[llvm] r278228 - [X86][SSE] Add support for combining target shuffles to MOVSS/MOVSD

Simon Pilgrim via llvm-commits llvm-commits at lists.llvm.org
Wed Aug 10 07:15:42 PDT 2016


Author: rksimon
Date: Wed Aug 10 09:15:41 2016
New Revision: 278228

URL: http://llvm.org/viewvc/llvm-project?rev=278228&view=rev
Log:
[X86][SSE] Add support for combining target shuffles to MOVSS/MOVSD

Only do this on pre-SSE41 targets where we should be lowering to BLENDPS/BLENDPD instead

Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
    llvm/trunk/test/CodeGen/X86/vector-shuffle-combining-ssse3.ll

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=278228&r1=278227&r2=278228&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Wed Aug 10 09:15:41 2016
@@ -24975,6 +24975,7 @@ static bool matchUnaryPermuteVectorShuff
 // TODO: Investigate sharing more of this with shuffle lowering.
 static bool matchBinaryVectorShuffle(MVT MaskVT, ArrayRef<int> Mask,
                                      SDValue &V1, SDValue &V2,
+                                     const X86Subtarget &Subtarget,
                                      unsigned &Shuffle, MVT &ShuffleVT) {
   bool FloatDomain = MaskVT.isFloatingPoint();
 
@@ -24991,6 +24992,23 @@ static bool matchBinaryVectorShuffle(MVT
       ShuffleVT = MVT::v4f32;
       return true;
     }
+    if (isTargetShuffleEquivalent(Mask, {0, 3}) && FloatDomain) {
+      // On SSE41 targets use BLENDPD (its commutable).
+      if (Subtarget.hasSSE2() && !Subtarget.hasSSE41()) {
+        std::swap(V1, V2);
+        Shuffle = X86ISD::MOVSD;
+        ShuffleVT = MVT::v2f64;
+        return true;
+      }
+    }
+    if (isTargetShuffleEquivalent(Mask, {4, 1, 2, 3}) && FloatDomain) {
+      // On SSE41 targets use BLENDPS (its commutable).
+      if (!Subtarget.hasSSE41()) {
+        Shuffle = X86ISD::MOVSS;
+        ShuffleVT = MVT::v4f32;
+        return true;
+      }
+    }
     if (isTargetShuffleEquivalent(Mask, {0, 0, 1, 1}) && FloatDomain) {
       V2 = V1;
       Shuffle = X86ISD::UNPCKL;
@@ -25209,8 +25227,8 @@ static bool combineX86ShuffleChain(Array
       return true;
     }
 
-    if (matchUnaryPermuteVectorShuffle(MaskVT, Mask, Subtarget, Shuffle, ShuffleVT,
-                                       PermuteImm)) {
+    if (matchUnaryPermuteVectorShuffle(MaskVT, Mask, Subtarget, Shuffle,
+                                       ShuffleVT, PermuteImm)) {
       if (Depth == 1 && Root.getOpcode() == Shuffle)
         return false; // Nothing to do!
       Res = DAG.getBitcast(ShuffleVT, V1);
@@ -25224,7 +25242,8 @@ static bool combineX86ShuffleChain(Array
     }
   }
 
-  if (matchBinaryVectorShuffle(MaskVT, Mask, V1, V2, Shuffle, ShuffleVT)) {
+  if (matchBinaryVectorShuffle(MaskVT, Mask, V1, V2, Subtarget, Shuffle,
+                               ShuffleVT)) {
     if (Depth == 1 && Root.getOpcode() == Shuffle)
       return false; // Nothing to do!
     V1 = DAG.getBitcast(ShuffleVT, V1);

Modified: llvm/trunk/test/CodeGen/X86/vector-shuffle-combining-ssse3.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/vector-shuffle-combining-ssse3.ll?rev=278228&r1=278227&r2=278228&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/vector-shuffle-combining-ssse3.ll (original)
+++ llvm/trunk/test/CodeGen/X86/vector-shuffle-combining-ssse3.ll Wed Aug 10 09:15:41 2016
@@ -9,13 +9,13 @@
 
 declare <16 x i8> @llvm.x86.ssse3.pshuf.b.128(<16 x i8>, <16 x i8>)
 
-define <16 x i8> @combine_vpshufb_zero(<16 x i8> %a0) {
-; SSE-LABEL: combine_vpshufb_zero:
+define <16 x i8> @combine_vpshufb_as_zero(<16 x i8> %a0) {
+; SSE-LABEL: combine_vpshufb_as_zero:
 ; SSE:       # BB#0:
 ; SSE-NEXT:    xorps %xmm0, %xmm0
 ; SSE-NEXT:    retq
 ;
-; AVX-LABEL: combine_vpshufb_zero:
+; AVX-LABEL: combine_vpshufb_as_zero:
 ; AVX:       # BB#0:
 ; AVX-NEXT:    vxorps %xmm0, %xmm0, %xmm0
 ; AVX-NEXT:    retq
@@ -25,13 +25,13 @@ define <16 x i8> @combine_vpshufb_zero(<
   ret <16 x i8> %res2
 }
 
-define <16 x i8> @combine_vpshufb_movq(<16 x i8> %a0) {
-; SSE-LABEL: combine_vpshufb_movq:
+define <16 x i8> @combine_vpshufb_as_movq(<16 x i8> %a0) {
+; SSE-LABEL: combine_vpshufb_as_movq:
 ; SSE:       # BB#0:
 ; SSE-NEXT:    movq {{.*#+}} xmm0 = xmm0[0],zero
 ; SSE-NEXT:    retq
 ;
-; AVX-LABEL: combine_vpshufb_movq:
+; AVX-LABEL: combine_vpshufb_as_movq:
 ; AVX:       # BB#0:
 ; AVX-NEXT:    vmovq {{.*#+}} xmm0 = xmm0[0],zero
 ; AVX-NEXT:    retq
@@ -40,6 +40,54 @@ define <16 x i8> @combine_vpshufb_movq(<
   ret <16 x i8> %res1
 }
 
+define <2 x double> @combine_pshufb_as_movsd(<2 x double> %a0, <2 x double> %a1) {
+; SSSE3-LABEL: combine_pshufb_as_movsd:
+; SSSE3:       # BB#0:
+; SSSE3-NEXT:    movsd {{.*#+}} xmm1 = xmm0[0],xmm1[1]
+; SSSE3-NEXT:    movapd %xmm1, %xmm0
+; SSSE3-NEXT:    retq
+;
+; SSE41-LABEL: combine_pshufb_as_movsd:
+; SSE41:       # BB#0:
+; SSE41-NEXT:    shufpd {{.*#+}} xmm1 = xmm1[1],xmm0[0]
+; SSE41-NEXT:    pshufb {{.*#+}} xmm1 = xmm1[8,9,10,11,12,13,14,15,0,1,2,3,4,5,6,7]
+; SSE41-NEXT:    movdqa %xmm1, %xmm0
+; SSE41-NEXT:    retq
+;
+; AVX-LABEL: combine_pshufb_as_movsd:
+; AVX:       # BB#0:
+; AVX-NEXT:    vshufpd {{.*#+}} xmm0 = xmm1[1],xmm0[0]
+; AVX-NEXT:    vpermilpd {{.*#+}} xmm0 = xmm0[1,0]
+; AVX-NEXT:    retq
+  %1 = shufflevector <2 x double> %a0, <2 x double> %a1, <2 x i32> <i32 3, i32 0>
+  %2 = bitcast <2 x double> %1 to <16 x i8>
+  %3 = tail call <16 x i8> @llvm.x86.ssse3.pshuf.b.128(<16 x i8> %2, <16 x i8> <i8 8, i8 9, i8 10, i8 11, i8 12, i8 13, i8 14, i8 15, i8 0, i8 1, i8 2, i8 3, i8 4, i8 5, i8 6, i8 7>)
+  %4 = bitcast <16 x i8> %3 to <2 x double>
+  ret <2 x double> %4
+}
+
+define <4 x float> @combine_pshufb_as_movss(<4 x float> %a0, <4 x float> %a1) {
+; SSSE3-LABEL: combine_pshufb_as_movss:
+; SSSE3:       # BB#0:
+; SSSE3-NEXT:    movss {{.*#+}} xmm0 = xmm1[0],xmm0[1,2,3]
+; SSSE3-NEXT:    retq
+;
+; SSE41-LABEL: combine_pshufb_as_movss:
+; SSE41:       # BB#0:
+; SSE41-NEXT:    blendps {{.*#+}} xmm0 = xmm1[0],xmm0[1,2,3]
+; SSE41-NEXT:    retq
+;
+; AVX-LABEL: combine_pshufb_as_movss:
+; AVX:       # BB#0:
+; AVX-NEXT:    vblendps {{.*#+}} xmm0 = xmm1[0],xmm0[1,2,3]
+; AVX-NEXT:    retq
+  %1 = shufflevector <4 x float> %a0, <4 x float> %a1, <4 x i32> <i32 4, i32 3, i32 2, i32 1>
+  %2 = bitcast <4 x float> %1 to <16 x i8>
+  %3 = tail call <16 x i8> @llvm.x86.ssse3.pshuf.b.128(<16 x i8> %2, <16 x i8> <i8 0, i8 1, i8 2, i8 3, i8 12, i8 13, i8 14, i8 15, i8 8, i8 9, i8 10, i8 11, i8 4, i8 5, i8 6, i8 7>)
+  %4 = bitcast <16 x i8> %3 to <4 x float>
+  ret <4 x float> %4
+}
+
 define <4 x float> @combine_pshufb_movddup(<4 x float> %a0) {
 ; SSE-LABEL: combine_pshufb_movddup:
 ; SSE:       # BB#0:




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