From: Simon Pilgrim <llvm-dev@redking.me.uk>
Date: Sat, 1 Oct 2016 16:04:28 +0000 (+0000)
Subject: [X86][SSE] Add support for combining target shuffles to binary BLEND
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=20e8247890f6a0ad2ec911531742551a6035388a;p=llvm

[X86][SSE] Add support for combining target shuffles to binary BLEND

We already had support for 1-input BLEND with zero - this adds support for 2-input BLEND as well.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283040 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 6c8def1c397..cd1ff4de70f 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -25160,7 +25160,7 @@ static bool matchBinaryPermuteVectorShuffle(MVT MaskVT, ArrayRef<int> Mask,
     }
   }
 
-  // Attempt to blend with zero.
+  // Attempt to combine to X86ISD::BLENDI.
   if (NumMaskElts <= 8 && ((Subtarget.hasSSE41() && MaskVT.is128BitVector()) ||
                            (Subtarget.hasAVX() && MaskVT.is256BitVector()))) {
     // Determine a type compatible with X86ISD::BLENDI.
@@ -25180,12 +25180,13 @@ static bool matchBinaryPermuteVectorShuffle(MVT MaskVT, ArrayRef<int> Mask,
         BlendVT = MVT::v8f32;
     }
 
+    unsigned BlendSize = BlendVT.getVectorNumElements();
+    unsigned MaskRatio = BlendSize / NumMaskElts;
+
+    // Can we blend with zero?
     if (isSequentialOrUndefOrZeroInRange(Mask, /*Pos*/ 0, /*Size*/ NumMaskElts,
                                          /*Low*/ 0) &&
         NumMaskElts <= BlendVT.getVectorNumElements()) {
-      unsigned BlendSize = BlendVT.getVectorNumElements();
-      unsigned MaskRatio = BlendSize / NumMaskElts;
-
       PermuteImm = 0;
       for (unsigned i = 0; i != BlendSize; ++i)
         if (Mask[i / MaskRatio] < 0)
@@ -25196,6 +25197,31 @@ static bool matchBinaryPermuteVectorShuffle(MVT MaskVT, ArrayRef<int> Mask,
       ShuffleVT = BlendVT;
       return true;
     }
+
+    // Attempt to match as a binary blend.
+    if (NumMaskElts <= BlendVT.getVectorNumElements()) {
+      bool MatchBlend = true;
+      for (int i = 0; i != NumMaskElts; ++i) {
+        int M = Mask[i];
+        if (M == SM_SentinelUndef)
+          continue;
+        else if (M == SM_SentinelZero)
+          MatchBlend = false;
+        else if ((M != i) && (M != (i + NumMaskElts)))
+          MatchBlend = false;
+      }
+
+      if (MatchBlend) {
+        PermuteImm = 0;
+        for (unsigned i = 0; i != BlendSize; ++i)
+          if ((int)NumMaskElts <= Mask[i / MaskRatio])
+            PermuteImm |= 1u << i;
+
+        Shuffle = X86ISD::BLENDI;
+        ShuffleVT = BlendVT;
+        return true;
+      }
+    }
   }
 
   // Attempt to combine to INSERTPS.
diff --git a/test/CodeGen/X86/vector-shuffle-256-v16.ll b/test/CodeGen/X86/vector-shuffle-256-v16.ll
index 15da1ec6814..b2a202dc522 100644
--- a/test/CodeGen/X86/vector-shuffle-256-v16.ll
+++ b/test/CodeGen/X86/vector-shuffle-256-v16.ll
@@ -851,13 +851,11 @@ define <16 x i16> @shuffle_v16i16_16_16_16_16_04_05_06_07_24_24_24_24_12_13_14_1
 ; AVX1-LABEL: shuffle_v16i16_16_16_16_16_04_05_06_07_24_24_24_24_12_13_14_15:
 ; AVX1:       # BB#0:
 ; AVX1-NEXT:    vextractf128 $1, %ymm0, %xmm2
-; AVX1-NEXT:    vpshufd {{.*#+}} xmm2 = xmm2[2,3,0,1]
 ; AVX1-NEXT:    vextractf128 $1, %ymm1, %xmm3
 ; AVX1-NEXT:    vpshuflw {{.*#+}} xmm3 = xmm3[0,0,0,0,4,5,6,7]
-; AVX1-NEXT:    vpunpcklqdq {{.*#+}} xmm2 = xmm3[0],xmm2[0]
-; AVX1-NEXT:    vpshufd {{.*#+}} xmm0 = xmm0[2,3,0,1]
+; AVX1-NEXT:    vpblendw {{.*#+}} xmm2 = xmm3[0,1,2,3],xmm2[4,5,6,7]
 ; AVX1-NEXT:    vpshuflw {{.*#+}} xmm1 = xmm1[0,0,0,0,4,5,6,7]
-; AVX1-NEXT:    vpunpcklqdq {{.*#+}} xmm0 = xmm1[0],xmm0[0]
+; AVX1-NEXT:    vpblendw {{.*#+}} xmm0 = xmm1[0,1,2,3],xmm0[4,5,6,7]
 ; AVX1-NEXT:    vinsertf128 $1, %xmm2, %ymm0, %ymm0
 ; AVX1-NEXT:    retq
 ;
diff --git a/test/CodeGen/X86/vector-shuffle-256-v32.ll b/test/CodeGen/X86/vector-shuffle-256-v32.ll
index b0834dd2693..2b7e312d09c 100644
--- a/test/CodeGen/X86/vector-shuffle-256-v32.ll
+++ b/test/CodeGen/X86/vector-shuffle-256-v32.ll
@@ -1157,15 +1157,13 @@ define <32 x i8> @shuffle_v32i8_32_32_32_32_32_32_32_32_08_09_10_11_12_13_14_15_
 ; AVX1-LABEL: shuffle_v32i8_32_32_32_32_32_32_32_32_08_09_10_11_12_13_14_15_48_48_48_48_48_48_48_48_24_25_26_27_28_29_30_31:
 ; AVX1:       # BB#0:
 ; AVX1-NEXT:    vextractf128 $1, %ymm0, %xmm2
-; AVX1-NEXT:    vpshufd {{.*#+}} xmm2 = xmm2[2,3,0,1]
 ; AVX1-NEXT:    vextractf128 $1, %ymm1, %xmm3
 ; AVX1-NEXT:    vpunpcklbw {{.*#+}} xmm3 = xmm3[0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7]
 ; AVX1-NEXT:    vpshuflw {{.*#+}} xmm3 = xmm3[0,0,0,0,4,5,6,7]
-; AVX1-NEXT:    vpunpcklqdq {{.*#+}} xmm2 = xmm3[0],xmm2[0]
-; AVX1-NEXT:    vpshufd {{.*#+}} xmm0 = xmm0[2,3,0,1]
+; AVX1-NEXT:    vpblendw {{.*#+}} xmm2 = xmm3[0,1,2,3],xmm2[4,5,6,7]
 ; AVX1-NEXT:    vpunpcklbw {{.*#+}} xmm1 = xmm1[0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7]
 ; AVX1-NEXT:    vpshuflw {{.*#+}} xmm1 = xmm1[0,0,0,0,4,5,6,7]
-; AVX1-NEXT:    vpunpcklqdq {{.*#+}} xmm0 = xmm1[0],xmm0[0]
+; AVX1-NEXT:    vpblendw {{.*#+}} xmm0 = xmm1[0,1,2,3],xmm0[4,5,6,7]
 ; AVX1-NEXT:    vinsertf128 $1, %xmm2, %ymm0, %ymm0
 ; AVX1-NEXT:    retq
 ;