Bug 270689 – [WPE] [LibWebRTC] Fix build for ARM 32-bit

• Component: New Bugs
• Status: RESOLVED FIXED

[Diego Pino]

When building WPE with build flag `--cmakeargs=-DUSE_GSTREAMER_WEBRTC=FALSE` (enables LibWebRTC) on ARM 32-bit, I got the following build error:

```
In file included from /home/dpino/WPEWebKit/Source/ThirdParty/libwebrtc/Source/third_party/pffft/src/pffft.c:155:
/home/dpino/WPEWebKit/Source/ThirdParty/libwebrtc/Source/third_party/pffft/src/pffft.c: In function ‘passf2_ps’:
/usr/lib/gcc/arm-linux-gnueabihf/11/include/arm_neon.h:1957:1: error: inlining failed in call to ‘always_inline’ ‘vsubq_f32’: target specific option mismatch
 1957 | vsubq_f32 (float32x4_t a, float32x4_t b)
```

This build error also happens in other files such as:

Source/webrtc/modules/audio_processing/aec3/adaptive_fir_filter.cc
Source/webrtc/modules/audio_processing/aec3/adaptive_fir_filter_erl.cc
Source/webrtc/modules/audio_processing/aec3/comfort_noise_generator.cc
Source/webrtc/modules/audio_processing/aec3/matched_filter.cc
Source/webrtc/modules/audio_processing/aec3/suppression_filter.cc
Source/webrtc/modules/audio_processing/aec3/suppression_gain.cc

These files need to be explicitly set with build flags "-mfpu=neon -mfloat-abi=hard". See:

- Source/ThirdParty/libwebrtc/Source/webrtc/modules/audio_processing/aec3/BUILD.gn
- Source/ThirdParty/libwebrtc/Source/third_party/pffft/README.txt

[Diego Pino]

Pull request: https://github.com/webkit/webkit/pull/25620

[EWS]

Committed 275915@main (565848432d81): <https://commits.webkit.org/275915@main>

Reviewed commits have been landed. Closing PR #25620 and removing active labels.

[Radar WebKit Bug Importer]

<rdar://problem/124399531>