gallium: add PIPE_SHADER_CAP_LOWER_IF_THRESHOLD

Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>

src/gallium/auxiliary/gallivm/lp_bld_limits.h

@@ -140,6 +140,7 @@ gallivm_get_shader_param(enum pipe_shader_cap param)
    case PIPE_SHADER_CAP_TGSI_FMA_SUPPORTED:
    case PIPE_SHADER_CAP_MAX_SHADER_BUFFERS:
    case PIPE_SHADER_CAP_MAX_SHADER_IMAGES:
+   case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
       return 0;
    case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT:
       return 32;

src/gallium/auxiliary/tgsi/tgsi_exec.h

@@ -534,6 +534,7 @@ tgsi_exec_get_shader_param(enum pipe_shader_cap param)
       return 1;
    case PIPE_SHADER_CAP_TGSI_DROUND_SUPPORTED:
    case PIPE_SHADER_CAP_TGSI_FMA_SUPPORTED:
+   case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
       return 0;
    case PIPE_SHADER_CAP_MAX_SHADER_BUFFERS:
       return PIPE_MAX_SHADER_BUFFERS;

src/gallium/docs/source/screen.rst

@@ -463,6 +463,10 @@ to be 0.
 * ``PIPE_SHADER_CAP_SUPPORTED_IRS``: Supported representations of the
   program.  It should be a mask of ``pipe_shader_ir`` bits.
 * ``PIPE_SHADER_CAP_MAX_SHADER_IMAGES``: Maximum number of image units.
+* ``PIPE_SHADER_CAP_LOWER_IF_THRESHOLD``: IF and ELSE branches with a lower
+  cost than this value should be lowered by the state tracker for better
+  performance. This is a tunable for the GLSL compiler and the behavior is
+  specific to the compiler.
 
 
 .. _pipe_compute_cap:

src/gallium/drivers/freedreno/freedreno_screen.c

@@ -499,6 +499,7 @@ fd_screen_get_shader_param(struct pipe_screen *pscreen, unsigned shader,
 		return 32;
 	case PIPE_SHADER_CAP_MAX_SHADER_BUFFERS:
 	case PIPE_SHADER_CAP_MAX_SHADER_IMAGES:
+	case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
 		return 0;
 	}
 	debug_printf("unknown shader param %d\n", param);

src/gallium/drivers/nouveau/nv30/nv30_screen.c

@@ -300,6 +300,7 @@ nv30_screen_get_shader_param(struct pipe_screen *pscreen, unsigned shader,
       case PIPE_SHADER_CAP_TGSI_ANY_INOUT_DECL_RANGE:
       case PIPE_SHADER_CAP_MAX_SHADER_BUFFERS:
       case PIPE_SHADER_CAP_MAX_SHADER_IMAGES:
+      case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
          return 0;
       default:
          debug_printf("unknown vertex shader param %d\n", param);
@@ -348,6 +349,7 @@ nv30_screen_get_shader_param(struct pipe_screen *pscreen, unsigned shader,
       case PIPE_SHADER_CAP_TGSI_ANY_INOUT_DECL_RANGE:
       case PIPE_SHADER_CAP_MAX_SHADER_BUFFERS:
       case PIPE_SHADER_CAP_MAX_SHADER_IMAGES:
+      case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
          return 0;
       default:
          debug_printf("unknown fragment shader param %d\n", param);

src/gallium/drivers/nouveau/nv50/nv50_screen.c

@@ -345,6 +345,7 @@ nv50_screen_get_shader_param(struct pipe_screen *pscreen, unsigned shader,
    case PIPE_SHADER_CAP_MAX_SHADER_BUFFERS:
    case PIPE_SHADER_CAP_SUPPORTED_IRS:
    case PIPE_SHADER_CAP_MAX_SHADER_IMAGES:
+   case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
       return 0;
    default:
       NOUVEAU_ERR("unknown PIPE_SHADER_CAP %d\n", param);

src/gallium/drivers/nouveau/nvc0/nvc0_screen.c

@@ -374,6 +374,7 @@ nvc0_screen_get_shader_param(struct pipe_screen *pscreen, unsigned shader,
       return 1;
    case PIPE_SHADER_CAP_TGSI_DFRACEXP_DLDEXP_SUPPORTED:
    case PIPE_SHADER_CAP_TGSI_ANY_INOUT_DECL_RANGE:
+   case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
       return 0;
    case PIPE_SHADER_CAP_MAX_SHADER_BUFFERS:
       return NVC0_MAX_BUFFERS;

src/gallium/drivers/r300/r300_screen.c

@@ -339,6 +339,7 @@ static int r300_get_shader_param(struct pipe_screen *pscreen, unsigned shader, e
         case PIPE_SHADER_CAP_TGSI_FMA_SUPPORTED:
         case PIPE_SHADER_CAP_MAX_SHADER_BUFFERS:
         case PIPE_SHADER_CAP_MAX_SHADER_IMAGES:
+        case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
             return 0;
         case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT:
             return 32;
@@ -401,6 +402,7 @@ static int r300_get_shader_param(struct pipe_screen *pscreen, unsigned shader, e
         case PIPE_SHADER_CAP_TGSI_FMA_SUPPORTED:
         case PIPE_SHADER_CAP_MAX_SHADER_BUFFERS:
         case PIPE_SHADER_CAP_MAX_SHADER_IMAGES:
+        case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
             return 0;
         case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT:
             return 32;

src/gallium/drivers/r600/r600_pipe.c

@@ -561,6 +561,7 @@ static int r600_get_shader_param(struct pipe_screen* pscreen, unsigned shader, e
 	case PIPE_SHADER_CAP_TGSI_DFRACEXP_DLDEXP_SUPPORTED:
 	case PIPE_SHADER_CAP_MAX_SHADER_BUFFERS:
 	case PIPE_SHADER_CAP_MAX_SHADER_IMAGES:
+	case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
 		return 0;
 	case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT:
 		/* due to a bug in the shader compiler, some loops hang

src/gallium/drivers/radeonsi/si_pipe.c

@@ -659,6 +659,7 @@ static int si_get_shader_param(struct pipe_screen* pscreen, unsigned shader, enu
 	case PIPE_SHADER_CAP_SUPPORTED_IRS:
 	case PIPE_SHADER_CAP_TGSI_DROUND_SUPPORTED:
 	case PIPE_SHADER_CAP_TGSI_DFRACEXP_DLDEXP_SUPPORTED:
+	case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
 		return 0;
 	}
 	return 0;

src/gallium/drivers/svga/svga_screen.c

@@ -499,6 +499,7 @@ vgpu9_get_shader_param(struct pipe_screen *screen, unsigned shader,
       case PIPE_SHADER_CAP_TGSI_ANY_INOUT_DECL_RANGE:
       case PIPE_SHADER_CAP_MAX_SHADER_BUFFERS:
       case PIPE_SHADER_CAP_MAX_SHADER_IMAGES:
+      case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
          return 0;
       case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT:
          return 32;
@@ -561,6 +562,7 @@ vgpu9_get_shader_param(struct pipe_screen *screen, unsigned shader,
       case PIPE_SHADER_CAP_TGSI_ANY_INOUT_DECL_RANGE:
       case PIPE_SHADER_CAP_MAX_SHADER_BUFFERS:
       case PIPE_SHADER_CAP_MAX_SHADER_IMAGES:
+      case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
          return 0;
       case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT:
          return 32;
@@ -656,6 +658,7 @@ vgpu10_get_shader_param(struct pipe_screen *screen, unsigned shader,
    case PIPE_SHADER_CAP_TGSI_ANY_INOUT_DECL_RANGE:
    case PIPE_SHADER_CAP_MAX_SHADER_BUFFERS:
    case PIPE_SHADER_CAP_MAX_SHADER_IMAGES:
+   case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
       return 0;
    case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT:
       return 32;

src/gallium/drivers/vc4/vc4_screen.c

@@ -402,6 +402,7 @@ vc4_screen_get_shader_param(struct pipe_screen *pscreen, unsigned shader,
 		return 32;
         case PIPE_SHADER_CAP_MAX_SHADER_BUFFERS:
         case PIPE_SHADER_CAP_MAX_SHADER_IMAGES:
+	case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
                 return 0;
         default:
                 fprintf(stderr, "unknown shader param %d\n", param);

src/gallium/drivers/virgl/virgl_screen.c

@@ -312,6 +312,7 @@ virgl_get_shader_param(struct pipe_screen *screen, unsigned shader, enum pipe_sh
          return 32;
       case PIPE_SHADER_CAP_MAX_CONST_BUFFER_SIZE:
          return 4096 * sizeof(float[4]);
+      case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
       default:
          return 0;
       }

src/gallium/include/pipe/p_defines.h

@@ -809,6 +809,7 @@ enum pipe_shader_cap
    PIPE_SHADER_CAP_MAX_SHADER_BUFFERS,
    PIPE_SHADER_CAP_SUPPORTED_IRS,
    PIPE_SHADER_CAP_MAX_SHADER_IMAGES,
+   PIPE_SHADER_CAP_LOWER_IF_THRESHOLD,
 };
 
 /**