nir, glsl: move pixel_center_integer/origin_upper_left to shader_info.fs

On GLSL that info is set as a layout qualifier when redeclaring
gl_FragCoord, so somehow tied to a specific variable. But in practice,
they behave as a global of the shader. On ARB programs they are set
using a global OPTION (defined at ARB_fragment_coord_conventions), and
on SPIR-V using ExecutionModes, that are also not tied specifically to
the builtin.

This patch moves that info from nir variable and ir variable to nir
shader and gl_program shader_info respectively, so the map is more
similar to SPIR-V, and ARB programs, instead of more similar to GLSL.

FWIW, shader_info.fs already had pixel_center_integer, so this change
also removes some redundancy. Also, as struct gl_program also includes
a shader_info, we removed gl_program::OriginUpperLeft and
PixelCenterInteger, as it would be superfluous.

This change was needed because recently spirv_to_nir changed the order
in which execution modes and variables are handled, so the variables
didn't get the correct values. Now the info is set on the shader
itself, and we don't need to go back to the builtin variable to set
it.

Fixes: e68871f6a ("spirv: Handle constants and types before execution
                   modes")

v2: (Jason)
   * glsl_to_nir: get the info before glsl_to_nir, while all the rest
     of the info gathering is happening
   * prog_to_nir: gather the info on a general info-gathering pass,
     not on variable setup.

v3: (Jason)
   * Squash with the patch that removes that info from ir variable
   * anv: assert that OriginUpperLeft is true. It should be already
     set by spirv_to_nir.
   * blorp: set origin_upper_left on its core "compile fragment
     shader", not just on some specific places (for this we added an
     helper on a previous patch).
   * prog_to_nir: no need to gather specifically this fragcoord modes
     as the full gl_program shader_info is copied.
   * spirv_to_nir: assert that we are a fragment shader when handling
     this execution modes.

v4: (reported by failing gitlab pipeline #18750)
   * state_tracker: update too due changes on ir.h/gl_program

v5:
   * blorp: minor change after change on previous patch
   * radeonsi: update due this change.

v6: (Timothy Arceri)
   * prog_to_nir: remove extra whitespace
   * shader_info: don't use :1 on origin_upper_left
   * glsl: program.fs.origin_upper_left/pixel_center_integer can be
     move out of the shader list loop

src/compiler/glsl/ast_to_hir.cpp

@@ -3670,8 +3670,6 @@ apply_layout_qualifier_to_variable(const struct ast_type_qualifier *qual,
          state->fs_redeclares_gl_fragcoord_with_no_layout_qualifiers;
    }
 
-   var->data.pixel_center_integer = qual->flags.q.pixel_center_integer;
-   var->data.origin_upper_left = qual->flags.q.origin_upper_left;
    if ((qual->flags.q.origin_upper_left || qual->flags.q.pixel_center_integer)
        && (strcmp(var->name, "gl_FragCoord") != 0)) {
       const char *const qual_string = (qual->flags.q.origin_upper_left)
@@ -4290,10 +4288,13 @@ get_variable_being_redeclared(ir_variable **var_ptr, YYLTYPE loc,
               && strcmp(var->name, "gl_FragCoord") == 0) {
       /* Allow redeclaration of gl_FragCoord for ARB_fcc layout
        * qualifiers.
+       *
+       * We don't really need to do anything here, just allow the
+       * redeclaration. Any error on the gl_FragCoord is handled on the ast
+       * level at apply_layout_qualifier_to_variable using the
+       * ast_type_qualifier and _mesa_glsl_parse_state, or later at
+       * linker.cpp.
        */
-      earlier->data.origin_upper_left = var->data.origin_upper_left;
-      earlier->data.pixel_center_integer = var->data.pixel_center_integer;
-
       /* According to section 4.3.7 of the GLSL 1.30 spec,
        * the following built-in varaibles can be redeclared with an
        * interpolation qualifier:

src/compiler/glsl/glsl_to_nir.cpp

@@ -168,6 +168,11 @@ glsl_to_nir(const struct gl_shader_program *shader_prog,
       shader->info.has_transform_feedback_varyings |=
          shader_prog->last_vert_prog->sh.LinkedTransformFeedback->NumVarying > 0;
 
+   if (shader->info.stage == MESA_SHADER_FRAGMENT) {
+      shader->info.fs.pixel_center_integer = sh->Program->info.fs.pixel_center_integer;
+      shader->info.fs.origin_upper_left = sh->Program->info.fs.origin_upper_left;
+   }
+
    return shader;
 }
 
@@ -398,8 +403,6 @@ nir_visitor::visit(ir_variable *ir)
    }
 
    var->data.interpolation = ir->data.interpolation;
-   var->data.origin_upper_left = ir->data.origin_upper_left;
-   var->data.pixel_center_integer = ir->data.pixel_center_integer;
    var->data.location_frac = ir->data.location_frac;
 
    switch (ir->data.depth_layout) {

src/compiler/glsl/ir.cpp

@@ -1725,8 +1725,6 @@ ir_variable::ir_variable(const struct glsl_type *type, const char *name,
    this->data.warn_extension_index = 0;
    this->constant_value = NULL;
    this->constant_initializer = NULL;
-   this->data.origin_upper_left = false;
-   this->data.pixel_center_integer = false;
    this->data.depth_layout = ir_depth_layout_none;
    this->data.used = false;
    this->data.always_active_io = false;

src/compiler/glsl/ir.h

@@ -711,14 +711,6 @@ public:
        */
       unsigned interpolation:2;
 
-      /**
-       * \name ARB_fragment_coord_conventions
-       * @{
-       */
-      unsigned origin_upper_left:1;
-      unsigned pixel_center_integer:1;
-      /*@}*/
-
       /**
        * Was the location explicitly set in the shader?
        *

src/compiler/glsl/linker.cpp

@@ -2049,9 +2049,11 @@ link_fs_inout_layout_qualifiers(struct gl_shader_program *prog,
          shader->SampleInterlockOrdered;
       linked_shader->Program->info.fs.sample_interlock_unordered |=
          shader->SampleInterlockUnordered;
-
       linked_shader->Program->sh.fs.BlendSupport |= shader->BlendSupport;
    }
+
+   linked_shader->Program->info.fs.pixel_center_integer = pixel_center_integer;
+   linked_shader->Program->info.fs.origin_upper_left = origin_upper_left;
 }
 
 /**

src/compiler/nir/nir.h

@@ -237,14 +237,6 @@ typedef struct nir_variable {
        */
       unsigned interpolation:2;
 
-      /**
-       * \name ARB_fragment_coord_conventions
-       * @{
-       */
-      unsigned origin_upper_left:1;
-      unsigned pixel_center_integer:1;
-      /*@}*/
-
       /**
        * If non-zero, then this variable may be packed along with other variables
        * into a single varying slot, so this offset should be applied when

src/compiler/nir/nir_lower_system_values.c

@@ -254,12 +254,6 @@ convert_block(nir_block *block, nir_builder *b)
          break;
       }
 
-      case SYSTEM_VALUE_FRAG_COORD:
-         assert(b->shader->info.stage == MESA_SHADER_FRAGMENT);
-         b->shader->info.fs.pixel_center_integer =
-            var->data.pixel_center_integer;
-         break;
-
       default:
          break;
       }

src/compiler/nir/nir_lower_wpos_ytransform.c

@@ -181,7 +181,7 @@ lower_fragcoord(lower_wpos_ytransform_state *state,
     * u,h -> l,i: (99.5 + 0.5) * -1 + 100 = 0
     */
 
-   if (fragcoord->data.origin_upper_left) {
+   if (state->shader->info.fs.origin_upper_left) {
       /* Fragment shader wants origin in upper-left */
       if (options->fs_coord_origin_upper_left) {
          /* the driver supports upper-left origin */
@@ -203,7 +203,7 @@ lower_fragcoord(lower_wpos_ytransform_state *state,
       }
    }
 
-   if (fragcoord->data.pixel_center_integer) {
+   if (state->shader->info.fs.pixel_center_integer) {
       /* Fragment shader wants pixel center integer */
       if (options->fs_coord_pixel_center_integer) {
          /* the driver supports pixel center integer */

src/compiler/shader_info.h

@@ -195,7 +195,13 @@ typedef struct shader_info {
 
          bool post_depth_coverage;
 
+         /**
+          * \name ARB_fragment_coord_conventions
+          * @{
+          */
          bool pixel_center_integer;
+         bool origin_upper_left;
+         /*@}*/
 
          bool pixel_interlock_ordered;
          bool pixel_interlock_unordered;

src/compiler/spirv/spirv_to_nir.c

@@ -3785,7 +3785,8 @@ vtn_handle_execution_mode(struct vtn_builder *b, struct vtn_value *entry_point,
    switch(mode->exec_mode) {
    case SpvExecutionModeOriginUpperLeft:
    case SpvExecutionModeOriginLowerLeft:
-      b->origin_upper_left =
+      vtn_assert(b->shader->info.stage == MESA_SHADER_FRAGMENT);
+      b->shader->info.fs.origin_upper_left =
          (mode->exec_mode == SpvExecutionModeOriginUpperLeft);
       break;
 
@@ -3908,7 +3909,8 @@ vtn_handle_execution_mode(struct vtn_builder *b, struct vtn_value *entry_point,
       break;
 
    case SpvExecutionModePixelCenterInteger:
-      b->pixel_center_integer = true;
+      vtn_assert(b->shader->info.stage == MESA_SHADER_FRAGMENT);
+      b->shader->info.fs.pixel_center_integer = true;
       break;
 
    case SpvExecutionModeXfb:

src/compiler/spirv/vtn_private.h

@@ -601,8 +601,6 @@ struct vtn_builder {
    const char *entry_point_name;
    struct vtn_value *entry_point;
    struct vtn_value *workgroup_size_builtin;
-   bool origin_upper_left;
-   bool pixel_center_integer;
    bool variable_pointers;
 
    struct vtn_function *func;

src/compiler/spirv/vtn_variables.c

@@ -1448,12 +1448,6 @@ apply_var_decoration(struct vtn_builder *b,
       case SpvBuiltInCullDistance:
          var_data->compact = true;
          break;
-      case SpvBuiltInFragCoord:
-         var_data->pixel_center_integer = b->pixel_center_integer;
-         /* fallthrough */
-      case SpvBuiltInSamplePosition:
-         var_data->origin_upper_left = b->origin_upper_left;
-         break;
       default:
          break;
       }

src/gallium/drivers/radeonsi/si_shader_nir.c

@@ -440,7 +440,7 @@ void si_nir_scan_shader(const struct nir_shader *nir,
 		/* Fragment shader position is a system value. */
 		if (nir->info.stage == MESA_SHADER_FRAGMENT &&
 		    variable->data.location == VARYING_SLOT_POS) {
-			if (variable->data.pixel_center_integer)
+			if (nir->info.fs.pixel_center_integer)
 				info->properties[TGSI_PROPERTY_FS_COORD_PIXEL_CENTER] =
 					TGSI_FS_COORD_PIXEL_CENTER_INTEGER;
 

src/intel/blorp/blorp_blit.c

@@ -87,7 +87,6 @@ brw_blorp_blit_vars_init(nir_builder *b, struct brw_blorp_blit_vars *v,
    v->frag_coord = nir_variable_create(b->shader, nir_var_shader_in,
                                        glsl_vec4_type(), "gl_FragCoord");
    v->frag_coord->data.location = VARYING_SLOT_POS;
-   v->frag_coord->data.origin_upper_left = true;
 
    v->color_out = nir_variable_create(b->shader, nir_var_shader_out,
                                       glsl_vec4_type(), "gl_FragColor");

src/intel/blorp/blorp_clear.c

@@ -74,7 +74,6 @@ blorp_params_get_clear_kernel(struct blorp_batch *batch,
          nir_variable_create(b.shader, nir_var_shader_in,
                              glsl_vec4_type(), "gl_FragCoord");
       frag_coord->data.location = VARYING_SLOT_POS;
-      frag_coord->data.origin_upper_left = true;
 
       nir_ssa_def *pos = nir_f2i32(&b, nir_load_var(&b, frag_coord));
       nir_ssa_def *comp = nir_umod(&b, nir_channel(&b, pos, 0),

src/intel/blorp/blorp_nir_builder.h

@@ -32,6 +32,8 @@ blorp_nir_init_shader(nir_builder *b,
    nir_builder_init_simple_shader(b, mem_ctx, stage, NULL);
    if (name != NULL)
       b->shader->info.name = ralloc_strdup(b->shader, name);
+   if (stage == MESA_SHADER_FRAGMENT)
+      b->shader->info.fs.origin_upper_left = true;
 }
 
 static inline nir_ssa_def *
@@ -42,7 +44,6 @@ blorp_nir_frag_coord(nir_builder *b)
                           glsl_vec4_type(), "gl_FragCoord");
 
    frag_coord->data.location = VARYING_SLOT_POS;
-   frag_coord->data.origin_upper_left = true;
 
    return nir_load_var(b, frag_coord);
 }

src/intel/vulkan/anv_nir_lower_input_attachments.c

@@ -35,7 +35,14 @@ load_frag_coord(nir_builder *b)
    nir_variable *pos = nir_variable_create(b->shader, nir_var_shader_in,
                                            glsl_vec4_type(), NULL);
    pos->data.location = VARYING_SLOT_POS;
-   pos->data.origin_upper_left = true;
+   /**
+    * From Vulkan spec:
+    *   "The OriginLowerLeft execution mode must not be used; fragment entry
+    *    points must declare OriginUpperLeft."
+    *
+    * So at this point origin_upper_left should be true
+    */
+   assert(b->shader->info.fs.origin_upper_left == true);
 
    return nir_load_var(b, pos);
 }

src/mesa/main/mtypes.h

@@ -2102,10 +2102,6 @@ struct gl_program
    /** Texture units used for samplerExternalOES */
    GLbitfield ExternalSamplersUsed;
 
-   /* Fragement shader only fields */
-   GLboolean OriginUpperLeft;
-   GLboolean PixelCenterInteger;
-
    /** Named parameters, constants, etc. from program text */
    struct gl_program_parameter_list *Parameters;
 

src/mesa/program/arbprogparse.c

@@ -117,8 +117,8 @@ _mesa_parse_arb_fragment_program(struct gl_context* ctx, GLenum target,
          program->SamplersUsed |= (1 << i);
    }
    program->ShadowSamplers = prog.ShadowSamplers;
-   program->OriginUpperLeft = state.option.OriginUpperLeft;
+   program->info.fs.origin_upper_left = state.option.OriginUpperLeft;
-   program->PixelCenterInteger = state.option.PixelCenterInteger;
+   program->info.fs.pixel_center_integer = state.option.PixelCenterInteger;
 
    program->info.fs.uses_discard = state.fragment.UsesKill;
 

src/mesa/program/ir_to_mesa.cpp

@@ -618,11 +618,6 @@ ir_to_mesa_visitor::find_variable_storage(const ir_variable *var)
 void
 ir_to_mesa_visitor::visit(ir_variable *ir)
 {
-   if (strcmp(ir->name, "gl_FragCoord") == 0) {
-      this->prog->OriginUpperLeft = ir->data.origin_upper_left;
-      this->prog->PixelCenterInteger = ir->data.pixel_center_integer;
-   }
-
    if (ir->data.mode == ir_var_uniform && strncmp(ir->name, "gl_", 3) == 0) {
       unsigned int i;
       const ir_state_slot *const slots = ir->get_state_slots();

src/mesa/program/prog_to_nir.c

@@ -890,10 +890,7 @@ setup_registers_and_variables(struct ptn_compile *c)
       var->data.index = 0;
 
       if (c->prog->Target == GL_FRAGMENT_PROGRAM_ARB) {
-         if (i == VARYING_SLOT_POS) {
+         if (i == VARYING_SLOT_FOGC) {
-            var->data.origin_upper_left = c->prog->OriginUpperLeft;
-            var->data.pixel_center_integer = c->prog->PixelCenterInteger;
-         } else if (i == VARYING_SLOT_FOGC) {
             /* fogcoord is defined as <f, 0.0, 0.0, 1.0>.  Make the actual
              * input variable a float, and create a local containing the
              * full vec4 value.
@@ -934,12 +931,6 @@ setup_registers_and_variables(struct ptn_compile *c)
       var->data.location = i;
       var->data.index = 0;
 
-      if (c->prog->Target == GL_FRAGMENT_PROGRAM_ARB &&
-          i == SYSTEM_VALUE_FRAG_COORD) {
-         var->data.origin_upper_left = c->prog->OriginUpperLeft;
-         var->data.pixel_center_integer = c->prog->PixelCenterInteger;
-      }
-
       c->sysval_vars[i] = var;
    }
 

src/mesa/state_tracker/st_glsl_to_tgsi.cpp

@@ -1136,11 +1136,6 @@ glsl_to_tgsi_visitor::find_variable_storage(ir_variable *var)
 void
 glsl_to_tgsi_visitor::visit(ir_variable *ir)
 {
-   if (strcmp(ir->name, "gl_FragCoord") == 0) {
-      this->prog->OriginUpperLeft = ir->data.origin_upper_left;
-      this->prog->PixelCenterInteger = ir->data.pixel_center_integer;
-   }
-
    if (ir->data.mode == ir_var_uniform && strncmp(ir->name, "gl_", 3) == 0) {
       unsigned int i;
       const ir_state_slot *const slots = ir->get_state_slots();
@@ -6422,7 +6417,7 @@ emit_wpos(struct st_context *st,
     * u,i -> l,h: (99.0 + 0.5) * -1 + 100 = 0.5
     * u,h -> l,i: (99.5 + 0.5) * -1 + 100 = 0
     */
-   if (program->OriginUpperLeft) {
+   if (program->info.fs.origin_upper_left) {
       /* Fragment shader wants origin in upper-left */
       if (pscreen->get_param(pscreen, PIPE_CAP_TGSI_FS_COORD_ORIGIN_UPPER_LEFT)) {
          /* the driver supports upper-left origin */
@@ -6449,7 +6444,7 @@ emit_wpos(struct st_context *st,
          assert(0);
    }
 
-   if (program->PixelCenterInteger) {
+   if (program->info.fs.pixel_center_integer) {
       /* Fragment shader wants pixel center integer */
       if (pscreen->get_param(pscreen, PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_INTEGER)) {
          /* the driver supports pixel center integer */

src/mesa/state_tracker/st_mesa_to_tgsi.c

@@ -734,7 +734,7 @@ emit_wpos(struct st_context *st,
     * u,i -> l,h: (99.0 + 0.5) * -1 + 100 = 0.5
     * u,h -> l,i: (99.5 + 0.5) * -1 + 100 = 0
     */
-   if (program->OriginUpperLeft) {
+   if (program->info.fs.origin_upper_left) {
       /* Fragment shader wants origin in upper-left */
       if (pscreen->get_param(pscreen,
                              PIPE_CAP_TGSI_FS_COORD_ORIGIN_UPPER_LEFT)) {
@@ -764,7 +764,7 @@ emit_wpos(struct st_context *st,
          assert(0);
    }
 
-   if (program->PixelCenterInteger) {
+   if (program->info.fs.pixel_center_integer) {
       /* Fragment shader wants pixel center integer */
       if (pscreen->get_param(pscreen,
                              PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_INTEGER)) {

src/mesa/swrast/s_fragprog.c

@@ -164,9 +164,9 @@ init_machine(struct gl_context *ctx, struct gl_program_machine *machine,
    GLfloat *wpos = span->array->attribs[VARYING_SLOT_POS][col];
 
    /* ARB_fragment_coord_conventions */
-   if (program->OriginUpperLeft)
+   if (program->info.fs.origin_upper_left)
       wpos[1] = ctx->DrawBuffer->Height - 1 - wpos[1];
-   if (!program->PixelCenterInteger) {
+   if (!program->info.fs.pixel_center_integer) {
       wpos[0] += 0.5F;
       wpos[1] += 0.5F;
    }