[Mesa-dev] [PATCH] glsl, st/shader_cache: check the whole sha1 for zero

[Timothy Arceri]

On 27/03/17 10:18, Grazvydas Ignotas wrote:
> On Sun, Mar 26, 2017 at 11:45 PM, Timothy Arceri <tarceri at itsqueeze.com> wrote:
>>
>>
>> On 27/03/17 03:30, Grazvydas Ignotas wrote:
>>>
>>> The checks were only looking at the first byte, while the intention
>>> seems to be to check if the whole sha1 is zero. This prevented all
>>> shaders with first byte zero in their sha1 from being saved.
>>>
>>> This shaves around a second from Deus Ex load time on a hot cache.
>>>
>>> Signed-off-by: Grazvydas Ignotas <notasas at gmail.com>
>>> ---
>>>  src/compiler/glsl/shader_cache.cpp       | 3 ++-
>>>  src/mesa/state_tracker/st_shader_cache.c | 3 ++-
>>>  2 files changed, 4 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/src/compiler/glsl/shader_cache.cpp
>>> b/src/compiler/glsl/shader_cache.cpp
>>> index 274bb8c..ea1bc01 100644
>>> --- a/src/compiler/glsl/shader_cache.cpp
>>> +++ b/src/compiler/glsl/shader_cache.cpp
>>> @@ -1219,11 +1219,12 @@ shader_cache_write_program_metadata(struct
>>> gl_context *ctx,
>>>      * generate a source from.
>>>      *
>>>      * TODO: In future we should use another method to generate a key for
>>> ff
>>>      * programs.
>>>      */
>>> -   if (*prog->data->sha1 == 0)
>>> +   static const char zero[sizeof(prog->data->sha1)] = {0};
>>
>>
>> I don't think this will compile on Windows.
>
> Why do you think so? From my experience msvc (forced to use it at
> work) is fine with sizeof(array) and zero initializers, and other code
> in src/compiler/glsl/ has used both already.

I was worried about zero[sizeof(prog->data->sha1)] as msvc seem very 
picky about that type of thing but if you say it works then that's fine.

>
> Gražvydas
>