spirv: Always declare FragCoord as a sysval

Now that all spirv_to_nir() users take care of converting sysvals to
varyings, we can unconditionally declare FragCoord as a sysval.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa@collabora.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13017>

src/amd/vulkan/radv_shader.c

@@ -521,7 +521,6 @@ radv_shader_compile_to_nir(struct radv_device *device, struct vk_shader_module *
          .push_const_addr_format = nir_address_format_logical,
          .shared_addr_format = nir_address_format_32bit_offset,
          .constant_addr_format = nir_address_format_64bit_global,
-         .frag_coord_is_sysval = true,
          .use_deref_buffer_array_length = true,
          .debug =
             {

src/broadcom/vulkan/v3dv_pipeline.c

@@ -190,7 +190,6 @@ static const struct spirv_to_nir_options default_spirv_options =  {
    .phys_ssbo_addr_format = nir_address_format_64bit_global,
    .push_const_addr_format = nir_address_format_logical,
    .shared_addr_format = nir_address_format_32bit_offset,
-   .frag_coord_is_sysval = false,
 };
 
 const nir_shader_compiler_options v3dv_nir_options = {

src/compiler/spirv/nir_spirv.h

@@ -58,11 +58,6 @@ enum nir_spirv_execution_environment {
 struct spirv_to_nir_options {
    enum nir_spirv_execution_environment environment;
 
-   /* Whether to make FragCoord to a system value, the same as
-    * GLSLFragCoordIsSysVal in GLSL.
-    */
-   bool frag_coord_is_sysval;
-
    /* Whether to keep ViewIndex as an input instead of rewriting to a sysval.
     */
    bool view_index_is_input;

src/compiler/spirv/vtn_variables.c

@@ -879,12 +879,8 @@ vtn_get_builtin_location(struct vtn_builder *b,
       break;
    case SpvBuiltInFragCoord:
       vtn_assert(*mode == nir_var_shader_in);
-      if (b->options && b->options->frag_coord_is_sysval) {
+      *mode = nir_var_system_value;
-         *mode = nir_var_system_value;
+      *location = SYSTEM_VALUE_FRAG_COORD;
-         *location = SYSTEM_VALUE_FRAG_COORD;
-      } else {
-         *location = VARYING_SLOT_POS;
-      }
       break;
    case SpvBuiltInPointCoord:
       *location = VARYING_SLOT_PNTC;

src/freedreno/vulkan/tu_shader.c

@@ -38,8 +38,6 @@ tu_spirv_to_nir(struct tu_device *dev,
 {
    /* TODO these are made-up */
    const struct spirv_to_nir_options spirv_options = {
-      .frag_coord_is_sysval = true,
-
       .ubo_addr_format = nir_address_format_vec2_index_32bit_offset,
       .ssbo_addr_format = nir_address_format_vec2_index_32bit_offset,
 

src/gallium/frontends/lavapipe/lvp_pipeline.c

@@ -514,7 +514,6 @@ lvp_shader_compile_to_ir(struct lvp_pipeline *pipeline,
       .phys_ssbo_addr_format = nir_address_format_64bit_global,
       .push_const_addr_format = nir_address_format_logical,
       .shared_addr_format = nir_address_format_32bit_offset,
-      .frag_coord_is_sysval = false,
    };
 
    nir = spirv_to_nir(spirv, module->size / 4,

src/intel/vulkan/anv_pipeline.c

@@ -108,7 +108,6 @@ anv_shader_compile_to_nir(struct anv_device *device,
       .module = module,
    };
    struct spirv_to_nir_options spirv_options = {
-      .frag_coord_is_sysval = true,
       .caps = {
          .demote_to_helper_invocation = true,
          .derivative_group = true,

src/mesa/main/glspirv.c

@@ -243,7 +243,6 @@ _mesa_spirv_to_nir(struct gl_context *ctx,
 
    const struct spirv_to_nir_options spirv_options = {
       .environment = NIR_SPIRV_OPENGL,
-      .frag_coord_is_sysval = ctx->Const.GLSLFragCoordIsSysVal,
       .use_deref_buffer_array_length = true,
       .caps = ctx->Const.SpirVCapabilities,
       .ubo_addr_format = nir_address_format_32bit_index_offset,