i965: Shorten sampler loops in precompile key setup.

Now that we have the number of samplers available, we don't need to
iterate over all 16.  This should be particularly helpful for vertex
shaders.

v2: Use the correct shader program (caught by Paul Berry).

This needs to initialize the exact same set of sampler swizzles as
the actual key setup, or else we end up doing recompiles due to some
being XYZW and others being 0.

Signed-off-by: Kenneth Graunke <[email protected]>
Reviewed-by: Paul Berry <[email protected]>

2 files changed, 4 insertions, 2 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index d111cbd28cd..52fa6f4a750 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -3157,7 +3157,8 @@ brw_fs_precompile(struct gl_context *ctx, struct gl_shader_program *prog)
 
    key.clamp_fragment_color = ctx->API == API_OPENGL_COMPAT;
 
-   for (int i = 0; i < MAX_SAMPLERS; i++) {
+   unsigned sampler_count = _mesa_fls(fp->Base.SamplersUsed);
+   for (unsigned i = 0; i < sampler_count; i++) {
       if (fp->Base.ShadowSamplers & (1 << i)) {
          /* Assume DEPTH_TEXTURE_MODE is the default: X, X, X, 1 */
          key.tex.swizzles[i] =
diff --git a/src/mesa/drivers/dri/i965/brw_vs.c b/src/mesa/drivers/dri/i965/brw_vs.c
index dcd14a319df..ee77b019740 100644
--- a/src/mesa/drivers/dri/i965/brw_vs.c
+++ b/src/mesa/drivers/dri/i965/brw_vs.c
@@ -530,7 +530,8 @@ brw_vs_precompile(struct gl_context *ctx, struct gl_shader_program *prog)
    key.base.program_string_id = bvp->id;
    key.base.clamp_vertex_color = ctx->API == API_OPENGL_COMPAT;
 
-   for (int i = 0; i < MAX_SAMPLERS; i++) {
+   unsigned sampler_count = _mesa_fls(vp->Base.SamplersUsed);
+   for (unsigned i = 0; i < sampler_count; i++) {
       if (vp->Base.ShadowSamplers & (1 << i)) {
          /* Assume DEPTH_TEXTURE_MODE is the default: X, X, X, 1 */
          key.base.tex.swizzles[i] =