From faea1c5ccc936d0159d55727df7617398c20130a Mon Sep 17 00:00:00 2001
From: Simon Pilgrim <llvm-dev@redking.me.uk>
Date: Thu, 9 Mar 2023 12:07:40 +0000
Subject: [PATCH] [X86] Add test case showing failure to fold
 concat_v32i8(trunc_v16i16(x),trunc_v16i16(y)) ->
 trunc_v32i16(concat_v16i16(x,y))

We have similar tests but nothing that should only fold on BWI targets
---
 llvm/test/CodeGen/X86/vector-trunc.ll | 74 +++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/llvm/test/CodeGen/X86/vector-trunc.ll b/llvm/test/CodeGen/X86/vector-trunc.ll
index c7bf6da..b3147c1 100644
--- a/llvm/test/CodeGen/X86/vector-trunc.ll
+++ b/llvm/test/CodeGen/X86/vector-trunc.ll
@@ -1743,6 +1743,80 @@ entry:
   ret i64 %1
 }
 
+define <32 x i8> @trunc2x16i16_32i8(<16 x i16> %a, <16 x i16> %b) {
+; SSE-LABEL: trunc2x16i16_32i8:
+; SSE:       # %bb.0: # %entry
+; SSE-NEXT:    movdqa {{.*#+}} xmm4 = [255,0,255,0,255,0,255,0,255,0,255,0,255,0,255,0]
+; SSE-NEXT:    pand %xmm4, %xmm1
+; SSE-NEXT:    pand %xmm4, %xmm0
+; SSE-NEXT:    packuswb %xmm1, %xmm0
+; SSE-NEXT:    pand %xmm4, %xmm3
+; SSE-NEXT:    pand %xmm2, %xmm4
+; SSE-NEXT:    packuswb %xmm3, %xmm4
+; SSE-NEXT:    movdqa %xmm4, %xmm1
+; SSE-NEXT:    retq
+;
+; AVX1-LABEL: trunc2x16i16_32i8:
+; AVX1:       # %bb.0: # %entry
+; AVX1-NEXT:    vmovaps {{.*#+}} ymm2 = [255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255]
+; AVX1-NEXT:    vandps %ymm2, %ymm0, %ymm0
+; AVX1-NEXT:    vextractf128 $1, %ymm0, %xmm3
+; AVX1-NEXT:    vpackuswb %xmm3, %xmm0, %xmm0
+; AVX1-NEXT:    vandps %ymm2, %ymm1, %ymm1
+; AVX1-NEXT:    vextractf128 $1, %ymm1, %xmm2
+; AVX1-NEXT:    vpackuswb %xmm2, %xmm1, %xmm1
+; AVX1-NEXT:    vinsertf128 $1, %xmm1, %ymm0, %ymm0
+; AVX1-NEXT:    retq
+;
+; AVX2-LABEL: trunc2x16i16_32i8:
+; AVX2:       # %bb.0: # %entry
+; AVX2-NEXT:    vpbroadcastw {{.*#+}} ymm2 = [255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255]
+; AVX2-NEXT:    vpand %ymm2, %ymm0, %ymm0
+; AVX2-NEXT:    vpand %ymm2, %ymm1, %ymm1
+; AVX2-NEXT:    vpackuswb %ymm1, %ymm0, %ymm0
+; AVX2-NEXT:    vpermq {{.*#+}} ymm0 = ymm0[0,2,1,3]
+; AVX2-NEXT:    retq
+;
+; AVX512F-LABEL: trunc2x16i16_32i8:
+; AVX512F:       # %bb.0: # %entry
+; AVX512F-NEXT:    vpmovzxwd {{.*#+}} zmm0 = ymm0[0],zero,ymm0[1],zero,ymm0[2],zero,ymm0[3],zero,ymm0[4],zero,ymm0[5],zero,ymm0[6],zero,ymm0[7],zero,ymm0[8],zero,ymm0[9],zero,ymm0[10],zero,ymm0[11],zero,ymm0[12],zero,ymm0[13],zero,ymm0[14],zero,ymm0[15],zero
+; AVX512F-NEXT:    vpmovdb %zmm0, %xmm0
+; AVX512F-NEXT:    vpmovzxwd {{.*#+}} zmm1 = ymm1[0],zero,ymm1[1],zero,ymm1[2],zero,ymm1[3],zero,ymm1[4],zero,ymm1[5],zero,ymm1[6],zero,ymm1[7],zero,ymm1[8],zero,ymm1[9],zero,ymm1[10],zero,ymm1[11],zero,ymm1[12],zero,ymm1[13],zero,ymm1[14],zero,ymm1[15],zero
+; AVX512F-NEXT:    vpmovdb %zmm1, %xmm1
+; AVX512F-NEXT:    vinserti128 $1, %xmm1, %ymm0, %ymm0
+; AVX512F-NEXT:    retq
+;
+; AVX512VL-LABEL: trunc2x16i16_32i8:
+; AVX512VL:       # %bb.0: # %entry
+; AVX512VL-NEXT:    vpmovzxwd {{.*#+}} zmm0 = ymm0[0],zero,ymm0[1],zero,ymm0[2],zero,ymm0[3],zero,ymm0[4],zero,ymm0[5],zero,ymm0[6],zero,ymm0[7],zero,ymm0[8],zero,ymm0[9],zero,ymm0[10],zero,ymm0[11],zero,ymm0[12],zero,ymm0[13],zero,ymm0[14],zero,ymm0[15],zero
+; AVX512VL-NEXT:    vpmovdb %zmm0, %xmm0
+; AVX512VL-NEXT:    vpmovzxwd {{.*#+}} zmm1 = ymm1[0],zero,ymm1[1],zero,ymm1[2],zero,ymm1[3],zero,ymm1[4],zero,ymm1[5],zero,ymm1[6],zero,ymm1[7],zero,ymm1[8],zero,ymm1[9],zero,ymm1[10],zero,ymm1[11],zero,ymm1[12],zero,ymm1[13],zero,ymm1[14],zero,ymm1[15],zero
+; AVX512VL-NEXT:    vpmovdb %zmm1, %xmm1
+; AVX512VL-NEXT:    vinserti128 $1, %xmm1, %ymm0, %ymm0
+; AVX512VL-NEXT:    retq
+;
+; AVX512BW-LABEL: trunc2x16i16_32i8:
+; AVX512BW:       # %bb.0: # %entry
+; AVX512BW-NEXT:    # kill: def $ymm1 killed $ymm1 def $zmm1
+; AVX512BW-NEXT:    # kill: def $ymm0 killed $ymm0 def $zmm0
+; AVX512BW-NEXT:    vpmovwb %zmm0, %ymm0
+; AVX512BW-NEXT:    vpmovwb %zmm1, %ymm1
+; AVX512BW-NEXT:    vinserti128 $1, %xmm1, %ymm0, %ymm0
+; AVX512BW-NEXT:    retq
+;
+; AVX512BWVL-LABEL: trunc2x16i16_32i8:
+; AVX512BWVL:       # %bb.0: # %entry
+; AVX512BWVL-NEXT:    vpmovwb %ymm0, %xmm0
+; AVX512BWVL-NEXT:    vpmovwb %ymm1, %xmm1
+; AVX512BWVL-NEXT:    vinserti128 $1, %xmm1, %ymm0, %ymm0
+; AVX512BWVL-NEXT:    retq
+entry:
+  %0 = trunc <16 x i16> %a to <16 x i8>
+  %1 = trunc <16 x i16> %b to <16 x i8>
+  %2 = shufflevector <16 x i8> %0, <16 x i8> %1, <32 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15, i32 16, i32 17, i32 18, i32 19, i32 20, i32 21, i32 22, i32 23, i32 24, i32 25, i32 26, i32 27, i32 28, i32 29, i32 30, i32 31>
+  ret <32 x i8> %2
+}
+
 define <16 x i8> @trunc2x8i16_16i8(<8 x i16> %a, <8 x i16> %b) {
 ; SSE2-LABEL: trunc2x8i16_16i8:
 ; SSE2:       # %bb.0: # %entry
-- 
2.7.4