[Mesa-dev] [PATCH 1/6] mesa: Create a _mesa_bitcount_64() function.

[Kenneth Graunke]

On 10/04/2011 07:00 AM, Brian Paul wrote:
> On 10/03/2011 04:11 PM, Paul Berry wrote:
>> The i965 driver already had a function to do this (brw_count_bits()),
>> but it was buggy (it only counted the bottom 32 bits) and it was
>> clumsy (it had a strange and broken fallback for non-GCC-like
>> compilers, which fortunately was never used).  Since Mesa already has
>> a _mesa_bitcount() function, it seems better to just create a
>> _mesa_bitcount_64() function rather than special-case this in the i965
>> driver.
>> ---
>>   src/mesa/drivers/dri/i965/brw_util.h |    7 ++-----
>>   src/mesa/main/imports.c              |   13 +++++++++++++
>>   src/mesa/main/imports.h              |    3 +++
>>   3 files changed, 18 insertions(+), 5 deletions(-)
>>
>> diff --git a/src/mesa/drivers/dri/i965/brw_util.h
>> b/src/mesa/drivers/dri/i965/brw_util.h
>> index 940a871..bbf36f6 100644
>> --- a/src/mesa/drivers/dri/i965/brw_util.h
>> +++ b/src/mesa/drivers/dri/i965/brw_util.h
>> @@ -34,15 +34,12 @@
>>   #define BRW_UTIL_H
>>
>>   #include "main/mtypes.h"
>> +#include "main/imports.h"
>>
>> -#ifdef __GNUC__
>> -#define brw_count_bits(v) __builtin_popcount(v)
>> -#else
>>   static inline GLuint brw_count_bits(uint64_t v)
>>   {
>> -    return _mesa_popcount(v>>32) + _mesa_popcount(v&0xffffffff);
>> +   return _mesa_bitcount_64(v);
>>   }
>> -#endif
> 
> I'm guessing you could eventually get rid of the brw_count_bits()
> wrapper altogether at some point.
> 
> Reviewed-by: Brian Paul <brianp at vmware.com>

I'd be glad to see that go, too.

Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>