1 files changed, 54 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 3da0d846f19..611bb5dc802 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -1244,6 +1244,55 @@ LegalizerHelper::lower(MachineInstr &MI, unsigned TypeIdx, LLT Ty) {
 }
 
 LegalizerHelper::LegalizeResult
+LegalizerHelper::fewerElementsVectorCasts(MachineInstr &MI, unsigned TypeIdx,
+                                          LLT NarrowTy) {
+  if (TypeIdx != 0)
+    return UnableToLegalize;
+
+  unsigned DstReg = MI.getOperand(0).getReg();
+  unsigned SrcReg = MI.getOperand(1).getReg();
+  LLT DstTy = MRI.getType(DstReg);
+  LLT SrcTy = MRI.getType(SrcReg);
+
+  LLT NarrowTy0 = NarrowTy;
+  LLT NarrowTy1;
+  unsigned NumParts;
+
+  if (NarrowTy.isScalar()) {
+    NumParts = DstTy.getNumElements();
+    NarrowTy1 = SrcTy.getElementType();
+  } else {
+    // Uneven breakdown not handled.
+    NumParts = DstTy.getNumElements() / NarrowTy.getNumElements();
+    if (NumParts * NarrowTy.getNumElements() != DstTy.getNumElements())
+      return UnableToLegalize;
+
+    NarrowTy1 = LLT::vector(NumParts, SrcTy.getElementType().getSizeInBits());
+  }
+
+  SmallVector<unsigned, 4> SrcRegs, DstRegs;
+  extractParts(SrcReg, NarrowTy1, NumParts, SrcRegs);
+
+  for (unsigned I = 0; I < NumParts; ++I) {
+    unsigned DstReg = MRI.createGenericVirtualRegister(NarrowTy0);
+    MachineInstr *NewInst = MIRBuilder.buildInstr(MI.getOpcode())
+      .addDef(DstReg)
+      .addUse(SrcRegs[I]);
+
+    NewInst->setFlags(MI.getFlags());
+    DstRegs.push_back(DstReg);
+  }
+
+  if (NarrowTy.isVector())
+    MIRBuilder.buildConcatVectors(DstReg, DstRegs);
+  else
+    MIRBuilder.buildBuildVector(DstReg, DstRegs);
+
+  MI.eraseFromParent();
+  return Legalized;
+}
+
+LegalizerHelper::LegalizeResult
 LegalizerHelper::fewerElementsVector(MachineInstr &MI, unsigned TypeIdx,
                                      LLT NarrowTy) {
   // FIXME: Don't know how to handle secondary types yet.
@@ -1377,6 +1426,11 @@ LegalizerHelper::fewerElementsVector(MachineInstr &MI, unsigned TypeIdx,
     MI.eraseFromParent();
     return Legalized;
   }
+  case TargetOpcode::G_ZEXT:
+  case TargetOpcode::G_SEXT:
+  case TargetOpcode::G_ANYEXT:
+  case TargetOpcode::G_FPEXT:
+    return fewerElementsVectorCasts(MI, TypeIdx, NarrowTy);
   }
 }