CHECK: [[AND3:%[0-9]+]]:_(s32) = G_AND [[COPY2]], [[C9]]
+    ; CHECK: [[COPY3:%[0-9]+]]:_(s32) = COPY [[C2]](s32)
+    ; CHECK: [[AND4:%[0-9]+]]:_(s32) = G_AND [[COPY3]], [[C10]]
     ; CHECK: [[SHL1:%[0-9]+]]:_(s32) = G_SHL [[AND4]], [[AND3]](s32)
-    ; CHECK: [[COPY6:%[0-9]+]]:_(s32) = COPY [[OR]](s32)
-    ; CHECK: [[COPY7:%[0-9]+]]:_(s32) = COPY [[SHL1]](s32)
-    ; CHECK: [[OR1:%[0-9]+]]:_(s32) = G_OR [[COPY6]], [[COPY7]]
-    ; CHECK: [[C11:%[0-9]+]]:_(s32) = G_CONSTANT i32 12
-    ; CHECK: [[COPY8:%[0-9]+]]:_(s32) = COPY [[C11]](s32)
-    ; CHECK: [[AND5:%[0-9]+]]:_(s32) = G_AND [[COPY8]], [[C8]]
-    ; CHECK: [[COPY9:%[0-9]+]]:_(s32) = COPY [[C3]](s32)
-    ; CHECK: [[AND6:%[0-9]+]]:_(s32) = G_AND [[COPY9]], [[C9]]
+    ; CHECK: [[TRUNC3:%[0-9]+]]:_(s16) = G_TRUNC [[SHL1]](s32)
+    ; CHECK: [[OR1:%[0-9]+]]:_(s16) = G_OR [[OR]], [[TRUNC3]]
+    ; CHECK: [[C12:%[0-9]+]]:_(s32) = G_CONSTANT i32 12
+    ; CHECK: [[COPY4:%[0-9]+]]:_(s32) = COPY [[C12]](s32)
+    ; CHECK: [[AND5:%[0-9]+]]:_(s32) = G_AND [[COPY4]], [[C9]]
+    ; CHECK: [[COPY5:%[0-9]+]]:_(s32) = COPY [[C3]](s32)
+    ; CHECK: [[AND6:%[0-9]+]]:_(s32) = G_AND [[COPY5]], [[C10]]
     ; CHECK: [[SHL2:%[0-9]+]]:_(s32) = G_SHL [[AND6]], [[AND5]](s32)
-    ; CHECK: [[COPY10:%[0-9]+]]:_(s32) = COPY [[OR1]](s32)
-    ; CHECK: [[COPY11:%[0-9]+]]:_(s32) = COPY [[SHL2]](s32)
-    ; CHECK: [[OR2:%[0-9]+]]:_(s32) = G_OR [[COPY10]], [[COPY11]]
-    ; CHECK: [[C12:%[0-9]+]]:_(s32) = G_CONSTANT i32 16
-    ; CHECK: [[COPY12:%[0-9]+]]:_(s32) = COPY [[C12]](s32)
-    ; CHECK: [[AND7:%[0-9]+]]:_(s32) = G_AND [[COPY12]], [[C8]]
-    ; CHECK: [[COPY13:%[0-9]+]]:_(s32) = COPY [[C4]](s32)
-    ; CHECK: [[AND8:%[0-9]+]]:_(s32) = G_AND [[COPY13]], [[C9]]
-    ; CHECK: [[SHL3:%[0-9]+]]:_(s32) = G_SHL [[AND8]], [[AND7]](s32)
-    ; CHECK: [[COPY14:%[0-9]+]]:_(s32) = COPY [[OR2]](s32)
-    ; CHECK: [[COPY15:%[0-9]+]]:_(s32) = COPY [[SHL3]](s32)
-    ; CHECK: [[OR3:%[0-9]+]]:_(s32) = G_OR [[COPY14]], [[COPY15]]
-    ; CHECK: [[C13:%[0-9]+]]:_(s32) = G_CONSTANT i32 20
-    ; CHECK: [[COPY16:%[0-9]+]]:_(s32) = COPY [[C13]](s32)
-    ; CHECK: [[AND9:%[0-9]+]]:_(s32) = G_AND [[COPY16]], [[C8]]
-    ; CHECK: [[COPY17:%[0-9]+]]:_(s32) = COPY [[C5]](s32)
-    ; CHECK: [[AND10:%[0-9]+]]:_(s32) = G_AND [[COPY17]], [[C9]]
-    ; CHECK: [[SHL4:%[0-9]+]]:_(s32) = G_SHL [[AND10]], [[AND9]](s32)
-    ; CHECK: [[COPY18:%[0-9]+]]:_(s32) = COPY [[OR3]](s32)
-    ; CHECK: [[COPY19:%[0-9]+]]:_(s32) = COPY [[SHL4]](s32)
-    ; CHECK: [[OR4:%[0-9]+]]:_(s32) = G_OR [[COPY18]], [[COPY19]]
-    ; CHECK: [[C14:%[0-9]+]]:_(s32) = G_CONSTANT i32 24
-    ; CHECK: [[COPY20:%[0-9]+]]:_(s32) = COPY [[C14]](s32)
-    ; CHECK: [[AND11:%[0-9]+]]:_(s32) = G_AND [[COPY20]], [[C8]]
-    ; CHECK: [[COPY21:%[0-9]+]]:_(s32) = COPY [[C6]](s32)
-    ; CHECK: [[AND12:%[0-9]+]]:_(s32) = G_AND [[COPY21]], [[C9]]
-    ; CHECK: [[SHL5:%[0-9]+]]:_(s32) = G_SHL [[AND12]], [[AND11]](s32)
-    ; CHECK: [[COPY22:%[0-9]+]]:_(s32) = COPY [[OR4]](s32)
-    ; CHECK: [[COPY23:%[0-9]+]]:_(s32) = COPY [[SHL5]](s32)
-    ; CHECK: [[OR5:%[0-9]+]]:_(s32) = G_OR [[COPY22]], [[COPY23]]
-    ; CHECK: [[TRUNC:%[0-9]+]]:_(s28) = G_TRUNC [[OR5]](s32)
-    ; CHECK: S_NOP 0, implicit [[TRUNC]](s28)
+    ; CHECK: [[TRUNC4:%[0-9]+]]:_(s16) = G_TRUNC [[SHL2]](s32)
+    ; CHECK: [[OR2:%[0-9]+]]:_(s16) = G_OR [[OR1]], [[TRUNC4]]
+    ; CHECK: [[TRUNC5:%[0-9]+]]:_(s16) = G_TRUNC [[C4]](s32)
+    ; CHECK: [[AND7:%[0-9]+]]:_(s16) = G_AND [[TRUNC5]], [[TRUNC]]
+    ; CHECK: [[C13:%[0-9]+]]:_(s32) = G_CONSTANT i32 4
+    ; CHECK: [[COPY6:%[0-9]+]]:_(s32) = COPY [[C13]](s32)
+    ; CHECK: [[AND8:%[0-9]+]]:_(s32) = G_AND [[COPY6]], [[C9]]
+    ; CHECK: [[COPY7:%[0-9]+]]:_(s32) = COPY [[C5]](s32)
+    ; CHECK: [[AND9:%[0-9]+]]:_(s32) = G_AND [[COPY7]], [[C10]]
+    ; CHECK: [[SHL3:%[0-9]+]]:_(s32) = G_SHL [[AND9]], [[AND8]](s32)
+    ; CHECK: [[TRUNC6:%[0-9]+]]:_(s16) = G_TRUNC [[SHL3]](s32)
+    ; CHECK: [[OR3:%[0-9]+]]:_(s16) = G_OR [[AND7]], [[TRUNC6]]
+    ; CHECK: [[C14:%[0-9]+]]:_(s32) = G_CONSTANT i32 8
+    ; CHECK: [[COPY8:%[0-9]+]]:_(s32) = COPY [[C14]](s32)
+    ; CHECK: [[AND10:%[0-9]+]]:_(s32) = G_AND [[COPY8]], [[C9]]
+    ; CHECK: [[COPY9:%[0-9]+]]:_(s32) = COPY [[C6]](s32)
+    ; CHECK: [[AND11:%[0-9]+]]:_(s32) = G_AND [[COPY9]], [[C10]]
+    ; CHECK: [[SHL4:%[0-9]+]]:_(s32) = G_SHL [[AND11]], [[AND10]](s32)
+    ; CHECK: [[TRUNC7:%[0-9]+]]:_(s16) = G_TRUNC [[SHL4]](s32)
+    ; CHECK: [[OR4:%[0-9]+]]:_(s16) = G_OR [[OR3]], [[TRUNC7]]
+    ; CHECK: [[C15:%[0-9]+]]:_(s32) = G_CONSTANT i32 12
+    ; CHECK: [[COPY10:%[0-9]+]]:_(s32) = COPY [[C15]](s32)
+    ; CHECK: [[AND12:%[0-9]+]]:_(s32) = G_AND [[COPY10]], [[C9]]
+    ; CHECK: [[COPY11:%[0-9]+]]:_(s32) = COPY [[DEF]](s32)
+    ; CHECK: [[AND13:%[0-9]+]]:_(s32) = G_AND [[COPY11]], [[C10]]
+    ; CHECK: [[SHL5:%[0-9]+]]:_(s32) = G_SHL [[AND13]], [[AND12]](s32)
+    ; CHECK: [[TRUNC8:%[0-9]+]]:_(s16) = G_TRUNC [[SHL5]](s32)
+    ; CHECK: [[OR5:%[0-9]+]]:_(s16) = G_OR [[OR4]], [[TRUNC8]]
+    ; CHECK: [[MV:%[0-9]+]]:_(s32) = G_MERGE_VALUES [[OR2]](s16), [[OR5]](s16)
+    ; CHECK: [[TRUNC9:%[0-9]+]]:_(s28) = G_TRUNC [[MV]](s32)
+    ; CHECK: S_NOP 0, implicit [[TRUNC9]](s28)
     %0:_(s4) = G_CONSTANT i4 0
     %1:_(s4) = G_CONSTANT i4 1
     %2:_(s4) = G_CONSTANT i4 2
@@ -548,6 +570,7 @@ body: |
     ; CHECK: [[C4:%[0-9]+]]:_(s32) = G_CONSTANT i32 4
     ; CHECK: [[C5:%[0-9]+]]:_(s32) = G_CONSTANT i32 5
     ; CHECK: [[C6:%[0-9]+]]:_(s32) = G_CONSTANT i32 6
+    ; CHECK: [[DEF:%[0-9]+]]:_(s32) = G_IMPLICIT_DEF
     ; CHECK: [[C7:%[0-9]+]]:_(s32) = G_CONSTANT i32 255
     ; CHECK: [[TRUNC:%[0-9]+]]:_(s16) = G_TRUNC [[C7]](s32)
     ; CHECK: [[TRUNC1:%[0-9]+]]:_(s16) = G_TRUNC [[C]](s32)
@@ -583,9 +606,18 @@ body: |
     ; CHECK: [[TRUNC6:%[0-9]+]]:_(s16) = G_TRUNC [[SHL2]](s32)
     ; CHECK: [[OR2:%[0-9]+]]:_(s16) = G_OR [[AND6]], [[TRUNC6]]
     ; CHECK: [[TRUNC7:%[0-9]+]]:_(s16) = G_TRUNC [[C6]](s32)
-    ; CHECK: [[MV:%[0-9]+]]:_(s64) = G_MERGE_VALUES [[OR]](s16), [[OR1]](s16), [[OR2]](s16), [[TRUNC7]](s16)
-    ; CHECK: [[TRUNC8:%[0-9]+]]:_(s56) = G_TRUNC [[MV]](s64)
-    ; CHECK: S_NOP 0, implicit [[TRUNC8]](s56)
+    ; CHECK: [[AND9:%[0-9]+]]:_(s16) = G_AND [[TRUNC7]], [[TRUNC]]
+    ; CHECK: [[C13:%[0-9]+]]:_(s32) = G_CONSTANT i32 8
+    ; CHECK: [[COPY6:%[0-9]+]]:_(s32) = COPY [[C13]](s32)
+    ; CHECK: [[AND10:%[0-9]+]]:_(s32) = G_AND [[COPY6]], [[C9]]
+    ; CHECK: [[COPY7:%[0-9]+]]:_(s32) = COPY [[DEF]](s32)
+    ; CHECK: [[AND11:%[0-9]+]]:_(s32) = G_AND [[COPY7]], [[C10]]
+    ; CHECK: [[SHL3:%[0-9]+]]:_(s32) = G_SHL [[AND11]], [[AND10]](s32)
+    ; CHECK: [[TRUNC8:%[0-9]+]]:_(s16) = G_TRUNC [[SHL3]](s32)
+    ; CHECK: [[OR3:%[0-9]+]]:_(s16) = G_OR [[AND9]], [[TRUNC8]]
+    ; CHECK: [[MV:%[0-9]+]]:_(s64) = G_MERGE_VALUES [[OR]](s16), [[OR1]](s16), [[OR2]](s16), [[OR3]](s16)
+    ; CHECK: [[TRUNC9:%[0-9]+]]:_(s56) = G_TRUNC [[MV]](s64)
+    ; CHECK: S_NOP 0, implicit [[TRUNC9]](s56)
     %0:_(s8) = G_CONSTANT i8 0
     %1:_(s8) = G_CONSTANT i8 1
     %2:_(s8) = G_CONSTANT i8 2
@@ -596,3 +628,160 @@ body: |
     %7:_(s56) = G_MERGE_VALUES %0, %1, %2, %3, %4, %5, %6
     S_NOP 0, implicit %7
 ...
+
+---
+name: test_merge_s68_s17_s17_s17_s17
+body: |
+  bb.0:
+    ; CHECK-LABEL: name: test_merge_s68_s17_s17_s17_s17
+    ; CHECK: [[TRUNC:%[0-9]+]]:_(s1) = G_TRUNC %142(s16)
+    ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CHECK: [[TRUNC1:%[0-9]+]]:_(s1) = G_TRUNC %143(s16)
+    ; CHECK: [[TRUNC2:%[0-9]+]]:_(s17) = G_TRUNC [[C]](s32)
+    ; CHECK: [[TRUNC3:%[0-9]+]]:_(s1) = G_TRUNC %144(s16)
+    ; CHECK: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
+    ; CHECK: [[TRUNC4:%[0-9]+]]:_(s1) = G_TRUNC %145(s16)
+    ; CHECK: [[TRUNC5:%[0-9]+]]:_(s17) = G_TRUNC [[C1]](s32)
+    ; CHECK: [[TRUNC6:%[0-9]+]]:_(s1) = G_TRUNC %146(s16)
+    ; CHECK: [[C2:%[0-9]+]]:_(s32) = G_CONSTANT i32 2
+    ; CHECK: [[TRUNC7:%[0-9]+]]:_(s1) = G_TRUNC %147(s16)
+    ; CHECK: [[TRUNC8:%[0-9]+]]:_(s17) = G_TRUNC [[C2]](s32)
+    ; CHECK: [[C3:%[0-9]+]]:_(s32) = G_CONSTANT i32 3
+    ; CHECK: [[TRUNC9:%[0-9]+]]:_(s17) = G_TRUNC [[C3]](s32)
+    ; CHECK: [[ZEXT:%[0-9]+]]:_(s272) = G_ZEXT [[TRUNC2]](s17)
+    ; CHECK: [[C4:%[0-9]+]]:_(s272) = G_CONSTANT i272 15
+    ; CHECK: [[SHL:%[0-9]+]]:_(s272) = G_SHL [[ZEXT]], [[C4]](s272)
+    ; CHECK: [[OR:%[0-9]+]]:_(s272) = G_OR [[ZEXT]], [[SHL]]
+    ; CHECK: [[C5:%[0-9]+]]:_(s272) = G_CONSTANT i272 30
+    ; CHECK: [[SHL1:%[0-9]+]]:_(s272) = G_SHL [[OR]], [[C5]](s272)
+    ; CHECK: [[OR1:%[0-9]+]]:_(s272) = G_OR [[OR]], [[SHL1]]
+    ; CHECK: [[C6:%[0-9]+]]:_(s272) = G_CONSTANT i272 45
+    ; CHECK: [[SHL2:%[0-9]+]]:_(s272) = G_SHL [[OR1]], [[C6]](s272)
+    ; CHECK: [[OR2:%[0-9]+]]:_(s272) = G_OR [[OR1]], [[SHL2]]
+    ; CHECK: [[C7:%[0-9]+]]:_(s272) = G_CONSTANT i272 60
+    ; CHECK: [[SHL3:%[0-9]+]]:_(s272) = G_SHL [[OR2]], [[C7]](s272)
+    ; CHECK: [[OR3:%[0-9]+]]:_(s272) = G_OR [[OR2]], [[SHL3]]
+    ; CHECK: [[C8:%[0-9]+]]:_(s272) = G_CONSTANT i272 75
+    ; CHECK: [[SHL4:%[0-9]+]]:_(s272) = G_SHL [[OR3]], [[C8]](s272)
+    ; CHECK: [[OR4:%[0-9]+]]:_(s272) = G_OR [[OR3]], [[SHL4]]
+    ; CHECK: [[C9:%[0-9]+]]:_(s272) = G_CONSTANT i272 90
+    ; CHECK: [[SHL5:%[0-9]+]]:_(s272) = G_SHL [[OR4]], [[C9]](s272)
+    ; CHECK: [[OR5:%[0-9]+]]:_(s272) = G_OR [[OR4]], [[SHL5]]
+    ; CHECK: [[C10:%[0-9]+]]:_(s272) = G_CONSTANT i272 105
+    ; CHECK: [[SHL6:%[0-9]+]]:_(s272) = G_SHL [[OR5]], [[C10]](s272)
+    ; CHECK: [[OR6:%[0-9]+]]:_(s272) = G_OR [[OR5]], [[SHL6]]
+    ; CHECK: [[C11:%[0-9]+]]:_(s272) = G_CONSTANT i272 120
+    ; CHECK: [[SHL7:%[0-9]+]]:_(s272) = G_SHL [[OR6]], [[C11]](s272)
+    ; CHECK: [[OR7:%[0-9]+]]:_(s272) = G_OR [[OR6]], [[SHL7]]
+    ; CHECK: [[C12:%[0-9]+]]:_(s272) = G_CONSTANT i272 135
+    ; CHECK: [[SHL8:%[0-9]+]]:_(s272) = G_SHL [[OR7]], [[C12]](s272)
+    ; CHECK: [[OR8:%[0-9]+]]:_(s272) = G_OR [[OR7]], [[SHL8]]
+    ; CHECK: [[C13:%[0-9]+]]:_(s272) = G_CONSTANT i272 150
+    ; CHECK: [[SHL9:%[0-9]+]]:_(s272) = G_SHL [[OR8]], [[C13]](s272)
+    ; CHECK: [[OR9:%[0-9]+]]:_(s272) = G_OR [[OR8]], [[SHL9]]
+    ; CHECK: [[C14:%[0-9]+]]:_(s272) = G_CONSTANT i272 165
+    ; CHECK: [[SHL10:%[0-9]+]]:_(s272) = G_SHL [[OR9]], [[C14]](s272)
+    ; CHECK: [[OR10:%[0-9]+]]:_(s272) = G_OR [[OR9]], [[SHL10]]
+    ; CHECK: [[C15:%[0-9]+]]:_(s272) = G_CONSTANT i272 180
+    ; CHECK: [[SHL11:%[0-9]+]]:_(s272) = G_SHL [[OR10]], [[C15]](s272)
+    ; CHECK: [[OR11:%[0-9]+]]:_(s272) = G_OR [[OR10]], [[SHL11]]
+    ; CHECK: [[C16:%[0-9]+]]:_(s272) = G_CONSTANT i272 195
+    ; CHECK: [[SHL12:%[0-9]+]]:_(s272) = G_SHL [[OR11]], [[C16]](s272)
+    ; CHECK: [[OR12:%[0-9]+]]:_(s272) = G_OR [[OR11]], [[SHL12]]
+    ; CHECK: [[C17:%[0-9]+]]:_(s272) = G_CONSTANT i272 210
+    ; CHECK: [[SHL13:%[0-9]+]]:_(s272) = G_SHL [[OR12]], [[C17]](s272)
+    ; CHECK: [[OR13:%[0-9]+]]:_(s272) = G_OR [[OR12]], [[SHL13]]
+    ; CHECK: [[C18:%[0-9]+]]:_(s272) = G_CONSTANT i272 225
+    ; CHECK: [[SHL14:%[0-9]+]]:_(s272) = G_SHL [[OR13]], [[C18]](s272)
+    ; CHECK: [[OR14:%[0-9]+]]:_(s272) = G_OR [[OR13]], [[SHL14]]
+    ; CHECK: [[C19:%[0-9]+]]:_(s272) = G_CONSTANT i272 240
+    ; CHECK: [[TRUNC10:%[0-9]+]]:_(s32) = G_TRUNC [[C19]](s272)
+    ; CHECK: [[C20:%[0-9]+]]:_(s32) = G_CONSTANT i32 136
+    ; CHECK: [[UV:%[0-9]+]]:_(s136), [[UV1:%[0-9]+]]:_(s136) = G_UNMERGE_VALUES [[OR14]](s272)
+    ; CHECK: [[SUB:%[0-9]+]]:_(s32) = G_SUB [[TRUNC10]], [[C20]]
+    ; CHECK: [[SUB1:%[0-9]+]]:_(s32) = G_SUB [[C20]], [[TRUNC10]]
+    ; CHECK: [[ICMP:%[0-9]+]]:_(s1) = G_ICMP intpred(ult), [[TRUNC10]](s32), [[C20]]
+    ; CHECK: [[ICMP1:%[0-9]+]]:_(s1) = G_ICMP intpred(eq), [[TRUNC10]](s32), [[C]]
+    ; CHECK: [[SHL15:%[0-9]+]]:_(s136) = G_SHL [[UV1]], [[TRUNC10]](s32)
+    ; CHECK: [[SHL16:%[0-9]+]]:_(s136) = G_SHL [[UV1]], [[TRUNC10]](s32)
+    ; CHECK: [[LSHR:%[0-9]+]]:_(s136) = G_LSHR [[UV]], [[SUB1]](s32)
+    ; CHECK: [[OR15:%[0-9]+]]:_(s136) = G_OR [[SHL16]], [[LSHR]]
+    ; CHECK: [[C21:%[0-9]+]]:_(s136) = G_CONSTANT i136 0
+    ; CHECK: [[SHL17:%[0-9]+]]:_(s136) = G_SHL [[UV]], [[SUB]](s32)
+    ; CHECK: [[SELECT:%[0-9]+]]:_(s136) = G_SELECT [[ICMP]](s1), [[SHL15]], [[C21]]
+    ; CHECK: [[SELECT1:%[0-9]+]]:_(s136) = G_SELECT [[ICMP]](s1), [[OR15]], [[SHL17]]
+    ; CHECK: [[EXTRACT:%[0-9]+]]:_(s64) = G_EXTRACT [[UV1]](s136), 0
+    ; CHECK: [[EXTRACT1:%[0-9]+]]:_(s64) = G_EXTRACT [[UV1]](s136), 64
+    ; CHECK: [[EXTRACT2:%[0-9]+]]:_(s8) = G_EXTRACT [[UV1]](s136), 128
+    ; CHECK: [[EXTRACT3:%[0-9]+]]:_(s64) = G_EXTRACT [[SELECT1]](s136), 0
+    ; CHECK: [[EXTRACT4:%[0-9]+]]:_(s64) = G_EXTRACT [[SELECT1]](s136), 64
+    ; CHECK: [[EXTRACT5:%[0-9]+]]:_(s8) = G_EXTRACT [[SELECT1]](s136), 128
+    ; CHECK: [[SELECT2:%[0-9]+]]:_(s64) = G_SELECT [[ICMP1]](s1), [[EXTRACT]], [[EXTRACT3]]
+    ; CHECK: [[SELECT3:%[0-9]+]]:_(s64) = G_SELECT [[ICMP1]](s1), [[EXTRACT1]], [[EXTRACT4]]
+    ; CHECK: [[SELECT4:%[0-9]+]]:_(s8) = G_SELECT [[ICMP1]](s1), [[EXTRACT2]], [[EXTRACT5]]
+    ; CHECK: [[DEF:%[0-9]+]]:_(s136) = G_IMPLICIT_DEF
+    ; CHECK: [[INSERT:%[0-9]+]]:_(s136) = G_INSERT [[DEF]], [[SELECT2]](s64), 0
+    ; CHECK: [[INSERT1:%[0-9]+]]:_(s136) = G_INSERT [[INSERT]], [[SELECT3]](s64), 64
+    ; CHECK: [[INSERT2:%[0-9]+]]:_(s136) = G_INSERT [[INSERT1]], [[SELECT4]](s8), 128
+    ; CHECK: [[MV:%[0-9]+]]:_(s272) = G_MERGE_VALUES [[SELECT]](s136), [[INSERT2]](s136)
+    ; CHECK: [[EXTRACT6:%[0-9]+]]:_(s64) = G_EXTRACT [[OR14]](s272), 0
+    ; CHECK: [[EXTRACT7:%[0-9]+]]:_(s64) = G_EXTRACT [[OR14]](s272), 64
+    ; CHECK: [[EXTRACT8:%[0-9]+]]:_(s64) = G_EXTRACT [[OR14]](s272), 128
+    ; CHECK: [[EXTRACT9:%[0-9]+]]:_(s64) = G_EXTRACT [[OR14]](s272), 192
+    ; CHECK: [[EXTRACT10:%[0-9]+]]:_(s16) = G_EXTRACT [[OR14]](s272), 256
+    ; CHECK: [[EXTRACT11:%[0-9]+]]:_(s64) = G_EXTRACT [[MV]](s272), 0
+    ; CHECK: [[EXTRACT12:%[0-9]+]]:_(s64) = G_EXTRACT [[MV]](s272), 64
+    ; CHECK: [[EXTRACT13:%[0-9]+]]:_(s64) = G_EXTRACT [[MV]](s272), 128
+    ; CHECK: [[EXTRACT14:%[0-9]+]]:_(s64) = G_EXTRACT [[MV]](s272), 192
+    ; CHECK: [[EXTRACT15:%[0-9]+]]:_(s16) = G_EXTRACT [[MV]](s272), 256
+    ; CHECK: [[OR16:%[0-9]+]]:_(s64) = G_OR [[EXTRACT6]], [[EXTRACT11]]
+    ; CHECK: [[OR17:%[0-9]+]]:_(s64) = G_OR [[EXTRACT7]], [[EXTRACT12]]
+    ; CHECK: [[OR18:%[0-9]+]]:_(s64) = G_OR [[EXTRACT8]], [[EXTRACT13]]
+    ; CHECK: [[OR19:%[0-9]+]]:_(s64) = G_OR [[EXTRACT9]], [[EXTRACT14]]
+    ; CHECK: [[OR20:%[0-9]+]]:_(s16) = G_OR [[EXTRACT10]], [[EXTRACT15]]
+    ; CHECK: [[DEF1:%[0-9]+]]:_(s512) = G_IMPLICIT_DEF
+    ; CHECK: [[TRUNC11:%[0-9]+]]:_(s272) = G_TRUNC [[DEF1]](s512)
+    ; CHECK: [[ANYEXT:%[0-9]+]]:_(s512) = G_ANYEXT [[TRUNC11]](s272)
+    ; CHECK: [[INSERT3:%[0-9]+]]:_(s512) = G_INSERT [[ANYEXT]], [[OR16]](s64), 0
+    ; CHECK: [[TRUNC12:%[0-9]+]]:_(s272) = G_TRUNC [[INSERT3]](s512)
+    ; CHECK: [[ANYEXT1:%[0-9]+]]:_(s512) = G_ANYEXT [[TRUNC12]](s272)
+    ; CHECK: [[INSERT4:%[0-9]+]]:_(s512) = G_INSERT [[ANYEXT1]], [[OR17]](s64), 64
+    ; CHECK: [[TRUNC13:%[0-9]+]]:_(s272) = G_TRUNC [[INSERT4]](s512)
+    ; CHECK: [[ANYEXT2:%[0-9]+]]:_(s512) = G_ANYEXT [[TRUNC13]](s272)
+    ; CHECK: [[INSERT5:%[0-9]+]]:_(s512) = G_INSERT [[ANYEXT2]], [[OR18]](s64), 128
+    ; CHECK: [[TRUNC14:%[0-9]+]]:_(s272) = G_TRUNC [[INSERT5]](s512)
+    ; CHECK: [[ANYEXT3:%[0-9]+]]:_(s512) = G_ANYEXT [[TRUNC14]](s272)
+    ; CHECK: [[INSERT6:%[0-9]+]]:_(s512) = G_INSERT [[ANYEXT3]], [[OR19]](s64), 192
+    ; CHECK: [[TRUNC15:%[0-9]+]]:_(s272) = G_TRUNC [[INSERT6]](s512)
+    ; CHECK: [[ANYEXT4:%[0-9]+]]:_(s512) = G_ANYEXT [[TRUNC15]](s272)
+    ; CHECK: [[INSERT7:%[0-9]+]]:_(s512) = G_INSERT [[ANYEXT4]], [[OR20]](s16), 256
+    ; CHECK: [[TRUNC16:%[0-9]+]]:_(s272) = G_TRUNC [[INSERT7]](s512)
+    ; CHECK: [[UV2:%[0-9]+]]:_(s16), [[UV3:%[0-9]+]]:_(s16), [[UV4:%[0-9]+]]:_(s16), [[UV5:%[0-9]+]]:_(s16), [[UV6:%[0-9]+]]:_(s16), [[UV7:%[0-9]+]]:_(s16), [[UV8:%[0-9]+]]:_(s16), [[UV9:%[0-9]+]]:_(s16), [[UV10:%[0-9]+]]:_(s16), [[UV11:%[0-9]+]]:_(s16), [[UV12:%[0-9]+]]:_(s16), [[UV13:%[0-9]+]]:_(s16), [[UV14:%[0-9]+]]:_(s16), [[UV15:%[0-9]+]]:_(s16), [[UV16:%[0-9]+]]:_(s16), [[UV17:%[0-9]+]]:_(s16), [[UV18:%[0-9]+]]:_(s16) = G_UNMERGE_VALUES [[TRUNC16]](s272)
+    ; CHECK: [[TRUNC17:%[0-9]+]]:_(s1) = G_TRUNC [[UV2]](s16)
+    ; CHECK: [[UV19:%[0-9]+]]:_(s1), [[UV20:%[0-9]+]]:_(s1), [[UV21:%[0-9]+]]:_(s1), [[UV22:%[0-9]+]]:_(s1), [[UV23:%[0-9]+]]:_(s1), [[UV24:%[0-9]+]]:_(s1), [[UV25:%[0-9]+]]:_(s1), [[UV26:%[0-9]+]]:_(s1), [[UV27:%[0-9]+]]:_(s1), [[UV28:%[0-9]+]]:_(s1), [[UV29:%[0-9]+]]:_(s1), [[UV30:%[0-9]+]]:_(s1), [[UV31:%[0-9]+]]:_(s1), [[UV32:%[0-9]+]]:_(s1), [[UV33:%[0-9]+]]:_(s1), [[UV34:%[0-9]+]]:_(s1), [[UV35:%[0-9]+]]:_(s1) = G_UNMERGE_VALUES [[TRUNC5]](s17)
+    ; CHECK: [[TRUNC18:%[0-9]+]]:_(s1) = G_TRUNC [[UV3]](s16)
+    ; CHECK: [[UV36:%[0-9]+]]:_(s1), [[UV37:%[0-9]+]]:_(s1), [[UV38:%[0-9]+]]:_(s1), [[UV39:%[0-9]+]]:_(s1), [[UV40:%[0-9]+]]:_(s1), [[UV41:%[0-9]+]]:_(s1), [[UV42:%[0-9]+]]:_(s1), [[UV43:%[0-9]+]]:_(s1), [[UV44:%[0-9]+]]:_(s1), [[UV45:%[0-9]+]]:_(s1), [[UV46:%[0-9]+]]:_(s1), [[UV47:%[0-9]+]]:_(s1), [[UV48:%[0-9]+]]:_(s1), [[UV49:%[0-9]+]]:_(s1), [[UV50:%[0-9]+]]:_(s1), [[UV51:%[0-9]+]]:_(s1), [[UV52:%[0-9]+]]:_(s1) = G_UNMERGE_VALUES [[TRUNC8]](s17)
+    ; CHECK: [[TRUNC19:%[0-9]+]]:_(s1) = G_TRUNC [[UV4]](s16)
+    ; CHECK: [[UV53:%[0-9]+]]:_(s1), [[UV54:%[0-9]+]]:_(s1), [[UV55:%[0-9]+]]:_(s1), [[UV56:%[0-9]+]]:_(s1), [[UV57:%[0-9]+]]:_(s1), [[UV58:%[0-9]+]]:_(s1), [[UV59:%[0-9]+]]:_(s1), [[UV60:%[0-9]+]]:_(s1), [[UV61:%[0-9]+]]:_(s1), [[UV62:%[0-9]+]]:_(s1), [[UV63:%[0-9]+]]:_(s1), [[UV64:%[0-9]+]]:_(s1), [[UV65:%[0-9]+]]:_(s1), [[UV66:%[0-9]+]]:_(s1), [[UV67:%[0-9]+]]:_(s1), [[UV68:%[0-9]+]]:_(s1), [[UV69:%[0-9]+]]:_(s1) = G_UNMERGE_VALUES [[TRUNC9]](s17)
+    ; CHECK: [[TRUNC20:%[0-9]+]]:_(s1) = G_TRUNC [[UV5]](s16)
+    ; CHECK: [[DEF2:%[0-9]+]]:_(s1) = G_IMPLICIT_DEF
+    ; CHECK: [[TRUNC21:%[0-9]+]]:_(s1) = G_TRUNC [[UV6]](s16)
+    ; CHECK: [[MV1:%[0-9]+]]:_(s32) = G_MERGE_VALUES [[TRUNC17]](s1), [[TRUNC18]](s1), [[TRUNC19]](s1), [[TRUNC20]](s1), [[TRUNC21]](s1), %14(s1), %15(s1), %16(s1), %17(s1), %18(s1), %19(s1), [[TRUNC]](s1), [[TRUNC1]](s1), [[TRUNC3]](s1), [[TRUNC4]](s1), [[TRUNC6]](s1), [[TRUNC7]](s1), [[UV19]](s1), [[UV20]](s1), [[UV21]](s1), [[UV22]](s1), [[UV23]](s1), [[UV24]](s1), [[UV25]](s1), [[UV26]](s1), [[UV27]](s1), [[UV28]](s1), [[UV29]](s1), [[UV30]](s1), [[UV31]](s1), [[UV32]](s1), [[UV33]](s1)
+    ; CHECK: [[TRUNC22:%[0-9]+]]:_(s1) = G_TRUNC [[UV7]](s16)
+    ; CHECK: [[MV2:%[0-9]+]]:_(s32) = G_MERGE_VALUES [[UV34]](s1), [[UV35]](s1), [[UV36]](s1), [[UV37]](s1), [[UV38]](s1), [[UV39]](s1), [[UV40]](s1), [[UV41]](s1), [[UV42]](s1), [[UV43]](s1), [[UV44]](s1), [[UV45]](s1), [[UV46]](s1), [[UV47]](s1), [[UV48]](s1), [[UV49]](s1), [[UV50]](s1), [[UV51]](s1), [[UV52]](s1), [[UV53]](s1), [[UV54]](s1), [[UV55]](s1), [[UV56]](s1), [[UV57]](s1), [[UV58]](s1), [[UV59]](s1), [[UV60]](s1), [[UV61]](s1), [[UV62]](s1), [[UV63]](s1), [[UV64]](s1), [[UV65]](s1)
+    ; CHECK: [[TRUNC23:%[0-9]+]]:_(s1) = G_TRUNC [[UV8]](s16)
+    ; CHECK: [[MV3:%[0-9]+]]:_(s32) = G_MERGE_VALUES [[UV66]](s1), [[UV67]](s1), [[UV68]](s1), [[UV69]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1), [[DEF2]](s1)
+    ; CHECK: [[TRUNC24:%[0-9]+]]:_(s1) = G_TRUNC [[UV9]](s16)
+    ; CHECK: [[MV4:%[0-9]+]]:_(s96) = G_MERGE_VALUES [[MV1]](s32), [[MV2]](s32), [[MV3]](s32)
+    ; CHECK: [[TRUNC25:%[0-9]+]]:_(s1) = G_TRUNC [[UV10]](s16)
+    ; CHECK: [[TRUNC26:%[0-9]+]]:_(s68) = G_TRUNC [[MV4]](s96)
+    ; CHECK: [[TRUNC27:%[0-9]+]]:_(s1) = G_TRUNC [[UV11]](s16)
+    ; CHECK: S_NOP 0, implicit [[TRUNC26]](s68)
+    ; CHECK: [[TRUNC28:%[0-9]+]]:_(s1) = G_TRUNC [[UV12]](s16)
+    %0:_(s17) = G_CONSTANT i17 0
+    %1:_(s17) = G_CONSTANT i17 1
+    %2:_(s17) = G_CONSTANT i17 2
+    %3:_(s17) = G_CONSTANT i17 3
+    %4:_(s68) = G_MERGE_VALUES %0, %1, %2, %3
+    S_NOP 0, implicit %4
+...

diff --git a/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp b/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
index 608c0ddf0847554c1f5f3e7148095d2ab7846388..2776f75fe1af4b785f7df148577750016dc47d64 100644 (file)
--- a/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
+++ b/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
@@ -908,8 +908,12 @@ TEST_F(GISelMITest, LowerMergeValues) {
   if (!TM)
     return;
 
+  const LLT S32 = LLT::scalar(32);
   const LLT S24 = LLT::scalar(24);
+  const LLT S21 = LLT::scalar(21);
+  const LLT S16 = LLT::scalar(16);
   const LLT S9 = LLT::scalar(9);
+  const LLT S8 = LLT::scalar(8);
   const LLT S3 = LLT::scalar(3);
 
   DefineLegalizerInfo(A, {
@@ -925,13 +929,80 @@ TEST_F(GISelMITest, LowerMergeValues) {
   // 24 = 3 3 3   3 3 3   3 3
   //     => 9
   //
-  // This can do 2 merges for the first parts, but has 2 leftover operands.
-  SmallVector<Register, 7> MergeOps;
+  // This can do 3 merges, but need an extra implicit_def.
+  SmallVector<Register, 8> Merge0Ops;
   for (int I = 0; I != 8; ++I)
-    MergeOps.push_back(B.buildConstant(S3, I).getReg(0));
+    Merge0Ops.push_back(B.buildConstant(S3, I).getReg(0));
 
-  auto Merge = B.buildMerge(S24, MergeOps);
-  EXPECT_EQ(LegalizerHelper::LegalizeResult::UnableToLegalize,
-            Helper.lower(*Merge, 1, S9));
+  auto Merge0 = B.buildMerge(S24, Merge0Ops);
+
+  // 21 = 3 3 3   3 3 3   3
+  //     => 9, 2 extra implicit_def needed
+  //
+  SmallVector<Register, 8> Merge1Ops;
+  for (int I = 0; I != 7; ++I)
+    Merge1Ops.push_back(B.buildConstant(S3, I).getReg(0));
+
+  auto Merge1 = B.buildMerge(S21, Merge1Ops);
+
+  SmallVector<Register, 8> Merge2Ops;
+  for (int I = 0; I != 2; ++I)
+    Merge2Ops.push_back(B.buildConstant(S8, I).getReg(0));
+
+    auto Merge2 = B.buildMerge(S16, Merge2Ops);
+
+
+  EXPECT_EQ(LegalizerHelper::LegalizeResult::Legalized,
+            Helper.widenScalar(*Merge0, 1, S9));
+  EXPECT_EQ(LegalizerHelper::LegalizeResult::Legalized,
+            Helper.widenScalar(*Merge1, 1, S9));
+
+  // Request a source size greater than the original destination size.
+  EXPECT_EQ(LegalizerHelper::LegalizeResult::Legalized,
+            Helper.widenScalar(*Merge2, 1, S32));
+
+  auto CheckStr = R"(
+  CHECK: [[K0:%[0-9]+]]:_(s3) = G_CONSTANT i3 0
+  CHECK-NEXT: [[K1:%[0-9]+]]:_(s3) = G_CONSTANT i3 1
+  CHECK-NEXT: [[K2:%[0-9]+]]:_(s3) = G_CONSTANT i3 2
+  CHECK-NEXT: [[K3:%[0-9]+]]:_(s3) = G_CONSTANT i3 3
+  CHECK-NEXT: [[K4:%[0-9]+]]:_(s3) = G_CONSTANT i3 -4
+  CHECK-NEXT: [[K5:%[0-9]+]]:_(s3) = G_CONSTANT i3 -3
+  CHECK-NEXT: [[K6:%[0-9]+]]:_(s3) = G_CONSTANT i3 -2
+  CHECK-NEXT: [[K7:%[0-9]+]]:_(s3) = G_CONSTANT i3 -1
+  CHECK-NEXT: [[IMPDEF0:%[0-9]+]]:_(s3) = G_IMPLICIT_DEF
+  CHECK-NEXT: [[MERGE0:%[0-9]+]]:_(s9) = G_MERGE_VALUES [[K0]]:_(s3), [[K1]]:_(s3), [[K2]]:_(s3)
+  CHECK-NEXT: [[MERGE1:%[0-9]+]]:_(s9) = G_MERGE_VALUES [[K3]]:_(s3), [[K4]]:_(s3), [[K5]]:_(s3)
+  CHECK-NEXT: [[MERGE2:%[0-9]+]]:_(s9) = G_MERGE_VALUES [[K6]]:_(s3), [[K7]]:_(s3), [[IMPDEF0]]:_(s3)
+  CHECK-NEXT: [[MERGE3:%[0-9]+]]:_(s27) = G_MERGE_VALUES [[MERGE0]]:_(s9), [[MERGE1]]:_(s9), [[MERGE2]]:_(s9)
+  CHECK-NEXT: (s24) = G_TRUNC [[MERGE3]]:_(s27)
+
+
+  CHECK: [[K8:%[0-9]+]]:_(s3) = G_CONSTANT i3 0
+  CHECK-NEXT: [[K9:%[0-9]+]]:_(s3) = G_CONSTANT i3 1
+  CHECK-NEXT: [[K10:%[0-9]+]]:_(s3) = G_CONSTANT i3 2
+  CHECK-NEXT: [[K11:%[0-9]+]]:_(s3) = G_CONSTANT i3 3
+  CHECK-NEXT: [[K12:%[0-9]+]]:_(s3) = G_CONSTANT i3 -4
+  CHECK-NEXT: [[K13:%[0-9]+]]:_(s3) = G_CONSTANT i3 -3
+  CHECK-NEXT: [[K14:%[0-9]+]]:_(s3) = G_CONSTANT i3 -2
+  CHECK-NEXT: [[IMPDEF1:%[0-9]+]]:_(s3) = G_IMPLICIT_DEF
+  CHECK-NEXT: [[MERGE4:%[0-9]+]]:_(s9) = G_MERGE_VALUES [[K8]]:_(s3), [[K9]]:_(s3), [[K10]]:_(s3)
+  CHECK-NEXT: [[MERGE5:%[0-9]+]]:_(s9) = G_MERGE_VALUES [[K11]]:_(s3), [[K12]]:_(s3), [[K13]]:_(s3)
+  CHECK-NEXT: [[MERGE6:%[0-9]+]]:_(s9) = G_MERGE_VALUES [[K14]]:_(s3), [[IMPDEF1]]:_(s3), [[IMPDEF1]]:_(s3)
+  CHECK-NEXT: [[MERGE7:%[0-9]+]]:_(s27) = G_MERGE_VALUES [[MERGE4]]:_(s9), [[MERGE5]]:_(s9), [[MERGE6]]:_(s9)
+  CHECK-NEXT: (s21) = G_TRUNC [[MERGE7]]:_(s27)
+
+
+  CHECK: [[K15:%[0-9]+]]:_(s8) = G_CONSTANT i8 0
+  CHECK-NEXT: [[K16:%[0-9]+]]:_(s8) = G_CONSTANT i8 1
+  CHECK-NEXT: [[ZEXT_K15:[0-9]+]]:_(s32) = G_ZEXT [[K15]]:_(s8)
+  CHECK-NEXT: [[ZEXT_K16:[0-9]+]]:_(s32) = G_ZEXT [[K16]]:_(s8)
+  [[K16:%[0-9]+]]:_(s32) = G_CONSTANT i32 8
+  [[SHL:%[0-9]+]]:_(s32) = G_SHL [[ZEXT_K16]]:_, [[K16]]:_(s32)
+  [[OR:%[0-9]+]]:_(s32) = G_OR [[ZEXT_K16]]:_, [[SHL]]:_
+  (s16) = G_TRUNC [[OR]]:_(s32)
+  )";
+
+  EXPECT_TRUE(CheckMachineFunction(*MF, CheckStr)) << *MF;
 }
 } // namespace