add ARB_derivative_control support

adds the new TGSI opcodes for fine derivs

Reviewed-by: Elie Tournier <elie.tournier@collabora.com>

src/virgl_hw.h

@@ -239,6 +239,7 @@ struct virgl_caps_bool_set1 {
         unsigned has_sample_shading:1;
         unsigned has_cull:1;
         unsigned conditional_render_inverted:1;
+        unsigned derivative_control:1;
 };
 
 /* endless expansion capabilites - current gallium has 252 formats */

src/vrend_renderer.c

@@ -6955,11 +6955,14 @@ void vrend_renderer_fill_caps(uint32_t set, uint32_t version,
    if (gl_ver >= 45) {
      caps->v1.bset.has_cull = 1;
      caps->v1.bset.conditional_render_inverted = 1;
+     caps->v1.bset.derivative_control = 1;
    } else {
      if (epoxy_has_gl_extension("GL_ARB_cull_distance"))
         caps->v1.bset.has_cull = 1;
      if (epoxy_has_gl_extension("GL_ARB_conditional_render_inverted"))
 	caps->v1.bset.conditional_render_inverted = 1;
+     if (epoxy_has_gl_extension("GL_ARB_derivative_control"))
+	caps->v1.bset.derivative_control = 1;
    }
 
    if (epoxy_has_gl_extension("GL_EXT_texture_mirror_clamp") ||

src/vrend_shader.c

@@ -158,6 +158,7 @@ struct dump_ctx {
    bool uses_sample_shading;
    bool uses_gpu_shader5;
    bool write_mul_temp;
+   bool derivative_control;
 };
 
 static inline const char *tgsi_proc_to_prefix(int shader_type)
@@ -2198,6 +2199,16 @@ iter_instruction(struct tgsi_iterate_context *iter,
       emit_op1("dFdy");
       EMIT_BUF_WITH_RET(ctx, buf);
       break;
+   case TGSI_OPCODE_DDX_FINE:
+      ctx->derivative_control = true;
+      emit_op1("dFdxFine");
+      EMIT_BUF_WITH_RET(ctx, buf);
+      break;
+   case TGSI_OPCODE_DDY_FINE:
+      ctx->derivative_control = true;
+      emit_op1("dFdyFine");
+      EMIT_BUF_WITH_RET(ctx, buf);
+      break;
    case TGSI_OPCODE_RCP:
       snprintf(buf, 255, "%s = %s(1.0/(%s));\n", dsts[0], dstconv, srcs[0]);
       EMIT_BUF_WITH_RET(ctx, buf);
@@ -2626,6 +2637,8 @@ static char *emit_header(struct dump_ctx *ctx, char *glsl_hdr)
          STRCAT_WITH_RET(glsl_hdr, "#extension GL_ARB_gpu_shader5 : require\n");
       if (ctx->num_cull_dist_prop || ctx->key->prev_stage_num_cull_out)
          STRCAT_WITH_RET(glsl_hdr, "#extension GL_ARB_cull_distance : require\n");
+      if (ctx->derivative_control)
+         STRCAT_WITH_RET(glsl_hdr, "#extension GL_ARB_derivative_control : require\n");
    }
    return glsl_hdr;
 }