From 9a8be20def31758eabd4918963a8d17e7b3569aa Mon Sep 17 00:00:00 2001
From: George Steed <george.steed@arm.com>
Date: Thu, 21 Mar 2024 16:55:31 +0000
Subject: [PATCH] [AArch64] Add :libyuv_sve library in preparation for SVE
 kernels

This commit only adds the bare minimum to get the new library building
through GN, the actual content of row_sve.cc is empty for now until we
start porting some kernels across.

Bug: libyuv:973
Change-Id: Ibdf4fc258761f3e507d700f27a405099c667ac75
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/5424738
Reviewed-by: Frank Barchard <fbarchard@chromium.org>
---
 BUILD.gn          | 32 ++++++++++++++++++++++++++++++++
 libyuv.gni        |  1 +
 source/row_sve.cc | 27 +++++++++++++++++++++++++++
 3 files changed, 60 insertions(+)
 create mode 100644 source/row_sve.cc

diff --git a/BUILD.gn b/BUILD.gn
index 32cc013f4..5bbf77ee0 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -35,6 +35,9 @@ config("libyuv_config") {
   if (!libyuv_use_neon) {
     defines += [ "LIBYUV_DISABLE_NEON" ]
   }
+  if (!libyuv_use_sve) {
+    defines += [ "LIBYUV_DISABLE_SVE" ]
+  }
   if (libyuv_disable_rvv) {
     defines += [ "LIBYUV_DISABLE_RVV" ]
   }
@@ -78,6 +81,10 @@ group("libyuv") {
     deps += [ ":libyuv_neon" ]
   }
 
+  if (libyuv_use_sve) {
+    deps += [ ":libyuv_sve" ]
+  }
+
   if (libyuv_use_msa) {
     deps += [ ":libyuv_msa" ]
   }
@@ -241,6 +248,31 @@ if (libyuv_use_neon) {
   }
 }
 
+if (libyuv_use_sve) {
+  static_library("libyuv_sve") {
+    sources = [
+      "source/row_sve.cc",
+    ]
+
+    deps = [ ":libyuv_internal" ]
+
+    public_configs = [ ":libyuv_config" ]
+
+    # Always enable optimization for Release and NaCl builds (to workaround
+    # crbug.com/538243).
+    if (!is_debug) {
+      configs -= [ "//build/config/compiler:default_optimization" ]
+
+      # Enable optimize for speed (-O2) over size (-Os).
+      # TODO(fbarchard): Consider optimize_speed which is O3.
+      configs += [ "//build/config/compiler:optimize_max" ]
+    }
+
+    # SVE2 is an Armv9-A feature.
+    cflags = [ "-march=armv9-a+sve2" ]
+  }
+}
+
 if (libyuv_use_msa) {
   static_library("libyuv_msa") {
     sources = [
diff --git a/libyuv.gni b/libyuv.gni
index 343160c36..6add96ad9 100644
--- a/libyuv.gni
+++ b/libyuv.gni
@@ -18,6 +18,7 @@ declare_args() {
   libyuv_use_neon =
       current_cpu == "arm64" ||
       (current_cpu == "arm" && (arm_use_neon || arm_optionally_use_neon))
+  libyuv_use_sve = current_cpu == "arm64"
   libyuv_use_msa =
       (current_cpu == "mips64el" || current_cpu == "mipsel") && mips_use_msa
   libyuv_use_mmi =
diff --git a/source/row_sve.cc b/source/row_sve.cc
new file mode 100644
index 000000000..670403c4a
--- /dev/null
+++ b/source/row_sve.cc
@@ -0,0 +1,27 @@
+/*
+ *  Copyright 2024 The LibYuv Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS. All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "libyuv/row.h"
+
+#ifdef __cplusplus
+namespace libyuv {
+extern "C" {
+#endif
+
+#if !defined(LIBYUV_DISABLE_SVE) && defined(__aarch64__)
+
+// TODO(libyuv:973) Port kernels to SVE/SVE2.
+
+#endif  // !defined(LIBYUV_DISABLE_SVE) && defined(__aarch64__)
+
+#ifdef __cplusplus
+}  // extern "C"
+}  // namespace libyuv
+#endif