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.

1 files changed, 2 insertions, 11 deletions

diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index f139e95fe39..b0227855c67 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -4746,8 +4746,6 @@ get_mesa_program(struct gl_context *ctx,
 {
    glsl_to_tgsi_visitor* v = new glsl_to_tgsi_visitor();
    struct gl_program *prog;
-   struct pipe_screen * screen = st_context(ctx)->pipe->screen;
-   unsigned pipe_shader_type;
    GLenum target;
    const char *target_string;
    bool progress;
@@ -4758,17 +4756,14 @@ get_mesa_program(struct gl_context *ctx,
    case GL_VERTEX_SHADER:
       target = GL_VERTEX_PROGRAM_ARB;
       target_string = "vertex";
-      pipe_shader_type = PIPE_SHADER_VERTEX;
       break;
    case GL_FRAGMENT_SHADER:
       target = GL_FRAGMENT_PROGRAM_ARB;
       target_string = "fragment";
-      pipe_shader_type = PIPE_SHADER_FRAGMENT;
       break;
    case GL_GEOMETRY_SHADER:
       target = GL_GEOMETRY_PROGRAM_NV;
       target_string = "geometry";
-      pipe_shader_type = PIPE_SHADER_GEOMETRY;
       break;
    default:
       assert(!"should not be reached");
@@ -4792,12 +4787,8 @@ get_mesa_program(struct gl_context *ctx,
    _mesa_generate_parameters_list_for_uniforms(shader_program, shader,
 					       prog->Parameters);
 
-   if (!screen->get_shader_param(screen, pipe_shader_type,
-                                 PIPE_SHADER_CAP_OUTPUT_READ)) {
-      /* Remove reads to output registers, and to varyings in vertex shaders. */
-      lower_output_reads(shader->ir);
-   }
-
+   /* Remove reads from output registers. */
+   lower_output_reads(shader->ir);
 
    /* Emit intermediate IR for main(). */
    visit_exec_list(shader->ir, v);