[llvm] r366660 - [X86] SimplifyDemandedVectorEltsForTargetNode - Move SUBV_BROADCAST narrowing handling. NFCI.

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Sun Jul 21 12:04:44 2019
New Revision: 366660

URL: http://llvm.org/viewvc/llvm-project?rev=366660&view=rev
Log:
[X86] SimplifyDemandedVectorEltsForTargetNode - Move SUBV_BROADCAST narrowing handling. NFCI.

Move the narrowing of SUBV_BROADCAST to where we handle all the other opcodes.

Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=366660&r1=366659&r2=366660&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Sun Jul 21 12:04:44 2019
@@ -34062,25 +34062,6 @@ bool X86TargetLowering::SimplifyDemanded
       return true;
     break;
   }
-  case X86ISD::SUBV_BROADCAST: {
-    // Reduce size of broadcast if we don't need the upper half.
-    unsigned HalfElts = NumElts / 2;
-    if (DemandedElts.extractBits(HalfElts, HalfElts).isNullValue()) {
-      SDValue Src = Op.getOperand(0);
-      MVT SrcVT = Src.getSimpleValueType();
-
-      SDValue Half = Src;
-      if (SrcVT.getVectorNumElements() != HalfElts) {
-        MVT HalfVT = MVT::getVectorVT(SrcVT.getScalarType(), HalfElts);
-        Half = TLO.DAG.getNode(X86ISD::SUBV_BROADCAST, SDLoc(Op), HalfVT, Src);
-      }
-
-      return TLO.CombineTo(Op, insertSubVector(TLO.DAG.getUNDEF(VT), Half, 0,
-                                               TLO.DAG, SDLoc(Op),
-                                               Half.getValueSizeInBits()));
-    }
-    break;
-  }
   case X86ISD::VPERMV: {
     SDValue Mask = Op.getOperand(0);
     APInt MaskUndef, MaskZero;
@@ -34135,6 +34116,19 @@ bool X86TargetLowering::SimplifyDemanded
           insertSubVector(UndefVec, ExtOp, 0, TLO.DAG, DL, ExtSizeInBits);
       return TLO.CombineTo(Op, Insert);
     }
+      // Subvector broadcast.
+    case X86ISD::SUBV_BROADCAST: {
+      SDLoc DL(Op);
+      SDValue Ext = Op.getOperand(0);
+      if (Ext.getValueSizeInBits() != ExtSizeInBits) {
+        MVT ExtSVT = Ext.getSimpleValueType().getScalarType();
+        MVT ExtVT =
+            MVT::getVectorVT(ExtSVT, ExtSizeInBits / ExtSVT.getSizeInBits());
+        Ext = TLO.DAG.getNode(X86ISD::SUBV_BROADCAST, DL, ExtVT, Ext);
+      }
+      return TLO.CombineTo(Op, insertSubVector(TLO.DAG.getUNDEF(VT), Ext, 0,
+                                               TLO.DAG, DL, ExtSizeInBits));
+    }
       // Byte shifts by immediate.
     case X86ISD::VSHLDQ:
     case X86ISD::VSRLDQ: