[llvm] 297b9bc - [X86][AVX] computeKnownBitsForTargetNode - add X86ISD::VBROADCAST handling for scalar sources

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2021-03-21T10:40:57Z
New Revision: 297b9bc3fade62b05839b17d970eb48cf10623a3

URL: https://github.com/llvm/llvm-project/commit/297b9bc3fade62b05839b17d970eb48cf10623a3
DIFF: https://github.com/llvm/llvm-project/commit/297b9bc3fade62b05839b17d970eb48cf10623a3.diff

LOG: [X86][AVX] computeKnownBitsForTargetNode - add X86ISD::VBROADCAST handling for scalar sources

The target shuffle code handles vector sources, but X86ISD::VBROADCAST can also accept a scalar source for splatting.

Suggested by @craig.topper on PR49658

Added: 
    

Modified: 
    llvm/lib/Target/X86/X86ISelLowering.cpp
    llvm/test/CodeGen/X86/combine-pmuldq.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 4b1cd7c26338..c6af291f24d9 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -34303,6 +34303,14 @@ void X86TargetLowering::computeKnownBitsForTargetNode(const SDValue Op,
     Known = Known.trunc(BitWidth);
     break;
   }
+  case X86ISD::VBROADCAST: {
+    SDValue Src = Op.getOperand(0);
+    if (!Src.getSimpleValueType().isVector()) {
+      Known = DAG.computeKnownBits(Src, Depth + 1);
+      return;
+    }
+    break;
+  }
   case X86ISD::ANDNP: {
     KnownBits Known2;
     Known = DAG.computeKnownBits(Op.getOperand(1), DemandedElts, Depth + 1);

diff  --git a/llvm/test/CodeGen/X86/combine-pmuldq.ll b/llvm/test/CodeGen/X86/combine-pmuldq.ll
index 86bae1899b9a..63e3c48e3520 100644
--- a/llvm/test/CodeGen/X86/combine-pmuldq.ll
+++ b/llvm/test/CodeGen/X86/combine-pmuldq.ll
@@ -324,24 +324,17 @@ define <8 x i32> @PR49658(i32* %ptr, i32 %mul) {
 ; AVX2-NEXT:    vpbroadcastq %xmm0, %ymm1
 ; AVX2-NEXT:    vpxor %xmm0, %xmm0, %xmm0
 ; AVX2-NEXT:    movq $-2097152, %rax # imm = 0xFFE00000
-; AVX2-NEXT:    vpsrlq $32, %ymm1, %ymm2
 ; AVX2-NEXT:    .p2align 4, 0x90
 ; AVX2-NEXT:  .LBB7_1: # %loop
 ; AVX2-NEXT:    # =>This Inner Loop Header: Depth=1
+; AVX2-NEXT:    vpmovzxdq {{.*#+}} ymm2 = mem[0],zero,mem[1],zero,mem[2],zero,mem[3],zero
 ; AVX2-NEXT:    vpmovzxdq {{.*#+}} ymm3 = mem[0],zero,mem[1],zero,mem[2],zero,mem[3],zero
-; AVX2-NEXT:    vpmovzxdq {{.*#+}} ymm4 = mem[0],zero,mem[1],zero,mem[2],zero,mem[3],zero
-; AVX2-NEXT:    vpmuludq %ymm4, %ymm1, %ymm5
-; AVX2-NEXT:    vpmuludq %ymm4, %ymm2, %ymm4
-; AVX2-NEXT:    vpsllq $32, %ymm4, %ymm4
-; AVX2-NEXT:    vpaddq %ymm4, %ymm5, %ymm4
-; AVX2-NEXT:    vpmuludq %ymm3, %ymm1, %ymm5
-; AVX2-NEXT:    vpmuludq %ymm3, %ymm2, %ymm3
-; AVX2-NEXT:    vpsllq $32, %ymm3, %ymm3
-; AVX2-NEXT:    vpaddq %ymm3, %ymm5, %ymm3
-; AVX2-NEXT:    vperm2i128 {{.*#+}} ymm5 = ymm4[2,3],ymm3[2,3]
-; AVX2-NEXT:    vinserti128 $1, %xmm3, %ymm4, %ymm3
-; AVX2-NEXT:    vshufps {{.*#+}} ymm3 = ymm3[1,3],ymm5[1,3],ymm3[5,7],ymm5[5,7]
-; AVX2-NEXT:    vpaddd %ymm0, %ymm3, %ymm0
+; AVX2-NEXT:    vpmuludq %ymm3, %ymm1, %ymm3
+; AVX2-NEXT:    vpmuludq %ymm2, %ymm1, %ymm2
+; AVX2-NEXT:    vperm2i128 {{.*#+}} ymm4 = ymm3[2,3],ymm2[2,3]
+; AVX2-NEXT:    vinserti128 $1, %xmm2, %ymm3, %ymm2
+; AVX2-NEXT:    vshufps {{.*#+}} ymm2 = ymm2[1,3],ymm4[1,3],ymm2[5,7],ymm4[5,7]
+; AVX2-NEXT:    vpaddd %ymm0, %ymm2, %ymm0
 ; AVX2-NEXT:    subq $-128, %rax
 ; AVX2-NEXT:    jne .LBB7_1
 ; AVX2-NEXT:  # %bb.2: # %end
@@ -353,18 +346,14 @@ define <8 x i32> @PR49658(i32* %ptr, i32 %mul) {
 ; AVX512VL-NEXT:    vpbroadcastq %rax, %zmm1
 ; AVX512VL-NEXT:    vpxor %xmm0, %xmm0, %xmm0
 ; AVX512VL-NEXT:    movq $-2097152, %rax # imm = 0xFFE00000
-; AVX512VL-NEXT:    vpsrlq $32, %zmm1, %zmm2
 ; AVX512VL-NEXT:    .p2align 4, 0x90
 ; AVX512VL-NEXT:  .LBB7_1: # %loop
 ; AVX512VL-NEXT:    # =>This Inner Loop Header: Depth=1
-; AVX512VL-NEXT:    vpmovzxdq {{.*#+}} zmm3 = mem[0],zero,mem[1],zero,mem[2],zero,mem[3],zero,mem[4],zero,mem[5],zero,mem[6],zero,mem[7],zero
-; AVX512VL-NEXT:    vpmuludq %zmm3, %zmm1, %zmm4
-; AVX512VL-NEXT:    vpmuludq %zmm3, %zmm2, %zmm3
-; AVX512VL-NEXT:    vpsllq $32, %zmm3, %zmm3
-; AVX512VL-NEXT:    vpaddq %zmm3, %zmm4, %zmm3
-; AVX512VL-NEXT:    vpsrlq $32, %zmm3, %zmm3
-; AVX512VL-NEXT:    vpmovqd %zmm3, %ymm3
-; AVX512VL-NEXT:    vpaddd %ymm0, %ymm3, %ymm0
+; AVX512VL-NEXT:    vpmovzxdq {{.*#+}} zmm2 = mem[0],zero,mem[1],zero,mem[2],zero,mem[3],zero,mem[4],zero,mem[5],zero,mem[6],zero,mem[7],zero
+; AVX512VL-NEXT:    vpmuludq %zmm2, %zmm1, %zmm2
+; AVX512VL-NEXT:    vpsrlq $32, %zmm2, %zmm2
+; AVX512VL-NEXT:    vpmovqd %zmm2, %ymm2
+; AVX512VL-NEXT:    vpaddd %ymm0, %ymm2, %ymm0
 ; AVX512VL-NEXT:    subq $-128, %rax
 ; AVX512VL-NEXT:    jne .LBB7_1
 ; AVX512VL-NEXT:  # %bb.2: # %end
@@ -380,7 +369,7 @@ define <8 x i32> @PR49658(i32* %ptr, i32 %mul) {
 ; AVX512DQVL-NEXT:  .LBB7_1: # %loop
 ; AVX512DQVL-NEXT:    # =>This Inner Loop Header: Depth=1
 ; AVX512DQVL-NEXT:    vpmovzxdq {{.*#+}} zmm2 = mem[0],zero,mem[1],zero,mem[2],zero,mem[3],zero,mem[4],zero,mem[5],zero,mem[6],zero,mem[7],zero
-; AVX512DQVL-NEXT:    vpmullq %zmm2, %zmm1, %zmm2
+; AVX512DQVL-NEXT:    vpmuludq %zmm2, %zmm1, %zmm2
 ; AVX512DQVL-NEXT:    vpsrlq $32, %zmm2, %zmm2
 ; AVX512DQVL-NEXT:    vpmovqd %zmm2, %ymm2
 ; AVX512DQVL-NEXT:    vpaddd %ymm0, %ymm2, %ymm0