Enable FIXED_POINT and -O3 for Opus when building for ARM.

third_party/opus/opus.gyp

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'variables': {
     'conditions': [
+      ['((OS=="android" or chromeos==1) and (target_arch=="arm" or target_arch=="arm64")) or (OS=="ios" and target_arch=="armv7")', {

[Sergey Ulanov, 2014/06/04 02:47:24]

Can this be simply 'target_arch=="arm" or target_arch=="arm64" or
target_arch=="armv7"'? AFAIK we don't build for ARM for any other OSes.
The conditions below can probably be cleaned up too.

[Solis, 2014/06/04 15:04:04]

l.776, l.845 of build/common.gypi mentions linux but wouldn't we want to enable
the same optimizations there?

+        'use_opus_fixed_point%': 1,
+      }, {
+        'use_opus_fixed_point%': 0,
+      }],
       ['((OS=="android" or chromeos==1) and target_arch=="arm") or (OS=="ios" and target_arch=="armv7")', {
-        'use_opus_fixed_point%': 1,
         'use_opus_arm_optimization%': 1,
       }, {
-        'use_opus_fixed_point%': 0,
         'use_opus_arm_optimization%': 0,
       }],
       ['(OS=="android" or chromeos==1) and target_arch=="arm"', {
         'use_opus_rtcd%': 1,
       }, {
         'use_opus_rtcd%': 0,
       }],
     ],
   },
   'targets': [
@@ skipping 25 matching lines @@
         }, {
           'defines': [
             'USE_ALLOCA',
             'inline=__inline',
           ],
           'msvs_disabled_warnings': [
             4305,  # Disable truncation warning in celt/pitch.c .
             4334,  # Disable 32-bit shift warning in src/opus_encoder.c .
           ],
         }],
-        [ 'os_posix==1 and OS!="android"', {
+        ['os_posix==1 and OS!="android"', {
           # Suppress a warning given by opus_decoder.c that tells us
           # optimizations are turned off.
           'cflags': [
             '-Wno-#pragma-messages',
           ],
           'xcode_settings': {
             'WARNING_CFLAGS': [
               '-Wno-#pragma-messages',
             ],
           },
         }],
+        ['os_posix==1 and (target_arch=="arm" or target_arch=="arm64")', {
+          'cflags!': ['-Os'],
+          'cflags': ['-O3'],

[Sergey Ulanov, 2014/06/04 02:47:24]

You can set release_optimize=3 instead of adding flags explicitly. E.g. see
ffmpeg.gyp:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/ffmpeg...

Any reason we need to limit this flag to ARM? Maybe use O3 on Intel too?

[Solis, 2014/06/04 15:04:04]

Setting release_optimize in ffmpeg.gyp doesn't appear to do anything. Try
changing it '3' for instance. .ninja's generated for OS=="android" will still
use -Os and other platforms will use -O2. Setting the variable would be a much
better solution than what is in this CL. If you have any idea how to do it I'm
all ears.
The only reason being I haven't tested it on anything but ARM and AFAIK we don't
have any automatic regression tests at this point... :/

[Sergey Ulanov, 2014/06/04 17:55:55]

You need to set it in this file, not if ffmpeg.gyp. ffmpeg.gyp is just an
example of how it can be done. And it does work for ffmpeg (I see -O2 in
ffmpeg.ninja). Note that the flag has to be set in the 'target_defaults'
section.
release_optimize should work for Android too. I've just verified it.
There are some tests we run as part of remoting_unittests.

[Solis, 2014/06/04 19:55:43]

As discussed over chat, there was a bug in common.gypi causing this to not
actually work (not for ffmpeg, not for opus).

+        }],
         ['use_opus_fixed_point==0', {
           'include_dirs': [
             'src/silk/float',
           ],
           'sources/': [
             ['exclude', '/fixed/[^/]*_FIX.(h|c)$'],
           ],
         }, {
           'defines': [
             'FIXED_POINT',
@@ skipping 55 matching lines @@
       'sources': [
         'src/src/opus_demo.c',
       ],
       'include_dirs': [
         'src/celt',
         'src/silk',
       ],
     },  # target opus_demo
   ]
 }