[Mesa-dev] [PATCH 08/15] i965/blorp: Implement proper texel fetch messages for Gen7.

[Paul Berry]

On Gen6, texel fetch is always accomplished using the SAMPLE_LD
message, which accepts arguments (u, v, r, lod, si).  On Gen7, there
are two* texel fetch messages: SAMPLE_LD for non-MSAA surfaces, taking
arguments (u, lod, v), and SAMPLE_LD2DSS for MSAA surfaces, taking
arguments (si, u, v).

*Technically, there are other texel fetch messages, but they are used
for "compressed" MSAA surfaces, which we don't yet support.

This patch adds the proper message types and argument orderings for
Gen7.
---
 src/mesa/drivers/dri/i965/brw_blorp_blit.cpp |   32 ++++++++++++++++++++++++-
 src/mesa/drivers/dri/i965/brw_defines.h      |    1 +
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp b/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
index 07e9dd7..afed517 100644
--- a/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
+++ b/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
@@ -944,15 +944,43 @@ brw_blorp_blit_program::sample()
 void
 brw_blorp_blit_program::texel_fetch()
 {
-   static const sampler_message_arg args[5] = {
+   static const sampler_message_arg gen6_args[5] = {
       SAMPLER_MESSAGE_ARG_U_INT,
       SAMPLER_MESSAGE_ARG_V_INT,
       SAMPLER_MESSAGE_ARG_ZERO_INT, /* R */
       SAMPLER_MESSAGE_ARG_ZERO_INT, /* LOD */
       SAMPLER_MESSAGE_ARG_SI_INT
    };
+   static const sampler_message_arg gen7_ld_args[3] = {
+      SAMPLER_MESSAGE_ARG_U_INT,
+      SAMPLER_MESSAGE_ARG_ZERO_INT, /* LOD */
+      SAMPLER_MESSAGE_ARG_V_INT
+   };
+   static const sampler_message_arg gen7_ld2dss_args[3] = {
+      SAMPLER_MESSAGE_ARG_SI_INT,
+      SAMPLER_MESSAGE_ARG_U_INT,
+      SAMPLER_MESSAGE_ARG_V_INT
+   };
 
-   texture_lookup(GEN5_SAMPLER_MESSAGE_SAMPLE_LD, args, s_is_zero ? 2 : 5);
+   switch (brw->intel.gen) {
+   case 6:
+      texture_lookup(GEN5_SAMPLER_MESSAGE_SAMPLE_LD, gen6_args,
+                     s_is_zero ? 2 : 5);
+      break;
+   case 7:
+      if (key->tex_samples > 0) {
+         texture_lookup(GEN7_SAMPLER_MESSAGE_SAMPLE_LD2DSS,
+                        gen7_ld2dss_args, ARRAY_SIZE(gen7_ld2dss_args));
+      } else {
+         assert(s_is_zero);
+         texture_lookup(GEN5_SAMPLER_MESSAGE_SAMPLE_LD, gen7_ld_args,
+                        ARRAY_SIZE(gen7_ld_args));
+      }
+      break;
+   default:
+      assert(false);
+      break;
+   };
 }
 
 void
diff --git a/src/mesa/drivers/dri/i965/brw_defines.h b/src/mesa/drivers/dri/i965/brw_defines.h
index aaab5a2..a087f70 100644
--- a/src/mesa/drivers/dri/i965/brw_defines.h
+++ b/src/mesa/drivers/dri/i965/brw_defines.h
@@ -830,6 +830,7 @@ enum brw_message_target {
 #define GEN5_SAMPLER_MESSAGE_SAMPLE_LOD_COMPARE  6
 #define GEN5_SAMPLER_MESSAGE_SAMPLE_LD           7
 #define GEN5_SAMPLER_MESSAGE_SAMPLE_RESINFO      10
+#define GEN7_SAMPLER_MESSAGE_SAMPLE_LD2DSS       31
 
 /* for GEN5 only */
 #define BRW_SAMPLER_SIMD_MODE_SIMD4X2                   0
-- 
1.7.7.6