i965/fs: introduce blorp specific rt-write for fs_generator

The compiler for blorp programs likes to emit instructions for
the message construction itself meaning that the generator needs
to skip any such when blorp programs are translated for the hw.
In addition, the binding table control is special for blorp
programs and the generator does not need to update the binding
tables associated with the compiler bookkeeping (this in fact
gets thrown away as the blorp compiler sets the program data
in its own way).

v2 (Paul): do not hardcode the binding table index but use
           fs_inst::target instead.

Signed-off-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Reviewed-by: Paul Berry <stereotype441@gmail.com>

src/mesa/drivers/dri/i965/brw_defines.h

@@ -753,6 +753,7 @@ enum opcode {
     * instructions.
     */
    FS_OPCODE_FB_WRITE = 128,
+   FS_OPCODE_BLORP_FB_WRITE,
    SHADER_OPCODE_RCP,
    SHADER_OPCODE_RSQ,
    SHADER_OPCODE_SQRT,

src/mesa/drivers/dri/i965/brw_fs.h

@@ -523,6 +523,7 @@ public:
 private:
    void generate_code(exec_list *instructions, FILE *dump_file);
    void generate_fb_write(fs_inst *inst);
+   void generate_blorp_fb_write(fs_inst *inst);
    void generate_pixel_xy(struct brw_reg dst, bool is_x);
    void generate_linterp(fs_inst *inst, struct brw_reg dst,
 			 struct brw_reg *src);

src/mesa/drivers/dri/i965/brw_fs_generator.cpp

@@ -190,6 +190,21 @@ fs_generator::generate_fb_write(fs_inst *inst)
    mark_surface_used(surf_index);
 }
 
+void
+fs_generator::generate_blorp_fb_write(fs_inst *inst)
+{
+   brw_fb_WRITE(p,
+                16 /* dispatch_width */,
+                inst->base_mrf,
+                brw_reg_from_fs_reg(&inst->src[0]),
+                BRW_DATAPORT_RENDER_TARGET_WRITE_SIMD16_SINGLE_SOURCE,
+                inst->target,
+                inst->mlen,
+                0,
+                true,
+                inst->header_present);
+}
+
 /* Computes the integer pixel x,y values from the origin.
  *
  * This is the basis of gl_FragCoord computation, but is also used
@@ -1726,6 +1741,10 @@ fs_generator::generate_code(exec_list *instructions, FILE *dump_file)
 	 generate_fb_write(inst);
 	 break;
 
+      case FS_OPCODE_BLORP_FB_WRITE:
+	 generate_blorp_fb_write(inst);
+	 break;
+
       case FS_OPCODE_MOV_DISPATCH_TO_FLAGS:
          generate_mov_dispatch_to_flags(inst);
          break;

src/mesa/drivers/dri/i965/brw_shader.cpp

@@ -406,6 +406,8 @@ brw_instruction_name(enum opcode op)
    switch (op) {
    case FS_OPCODE_FB_WRITE:
       return "fb_write";
+   case FS_OPCODE_BLORP_FB_WRITE:
+      return "blorp_fb_write";
 
    case SHADER_OPCODE_RCP:
       return "rcp";