[Mesa-dev] [PATCH] i965: set size of txf_mcs payload vgrf properly

[Chris Forbes]

Previously we left the size of this vgrf as 1, which caused register
allocation to be subtly broken. If we were lucky we would explode in
the post-alloc instruction scheduler; if we were unlucky we'd just stomp
on someone else and get broken rendering.

Fixes crash when running `tesseract` with the following settings:

   msaa 4
   glineardepth 0

Also fixes the piglit test:

  arb_sample_shading-builtin-gl-sample-id

Signed-off-by: Chris Forbes <chrisf at ijw.co.nz>
Cc: Anuj Phogat <anuj.phogat at gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=72859
---
 src/mesa/drivers/dri/i965/brw_fs_visitor.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
index 8e516a5..53cd0a1 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
@@ -1549,6 +1549,7 @@ fs_visitor::emit_mcs_fetch(ir_texture *ir, fs_reg coordinate, int sampler)
    }
 
    fs_inst *inst = emit(SHADER_OPCODE_TXF_MCS, dest, payload);
+   virtual_grf_sizes[payload.reg] = next.reg_offset;
    inst->base_mrf = -1;
    inst->mlen = next.reg_offset * reg_width;
    inst->header_present = false;
-- 
1.8.5.2