[Mesa-dev] [PATCH 1/3] st/mesa: use MIN2 macro in favour of custom _min function

[Marek Olšák]

The main reason _min exists is that it evaluates each parameter once,
while MIN2 evaluates each parameter twice, so in this case, MIN2 calls
the get_param function twice, which may not be desirable. The same for
the other macros.

Marek

On Fri, Feb 21, 2014 at 11:59 PM, Emil Velikov <emil.l.velikov at gmail.com> wrote:
> Signed-off-by: Emil Velikov <emil.l.velikov at gmail.com>
> ---
>  src/mesa/state_tracker/st_extensions.c | 27 +++++++++++----------------
>  1 file changed, 11 insertions(+), 16 deletions(-)
>
> diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
> index e43e7b4..a909b71 100644
> --- a/src/mesa/state_tracker/st_extensions.c
> +++ b/src/mesa/state_tracker/st_extensions.c
> @@ -39,11 +39,6 @@
>  #include "st_extensions.h"
>  #include "st_format.h"
>
> -static unsigned _min(unsigned a, unsigned b)
> -{
> -   return (a < b) ? a : b;
> -}
> -
>  static float _maxf(float a, float b)
>  {
>     return (a > b) ? a : b;
> @@ -72,19 +67,19 @@ void st_init_limits(struct st_context *st)
>     boolean can_ubo = TRUE;
>
>     c->MaxTextureLevels
> -      = _min(screen->get_param(screen, PIPE_CAP_MAX_TEXTURE_2D_LEVELS),
> +      = MIN2(screen->get_param(screen, PIPE_CAP_MAX_TEXTURE_2D_LEVELS),
>              MAX_TEXTURE_LEVELS);
>
>     c->Max3DTextureLevels
> -      = _min(screen->get_param(screen, PIPE_CAP_MAX_TEXTURE_3D_LEVELS),
> +      = MIN2(screen->get_param(screen, PIPE_CAP_MAX_TEXTURE_3D_LEVELS),
>              MAX_3D_TEXTURE_LEVELS);
>
>     c->MaxCubeTextureLevels
> -      = _min(screen->get_param(screen, PIPE_CAP_MAX_TEXTURE_CUBE_LEVELS),
> +      = MIN2(screen->get_param(screen, PIPE_CAP_MAX_TEXTURE_CUBE_LEVELS),
>              MAX_CUBE_TEXTURE_LEVELS);
>
>     c->MaxTextureRectSize
> -      = _min(1 << (c->MaxTextureLevels - 1), MAX_TEXTURE_RECT_SIZE);
> +      = MIN2(1 << (c->MaxTextureLevels - 1), MAX_TEXTURE_RECT_SIZE);
>
>     c->MaxArrayTextureLayers
>        = screen->get_param(screen, PIPE_CAP_MAX_TEXTURE_ARRAY_LAYERS);
> @@ -168,7 +163,7 @@ void st_init_limits(struct st_context *st)
>        }
>
>        pc->MaxTextureImageUnits =
> -         _min(screen->get_shader_param(screen, sh,
> +         MIN2(screen->get_shader_param(screen, sh,
>                                         PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS),
>                MAX_TEXTURE_IMAGE_UNITS);
>
> @@ -185,7 +180,7 @@ void st_init_limits(struct st_context *st)
>        pc->MaxTemps           = pc->MaxNativeTemps           =
>           screen->get_shader_param(screen, sh, PIPE_SHADER_CAP_MAX_TEMPS);
>        pc->MaxAddressRegs     = pc->MaxNativeAddressRegs     =
> -         _min(screen->get_shader_param(screen, sh, PIPE_SHADER_CAP_MAX_ADDRS),
> +         MIN2(screen->get_shader_param(screen, sh, PIPE_SHADER_CAP_MAX_ADDRS),
>                MAX_PROGRAM_ADDRESS_REGS);
>        pc->MaxParameters      = pc->MaxNativeParameters      =
>           screen->get_shader_param(screen, sh, PIPE_SHADER_CAP_MAX_CONSTS);
> @@ -196,7 +191,7 @@ void st_init_limits(struct st_context *st)
>           screen->get_shader_param(screen, sh, PIPE_SHADER_CAP_MAX_CONST_BUFFERS);
>        if (pc->MaxUniformBlocks)
>           pc->MaxUniformBlocks -= 1; /* The first one is for ordinary uniforms. */
> -      pc->MaxUniformBlocks = _min(pc->MaxUniformBlocks, MAX_UNIFORM_BUFFERS);
> +      pc->MaxUniformBlocks = MIN2(pc->MaxUniformBlocks, MAX_UNIFORM_BUFFERS);
>
>        pc->MaxCombinedUniformComponents = (pc->MaxUniformComponents +
>                                            c->MaxUniformBlockSize / 4 *
> @@ -240,16 +235,16 @@ void st_init_limits(struct st_context *st)
>     }
>
>     c->MaxCombinedTextureImageUnits =
> -         _min(c->Program[MESA_SHADER_VERTEX].MaxTextureImageUnits +
> +         MIN2(c->Program[MESA_SHADER_VERTEX].MaxTextureImageUnits +
>                c->Program[MESA_SHADER_GEOMETRY].MaxTextureImageUnits +
>                c->Program[MESA_SHADER_FRAGMENT].MaxTextureImageUnits,
>                MAX_COMBINED_TEXTURE_IMAGE_UNITS);
>
>     /* This depends on program constants. */
>     c->MaxTextureCoordUnits
> -      = _min(c->Program[MESA_SHADER_FRAGMENT].MaxTextureImageUnits, MAX_TEXTURE_COORD_UNITS);
> +      = MIN2(c->Program[MESA_SHADER_FRAGMENT].MaxTextureImageUnits, MAX_TEXTURE_COORD_UNITS);
>
> -   c->MaxTextureUnits = _min(c->Program[MESA_SHADER_FRAGMENT].MaxTextureImageUnits, c->MaxTextureCoordUnits);
> +   c->MaxTextureUnits = MIN2(c->Program[MESA_SHADER_FRAGMENT].MaxTextureImageUnits, c->MaxTextureCoordUnits);
>
>     c->Program[MESA_SHADER_VERTEX].MaxAttribs = MIN2(c->Program[MESA_SHADER_VERTEX].MaxAttribs, 16);
>
> @@ -749,7 +744,7 @@ void st_init_extensions(struct st_context *st)
>        ctx->Extensions.ARB_texture_buffer_object = GL_TRUE;
>
>        ctx->Const.MaxTextureBufferSize =
> -         _min(screen->get_param(screen, PIPE_CAP_MAX_TEXTURE_BUFFER_SIZE),
> +         MIN2(screen->get_param(screen, PIPE_CAP_MAX_TEXTURE_BUFFER_SIZE),
>                (1u << 31) - 1);
>        ctx->Const.TextureBufferOffsetAlignment =
>           screen->get_param(screen, PIPE_CAP_TEXTURE_BUFFER_OFFSET_ALIGNMENT);
> --
> 1.9.0
>
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