From 591eab88442690bb4f07a4683015d01e58f7f997 Mon Sep 17 00:00:00 2001
From: Bill Wendling <isanbard@gmail.com>
Date: Tue, 24 Apr 2007 21:16:55 +0000
Subject: [PATCH] Support for the special case of a vector with the canonical
 form:

        vector_shuffle v1, v2, <2, 6, 3, 7>

I.e.

         vector_shuffle v, undef, <2, 2, 3, 3>

MMX only has a shuffle for v4i16 vectors. It needs to use the unpackh for
this type of operation.

llvm-svn: 36403
---
 llvm/lib/Target/X86/X86ISelLowering.cpp | 32 +++++++++++++++++++++++--
 llvm/lib/Target/X86/X86ISelLowering.h   |  5 ++++
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index e63545d88778..996ffe94ecc0 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -379,6 +379,8 @@ X86TargetLowering::X86TargetLowering(TargetMachine &TM)
 
     setOperationAction(ISD::SCALAR_TO_VECTOR,   MVT::v8i8,  Custom);
     setOperationAction(ISD::SCALAR_TO_VECTOR,   MVT::v4i16, Custom);
+    setOperationAction(ISD::SCALAR_TO_VECTOR,   MVT::v2i32, Custom);
+    setOperationAction(ISD::SCALAR_TO_VECTOR,   MVT::v1i64, Custom);
   }
 
   if (Subtarget->hasSSE1()) {
@@ -1776,7 +1778,7 @@ bool X86::isUNPCKL_v_undef_Mask(SDNode *N) {
   assert(N->getOpcode() == ISD::BUILD_VECTOR);
 
   unsigned NumElems = N->getNumOperands();
-  if (NumElems != 4 && NumElems != 8 && NumElems != 16)
+  if (NumElems != 2 && NumElems != 4 && NumElems != 8 && NumElems != 16)
     return false;
 
   for (unsigned i = 0, j = 0; i != NumElems; i += 2, ++j) {
@@ -1792,6 +1794,29 @@ bool X86::isUNPCKL_v_undef_Mask(SDNode *N) {
   return true;
 }
 
+/// isUNPCKH_v_undef_Mask - Special case of isUNPCKHMask for canonical form
+/// of vector_shuffle v, v, <2, 6, 3, 7>, i.e. vector_shuffle v, undef,
+/// <2, 2, 3, 3>
+bool X86::isUNPCKH_v_undef_Mask(SDNode *N) {
+  assert(N->getOpcode() == ISD::BUILD_VECTOR);
+
+  unsigned NumElems = N->getNumOperands();
+  if (NumElems != 2 && NumElems != 4 && NumElems != 8 && NumElems != 16)
+    return false;
+
+  for (unsigned i = 0, j = NumElems / 2; i != NumElems; i += 2, ++j) {
+    SDOperand BitI  = N->getOperand(i);
+    SDOperand BitI1 = N->getOperand(i + 1);
+
+    if (!isUndefOrEqual(BitI, j))
+      return false;
+    if (!isUndefOrEqual(BitI1, j))
+      return false;
+  }
+
+  return true;
+}
+
 /// isMOVLMask - Return true if the specified VECTOR_SHUFFLE operand
 /// specifies a shuffle of elements that is suitable for input to MOVSS,
 /// MOVSD, and MOVD, i.e. setting the lowest element.
@@ -2432,7 +2457,7 @@ X86TargetLowering::LowerBUILD_VECTOR(SDOperand Op, SelectionDAG &DAG) {
     }
   }
 
-  // Let legalizer expand 2-wide build_vector's.
+  // Let legalizer expand 2-wide build_vectors.
   if (EVTBits == 64)
     return SDOperand();
 
@@ -2591,6 +2616,7 @@ X86TargetLowering::LowerVECTOR_SHUFFLE(SDOperand Op, SelectionDAG &DAG) {
   }
 
   if (X86::isUNPCKL_v_undef_Mask(PermMask.Val) ||
+      X86::isUNPCKH_v_undef_Mask(PermMask.Val) ||
       X86::isUNPCKLMask(PermMask.Val) ||
       X86::isUNPCKHMask(PermMask.Val))
     return Op;
@@ -2619,6 +2645,7 @@ X86TargetLowering::LowerVECTOR_SHUFFLE(SDOperand Op, SelectionDAG &DAG) {
     // Commute is back and try unpck* again.
     Op = CommuteVectorShuffle(Op, V1, V2, PermMask, DAG);
     if (X86::isUNPCKL_v_undef_Mask(PermMask.Val) ||
+        X86::isUNPCKH_v_undef_Mask(PermMask.Val) ||
         X86::isUNPCKLMask(PermMask.Val) ||
         X86::isUNPCKHMask(PermMask.Val))
       return Op;
@@ -4231,6 +4258,7 @@ X86TargetLowering::isShuffleMaskLegal(SDOperand Mask, MVT::ValueType VT) const {
           isPSHUFHW_PSHUFLWMask(Mask.Val) ||
           X86::isUNPCKLMask(Mask.Val) ||
           X86::isUNPCKL_v_undef_Mask(Mask.Val) ||
+          X86::isUNPCKH_v_undef_Mask(Mask.Val) ||
           X86::isUNPCKHMask(Mask.Val));
 }
 
diff --git a/llvm/lib/Target/X86/X86ISelLowering.h b/llvm/lib/Target/X86/X86ISelLowering.h
index 88064d37c6e6..87022faab42c 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.h
+++ b/llvm/lib/Target/X86/X86ISelLowering.h
@@ -231,6 +231,11 @@ namespace llvm {
    /// <0, 0, 1, 1>
    bool isUNPCKL_v_undef_Mask(SDNode *N);
 
+   /// isUNPCKH_v_undef_Mask - Special case of isUNPCKHMask for canonical form
+   /// of vector_shuffle v, v, <2, 6, 3, 7>, i.e. vector_shuffle v, undef,
+   /// <2, 2, 3, 3>
+   bool isUNPCKH_v_undef_Mask(SDNode *N);
+
    /// isMOVLMask - Return true if the specified VECTOR_SHUFFLE operand
    /// specifies a shuffle of elements that is suitable for input to MOVSS,
    /// MOVSD, and MOVD, i.e. setting the lowest element.