From bfdae9149e00bd5c2521db3e75669ae043eed5cc Mon Sep 17 00:00:00 2001 From: Neil Roberts Date: Fri, 8 May 2015 17:35:18 +0100 Subject: [PATCH] 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 Reviewed-by: Chris Forbes --- 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 b2701b89689..3414d92efde 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. */ -- 2.30.2