Mesa (master): i965/vec4: Use the sampler for pull constant loads on Broadwell.

[Kenneth Graunke]

Module: Mesa
Branch: master
Commit: 5d8e246ac86b4a94a0c2cf2bc707eceb3fe20cb6
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=5d8e246ac86b4a94a0c2cf2bc707eceb3fe20cb6

Author: Kenneth Graunke <kenneth at whitecape.org>
Date:   Sat Jun 14 12:58:03 2014 -0700

i965/vec4: Use the sampler for pull constant loads on Broadwell.

We've used the LD sampler message for pull constant loads on earlier
hardware for some time, and also were already using it for the FS on
Broadwell.  This patch makes us use it for Broadwell VS/GS as well.

I believe that when I wrote this code in 2012, we still used the data
port in some cases, and I somehow neglected to convert it while
rebasing.

Improves performance in GLBenchmark 2.7 Egypt by 416.978% +/- 2.25821%
(n = 17).  Many other applications should benefit similarly: this speeds
up uniform array access in the VS, which is commonly used for skinning
shaders, among other things.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Matt Turner <mattst88 at gmail.com>
Reviewed-by: Jordan Justen <jordan.l.justen at intel.com>
Tested-by: Ben Widawsky <ben at bwidawsk.net>
Cc: "10.2" <mesa-stable at lists.freedesktop.org>

---

 src/mesa/drivers/dri/i965/gen8_vec4_generator.cpp |   16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/gen8_vec4_generator.cpp b/src/mesa/drivers/dri/i965/gen8_vec4_generator.cpp
index 14070cd..82ea45a 100644
--- a/src/mesa/drivers/dri/i965/gen8_vec4_generator.cpp
+++ b/src/mesa/drivers/dri/i965/gen8_vec4_generator.cpp
@@ -444,14 +444,14 @@ gen8_vec4_generator::generate_pull_constant_load(vec4_instruction *inst,
    gen8_instruction *send = next_inst(BRW_OPCODE_SEND);
    gen8_set_dst(brw, send, dst);
    gen8_set_src0(brw, send, offset);
-   gen8_set_dp_message(brw, send, GEN7_SFID_DATAPORT_DATA_CACHE,
-                       surf_index,
-                       GEN6_DATAPORT_READ_MESSAGE_OWORD_DUAL_BLOCK_READ,
-                       0,      /* message control */
-                       1,      /* mlen */
-                       1,      /* rlen */
-                       false,  /* no header */
-                       false); /* EOT */
+   gen8_set_sampler_message(brw, send,
+                            surf_index,
+                            0, /* The LD message ignores the sampler unit. */
+                            GEN5_SAMPLER_MESSAGE_SAMPLE_LD,
+                            1,      /* rlen */
+                            1,      /* mlen */
+                            false,  /* no header */
+                            BRW_SAMPLER_SIMD_MODE_SIMD4X2);
 
    brw_mark_surface_used(&prog_data->base, surf_index);
 }