[llvm-branch-commits] [llvm] release/18.x: [X86] Add missing subvector_subreg_lowering for BF16 (#83720) (PR #83834)

[Tom Stellard via llvm-branch-commits]

https://github.com/tstellar updated https://github.com/llvm/llvm-project/pull/83834

>From 26a1d6601d727a96f4301d0d8647b5a42760ae0c Mon Sep 17 00:00:00 2001
From: Phoebe Wang <phoebe.wang at intel.com>
Date: Mon, 4 Mar 2024 18:09:41 +0800
Subject: [PATCH] [X86] Add missing subvector_subreg_lowering for BF16 (#83720)

---
 llvm/lib/Target/X86/X86InstrVecCompiler.td    |  3 +++
 .../CodeGen/X86/avx512bf16-vl-intrinsics.ll   | 22 +++++++++++++++++++
 llvm/test/CodeGen/X86/bfloat.ll               |  1 -
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/Target/X86/X86InstrVecCompiler.td b/llvm/lib/Target/X86/X86InstrVecCompiler.td
index bbd19cf8d5b25e..461b2badc13134 100644
--- a/llvm/lib/Target/X86/X86InstrVecCompiler.td
+++ b/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
diff --git a/llvm/test/CodeGen/X86/avx512bf16-vl-intrinsics.ll b/llvm/test/CodeGen/X86/avx512bf16-vl-intrinsics.ll
index 0826faa1071b01..482713e12d15c7 100644
--- a/llvm/test/CodeGen/X86/avx512bf16-vl-intrinsics.ll
+++ b/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
+}
diff --git a/llvm/test/CodeGen/X86/bfloat.ll b/llvm/test/CodeGen/X86/bfloat.ll
index f2d3c4fb34199e..cd1dba17611628 100644
--- a/llvm/test/CodeGen/X86/bfloat.ll
+++ b/llvm/test/CodeGen/X86/bfloat.ll
@@ -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