[Mesa-dev] [PATCH 26/29] mesa: Use bitmask/ffs to iterate the enabled textures.

[Mathias.Froehlich at gmx.net]

From: Mathias Fröhlich <mathias.froehlich at web.de>

Replaces an iterate and test bit in a bitmask loop by a
loop only iterating over the bits set in the bitmask.

Signed-off-by: Mathias Fröhlich <Mathias.Froehlich at web.de>
---
 src/mesa/main/texstate.c | 31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/src/mesa/main/texstate.c b/src/mesa/main/texstate.c
index 3543369..411073a 100644
--- a/src/mesa/main/texstate.c
+++ b/src/mesa/main/texstate.c
@@ -611,7 +611,7 @@ update_ff_texture_state(struct gl_context *ctx,
 
    for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
       struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
-      GLuint texIndex;
+      GLbitfield mask;
       bool complete;
 
       if (texUnit->Enabled == 0x0)
@@ -651,20 +651,21 @@ update_ff_texture_state(struct gl_context *ctx,
        *      undefined."
        */
       complete = false;
-      for (texIndex = 0; texIndex < NUM_TEXTURE_TARGETS; texIndex++) {
-         if (texUnit->Enabled & (1 << texIndex)) {
-            struct gl_texture_object *texObj = texUnit->CurrentTex[texIndex];
-            struct gl_sampler_object *sampler = texUnit->Sampler ?
-               texUnit->Sampler : &texObj->Sampler;
-
-            if (!_mesa_is_texture_complete(texObj, sampler)) {
-               _mesa_test_texobj_completeness(ctx, texObj);
-            }
-            if (_mesa_is_texture_complete(texObj, sampler)) {
-               _mesa_reference_texobj(&texUnit->_Current, texObj);
-               complete = true;
-               break;
-            }
+      mask = texUnit->Enabled;
+      while (mask) {
+         int texIndex = ffs(mask) - 1;
+         struct gl_texture_object *texObj = texUnit->CurrentTex[texIndex];
+         struct gl_sampler_object *sampler = texUnit->Sampler ?
+            texUnit->Sampler : &texObj->Sampler;
+         mask ^= (1u << texIndex);
+
+         if (!_mesa_is_texture_complete(texObj, sampler)) {
+            _mesa_test_texobj_completeness(ctx, texObj);
+         }
+         if (_mesa_is_texture_complete(texObj, sampler)) {
+            _mesa_reference_texobj(&texUnit->_Current, texObj);
+            complete = true;
+            break;
          }
       }
 
-- 
2.5.5