Mesa (master): st/mesa: use PK2H/UP2H when supported

[Ilia Mirkin]

Module: Mesa
Branch: master
Commit: 20dee333f3790b0a8f197efeaa54f91522cb606a
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=20dee333f3790b0a8f197efeaa54f91522cb606a

Author: Ilia Mirkin <imirkin at alum.mit.edu>
Date:   Thu Oct 29 02:52:57 2015 -0400

st/mesa: use PK2H/UP2H when supported

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
Reviewed-by: Edward O'Callaghan <eocallaghan at alterapraxis.com>
Reviewed-by: Roland Scheidegger <sroland at vmware.com>

---

 src/mesa/state_tracker/st_context.c        |    2 ++
 src/mesa/state_tracker/st_context.h        |    1 +
 src/mesa/state_tracker/st_glsl_to_tgsi.cpp |   16 +++++++++++-----
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/src/mesa/state_tracker/st_context.c b/src/mesa/state_tracker/st_context.c
index 2fb792d..724c3c5 100644
--- a/src/mesa/state_tracker/st_context.c
+++ b/src/mesa/state_tracker/st_context.c
@@ -248,6 +248,8 @@ st_create_context_priv( struct gl_context *ctx, struct pipe_context *pipe,
           PIPE_QUIRK_TEXTURE_BORDER_COLOR_SWIZZLE_R600));
    st->has_time_elapsed =
       screen->get_param(screen, PIPE_CAP_QUERY_TIME_ELAPSED);
+   st->has_half_float_packing =
+      screen->get_param(screen, PIPE_CAP_TGSI_PACK_HALF_FLOAT);
 
    /* GL limits and extensions */
    st_init_limits(st->pipe->screen, &ctx->Const, &ctx->Extensions);
diff --git a/src/mesa/state_tracker/st_context.h b/src/mesa/state_tracker/st_context.h
index 60a9a4b..276fa63 100644
--- a/src/mesa/state_tracker/st_context.h
+++ b/src/mesa/state_tracker/st_context.h
@@ -101,6 +101,7 @@ struct st_context
    boolean prefer_blit_based_texture_transfer;
    boolean force_persample_in_shader;
    boolean has_shareable_shaders;
+   boolean has_half_float_packing;
 
    /**
     * If a shader can be created when we get its source.
diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index cdbe2f4..2adb57d 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -2163,15 +2163,20 @@ glsl_to_tgsi_visitor::visit(ir_expression *ir)
       }
       break;
 
+   case ir_unop_pack_half_2x16:
+      emit_asm(ir, TGSI_OPCODE_PK2H, result_dst, op[0]);
+      break;
+   case ir_unop_unpack_half_2x16:
+      emit_asm(ir, TGSI_OPCODE_UP2H, result_dst, op[0]);
+      break;
+
    case ir_unop_pack_snorm_2x16:
    case ir_unop_pack_unorm_2x16:
-   case ir_unop_pack_half_2x16:
    case ir_unop_pack_snorm_4x8:
    case ir_unop_pack_unorm_4x8:
 
    case ir_unop_unpack_snorm_2x16:
    case ir_unop_unpack_unorm_2x16:
-   case ir_unop_unpack_half_2x16:
    case ir_unop_unpack_half_2x16_split_x:
    case ir_unop_unpack_half_2x16_split_y:
    case ir_unop_unpack_snorm_4x8:
@@ -5853,13 +5858,14 @@ st_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
                                LOWER_PACK_SNORM_4x8 |
                                LOWER_UNPACK_SNORM_4x8 |
                                LOWER_UNPACK_UNORM_4x8 |
-                               LOWER_PACK_UNORM_4x8 |
-                               LOWER_PACK_HALF_2x16 |
-                               LOWER_UNPACK_HALF_2x16;
+                               LOWER_PACK_UNORM_4x8;
 
          if (ctx->Extensions.ARB_gpu_shader5)
             lower_inst |= LOWER_PACK_USE_BFI |
                           LOWER_PACK_USE_BFE;
+         if (!ctx->st->has_half_float_packing)
+            lower_inst |= LOWER_PACK_HALF_2x16 |
+                          LOWER_UNPACK_HALF_2x16;
 
          lower_packing_builtins(ir, lower_inst);
       }