glsl: remove Lower{TCS,TES}PatchVerticesIn

Intel was the only user and now NIR can do the lowering.

v2: do not try to handle it as a system value directly for the SPIR-V
    path. In GL we rather handle it as a uniform like we do for the
    GLSL path (Jason).

v3: drop LowerTESPatchVerticesIn as well (Jason)

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

src/compiler/glsl/builtin_variables.cpp

@@ -38,11 +38,6 @@ static const struct gl_builtin_uniform_element gl_NumSamples_elements[] = {
    {NULL, {STATE_NUM_SAMPLES, 0, 0}, SWIZZLE_XXXX}
 };
 
-/* only for TCS */
-static const struct gl_builtin_uniform_element gl_PatchVerticesIn_elements[] = {
-   {NULL, {STATE_INTERNAL, STATE_TCS_PATCH_VERTICES_IN}, SWIZZLE_XXXX}
-};
-
 static const struct gl_builtin_uniform_element gl_DepthRange_elements[] = {
    {"near", {STATE_DEPTH_RANGE, 0, 0}, SWIZZLE_XXXX},
    {"far", {STATE_DEPTH_RANGE, 0, 0}, SWIZZLE_YYYY},
@@ -240,7 +235,6 @@ static const struct gl_builtin_uniform_element gl_NormalMatrix_elements[] = {
 #define STATEVAR(name) {#name, name ## _elements, ARRAY_SIZE(name ## _elements)}
 
 static const struct gl_builtin_uniform_desc _mesa_builtin_uniform_desc[] = {
-   STATEVAR(gl_PatchVerticesIn),
    STATEVAR(gl_NumSamples),
    STATEVAR(gl_DepthRange),
    STATEVAR(gl_ClipPlane),
@@ -1067,12 +1061,7 @@ builtin_variable_generator::generate_tcs_special_vars()
 {
    add_system_value(SYSTEM_VALUE_PRIMITIVE_ID, int_t, "gl_PrimitiveID");
    add_system_value(SYSTEM_VALUE_INVOCATION_ID, int_t, "gl_InvocationID");
-
+   add_system_value(SYSTEM_VALUE_VERTICES_IN, int_t, "gl_PatchVerticesIn");
-   if (state->ctx->Const.LowerTCSPatchVerticesIn) {
-      add_uniform(int_t, "gl_PatchVerticesIn");
-   } else {
-      add_system_value(SYSTEM_VALUE_VERTICES_IN, int_t, "gl_PatchVerticesIn");
-   }
 
    add_output(VARYING_SLOT_TESS_LEVEL_OUTER, array(float_t, 4),
               "gl_TessLevelOuter")->data.patch = 1;

src/compiler/glsl/linker.cpp

@@ -2502,7 +2502,7 @@ resize_tes_inputs(struct gl_context *ctx,
       ir->accept(&input_resize_visitor);
    }
 
-   if (tcs || ctx->Const.LowerTESPatchVerticesIn) {
+   if (tcs) {
       /* Convert the gl_PatchVerticesIn system value into a constant, since
        * the value is known at this point.
        */
@@ -2513,20 +2513,8 @@ resize_tes_inputs(struct gl_context *ctx,
             void *mem_ctx = ralloc_parent(var);
             var->data.location = 0;
             var->data.explicit_location = false;
-            if (tcs) {
+            var->data.mode = ir_var_auto;
-               var->data.mode = ir_var_auto;
+            var->constant_value = new(mem_ctx) ir_constant(num_vertices);
-               var->constant_value = new(mem_ctx) ir_constant(num_vertices);
-            } else {
-               var->data.mode = ir_var_uniform;
-               var->data.how_declared = ir_var_hidden;
-               var->allocate_state_slots(1);
-               ir_state_slot *slot0 = &var->get_state_slots()[0];
-               slot0->swizzle = SWIZZLE_XXXX;
-               slot0->tokens[0] = STATE_INTERNAL;
-               slot0->tokens[1] = STATE_TES_PATCH_VERTICES_IN;
-               for (int i = 2; i < STATE_LENGTH; i++)
-                  slot0->tokens[i] = 0;
-            }
          }
       }
    }

src/mesa/drivers/dri/i965/brw_context.c

@@ -537,8 +537,6 @@ brw_initialize_context_constants(struct brw_context *brw)
       ctx->Const.MaxClipPlanes = 8;
 
    ctx->Const.GLSLTessLevelsAsInputs = true;
-   ctx->Const.LowerTCSPatchVerticesIn = devinfo->gen >= 8;
-   ctx->Const.LowerTESPatchVerticesIn = true;
    ctx->Const.PrimitiveRestartForPatches = true;
 
    ctx->Const.Program[MESA_SHADER_VERTEX].MaxNativeInstructions = 16 * 1024;

src/mesa/main/mtypes.h

@@ -4020,8 +4020,6 @@ struct gl_constants
    GLuint MaxTessPatchComponents;
    GLuint MaxTessControlTotalOutputComponents;
    bool LowerTessLevel; /**< Lower gl_TessLevel* from float[n] to vecn? */
-   bool LowerTCSPatchVerticesIn; /**< Lower gl_PatchVerticesIn to a uniform */
-   bool LowerTESPatchVerticesIn; /**< Lower gl_PatchVerticesIn to a uniform */
    bool PrimitiveRestartForPatches;
    bool LowerCsDerivedVariables;    /**< Lower gl_GlobalInvocationID and
                                      *   gl_LocalInvocationIndex based on