[X86] Handle repeated blend mask in combineConcatVectorOps

[XinWang10]

1d27669e8ad07f8f2 add support for fold 512-bit concat(blendi(x,y,c0),blendi(z,w,c1)) to AVX512BW mask select.
But when the type of subvector is v16i16, we need to generate repeated mask to make the result correct.
The subnode looks like t87: v16i16 = X86ISD::BLENDI t132, t58, TargetConstant:i8<-86>.

[llvmbot]

@llvm/pr-subscribers-backend-x86

Author: None (XinWang10)

Changes

1d27669e8ad07f8f2 add support for fold 512-bit concat(blendi(x,y,c0),ble…
…ndi(z,w,c1)) to AVX512BW mask select.
But when the type of subvector is v16i16, we need to generate repeated mask to make the result correct.
The subnode looks like t87: v16i16 = X86ISD::BLENDI t132, t58, TargetConstant:i8<-86>.

---

Full diff: https://github.com/llvm/llvm-project/pull/82155.diff

2 Files Affected:

• (modified) llvm/lib/Target/X86/X86ISelLowering.cpp (+5)
• (modified) llvm/test/CodeGen/X86/vector-interleaved-store-i8-stride-8.ll (+8-8)

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index be123e18016115..d9657e1aeb8026 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -55226,6 +55226,11 @@ static SDValue combineConcatVectorOps(const SDLoc &DL, MVT VT,
       if (NumOps == 2 && VT.is512BitVector() && Subtarget.useBWIRegs()) {
         uint64_t Mask0 = Ops[0].getConstantOperandVal(2);
         uint64_t Mask1 = Ops[1].getConstantOperandVal(2);
+        // MVT::v16i16 has repeated blend mask.
+        if (Op0.getSimpleValueType() == MVT::v16i16) {
+          Mask0 = (Mask0 << 8) | Mask0;
+          Mask1 = (Mask1 << 8) | Mask1;
+        }
         uint64_t Mask = (Mask1 << (VT.getVectorNumElements() / 2)) | Mask0;
         MVT MaskSVT = MVT::getIntegerVT(VT.getVectorNumElements());
         MVT MaskVT = MVT::getVectorVT(MVT::i1, VT.getVectorNumElements());
diff --git a/llvm/test/CodeGen/X86/vector-interleaved-store-i8-stride-8.ll b/llvm/test/CodeGen/X86/vector-interleaved-store-i8-stride-8.ll
index dd3f96322bcc12..d8fd21f4877f01 100644
--- a/llvm/test/CodeGen/X86/vector-interleaved-store-i8-stride-8.ll
+++ b/llvm/test/CodeGen/X86/vector-interleaved-store-i8-stride-8.ll
@@ -2080,7 +2080,7 @@ define void @store_i8_stride8_vf16(ptr %in.vecptr0, ptr %in.vecptr1, ptr %in.vec
 ; AVX512BW-NEXT:    vpermq {{.*#+}} zmm6 = zmm3[0,2,0,2,4,6,4,6]
 ; AVX512BW-NEXT:    vmovdqa64 {{.*#+}} zmm7 = [u,u,u,u,u,u,0,8,u,u,u,u,u,u,1,9,u,u,u,u,u,u,2,10,u,u,u,u,u,u,3,11,u,u,u,u,u,u,4,12,u,u,u,u,u,u,5,13,u,u,u,u,u,u,6,14,u,u,u,u,u,u,7,15]
 ; AVX512BW-NEXT:    vpshufb %zmm7, %zmm6, %zmm6
-; AVX512BW-NEXT:    movl $8913032, %ecx # imm = 0x880088
+; AVX512BW-NEXT:    movl $-2004318072, %ecx # imm = 0x88888888
 ; AVX512BW-NEXT:    kmovd %ecx, %k1
 ; AVX512BW-NEXT:    vmovdqu16 %zmm6, %zmm4 {%k1}
 ; AVX512BW-NEXT:    vinserti64x4 $1, %ymm0, %zmm0, %zmm0
@@ -2091,7 +2091,7 @@ define void @store_i8_stride8_vf16(ptr %in.vecptr0, ptr %in.vecptr1, ptr %in.vec
 ; AVX512BW-NEXT:    vpermq {{.*#+}} zmm9 = zmm1[0,2,0,2,4,6,4,6]
 ; AVX512BW-NEXT:    vpmovsxdq {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %zmm10
 ; AVX512BW-NEXT:    vpshufb %zmm10, %zmm9, %zmm9
-; AVX512BW-NEXT:    movl $2228258, %ecx # imm = 0x220022
+; AVX512BW-NEXT:    movl $572662306, %ecx # imm = 0x22222222
 ; AVX512BW-NEXT:    kmovd %ecx, %k2
 ; AVX512BW-NEXT:    vmovdqu16 %zmm9, %zmm6 {%k2}
 ; AVX512BW-NEXT:    movw $-21846, %cx # imm = 0xAAAA
@@ -2136,7 +2136,7 @@ define void @store_i8_stride8_vf16(ptr %in.vecptr0, ptr %in.vecptr1, ptr %in.vec
 ; AVX512BW-FCP-NEXT:    vpermq {{.*#+}} zmm8 = zmm2[0,2,0,2,4,6,4,6]
 ; AVX512BW-FCP-NEXT:    vpmovsxwd {{.*#+}} zmm9 = [0,2048,0,2305,0,2562,0,2819,0,3076,0,3333,0,3590,0,3847]
 ; AVX512BW-FCP-NEXT:    vpshufb %zmm9, %zmm8, %zmm8
-; AVX512BW-FCP-NEXT:    movl $8913032, %ecx # imm = 0x880088
+; AVX512BW-FCP-NEXT:    movl $-2004318072, %ecx # imm = 0x88888888
 ; AVX512BW-FCP-NEXT:    kmovd %ecx, %k1
 ; AVX512BW-FCP-NEXT:    vmovdqu16 %zmm3, %zmm8 {%k1}
 ; AVX512BW-FCP-NEXT:    vpermt2q %zmm4, %zmm6, %zmm1
@@ -2146,7 +2146,7 @@ define void @store_i8_stride8_vf16(ptr %in.vecptr0, ptr %in.vecptr1, ptr %in.vec
 ; AVX512BW-FCP-NEXT:    vpermq {{.*#+}} zmm6 = zmm0[0,2,0,2,4,6,4,6]
 ; AVX512BW-FCP-NEXT:    vpmovsxwq {{.*#+}} zmm10 = [2048,2305,2562,2819,3076,3333,3590,3847]
 ; AVX512BW-FCP-NEXT:    vpshufb %zmm10, %zmm6, %zmm6
-; AVX512BW-FCP-NEXT:    movl $2228258, %ecx # imm = 0x220022
+; AVX512BW-FCP-NEXT:    movl $572662306, %ecx # imm = 0x22222222
 ; AVX512BW-FCP-NEXT:    kmovd %ecx, %k2
 ; AVX512BW-FCP-NEXT:    vmovdqu16 %zmm1, %zmm6 {%k2}
 ; AVX512BW-FCP-NEXT:    movw $-21846, %cx # imm = 0xAAAA
@@ -2193,7 +2193,7 @@ define void @store_i8_stride8_vf16(ptr %in.vecptr0, ptr %in.vecptr1, ptr %in.vec
 ; AVX512DQ-BW-NEXT:    vpermq {{.*#+}} zmm6 = zmm3[0,2,0,2,4,6,4,6]
 ; AVX512DQ-BW-NEXT:    vmovdqa64 {{.*#+}} zmm7 = [u,u,u,u,u,u,0,8,u,u,u,u,u,u,1,9,u,u,u,u,u,u,2,10,u,u,u,u,u,u,3,11,u,u,u,u,u,u,4,12,u,u,u,u,u,u,5,13,u,u,u,u,u,u,6,14,u,u,u,u,u,u,7,15]
 ; AVX512DQ-BW-NEXT:    vpshufb %zmm7, %zmm6, %zmm6
-; AVX512DQ-BW-NEXT:    movl $8913032, %ecx # imm = 0x880088
+; AVX512DQ-BW-NEXT:    movl $-2004318072, %ecx # imm = 0x88888888
 ; AVX512DQ-BW-NEXT:    kmovd %ecx, %k1
 ; AVX512DQ-BW-NEXT:    vmovdqu16 %zmm6, %zmm4 {%k1}
 ; AVX512DQ-BW-NEXT:    vinserti64x4 $1, %ymm0, %zmm0, %zmm0
@@ -2204,7 +2204,7 @@ define void @store_i8_stride8_vf16(ptr %in.vecptr0, ptr %in.vecptr1, ptr %in.vec
 ; AVX512DQ-BW-NEXT:    vpermq {{.*#+}} zmm9 = zmm1[0,2,0,2,4,6,4,6]
 ; AVX512DQ-BW-NEXT:    vpmovsxdq {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %zmm10
 ; AVX512DQ-BW-NEXT:    vpshufb %zmm10, %zmm9, %zmm9
-; AVX512DQ-BW-NEXT:    movl $2228258, %ecx # imm = 0x220022
+; AVX512DQ-BW-NEXT:    movl $572662306, %ecx # imm = 0x22222222
 ; AVX512DQ-BW-NEXT:    kmovd %ecx, %k2
 ; AVX512DQ-BW-NEXT:    vmovdqu16 %zmm9, %zmm6 {%k2}
 ; AVX512DQ-BW-NEXT:    movw $-21846, %cx # imm = 0xAAAA
@@ -2249,7 +2249,7 @@ define void @store_i8_stride8_vf16(ptr %in.vecptr0, ptr %in.vecptr1, ptr %in.vec
 ; AVX512DQ-BW-FCP-NEXT:    vpermq {{.*#+}} zmm8 = zmm2[0,2,0,2,4,6,4,6]
 ; AVX512DQ-BW-FCP-NEXT:    vpmovsxwd {{.*#+}} zmm9 = [0,2048,0,2305,0,2562,0,2819,0,3076,0,3333,0,3590,0,3847]
 ; AVX512DQ-BW-FCP-NEXT:    vpshufb %zmm9, %zmm8, %zmm8
-; AVX512DQ-BW-FCP-NEXT:    movl $8913032, %ecx # imm = 0x880088
+; AVX512DQ-BW-FCP-NEXT:    movl $-2004318072, %ecx # imm = 0x88888888
 ; AVX512DQ-BW-FCP-NEXT:    kmovd %ecx, %k1
 ; AVX512DQ-BW-FCP-NEXT:    vmovdqu16 %zmm3, %zmm8 {%k1}
 ; AVX512DQ-BW-FCP-NEXT:    vpermt2q %zmm4, %zmm6, %zmm1
@@ -2259,7 +2259,7 @@ define void @store_i8_stride8_vf16(ptr %in.vecptr0, ptr %in.vecptr1, ptr %in.vec
 ; AVX512DQ-BW-FCP-NEXT:    vpermq {{.*#+}} zmm6 = zmm0[0,2,0,2,4,6,4,6]
 ; AVX512DQ-BW-FCP-NEXT:    vpmovsxwq {{.*#+}} zmm10 = [2048,2305,2562,2819,3076,3333,3590,3847]
 ; AVX512DQ-BW-FCP-NEXT:    vpshufb %zmm10, %zmm6, %zmm6
-; AVX512DQ-BW-FCP-NEXT:    movl $2228258, %ecx # imm = 0x220022
+; AVX512DQ-BW-FCP-NEXT:    movl $572662306, %ecx # imm = 0x22222222
 ; AVX512DQ-BW-FCP-NEXT:    kmovd %ecx, %k2
 ; AVX512DQ-BW-FCP-NEXT:    vmovdqu16 %zmm1, %zmm6 {%k2}
 ; AVX512DQ-BW-FCP-NEXT:    movw $-21846, %cx # imm = 0xAAAA

[RKSimon]

Nice catch! LGTM

[XinWang10]

Thanks for review~