Bug 1905842 - add dotprod and SVE CPU config;r=glandium

Differential Revision: https://phabricator.services.mozilla.com/D215667

build/moz.configure/toolchain.configure

@@ -3874,6 +3874,26 @@ set_config(
     ),
 )
 
+set_config(
+    "SVE2_FLAGS",
+    ["-march=armv9-a+sve2"],
+    try_compile(
+        check_msg="for ARM SVE2 target feature",
+        flags=["-march=armv9-a+sve2"],
+        when=is_aarch64_target,
+    ),
+)
+
+set_config(
+    "DOTPROD_FLAGS",
+    ["-march=armv8.2-a+dotprod"],
+    try_compile(
+        check_msg="for ARM dotprod target feature",
+        flags=["-march=armv8.2-a+dotprod"],
+                when=is_aarch64_target,
+    ),
+)
+
 # dtrace support
 ##
 option("--enable-dtrace", help="Build with dtrace support")

media/libyuv/moz.build

@@ -9,6 +9,9 @@ with Files("**"):
 
 include('/build/gyp.mozbuild')
 
+gyp_vars['moz_have_arm_sve2'] = 1 if CONFIG['SVE2_FLAGS'] else 0
+gyp_vars['moz_have_arm_i8mm_and_dot_prod'] = 1 if CONFIG['NEON_I8MM_FLAGS'] and CONFIG['DOTPROD_FLAGS'] else 0
+
 # Set gyp vars that libyuv needs when building under various analysis tools.
 gyp_vars_copy = gyp_vars.copy()
 if CONFIG['MOZ_VALGRIND']: