gallium: remove PIPE_SHADER_CAP_OUTPUT_READ

r600g is the only driver which has made use of it. The reason the CAP was
added was to fix some piglit tests when the GLSL pass lower_output_reads
didn't exist.

However, not removing output reads breaks the fallback for glClampColorARB,
which assumes outputs are not readable. The fix would be non-trivial
and my personal preference is to remove the CAP, considering that reading
outputs is uncommon and that we can now use lower_output_reads to fix
the issue that the CAP was supposed to workaround in the first place.

7 files changed, 0 insertions, 15 deletions

diff --git a/src/gallium/drivers/i915/i915_screen.c b/src/gallium/drivers/i915/i915_screen.c
index 61340f3a588..9703210e933 100644
--- a/src/gallium/drivers/i915/i915_screen.c
+++ b/src/gallium/drivers/i915/i915_screen.c
@@ -151,8 +151,6 @@ i915_get_shader_param(struct pipe_screen *screen, unsigned shader, enum pipe_sha
          return 0;
       case PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS:
          return I915_TEX_UNITS;
-      case PIPE_SHADER_CAP_OUTPUT_READ:
-         return 0;
       default:
          debug_printf("%s: Unknown cap %u.\n", __FUNCTION__, cap);
          return 0;
diff --git a/src/gallium/drivers/nv50/nv50_screen.c b/src/gallium/drivers/nv50/nv50_screen.c
index 1d5359327bc..27566e24108 100644
--- a/src/gallium/drivers/nv50/nv50_screen.c
+++ b/src/gallium/drivers/nv50/nv50_screen.c
@@ -206,8 +206,6 @@ nv50_screen_get_shader_param(struct pipe_screen *pscreen, unsigned shader,
       return 0;
    case PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS:
       return 32;
-   case PIPE_SHADER_CAP_OUTPUT_READ:
-      return 0; /* maybe support this for fragment shaders ? */
    default:
       NOUVEAU_ERR("unknown PIPE_SHADER_CAP %d\n", param);
       return 0;
diff --git a/src/gallium/drivers/nvc0/nvc0_screen.c b/src/gallium/drivers/nvc0/nvc0_screen.c
index abc04ab7b8b..f7637eedc43 100644
--- a/src/gallium/drivers/nvc0/nvc0_screen.c
+++ b/src/gallium/drivers/nvc0/nvc0_screen.c
@@ -202,8 +202,6 @@ nvc0_screen_get_shader_param(struct pipe_screen *pscreen, unsigned shader,
    case PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLER_VIEWS:
       return 32;
       */
-   case PIPE_SHADER_CAP_OUTPUT_READ:
-      return 0; /* shader != PIPE_SHADER_TESSELLATION_CONTROL; */
    default:
       NOUVEAU_ERR("unknown PIPE_SHADER_CAP %d\n", param);
       return 0;
diff --git a/src/gallium/drivers/r300/r300_screen.c b/src/gallium/drivers/r300/r300_screen.c
index 9ac5781e949..1a8e789fdc3 100644
--- a/src/gallium/drivers/r300/r300_screen.c
+++ b/src/gallium/drivers/r300/r300_screen.c
@@ -210,7 +210,6 @@ static int r300_get_shader_param(struct pipe_screen *pscreen, unsigned shader, e
         case PIPE_SHADER_CAP_INDIRECT_CONST_ADDR:
         case PIPE_SHADER_CAP_SUBROUTINES:
         case PIPE_SHADER_CAP_INTEGERS:
-        case PIPE_SHADER_CAP_OUTPUT_READ:
             return 0;
         }
         break;
@@ -256,7 +255,6 @@ static int r300_get_shader_param(struct pipe_screen *pscreen, unsigned shader, e
         case PIPE_SHADER_CAP_SUBROUTINES:
         case PIPE_SHADER_CAP_INTEGERS:
         case PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS:
-        case PIPE_SHADER_CAP_OUTPUT_READ:
             return 0;
         }
         break;
diff --git a/src/gallium/drivers/r600/r600_pipe.c b/src/gallium/drivers/r600/r600_pipe.c
index 53f9bd6554f..7c828041f83 100644
--- a/src/gallium/drivers/r600/r600_pipe.c
+++ b/src/gallium/drivers/r600/r600_pipe.c
@@ -541,8 +541,6 @@ static int r600_get_shader_param(struct pipe_screen* pscreen, unsigned shader, e
 		return 0;
 	case PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS:
 		return 16;
-	case PIPE_SHADER_CAP_OUTPUT_READ:
-		return 1;
 	}
 	return 0;
 }
diff --git a/src/gallium/drivers/svga/svga_screen.c b/src/gallium/drivers/svga/svga_screen.c
index a4de4932652..fe6e6a030b0 100644
--- a/src/gallium/drivers/svga/svga_screen.c
+++ b/src/gallium/drivers/svga/svga_screen.c
@@ -262,8 +262,6 @@ static int svga_get_shader_param(struct pipe_screen *screen, unsigned shader, en
          return 0;
       case PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS:
          return 16;
-      case PIPE_SHADER_CAP_OUTPUT_READ:
-         return 0;
       }
       break;
    case PIPE_SHADER_VERTEX:
@@ -307,8 +305,6 @@ static int svga_get_shader_param(struct pipe_screen *screen, unsigned shader, en
          return 0;
       case PIPE_SHADER_CAP_INTEGERS:
          return 0;
-      case PIPE_SHADER_CAP_OUTPUT_READ:
-         return 0;
       default:
          break;
       }
diff --git a/src/gallium/include/pipe/p_defines.h b/src/gallium/include/pipe/p_defines.h
index 4155178dda4..096749bd37d 100644
--- a/src/gallium/include/pipe/p_defines.h
+++ b/src/gallium/include/pipe/p_defines.h
@@ -533,7 +533,6 @@ enum pipe_shader_cap
    PIPE_SHADER_CAP_SUBROUTINES = 16, /* BGNSUB, ENDSUB, CAL, RET */
    PIPE_SHADER_CAP_INTEGERS = 17,
    PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS = 18,
-   PIPE_SHADER_CAP_OUTPUT_READ = 19
 };