From: Eric Anholt <eric@anholt.net>
Date: Thu, 14 Feb 2013 05:21:45 +0000 (-0800)
Subject: i965/gen7: Set up all samplers even if samplers are sparsely used.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=5bb05c6e6d596d66c177e42a36128d2ca2e300aa;p=mesa.git

i965/gen7: Set up all samplers even if samplers are sparsely used.

In GLSL, sampler indices are allocated contiguously from 0.  But in the
case of ARB_fragment_program (and possibly fixed function), an app that
uses texture 0 and 2 will use sampler indices 0 and 2, so we were only
allocating space for samplers 0 and 1 and setting up sampler 0.  We
would read garbage for sampler 2, resulting in flickering textures and
an angry simulator.

Fixes bad rendering in 0 A.D. and ETQW.  This was fixed for pre-gen7 by
28f4be9eb91b12a2c6b1db6660cca71a98c486ec

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=25201
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=58680
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
NOTE: This is a candidate for stable branches.
---

diff --git a/src/mesa/drivers/dri/i965/gen7_sampler_state.c b/src/mesa/drivers/dri/i965/gen7_sampler_state.c
index 6f0a757380b..1fb947f80c8 100644
--- a/src/mesa/drivers/dri/i965/gen7_sampler_state.c
+++ b/src/mesa/drivers/dri/i965/gen7_sampler_state.c
@@ -196,7 +196,7 @@ gen7_upload_samplers(struct brw_context *brw)
 
    GLbitfield SamplersUsed = vs->SamplersUsed | fs->SamplersUsed;
 
-   brw->sampler.count = _mesa_bitcount(SamplersUsed);
+   brw->sampler.count = _mesa_fls(SamplersUsed);
 
    if (brw->sampler.count == 0)
       return;