[Mesa-dev] [PATCH] mesa: Enable LTO compilation

[Matt Turner]

On Mon, May 30, 2016 at 11:02 AM, ⚛ <0xe2.0x9a.0x9b at gmail.com> wrote:
>
> On Mon, May 30, 2016 at 7:39 PM, Matt Turner <mattst88 at gmail.com> wrote:
>>
>> On Mon, May 30, 2016 at 10:28 AM, <0xe2.0x9a.0x9b at gmail.com> wrote:
>> > This patch enables compilation with -flto.
>> >
>> > The performance benefits of LTO (GCC 4.9 & 6.1) are about 1% for glxgears.
>> > Performance changes in OpenGL games haven't been measured yet, my feeling is
>> > that they are negligible.
>>
>> Without a compelling reason, I don't think the build system should be
>> adding compiler flags like this.
>
>
> What does it mean "like this". The patched build system only checks whether -flto works because it needs to be disabled in mesa/src/mapi.
>
>>
>> -flto makes debugging impossible, at least the last time I tried it
>> with gcc. I don't think that's something we would want enabled
>> whenever it's supported.
>
>
> "Enable LTO compilation" means the person compiling Mesa can choose whether to use -flto.

Oh, I see. I misunderstood the patch initially.

Because src/mapi cannot be compiled with -flto, this patch *disables*
-flto in that directory if it is enabled. Interesting.

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