[X86][SSE4A] Add support for shuffle combining to EXTRQ.

llvm-svn: 307254

2 files changed, 40 insertions, 25 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index f1269822463..02c8ec4d8f7 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -9364,7 +9364,7 @@ static bool matchVectorShuffleAsEXTRQ(MVT VT, SDValue &V1, SDValue &V2,
   int Idx = -1;
   for (int i = 0; i != Len; ++i) {
     int M = Mask[i];
-    if (M < 0)
+    if (M == SM_SentinelUndef)
       continue;
     SDValue &V = (M < Size ? V1 : V2);
     M = M % Size;
@@ -27696,6 +27696,33 @@ static bool combineX86ShuffleChain(ArrayRef<SDValue> Inputs, SDValue Root,
     return true;
   }
 
+  // Annoyingly, SSE4A instructions don't map into the above match helpers.
+  if (Subtarget.hasSSE4A() && AllowIntDomain && RootSizeInBits == 128) {
+    ShuffleVT = MVT::getIntegerVT(MaskEltSizeInBits);
+    ShuffleVT = MVT::getVectorVT(ShuffleVT, NumMaskElts);
+
+    APInt Zeroable(NumMaskElts, 0);
+    for (unsigned i = 0; i != NumMaskElts; ++i)
+      if (isUndefOrZero(Mask[i]))
+        Zeroable.setBit(i);
+
+    uint64_t BitLen, BitIdx;
+    if (matchVectorShuffleAsEXTRQ(ShuffleVT, V1, V2, Mask, BitLen, BitIdx,
+                                  Zeroable)) {
+      if (Depth == 1 && Root.getOpcode() == X86ISD::EXTRQI)
+        return false; // Nothing to do!
+      V1 = DAG.getBitcast(ShuffleVT, V1);
+      DCI.AddToWorklist(V1.getNode());
+      Res = DAG.getNode(X86ISD::EXTRQI, DL, ShuffleVT, V1,
+                        DAG.getConstant(BitLen, DL, MVT::i8),
+                        DAG.getConstant(BitIdx, DL, MVT::i8));
+      DCI.AddToWorklist(Res.getNode());
+      DCI.CombineTo(Root.getNode(), DAG.getBitcast(RootVT, Res),
+                    /*AddTo*/ true);
+      return true;
+    }
+  }
+
   // Don't try to re-form single instruction chains under any circumstances now
   // that we've done encoding canonicalization for them.
   if (Depth < 2)
diff --git a/llvm/test/CodeGen/X86/vector-shuffle-combining-sse4a.ll b/llvm/test/CodeGen/X86/vector-shuffle-combining-sse4a.ll
index 1669317f4aa..9d9c29121f8 100644
--- a/llvm/test/CodeGen/X86/vector-shuffle-combining-sse4a.ll
+++ b/llvm/test/CodeGen/X86/vector-shuffle-combining-sse4a.ll
@@ -9,30 +9,20 @@
 declare <16 x i8> @llvm.x86.ssse3.pshuf.b.128(<16 x i8>, <16 x i8>)
 
 define <16 x i8> @combine_extrqi_pshufb_16i8(<16 x i8> %a0) {
-; SSE-LABEL: combine_extrqi_pshufb_16i8:
-; SSE:       # BB#0:
-; SSE-NEXT:    pshufb {{.*#+}} xmm0 = xmm0[1,2],zero,zero,zero,zero,zero,zero,xmm0[u,u,u,u,u,u,u,u]
-; SSE-NEXT:    retq
-;
-; AVX-LABEL: combine_extrqi_pshufb_16i8:
-; AVX:       # BB#0:
-; AVX-NEXT:    vpshufb {{.*#+}} xmm0 = xmm0[1,2],zero,zero,zero,zero,zero,zero,xmm0[u,u,u,u,u,u,u,u]
-; AVX-NEXT:    retq
+; ALL-LABEL: combine_extrqi_pshufb_16i8:
+; ALL:       # BB#0:
+; ALL-NEXT:    extrq {{.*#+}} xmm0 = xmm0[1,2],zero,zero,zero,zero,zero,zero,xmm0[u,u,u,u,u,u,u,u]
+; ALL-NEXT:    retq
   %1 = shufflevector <16 x i8> %a0, <16 x i8> zeroinitializer, <16 x i32> <i32 1, i32 2, i32 16, i32 16, i32 16, i32 16, i32 16, i32 16, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef>
   %2 = tail call <16 x i8> @llvm.x86.ssse3.pshuf.b.128(<16 x i8> %1, <16 x i8> <i8 0, i8 1, i8 2, i8 3, i8 4, i8 255, i8 255, i8 255, i8 undef, i8 undef, i8 undef, i8 undef, i8 undef, i8 undef, i8 undef, i8 undef>)
   ret <16 x i8> %2
 }
 
 define <8 x i16> @combine_extrqi_pshufb_8i16(<8 x i16> %a0) {
-; SSE-LABEL: combine_extrqi_pshufb_8i16:
-; SSE:       # BB#0:
-; SSE-NEXT:    pshufb {{.*#+}} xmm0 = xmm0[2,3],zero,zero,zero,zero,zero,zero,xmm0[u,u,u,u,u,u,u,u]
-; SSE-NEXT:    retq
-;
-; AVX-LABEL: combine_extrqi_pshufb_8i16:
-; AVX:       # BB#0:
-; AVX-NEXT:    vpshufb {{.*#+}} xmm0 = xmm0[2,3],zero,zero,zero,zero,zero,zero,xmm0[u,u,u,u,u,u,u,u]
-; AVX-NEXT:    retq
+; ALL-LABEL: combine_extrqi_pshufb_8i16:
+; ALL:       # BB#0:
+; ALL-NEXT:    extrq {{.*#+}} xmm0 = xmm0[2,3],zero,zero,zero,zero,zero,zero,xmm0[u,u,u,u,u,u,u,u]
+; ALL-NEXT:    retq
   %1 = shufflevector <8 x i16> %a0, <8 x i16> zeroinitializer, <8 x i32> <i32 1, i32 2, i32 8, i32 8, i32 undef, i32 undef, i32 undef, i32 undef>
   %2 = bitcast <8 x i16> %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 255, i8 255, i8 255, i8 255, i8 255, i8 255, i8 undef, i8 undef, i8 undef, i8 undef, i8 undef, i8 undef, i8 undef, i8 undef>)
@@ -43,9 +33,8 @@ define <8 x i16> @combine_extrqi_pshufb_8i16(<8 x i16> %a0) {
 define <16 x i8> @combine_insertqi_pshufb_16i8(<16 x i8> %a0, <16 x i8> %a1) {
 ; SSSE3-LABEL: combine_insertqi_pshufb_16i8:
 ; SSSE3:       # BB#0:
-; SSSE3-NEXT:    movl $65535, %eax # imm = 0xFFFF
-; SSSE3-NEXT:    movd %eax, %xmm0
-; SSSE3-NEXT:    pand %xmm1, %xmm0
+; SSSE3-NEXT:    extrq {{.*#+}} xmm1 = xmm1[0,1],zero,zero,zero,zero,zero,zero,xmm1[u,u,u,u,u,u,u,u]
+; SSSE3-NEXT:    movdqa %xmm1, %xmm0
 ; SSSE3-NEXT:    retq
 ;
 ; SSE42-LABEL: combine_insertqi_pshufb_16i8:
@@ -65,9 +54,8 @@ define <16 x i8> @combine_insertqi_pshufb_16i8(<16 x i8> %a0, <16 x i8> %a1) {
 define <8 x i16> @combine_insertqi_pshufb_8i16(<8 x i16> %a0, <8 x i16> %a1) {
 ; SSSE3-LABEL: combine_insertqi_pshufb_8i16:
 ; SSSE3:       # BB#0:
-; SSSE3-NEXT:    movl $65535, %eax # imm = 0xFFFF
-; SSSE3-NEXT:    movd %eax, %xmm0
-; SSSE3-NEXT:    pand %xmm1, %xmm0
+; SSSE3-NEXT:    extrq {{.*#+}} xmm1 = xmm1[0,1],zero,zero,zero,zero,zero,zero,xmm1[u,u,u,u,u,u,u,u]
+; SSSE3-NEXT:    movdqa %xmm1, %xmm0
 ; SSSE3-NEXT:    retq
 ;
 ; SSE42-LABEL: combine_insertqi_pshufb_8i16: