967422 - ./configure incorrectly detects ARM SIMD/NEON support on impossible targets

Status: RESOLVED WONTFIX

(Thunderbird :: Build Config, defect)

Description

[gordan]

Attachment: arm-simd-neon-fix.patch

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Firefox/24.0 (Beta/Release)
Build ID: 20131212142940

Steps to reproduce:

./configure on armv5tel non-FPU target erroneously detects NEON supports, which causes the build to fail when trying to build using NEON code implementations.


Actual results:

During ./configure:
checking for ARM NEON support in compiler... yes

During build:
../../gfx/ycbcr/ycbcr_to_rgb565.o: In function `mozilla::gfx::ConvertYCbCrToRGB565(unsigned char const*, unsigned char const*, unsigned char const*, unsigned char*, int, int, int, int, int, int, int, mozilla::gfx::YUVType)':
/home/mock/rpmbuild/BUILD/thunderbird-24.2.0/comm-esr24/mozilla/gfx/ycbcr/ycbcr_to_rgb565.cpp:629: undefined reference to `mozilla::gfx::yuv42x_to_rgb565_row_neon(unsigned short*, unsigned char const*, unsigned char const*, unsigned char const*, int, int)'



Expected results:

NEON shouldn't even be checked unless MOZ_ARCH=armv7-a, certainly not if MOZ_ARCH=armv5te. In such cases SIMD and NEON detection should be skipped and corresponding values set to 0.

Attached patch fixes the problem.

Comment 1

[gordan]

This SIMD/NEON misdetection issue also affects Firefox (xulrunner).

Comment 2

[Joshua Cranmer [:jcranmer]]

Thunderbird 24 is unsupported. If it's still an issue, this would be a Core build config issue.