Issue #888 - Enable dav1d SIMD on more architectures

python/mozbuild/mozbuild/frontend/context.py

@@ -1803,6 +1803,17 @@ VARIABLES = {
         If yasm is not available on this system, or does not support the
         current target architecture, an error will be raised.
         """),
+
+    'USE_NASM': (bool, bool,
+        """Use the nasm assembler to assemble assembly files from SOURCES.
+
+        By default, the build will use the toolchain assembler, $(AS), to
+        assemble source files in assembly language (.s or .asm files). Setting
+        this value to ``True`` will cause it to use nasm instead.
+
+        If nasm is not available on this system, or does not support the
+        current target architecture, an error will be raised.
+        """),
 }
 
 # Sanity check: we don't want any variable above to have a list as storage type.

python/mozbuild/mozbuild/frontend/emitter.py

@@ -1006,6 +1006,14 @@ class TreeMetadataEmitter(LoggingMixin):
             passthru.variables['ASFLAGS'] = context.config.substs.get('YASM_ASFLAGS')
             passthru.variables['AS_DASH_C_FLAG'] = ''
 
+        if context.get('USE_NASM') is True:
+            nasm = context.config.substs.get('NASM')
+            if not nasm or not context.config.substs.get('HAVE_NASM'):
+                raise SandboxValidationError('nasm 2.14 or later is not available', context)
+            passthru.variables['AS'] = nasm
+            passthru.variables['ASFLAGS'] = context.config.substs.get('NASM_ASFLAGS')
+            passthru.variables['AS_DASH_C_FLAG'] = ''
+
         for (symbol, cls) in [
                 ('ANDROID_RES_DIRS', AndroidResDirs),
                 ('ANDROID_EXTRA_RES_DIRS', AndroidExtraResDirs),