Bug 90666 – GCC can't compile NEONHelpers.h

• Status: RESOLVED
• Resolution: FIXED
• Component: SVG

Here is error message. It seems some platforms enabling uninitialized variable warning (see below.)

third_party/WebKit/Source/WebCore/platform/graphics/filters/arm/NEONHelpers.h: In function 'float32x4_t WebCore::loadRGBA8AsFloat(uint32_t*)':
third_party/WebKit/Source/WebCore/platform/graphics/filters/arm/NEONHelpers.h:40:65: error: 'temporary1' is used uninitialized in this function [-Werror=uninitialized]

Could you fix this? Sorry, I'm not familiar with ARM and NEON.
Thanks in advance.

Introduced by:
http://trac.webkit.org/changeset/121900

[Zoltan Herczeg]

Gabor is working on it.

[Gabor Rapcsanyi]

Created attachment 151044 [details]
proposed patch

Fixed the defines of NEON intrinsics.

[Zoltan Herczeg]

Comment on attachment 151044 [details]
proposed patch

r=me

Can we do something like below?

uint32x2_t temporary0 = 0;
uint32x2_t temporary1 = vset_lane_u32(*source, temporary0, 0);

I'm not sure how to initialize uint32x2_t.

[Gabor Rapcsanyi]

(In reply to comment #5)
> Can we do something like below?
> 
> uint32x2_t temporary0 = 0;
> uint32x2_t temporary1 = vset_lane_u32(*source, temporary0, 0);
> 
> I'm not sure how to initialize uint32x2_t.

Yes this just hide the problem from older compilers.

I made another bug for the real problem: 
https://bugs.webkit.org/show_bug.cgi?id=90669

[Zoltan Herczeg]

> Yes this just hide the problem from older compilers.

The ifdefs were clearly wrong, if ARM_NEON_INTRINSICS is not defined, it should not be compiled.

On the long run, we should do something with the uninitalized variable. From our point if view, the initialization is really unnecessary, and would reduce the performance. Would be good to tell the compiler to ignore this message.

[Gabor Rapcsanyi]

Patch landed: http://trac.webkit.org/changeset/121951