Recognize Neon VDUP shuffles during legalization instead of selection.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78852 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 18 insertions, 23 deletions

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index f348fe2021..f2b6686e36 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -487,6 +487,7 @@ const char *ARMTargetLowering::getTargetNodeName(unsigned Opcode) const {
   case ARMISD::VREV64:        return "ARMISD::VREV64";
   case ARMISD::VREV32:        return "ARMISD::VREV32";
   case ARMISD::VREV16:        return "ARMISD::VREV16";
+  case ARMISD::VSPLAT0:       return "ARMISD::VSPLAT0";
   }
 }
 
@@ -2440,6 +2441,8 @@ static SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) {
   DebugLoc dl = Op.getDebugLoc();
   EVT VT = Op.getValueType();
 
+  if (SVN->isSplat() && SVN->getSplatIndex() == 0)
+    return DAG.getNode(ARMISD::VSPLAT0, dl, VT, SVN->getOperand(0));
   if (isVREVMask(SVN, 64))
     return DAG.getNode(ARMISD::VREV64, dl, VT, SVN->getOperand(0));
   if (isVREVMask(SVN, 32))
diff --git a/lib/Target/ARM/ARMISelLowering.h b/lib/Target/ARM/ARMISelLowering.h
index 328959a24d..57f3c4d012 100644
--- a/lib/Target/ARM/ARMISelLowering.h
+++ b/lib/Target/ARM/ARMISelLowering.h
@@ -129,7 +129,8 @@ namespace llvm {
       // Vector shuffles:
       VREV64,       // reverse elements within 64-bit doublewords
       VREV32,       // reverse elements within 32-bit words
-      VREV16        // reverse elements within 16-bit halfwords
+      VREV16,       // reverse elements within 16-bit halfwords
+      VSPLAT0       // duplicate element 0 into all elements
     };
   }
 
diff --git a/lib/Target/ARM/ARMInstrNEON.td b/lib/Target/ARM/ARMInstrNEON.td
index 7654be7b3f..38e8800e03 100644
--- a/lib/Target/ARM/ARMInstrNEON.td
+++ b/lib/Target/ARM/ARMInstrNEON.td
@@ -99,6 +99,7 @@ def SDTARMVSHUF   : SDTypeProfile<1, 1, [SDTCisVec<0>, SDTCisSameAs<0, 1>]>;
 def NEONvrev64    : SDNode<"ARMISD::VREV64", SDTARMVSHUF>;
 def NEONvrev32    : SDNode<"ARMISD::VREV32", SDTARMVSHUF>;
 def NEONvrev16    : SDNode<"ARMISD::VREV16", SDTARMVSHUF>;
+def NEONvsplat0   : SDNode<"ARMISD::VSPLAT0", SDTARMVSHUF>;
 
 //===----------------------------------------------------------------------===//
 // NEON operand definitions
@@ -1744,20 +1745,14 @@ def : Pat<(v2f64 (insertelt QPR:$src1, DPR:$src2, imm:$src3)),
 
 //   VDUP     : Vector Duplicate (from ARM core register to all elements)
 
-def splat_lo : PatFrag<(ops node:$lhs, node:$rhs),
-                       (vector_shuffle node:$lhs, node:$rhs), [{
-  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(N);
-  return SVOp->isSplat() && SVOp->getSplatIndex() == 0;
-}]>;
-
 class VDUPD<bits<8> opcod1, bits<2> opcod3, string asmSize, ValueType Ty>
   : NVDup<opcod1, 0b1011, opcod3, (outs DPR:$dst), (ins GPR:$src),
           NoItinerary, "vdup", !strconcat(asmSize, "\t$dst, $src"),
-          [(set DPR:$dst, (Ty (splat_lo (scalar_to_vector GPR:$src), undef)))]>;
+          [(set DPR:$dst, (Ty (NEONvsplat0 (scalar_to_vector GPR:$src))))]>;
 class VDUPQ<bits<8> opcod1, bits<2> opcod3, string asmSize, ValueType Ty>
   : NVDup<opcod1, 0b1011, opcod3, (outs QPR:$dst), (ins GPR:$src),
           NoItinerary, "vdup", !strconcat(asmSize, "\t$dst, $src"),
-          [(set QPR:$dst, (Ty (splat_lo (scalar_to_vector GPR:$src), undef)))]>;
+          [(set QPR:$dst, (Ty (NEONvsplat0 (scalar_to_vector GPR:$src))))]>;
 
 def  VDUP8d   : VDUPD<0b11101100, 0b00, ".8", v8i8>;
 def  VDUP16d  : VDUPD<0b11101000, 0b01, ".16", v4i16>;
@@ -1768,16 +1763,14 @@ def  VDUP32q  : VDUPQ<0b11101010, 0b00, ".32", v4i32>;
 
 def  VDUPfd   : NVDup<0b11101000, 0b1011, 0b00, (outs DPR:$dst), (ins GPR:$src),
                       NoItinerary, "vdup", ".32\t$dst, $src",
-                      [(set DPR:$dst, (v2f32 (splat_lo
-                                              (scalar_to_vector
-                                               (f32 (bitconvert GPR:$src))),
-                                              undef)))]>;
+                      [(set DPR:$dst,
+                        (v2f32 (NEONvsplat0 (scalar_to_vector
+                                             (f32 (bitconvert GPR:$src))))))]>;
 def  VDUPfq   : NVDup<0b11101010, 0b1011, 0b00, (outs QPR:$dst), (ins GPR:$src),
                       NoItinerary, "vdup", ".32\t$dst, $src",
-                      [(set QPR:$dst, (v4f32 (splat_lo
-                                              (scalar_to_vector
-                                               (f32 (bitconvert GPR:$src))),
-                                              undef)))]>;
+                      [(set QPR:$dst,
+                        (v4f32 (NEONvsplat0 (scalar_to_vector
+                                             (f32 (bitconvert GPR:$src))))))]>;
 
 //   VDUP     : Vector Duplicate Lane (from scalar to all elements)
 
@@ -1819,16 +1812,14 @@ def VDUPLNfq  : VDUPLNQ<0b01, 0b00, "vdup.32", v4f32, v2f32>;
 def VDUPfdf   : N2V<0b11, 0b11, 0b01, 0b00, 0b11000, 0, 0,
                     (outs DPR:$dst), (ins SPR:$src),
                     NoItinerary, "vdup.32\t$dst, ${src:lane}", "",
-                    [(set DPR:$dst, (v2f32 (splat_lo
-                                            (scalar_to_vector SPR:$src),
-                                            undef)))]>;
+                    [(set DPR:$dst, (v2f32 (NEONvsplat0
+                                            (scalar_to_vector SPR:$src))))]>;
 
 def VDUPfqf   : N2V<0b11, 0b11, 0b01, 0b00, 0b11000, 1, 0,
                     (outs QPR:$dst), (ins SPR:$src),
                     NoItinerary, "vdup.32\t$dst, ${src:lane}", "",
-                    [(set QPR:$dst, (v4f32 (splat_lo
-                                            (scalar_to_vector SPR:$src),
-                                            undef)))]>;
+                    [(set QPR:$dst, (v4f32 (NEONvsplat0
+                                            (scalar_to_vector SPR:$src))))]>;
 
 //   VMOVN    : Vector Narrowing Move
 defm VMOVN    : N2VNInt_HSD<0b11,0b11,0b10,0b00100,0,0, "vmovn.i",