[gn] Test building AVX512

Because we don't test it in Github Actions, AVX512 support
has bit-rotted in GN a bit. Should take care of a cluster of
failures in the latest Chrome integration attempt. [1]

Also simplify/unify things for 32-bit.

[1] https://chromium-review.googlesource.com/c/chromium/src/+/7615883?tab=checks

PiperOrigin-RevId: 916227360

Author: Sentimentron

.github/workflows/build.yml

@@ -380,11 +380,19 @@ jobs:
         run: |
           git cl format --presubmit --no-clang-format --no-python --diff
         working-directory: ${{ github.workspace }}/xnnpack
-      - name: Generate build files
+      - name: Generate build files (with AVX512)
+        run: |
+          gn gen --check --args="is_debug=false clang_use_chrome_plugins=false dcheck_always_on=true cc_wrapper=\"ccache\" symbol_level=0 xnnpack_enable_avx512=true target_cpu=\"x64\" use_siso=true" out/x64.dchecks
+        working-directory: ${{ github.workspace }}/xnnpack
+      - name: Build all targets (Release + debug checks, with AVX512)
+        run: |
+          autoninja -C out/x64.dchecks
+        working-directory: ${{ github.workspace }}/xnnpack
+      - name: Generate build files (no AVX512)
         run: |
           gn gen --check --args="is_debug=false clang_use_chrome_plugins=false dcheck_always_on=true cc_wrapper=\"ccache\" symbol_level=0 xnnpack_enable_avx512=false target_cpu=\"x64\" use_siso=true" out/x64.dchecks
         working-directory: ${{ github.workspace }}/xnnpack
-      - name: Build all targets (Release + debug checks)
+      - name: Build all targets (Release + debug checks, without AVX512)
         run: |
           autoninja -C out/x64.dchecks
         working-directory: ${{ github.workspace }}/xnnpack

BUILD.gn

@@ -51,6 +51,7 @@ import("gen/avx256vnni_microkernels.bzl")
 import("gen/avx256vnnigfni_microkernels.bzl")
 import("gen/avx2_microkernels.bzl")
 import("gen/avx512amx_microkernels.bzl")
+import("gen/avx512bf16_microkernels.bzl")
 import("gen/avx512f_microkernels.bzl")
 import("gen/avx512fp16_microkernels.bzl")
 import("gen/avx512skx_microkernels.bzl")
@@ -617,14 +618,11 @@ if (current_cpu == "x64" || current_cpu == "x86") {
     sources += ALL_AVX512AMX_MICROKERNEL_SRCS
     sources += ALL_AVX512SKX_MICROKERNEL_SRCS
     sources += ALL_AVX512VBMI_MICROKERNEL_SRCS
-
-    if (current_cpu == "x64") {
-      # VNNI extensions are only supported for x64
-      sources += ALL_AVX256VNNI_MICROKERNEL_SRCS
-      sources += ALL_AVX256VNNIGFNI_MICROKERNEL_SRCS
-      sources += ALL_AVX512VNNI_MICROKERNEL_SRCS
-      sources += ALL_AVX512VNNIGFNI_MICROKERNEL_SRCS
-    }
+    sources += ALL_AVX512BF16_MICROKERNEL_SRCS
+    sources += ALL_AVX256VNNI_MICROKERNEL_SRCS
+    sources += ALL_AVX256VNNIGFNI_MICROKERNEL_SRCS
+    sources += ALL_AVX512VNNI_MICROKERNEL_SRCS
+    sources += ALL_AVX512VNNIGFNI_MICROKERNEL_SRCS
 
     cflags = [
       "-mavx512f",
@@ -635,14 +633,11 @@ if (current_cpu == "x64" || current_cpu == "x86") {
       "-mamx-int8",
       "-mgfni",
       "-mavx512vbmi",
+      "-mavx512bf16",
+      "-mavxvnniint8",
+      "-mavxvnni",
+      "-mavx512vnni",
     ]
-    if (current_cpu == "x64") {
-      cflags += [
-        "-mavxvnniint8",
-        "-mavxvnni",
-        "-mavx512vnni",
-      ]
-    }
   }
   xnnpack_source_set("avx_microkernels") {
     deps = [