X86: deduplicate V[SZ]EXT_MOVL and V[SZ]EXT nodes

I believe VZEXT_MOVL means "zero all vector elements except the first" (and
should have identical input & output types) whereas VZEXT means "zero extend
each element of a vector (discarding higher elements if necessary)".

For example:
    (v4i32 (vzext (v16i8 ...)))

should zero extend the low 4 bytes of the incoming vector to 32-bits,
discarding higher bytes.

However, somewhere in the past, these two concepts had become confused, even
leading to a nonsensical VSEXT_MOVL.

This re-merges the nodes where appropriate (all VSEXT_MOVL -> VSEXT, VZEXT_MOVL
-> VZEXT when it's an actual extension).

rdar://problem/15981990

llvm-svn: 200918

1 files changed, 4 insertions, 5 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 5dca225593f..a945284fa6e 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -9032,7 +9032,7 @@ static SDValue LowerAVXExtend(SDValue Op, SelectionDAG &DAG,
     return SDValue();
 
   if (Subtarget->hasInt256())
-    return DAG.getNode(X86ISD::VZEXT_MOVL, dl, VT, In);
+    return DAG.getNode(X86ISD::VZEXT, dl, VT, In);
 
   SDValue ZeroVec = getZeroVector(InVT, Subtarget, DAG, dl);
   SDValue Undef = DAG.getUNDEF(InVT);
@@ -10617,7 +10617,7 @@ static SDValue LowerSIGN_EXTEND(SDValue Op, const X86Subtarget *Subtarget,
     return SDValue();
 
   if (Subtarget->hasInt256())
-    return DAG.getNode(X86ISD::VSEXT_MOVL, dl, VT, In);
+    return DAG.getNode(X86ISD::VSEXT, dl, VT, In);
 
   // Optimize vectors in AVX mode
   // Sign extend  v8i16 to v8i32 and
@@ -10646,8 +10646,8 @@ static SDValue LowerSIGN_EXTEND(SDValue Op, const X86Subtarget *Subtarget,
   MVT HalfVT = MVT::getVectorVT(VT.getScalarType(),
                                 VT.getVectorNumElements()/2);
 
-  OpLo = DAG.getNode(X86ISD::VSEXT_MOVL, dl, HalfVT, OpLo);
-  OpHi = DAG.getNode(X86ISD::VSEXT_MOVL, dl, HalfVT, OpHi);
+  OpLo = DAG.getNode(X86ISD::VSEXT, dl, HalfVT, OpLo);
+  OpHi = DAG.getNode(X86ISD::VSEXT, dl, HalfVT, OpHi);
 
   return DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, OpLo, OpHi);
 }
@@ -14017,7 +14017,6 @@ const char *X86TargetLowering::getTargetNodeName(unsigned Opcode) const {
   case X86ISD::ATOMAND64_DAG:      return "X86ISD::ATOMAND64_DAG";
   case X86ISD::ATOMNAND64_DAG:     return "X86ISD::ATOMNAND64_DAG";
   case X86ISD::VZEXT_MOVL:         return "X86ISD::VZEXT_MOVL";
-  case X86ISD::VSEXT_MOVL:         return "X86ISD::VSEXT_MOVL";
   case X86ISD::VZEXT_LOAD:         return "X86ISD::VZEXT_LOAD";
   case X86ISD::VZEXT:              return "X86ISD::VZEXT";
   case X86ISD::VSEXT:              return "X86ISD::VSEXT";