[X86][SSE] combineSubToSubus - add v16i32 handling on pre-AVX512BW targets.

RKSimon · RKSimon · commit 7e44208115b3 · 2021-01-12T13:44:11.000Z
v16i32 -&gt; v16i16/v8i16 truncation is now good enough using PACKSS/PACKUS + shuffle combining that its no longer necessary to early-out on pre-AVX512BW targets.

This was noticed while looking at completing PR40111 and moving combineSubToSubus to DAGCombine entirely.
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -48756,9 +48756,9 @@ static SDValue combineSubToSubus(SDNode *N, SelectionDAG &DAG,
 
   // PSUBUS is supported, starting from SSE2.
   EVT EltVT = VT.getVectorElementType();
-  if (!(Subtarget.hasSSE2() && (EltVT == MVT::i8 || EltVT == MVT::i16 ||
-                                VT == MVT::v8i32 || VT == MVT::v8i64)) &&
-      !(Subtarget.useBWIRegs() && (VT == MVT::v16i32)))
+  if (!(Subtarget.hasSSE2() &&
+        (EltVT == MVT::i8 || EltVT == MVT::i16 || VT == MVT::v8i32 ||
+         VT == MVT::v8i64 || VT == MVT::v16i32)))
     return SDValue();
 
   SDValue SubusLHS, SubusRHS;
@@ -48795,8 +48795,8 @@ static SDValue combineSubToSubus(SDNode *N, SelectionDAG &DAG,
     SDValue MinRHS = Op1.getOperand(0).getOperand(1);
     EVT TruncVT = Op1.getOperand(0).getValueType();
     if (!(Subtarget.hasSSE2() &&
-          (TruncVT == MVT::v8i32 || TruncVT == MVT::v8i64)) &&
-        !(Subtarget.useBWIRegs() && (TruncVT == MVT::v16i32)))
+          (TruncVT == MVT::v8i32 || TruncVT == MVT::v8i64 ||
+           TruncVT == MVT::v16i32)))
       return SDValue();
     SDValue OpToSaturate;
     if (MinLHS.getOpcode() == ISD::ZERO_EXTEND &&
diff --git a/llvm/test/CodeGen/X86/psubus.ll b/llvm/test/CodeGen/X86/psubus.ll
@@ -1737,141 +1737,125 @@ vector.ph:
 define <16 x i16> @psubus_16i32_max(<16 x i16> %x, <16 x i32> %y) nounwind {
 ; SSE2-LABEL: psubus_16i32_max:
 ; SSE2:       # %bb.0: # %vector.ph
-; SSE2-NEXT:    movdqa %xmm1, %xmm8
-; SSE2-NEXT:    pxor %xmm7, %xmm7
-; SSE2-NEXT:    punpcklwd {{.*#+}} xmm1 = xmm1[0],xmm7[0],xmm1[1],xmm7[1],xmm1[2],xmm7[2],xmm1[3],xmm7[3]
-; SSE2-NEXT:    punpckhwd {{.*#+}} xmm8 = xmm8[4],xmm7[4],xmm8[5],xmm7[5],xmm8[6],xmm7[6],xmm8[7],xmm7[7]
-; SSE2-NEXT:    movdqa %xmm0, %xmm10
-; SSE2-NEXT:    punpcklwd {{.*#+}} xmm10 = xmm10[0],xmm7[0],xmm10[1],xmm7[1],xmm10[2],xmm7[2],xmm10[3],xmm7[3]
-; SSE2-NEXT:    punpckhwd {{.*#+}} xmm0 = xmm0[4],xmm7[4],xmm0[5],xmm7[5],xmm0[6],xmm7[6],xmm0[7],xmm7[7]
-; SSE2-NEXT:    movdqa {{.*#+}} xmm7 = [2147483648,2147483648,2147483648,2147483648]
-; SSE2-NEXT:    movdqa %xmm3, %xmm6
-; SSE2-NEXT:    pxor %xmm7, %xmm6
-; SSE2-NEXT:    movdqa %xmm0, %xmm9
-; SSE2-NEXT:    por %xmm7, %xmm9
-; SSE2-NEXT:    pcmpgtd %xmm6, %xmm9
-; SSE2-NEXT:    pand %xmm9, %xmm0
-; SSE2-NEXT:    pandn %xmm3, %xmm9
-; SSE2-NEXT:    por %xmm0, %xmm9
-; SSE2-NEXT:    movdqa %xmm2, %xmm6
-; SSE2-NEXT:    pxor %xmm7, %xmm6
-; SSE2-NEXT:    movdqa %xmm10, %xmm0
-; SSE2-NEXT:    por %xmm7, %xmm0
-; SSE2-NEXT:    pcmpgtd %xmm6, %xmm0
-; SSE2-NEXT:    pand %xmm0, %xmm10
-; SSE2-NEXT:    pandn %xmm2, %xmm0
-; SSE2-NEXT:    por %xmm10, %xmm0
-; SSE2-NEXT:    movdqa %xmm5, %xmm10
-; SSE2-NEXT:    pxor %xmm7, %xmm10
-; SSE2-NEXT:    movdqa %xmm8, %xmm6
-; SSE2-NEXT:    por %xmm7, %xmm6
-; SSE2-NEXT:    pcmpgtd %xmm10, %xmm6
-; SSE2-NEXT:    pand %xmm6, %xmm8
-; SSE2-NEXT:    pandn %xmm5, %xmm6
-; SSE2-NEXT:    por %xmm8, %xmm6
-; SSE2-NEXT:    movdqa %xmm4, %xmm8
-; SSE2-NEXT:    pxor %xmm7, %xmm8
-; SSE2-NEXT:    por %xmm1, %xmm7
-; SSE2-NEXT:    pcmpgtd %xmm8, %xmm7
-; SSE2-NEXT:    pand %xmm7, %xmm1
-; SSE2-NEXT:    pandn %xmm4, %xmm7
-; SSE2-NEXT:    por %xmm7, %xmm1
-; SSE2-NEXT:    psubd %xmm4, %xmm1
-; SSE2-NEXT:    psubd %xmm5, %xmm6
-; SSE2-NEXT:    psubd %xmm2, %xmm0
-; SSE2-NEXT:    psubd %xmm3, %xmm9
-; SSE2-NEXT:    pslld $16, %xmm9
-; SSE2-NEXT:    psrad $16, %xmm9
-; SSE2-NEXT:    pslld $16, %xmm0
-; SSE2-NEXT:    psrad $16, %xmm0
-; SSE2-NEXT:    packssdw %xmm9, %xmm0
+; SSE2-NEXT:    movdqa {{.*#+}} xmm9 = [2147483648,2147483648,2147483648,2147483648]
+; SSE2-NEXT:    movdqa %xmm3, %xmm8
+; SSE2-NEXT:    pxor %xmm9, %xmm8
+; SSE2-NEXT:    movdqa {{.*#+}} xmm7 = [2147549183,2147549183,2147549183,2147549183]
+; SSE2-NEXT:    movdqa %xmm7, %xmm6
+; SSE2-NEXT:    pcmpgtd %xmm8, %xmm6
+; SSE2-NEXT:    pcmpeqd %xmm8, %xmm8
+; SSE2-NEXT:    pand %xmm6, %xmm3
+; SSE2-NEXT:    pxor %xmm8, %xmm6
+; SSE2-NEXT:    por %xmm3, %xmm6
 ; SSE2-NEXT:    pslld $16, %xmm6
 ; SSE2-NEXT:    psrad $16, %xmm6
-; SSE2-NEXT:    pslld $16, %xmm1
+; SSE2-NEXT:    movdqa %xmm2, %xmm10
+; SSE2-NEXT:    pxor %xmm9, %xmm10
+; SSE2-NEXT:    movdqa %xmm7, %xmm3
+; SSE2-NEXT:    pcmpgtd %xmm10, %xmm3
+; SSE2-NEXT:    pand %xmm3, %xmm2
+; SSE2-NEXT:    pxor %xmm8, %xmm3
+; SSE2-NEXT:    por %xmm2, %xmm3
+; SSE2-NEXT:    pslld $16, %xmm3
+; SSE2-NEXT:    psrad $16, %xmm3
+; SSE2-NEXT:    packssdw %xmm6, %xmm3
+; SSE2-NEXT:    movdqa %xmm5, %xmm2
+; SSE2-NEXT:    pxor %xmm9, %xmm2
+; SSE2-NEXT:    movdqa %xmm7, %xmm6
+; SSE2-NEXT:    pcmpgtd %xmm2, %xmm6
+; SSE2-NEXT:    pand %xmm6, %xmm5
+; SSE2-NEXT:    pxor %xmm8, %xmm6
+; SSE2-NEXT:    por %xmm5, %xmm6
+; SSE2-NEXT:    pslld $16, %xmm6
+; SSE2-NEXT:    psrad $16, %xmm6
+; SSE2-NEXT:    pxor %xmm4, %xmm9
+; SSE2-NEXT:    pcmpgtd %xmm9, %xmm7
+; SSE2-NEXT:    pxor %xmm7, %xmm8
+; SSE2-NEXT:    pand %xmm4, %xmm7
+; SSE2-NEXT:    por %xmm8, %xmm7
+; SSE2-NEXT:    pslld $16, %xmm7
+; SSE2-NEXT:    psrad $16, %xmm7
+; SSE2-NEXT:    packssdw %xmm6, %xmm7
+; SSE2-NEXT:    psubusw %xmm7, %xmm1
+; SSE2-NEXT:    psubusw %xmm3, %xmm0
+; SSE2-NEXT:    punpckhwd {{.*#+}} xmm2 = xmm2[4],xmm0[4],xmm2[5],xmm0[5],xmm2[6],xmm0[6],xmm2[7],xmm0[7]
+; SSE2-NEXT:    psrad $16, %xmm2
+; SSE2-NEXT:    punpcklwd {{.*#+}} xmm0 = xmm0[0,0,1,1,2,2,3,3]
+; SSE2-NEXT:    psrad $16, %xmm0
+; SSE2-NEXT:    packssdw %xmm2, %xmm0
+; SSE2-NEXT:    punpckhwd {{.*#+}} xmm2 = xmm2[4],xmm1[4],xmm2[5],xmm1[5],xmm2[6],xmm1[6],xmm2[7],xmm1[7]
+; SSE2-NEXT:    psrad $16, %xmm2
+; SSE2-NEXT:    punpcklwd {{.*#+}} xmm1 = xmm1[0,0,1,1,2,2,3,3]
 ; SSE2-NEXT:    psrad $16, %xmm1
-; SSE2-NEXT:    packssdw %xmm6, %xmm1
+; SSE2-NEXT:    packssdw %xmm2, %xmm1
 ; SSE2-NEXT:    retq
 ;
 ; SSSE3-LABEL: psubus_16i32_max:
 ; SSSE3:       # %bb.0: # %vector.ph
-; SSSE3-NEXT:    movdqa %xmm1, %xmm8
-; SSSE3-NEXT:    pxor %xmm7, %xmm7
-; SSSE3-NEXT:    punpcklwd {{.*#+}} xmm1 = xmm1[0],xmm7[0],xmm1[1],xmm7[1],xmm1[2],xmm7[2],xmm1[3],xmm7[3]
-; SSSE3-NEXT:    punpckhwd {{.*#+}} xmm8 = xmm8[4],xmm7[4],xmm8[5],xmm7[5],xmm8[6],xmm7[6],xmm8[7],xmm7[7]
-; SSSE3-NEXT:    movdqa %xmm0, %xmm10
-; SSSE3-NEXT:    punpcklwd {{.*#+}} xmm10 = xmm10[0],xmm7[0],xmm10[1],xmm7[1],xmm10[2],xmm7[2],xmm10[3],xmm7[3]
-; SSSE3-NEXT:    punpckhwd {{.*#+}} xmm0 = xmm0[4],xmm7[4],xmm0[5],xmm7[5],xmm0[6],xmm7[6],xmm0[7],xmm7[7]
-; SSSE3-NEXT:    movdqa {{.*#+}} xmm7 = [2147483648,2147483648,2147483648,2147483648]
-; SSSE3-NEXT:    movdqa %xmm3, %xmm6
-; SSSE3-NEXT:    pxor %xmm7, %xmm6
-; SSSE3-NEXT:    movdqa %xmm0, %xmm9
-; SSSE3-NEXT:    por %xmm7, %xmm9
-; SSSE3-NEXT:    pcmpgtd %xmm6, %xmm9
-; SSSE3-NEXT:    pand %xmm9, %xmm0
-; SSSE3-NEXT:    pandn %xmm3, %xmm9
-; SSSE3-NEXT:    por %xmm0, %xmm9
-; SSSE3-NEXT:    movdqa %xmm2, %xmm6
-; SSSE3-NEXT:    pxor %xmm7, %xmm6
-; SSSE3-NEXT:    movdqa %xmm10, %xmm0
-; SSSE3-NEXT:    por %xmm7, %xmm0
-; SSSE3-NEXT:    pcmpgtd %xmm6, %xmm0
-; SSSE3-NEXT:    pand %xmm0, %xmm10
-; SSSE3-NEXT:    pandn %xmm2, %xmm0
-; SSSE3-NEXT:    por %xmm10, %xmm0
-; SSSE3-NEXT:    movdqa %xmm5, %xmm10
-; SSSE3-NEXT:    pxor %xmm7, %xmm10
-; SSSE3-NEXT:    movdqa %xmm8, %xmm6
-; SSSE3-NEXT:    por %xmm7, %xmm6
-; SSSE3-NEXT:    pcmpgtd %xmm10, %xmm6
-; SSSE3-NEXT:    pand %xmm6, %xmm8
-; SSSE3-NEXT:    pandn %xmm5, %xmm6
-; SSSE3-NEXT:    por %xmm8, %xmm6
-; SSSE3-NEXT:    movdqa %xmm4, %xmm8
-; SSSE3-NEXT:    pxor %xmm7, %xmm8
-; SSSE3-NEXT:    por %xmm1, %xmm7
-; SSSE3-NEXT:    pcmpgtd %xmm8, %xmm7
-; SSSE3-NEXT:    pand %xmm7, %xmm1
-; SSSE3-NEXT:    pandn %xmm4, %xmm7
-; SSSE3-NEXT:    por %xmm7, %xmm1
-; SSSE3-NEXT:    psubd %xmm4, %xmm1
-; SSSE3-NEXT:    psubd %xmm5, %xmm6
-; SSSE3-NEXT:    psubd %xmm2, %xmm0
-; SSSE3-NEXT:    psubd %xmm3, %xmm9
-; SSSE3-NEXT:    pslld $16, %xmm9
-; SSSE3-NEXT:    psrad $16, %xmm9
-; SSSE3-NEXT:    pslld $16, %xmm0
-; SSSE3-NEXT:    psrad $16, %xmm0
-; SSSE3-NEXT:    packssdw %xmm9, %xmm0
+; SSSE3-NEXT:    movdqa {{.*#+}} xmm9 = [2147483648,2147483648,2147483648,2147483648]
+; SSSE3-NEXT:    movdqa %xmm3, %xmm8
+; SSSE3-NEXT:    pxor %xmm9, %xmm8
+; SSSE3-NEXT:    movdqa {{.*#+}} xmm7 = [2147549183,2147549183,2147549183,2147549183]
+; SSSE3-NEXT:    movdqa %xmm7, %xmm6
+; SSSE3-NEXT:    pcmpgtd %xmm8, %xmm6
+; SSSE3-NEXT:    pcmpeqd %xmm8, %xmm8
+; SSSE3-NEXT:    pand %xmm6, %xmm3
+; SSSE3-NEXT:    pxor %xmm8, %xmm6
+; SSSE3-NEXT:    por %xmm3, %xmm6
+; SSSE3-NEXT:    pslld $16, %xmm6
+; SSSE3-NEXT:    psrad $16, %xmm6
+; SSSE3-NEXT:    movdqa %xmm2, %xmm10
+; SSSE3-NEXT:    pxor %xmm9, %xmm10
+; SSSE3-NEXT:    movdqa %xmm7, %xmm3
+; SSSE3-NEXT:    pcmpgtd %xmm10, %xmm3
+; SSSE3-NEXT:    pand %xmm3, %xmm2
+; SSSE3-NEXT:    pxor %xmm8, %xmm3
+; SSSE3-NEXT:    por %xmm2, %xmm3
+; SSSE3-NEXT:    pslld $16, %xmm3
+; SSSE3-NEXT:    psrad $16, %xmm3
+; SSSE3-NEXT:    packssdw %xmm6, %xmm3
+; SSSE3-NEXT:    movdqa %xmm5, %xmm2
+; SSSE3-NEXT:    pxor %xmm9, %xmm2
+; SSSE3-NEXT:    movdqa %xmm7, %xmm6
+; SSSE3-NEXT:    pcmpgtd %xmm2, %xmm6
+; SSSE3-NEXT:    pand %xmm6, %xmm5
+; SSSE3-NEXT:    pxor %xmm8, %xmm6
+; SSSE3-NEXT:    por %xmm5, %xmm6
 ; SSSE3-NEXT:    pslld $16, %xmm6
 ; SSSE3-NEXT:    psrad $16, %xmm6
-; SSSE3-NEXT:    pslld $16, %xmm1
+; SSSE3-NEXT:    pxor %xmm4, %xmm9
+; SSSE3-NEXT:    pcmpgtd %xmm9, %xmm7
+; SSSE3-NEXT:    pxor %xmm7, %xmm8
+; SSSE3-NEXT:    pand %xmm4, %xmm7
+; SSSE3-NEXT:    por %xmm8, %xmm7
+; SSSE3-NEXT:    pslld $16, %xmm7
+; SSSE3-NEXT:    psrad $16, %xmm7
+; SSSE3-NEXT:    packssdw %xmm6, %xmm7
+; SSSE3-NEXT:    psubusw %xmm7, %xmm1
+; SSSE3-NEXT:    psubusw %xmm3, %xmm0
+; SSSE3-NEXT:    punpckhwd {{.*#+}} xmm2 = xmm2[4],xmm0[4],xmm2[5],xmm0[5],xmm2[6],xmm0[6],xmm2[7],xmm0[7]
+; SSSE3-NEXT:    psrad $16, %xmm2
+; SSSE3-NEXT:    punpcklwd {{.*#+}} xmm0 = xmm0[0,0,1,1,2,2,3,3]
+; SSSE3-NEXT:    psrad $16, %xmm0
+; SSSE3-NEXT:    packssdw %xmm2, %xmm0
+; SSSE3-NEXT:    punpckhwd {{.*#+}} xmm2 = xmm2[4],xmm1[4],xmm2[5],xmm1[5],xmm2[6],xmm1[6],xmm2[7],xmm1[7]
+; SSSE3-NEXT:    psrad $16, %xmm2
+; SSSE3-NEXT:    punpcklwd {{.*#+}} xmm1 = xmm1[0,0,1,1,2,2,3,3]
 ; SSSE3-NEXT:    psrad $16, %xmm1
-; SSSE3-NEXT:    packssdw %xmm6, %xmm1
+; SSSE3-NEXT:    packssdw %xmm2, %xmm1
 ; SSSE3-NEXT:    retq
 ;
 ; SSE41-LABEL: psubus_16i32_max:
 ; SSE41:       # %bb.0: # %vector.ph
-; SSE41-NEXT:    pxor %xmm8, %xmm8
-; SSE41-NEXT:    pmovzxwd {{.*#+}} xmm6 = xmm1[0],zero,xmm1[1],zero,xmm1[2],zero,xmm1[3],zero
-; SSE41-NEXT:    punpckhwd {{.*#+}} xmm1 = xmm1[4],xmm8[4],xmm1[5],xmm8[5],xmm1[6],xmm8[6],xmm1[7],xmm8[7]
-; SSE41-NEXT:    pmovzxwd {{.*#+}} xmm7 = xmm0[0],zero,xmm0[1],zero,xmm0[2],zero,xmm0[3],zero
-; SSE41-NEXT:    punpckhwd {{.*#+}} xmm0 = xmm0[4],xmm8[4],xmm0[5],xmm8[5],xmm0[6],xmm8[6],xmm0[7],xmm8[7]
-; SSE41-NEXT:    pmaxud %xmm3, %xmm0
-; SSE41-NEXT:    pmaxud %xmm2, %xmm7
-; SSE41-NEXT:    pmaxud %xmm5, %xmm1
-; SSE41-NEXT:    pmaxud %xmm4, %xmm6
-; SSE41-NEXT:    psubd %xmm4, %xmm6
-; SSE41-NEXT:    psubd %xmm5, %xmm1
-; SSE41-NEXT:    psubd %xmm2, %xmm7
-; SSE41-NEXT:    psubd %xmm3, %xmm0
-; SSE41-NEXT:    pblendw {{.*#+}} xmm0 = xmm0[0],xmm8[1],xmm0[2],xmm8[3],xmm0[4],xmm8[5],xmm0[6],xmm8[7]
-; SSE41-NEXT:    pblendw {{.*#+}} xmm7 = xmm7[0],xmm8[1],xmm7[2],xmm8[3],xmm7[4],xmm8[5],xmm7[6],xmm8[7]
-; SSE41-NEXT:    packusdw %xmm0, %xmm7
-; SSE41-NEXT:    pblendw {{.*#+}} xmm1 = xmm1[0],xmm8[1],xmm1[2],xmm8[3],xmm1[4],xmm8[5],xmm1[6],xmm8[7]
-; SSE41-NEXT:    pblendw {{.*#+}} xmm6 = xmm6[0],xmm8[1],xmm6[2],xmm8[3],xmm6[4],xmm8[5],xmm6[6],xmm8[7]
-; SSE41-NEXT:    packusdw %xmm1, %xmm6
-; SSE41-NEXT:    movdqa %xmm7, %xmm0
-; SSE41-NEXT:    movdqa %xmm6, %xmm1
+; SSE41-NEXT:    movdqa {{.*#+}} xmm6 = [65535,65535,65535,65535]
+; SSE41-NEXT:    pminud %xmm6, %xmm5
+; SSE41-NEXT:    pminud %xmm6, %xmm4
+; SSE41-NEXT:    packusdw %xmm5, %xmm4
+; SSE41-NEXT:    pminud %xmm6, %xmm3
+; SSE41-NEXT:    pminud %xmm6, %xmm2
+; SSE41-NEXT:    packusdw %xmm3, %xmm2
+; SSE41-NEXT:    psubusw %xmm2, %xmm0
+; SSE41-NEXT:    psubusw %xmm4, %xmm1
 ; SSE41-NEXT:    retq
 ;
 ; AVX1-LABEL: psubus_16i32_max:
@@ -1894,16 +1878,11 @@ define <16 x i16> @psubus_16i32_max(<16 x i16> %x, <16 x i32> %y) nounwind {
 ; AVX2-LABEL: psubus_16i32_max:
 ; AVX2:       # %bb.0: # %vector.ph
 ; AVX2-NEXT:    vpbroadcastd {{.*#+}} ymm3 = [65535,65535,65535,65535,65535,65535,65535,65535]
-; AVX2-NEXT:    vpminud %ymm3, %ymm1, %ymm1
-; AVX2-NEXT:    vextracti128 $1, %ymm1, %xmm4
-; AVX2-NEXT:    vpackusdw %xmm4, %xmm1, %xmm1
 ; AVX2-NEXT:    vpminud %ymm3, %ymm2, %ymm2
-; AVX2-NEXT:    vextracti128 $1, %ymm2, %xmm3
-; AVX2-NEXT:    vpackusdw %xmm3, %xmm2, %xmm2
-; AVX2-NEXT:    vextracti128 $1, %ymm0, %xmm3
-; AVX2-NEXT:    vpsubusw %xmm2, %xmm3, %xmm2
-; AVX2-NEXT:    vpsubusw %xmm1, %xmm0, %xmm0
-; AVX2-NEXT:    vinserti128 $1, %xmm2, %ymm0, %ymm0
+; AVX2-NEXT:    vpminud %ymm3, %ymm1, %ymm1
+; AVX2-NEXT:    vpackusdw %ymm2, %ymm1, %ymm1
+; AVX2-NEXT:    vpermq {{.*#+}} ymm1 = ymm1[0,2,1,3]
+; AVX2-NEXT:    vpsubusw %ymm1, %ymm0, %ymm0
 ; AVX2-NEXT:    retq
 ;
 ; AVX512-LABEL: psubus_16i32_max:
