[X86] Add missing subvector_subreg_lowering for BF16 (#83720)

Fixes: #83358

Author: phoebewang

llvm/lib/Target/X86/X86InstrVecCompiler.td

@@ -83,6 +83,7 @@ defm : subvector_subreg_lowering<VR128, v2f64, VR256, v4f64,  sub_xmm>;
 defm : subvector_subreg_lowering<VR128, v8i16, VR256, v16i16, sub_xmm>;
 defm : subvector_subreg_lowering<VR128, v16i8, VR256, v32i8,  sub_xmm>;
 defm : subvector_subreg_lowering<VR128, v8f16, VR256, v16f16, sub_xmm>;
+defm : subvector_subreg_lowering<VR128, v8bf16, VR256, v16bf16, sub_xmm>;
 
 // A 128-bit subvector extract from the first 512-bit vector position is a
 // subregister copy that needs no instruction. Likewise, a 128-bit subvector
@@ -95,6 +96,7 @@ defm : subvector_subreg_lowering<VR128, v2f64, VR512, v8f64,  sub_xmm>;
 defm : subvector_subreg_lowering<VR128, v8i16, VR512, v32i16, sub_xmm>;
 defm : subvector_subreg_lowering<VR128, v16i8, VR512, v64i8,  sub_xmm>;
 defm : subvector_subreg_lowering<VR128, v8f16, VR512, v32f16, sub_xmm>;
+defm : subvector_subreg_lowering<VR128, v8bf16, VR512, v32bf16, sub_xmm>;
 
 // A 128-bit subvector extract from the first 512-bit vector position is a
 // subregister copy that needs no instruction. Likewise, a 128-bit subvector
@@ -107,6 +109,7 @@ defm : subvector_subreg_lowering<VR256, v4f64,  VR512, v8f64,  sub_ymm>;
 defm : subvector_subreg_lowering<VR256, v16i16, VR512, v32i16, sub_ymm>;
 defm : subvector_subreg_lowering<VR256, v32i8,  VR512, v64i8,  sub_ymm>;
 defm : subvector_subreg_lowering<VR256, v16f16, VR512, v32f16, sub_ymm>;
+defm : subvector_subreg_lowering<VR256, v16bf16, VR512, v32bf16, sub_ymm>;
 
 
 // If we're inserting into an all zeros vector, just use a plain move which

llvm/test/CodeGen/X86/avx512bf16-vl-intrinsics.ll

@@ -381,3 +381,25 @@ entry:
   %1 = shufflevector <8 x bfloat> %0, <8 x bfloat> undef, <16 x i32> zeroinitializer
   ret <16 x bfloat> %1
 }
+
+define <16 x i32> @pr83358() {
+; X86-LABEL: pr83358:
+; X86:       # %bb.0:
+; X86-NEXT:    vcvtneps2bf16y {{\.?LCPI[0-9]+_[0-9]+}}, %xmm0 # encoding: [0x62,0xf2,0x7e,0x28,0x72,0x05,A,A,A,A]
+; X86-NEXT:    # fixup A - offset: 6, value: {{\.?LCPI[0-9]+_[0-9]+}}, kind: FK_Data_4
+; X86-NEXT:    vshufi64x2 $0, %zmm0, %zmm0, %zmm0 # encoding: [0x62,0xf3,0xfd,0x48,0x43,0xc0,0x00]
+; X86-NEXT:    # zmm0 = zmm0[0,1,0,1,0,1,0,1]
+; X86-NEXT:    retl # encoding: [0xc3]
+;
+; X64-LABEL: pr83358:
+; X64:       # %bb.0:
+; X64-NEXT:    vcvtneps2bf16y {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0 # encoding: [0x62,0xf2,0x7e,0x28,0x72,0x05,A,A,A,A]
+; X64-NEXT:    # fixup A - offset: 6, value: {{\.?LCPI[0-9]+_[0-9]+}}-4, kind: reloc_riprel_4byte
+; X64-NEXT:    vshufi64x2 $0, %zmm0, %zmm0, %zmm0 # encoding: [0x62,0xf3,0xfd,0x48,0x43,0xc0,0x00]
+; X64-NEXT:    # zmm0 = zmm0[0,1,0,1,0,1,0,1]
+; X64-NEXT:    retq # encoding: [0xc3]
+  %1 = call <8 x bfloat> @llvm.x86.avx512bf16.cvtneps2bf16.256(<8 x float> <float 1.000000e+00, float 2.000000e+00, float 3.000000e+00, float 4.000000e+00, float 5.000000e+00, float 6.000000e+00, float 7.000000e+00, float 8.000000e+00>)
+  %2 = bitcast <8 x bfloat> %1 to <4 x i32>
+  %3 = shufflevector <4 x i32> %2, <4 x i32> undef, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 0, i32 1, i32 2, i32 3, i32 0, i32 1, i32 2, i32 3, i32 0, i32 1, i32 2, i32 3>
+  ret <16 x i32> %3
+}

llvm/test/CodeGen/X86/bfloat.ll

@@ -511,7 +511,7 @@ define void @fold_ext_trunc(ptr %pa, ptr %pc) nounwind {
 define bfloat @fold_ext_trunc2(bfloat %a) nounwind {
 ; X86-LABEL: fold_ext_trunc2:
 ; X86:       # %bb.0:
-; X86-NEXT:    vmovsh {{[0-9]+}}(%esp), %xmm0
+; X86-NEXT:    vmovsh {{.*#+}} xmm0 = mem[0],zero,zero,zero,zero,zero,zero,zero
 ; X86-NEXT:    retl
 ;
 ; CHECK-LABEL: fold_ext_trunc2:
@@ -934,8 +934,8 @@ define <8 x bfloat> @addv(<8 x bfloat> %a, <8 x bfloat> %b) nounwind {
 define <2 x bfloat> @pr62997(bfloat %a, bfloat %b) {
 ; X86-LABEL: pr62997:
 ; X86:       # %bb.0:
-; X86-NEXT:    vmovsh {{[0-9]+}}(%esp), %xmm0
-; X86-NEXT:    vmovsh {{[0-9]+}}(%esp), %xmm1
+; X86-NEXT:    vmovsh {{.*#+}} xmm0 = mem[0],zero,zero,zero,zero,zero,zero,zero
+; X86-NEXT:    vmovsh {{.*#+}} xmm1 = mem[0],zero,zero,zero,zero,zero,zero,zero
 ; X86-NEXT:    vpunpcklwd {{.*#+}} xmm0 = xmm0[0],xmm1[0],xmm0[1],xmm1[1],xmm0[2],xmm1[2],xmm0[3],xmm1[3]
 ; X86-NEXT:    retl
 ;
@@ -2423,7 +2423,6 @@ define <16 x bfloat> @fptrunc_v16f32(<16 x float> %a) nounwind {
 ; AVXNC-LABEL: fptrunc_v16f32:
 ; AVXNC:       # %bb.0:
 ; AVXNC-NEXT:    {vex} vcvtneps2bf16 %ymm0, %xmm0
-; AVXNC-NEXT:    vinsertf128 $0, %xmm0, %ymm0, %ymm0
 ; AVXNC-NEXT:    {vex} vcvtneps2bf16 %ymm1, %xmm1
 ; AVXNC-NEXT:    vinsertf128 $1, %xmm1, %ymm0, %ymm0
 ; AVXNC-NEXT:    retq