Module: Mesa
Branch: master
Commit: bfdae9149e00bd5c2521db3e75669ae043eed5cc
URL:
http://cgit.freedesktop.org/mesa/mesa/commit/?id=bfdae9149e00bd5c2521db3e75669ae043eed5cc
Author: Neil Roberts <n...@linux.intel.com>
Date: Fri May 8 17:35:18 2015 +0100
i965/fs: Disable opt_sampler_eot for textureGather
The opt_sampler_eot optimisation seems to break when the last
instruction is SHADER_OPCODE_TG4. A bunch of Piglit tests end up doing
this so it causes a lot of regressions. I can't find any documentation
or known workarounds to indicate that this is expected behaviour, but
considering that this is probably a pretty unlikely situation in a
real use case we might as well disable it in order to avoid the
regressions. In total this fixes 451 tests.
Reviewed-by: Ben Widawsky <b...@bwidawsk.net>
Reviewed-by: Chris Forbes <chr...@ijw.co.nz>
---
src/mesa/drivers/dri/i965/brw_fs.cpp | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp
b/src/mesa/drivers/dri/i965/brw_fs.cpp
index b2701b8..3414d92 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -2658,6 +2658,16 @@ fs_visitor::opt_sampler_eot()
if (unlikely(tex_inst->is_head_sentinel()) || !tex_inst->is_tex())
return false;
+ /* This optimisation doesn't seem to work for textureGather for some
+ * reason. I can't find any documentation or known workarounds to indicate
+ * that this is expected, but considering that it is probably pretty
+ * unlikely that a shader would directly write out the results from
+ * textureGather we might as well just disable it.
+ */
+ if (tex_inst->opcode == SHADER_OPCODE_TG4 ||
+ tex_inst->opcode == SHADER_OPCODE_TG4_OFFSET)
+ return false;
+
/* If there's no header present, we need to munge the LOAD_PAYLOAD as well.
* It's very likely to be the previous instruction.
*/
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