glsl: Count shader inputs and outputs separately

Starting with OpenGL 3.2 input limits and output limits for stages may
not match.  This means they need to be accounted separately.

No piglit regressions.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Paul Berry <stereotype441@gmail.com>

src/glsl/link_varyings.cpp

@@ -1220,39 +1220,98 @@ assign_varying_locations(struct gl_context *ctx,
 }
 
 bool
-check_against_varying_limit(struct gl_context *ctx,
-                            struct gl_shader_program *prog,
-                            gl_shader *consumer)
+check_against_output_limit(struct gl_context *ctx,
+                           struct gl_shader_program *prog,
+                           gl_shader *producer)
 {
-   unsigned varying_vectors = 0;
+   unsigned output_vectors = 0;
+
+   foreach_list(node, producer->ir) {
+      ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+      if (var && var->mode == ir_var_shader_out &&
+          is_varying_var(producer->Type, var)) {
+         output_vectors += var->type->count_attribute_slots();
+      }
+   }
+
+   unsigned max_output_components;
+   switch (producer->Type) {
+   case GL_VERTEX_SHADER:
+      max_output_components = ctx->Const.VertexProgram.MaxOutputComponents;
+      break;
+   case GL_GEOMETRY_SHADER:
+      max_output_components = ctx->Const.GeometryProgram.MaxOutputComponents;
+      break;
+   case GL_FRAGMENT_SHADER:
+   default:
+      assert(!"Should not get here.");
+      return false;
+   }
+
+   const unsigned output_components = output_vectors * 4;
+   if (output_components > max_output_components) {
+      if (ctx->API == API_OPENGLES2 || prog->IsES)
+         linker_error(prog, "shader uses too many output vectors "
+                      "(%u > %u)\n",
+                      output_vectors,
+                      max_output_components / 4);
+      else
+         linker_error(prog, "shader uses too many output components "
+                      "(%u > %u)\n",
+                      output_components,
+                      max_output_components);
+
+      return false;
+   }
+
+   return true;
+}
+
+bool
+check_against_input_limit(struct gl_context *ctx,
+                          struct gl_shader_program *prog,
+                          gl_shader *consumer)
+{
+   unsigned input_vectors = 0;
 
    foreach_list(node, consumer->ir) {
       ir_variable *const var = ((ir_instruction *) node)->as_variable();
 
       if (var && var->mode == ir_var_shader_in &&
           is_varying_var(consumer->Type, var)) {
-         /* The packing rules used for vertex shader inputs are also
-          * used for fragment shader inputs.
-          */
-         varying_vectors += var->type->count_attribute_slots();
+         input_vectors += var->type->count_attribute_slots();
       }
    }
 
-   if (ctx->API == API_OPENGLES2 || prog->IsES) {
-      if (varying_vectors > ctx->Const.MaxVarying) {
-         linker_error(prog, "shader uses too many varying vectors "
+   unsigned max_input_components;
+   switch (consumer->Type) {
+   case GL_GEOMETRY_SHADER:
+      max_input_components = ctx->Const.GeometryProgram.MaxInputComponents;
+      break;
+   case GL_FRAGMENT_SHADER:
+      max_input_components = ctx->Const.FragmentProgram.MaxInputComponents;
+      break;
+   case GL_VERTEX_SHADER:
+   default:
+      assert(!"Should not get here.");
+      return false;
+   }
+
+   const unsigned input_components = input_vectors * 4;
+   if (input_components > max_input_components) {
+      if (ctx->API == API_OPENGLES2 || prog->IsES)
+         linker_error(prog, "shader uses too many input vectors "
                       "(%u > %u)\n",
-                      varying_vectors, ctx->Const.MaxVarying);
-         return false;
-      }
-   } else {
-      const unsigned float_components = varying_vectors * 4;
-      if (float_components > ctx->Const.MaxVarying * 4) {
-         linker_error(prog, "shader uses too many varying components "
+                      input_vectors,
+                      max_input_components / 4);
+      else
+         linker_error(prog, "shader uses too many input components "
                       "(%u > %u)\n",
-                      float_components, ctx->Const.MaxVarying * 4);
-         return false;
-      }
+                      input_components,
+                      max_input_components);
+
+      return false;
    }
 
    return true;

src/glsl/link_varyings.h

@@ -237,8 +237,13 @@ assign_varying_locations(struct gl_context *ctx,
                          unsigned gs_input_vertices);
 
 bool
-check_against_varying_limit(struct gl_context *ctx,
-                            struct gl_shader_program *prog,
-                            gl_shader *consumer);
+check_against_output_limit(struct gl_context *ctx,
+                           struct gl_shader_program *prog,
+                           gl_shader *producer);
+
+bool
+check_against_input_limit(struct gl_context *ctx,
+                          struct gl_shader_program *prog,
+                          gl_shader *consumer);
 
 #endif /* GLSL_LINK_VARYINGS_H */

src/glsl/linker.cpp

@@ -2203,7 +2203,9 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
          ;
 
       /* This must be done after all dead varyings are eliminated. */
-      if (!check_against_varying_limit(ctx, prog, sh_next))
+      if (!check_against_output_limit(ctx, prog, sh_i))
+         goto done;
+      if (!check_against_input_limit(ctx, prog, sh_next))
          goto done;
 
       next = i;