[Mesa-dev] [PATCH] i965/skl: Use 1 register for uniform pull constant payload

[Ben Widawsky]

When under dispatch_width=16 the previous code would allocate 2 registers for
the payload when only one is needed. This manifested itself through bugs on SKL
which needs to mess with this instruction.

Ken though this might impact shader-db, but apparently it doesn't

Cc: Kenneth Graunke <kenneth at whitecape.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89118
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88999
Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
 src/mesa/drivers/dri/i965/brw_fs.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index c46e1d7..24125cc 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -3062,7 +3062,7 @@ fs_visitor::lower_uniform_pull_constant_loads()
          assert(const_offset_reg.file == IMM &&
                 const_offset_reg.type == BRW_REGISTER_TYPE_UD);
          const_offset_reg.fixed_hw_reg.dw1.ud /= 4;
-         fs_reg payload = vgrf(glsl_type::uint_type);
+         fs_reg payload = fs_reg(GRF, alloc.allocate(1));
 
          /* We have to use a message header on Skylake to get SIMD4x2 mode.
           * Reserve space for the register.
-- 
2.3.0