nir: Drop the vs_inputs_dual_locations option

It was very inconsistently handled; the only things that made use of it
were glsl_to_nir, glspirv, and nir_gather_info.  In particular,
nir_lower_io completely ignored it so anyone using nir_lower_io on
64-bit vertex attributes was going to be in for a shock.  Also, as of
the previous commit, it's set by every driver that supports 64-bit
vertex attributes.  There's no longer any reason to have it be an option
so let's just delete it.

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>

src/amd/vulkan/radv_shader.c

@@ -71,7 +71,6 @@ static const struct nir_shader_compiler_options nir_options = {
 	.lower_extract_word = true,
 	.lower_ffma = true,
 	.lower_fpow = true,
-	.vs_inputs_dual_locations = true,
 	.max_unroll_iterations = 32
 };
 

src/compiler/glsl/glsl_to_nir.cpp

@@ -149,11 +149,8 @@ glsl_to_nir(const struct gl_shader_program *shader_prog,
     * two locations. For instance, if we have in the IR code a dvec3 attr0 in
     * location 0 and vec4 attr1 in location 1, in NIR attr0 will use
     * locations/slots 0 and 1, and attr1 will use location/slot 2 */
-   if (shader->info.stage == MESA_SHADER_VERTEX) {
-      sh->Program->DualSlotInputs = nir_get_dual_slot_attributes(shader);
-      if (options->vs_inputs_dual_locations)
-         nir_remap_dual_slot_attributes(shader, sh->Program->DualSlotInputs);
-   }
+   if (shader->info.stage == MESA_SHADER_VERTEX)
+      nir_remap_dual_slot_attributes(shader, &sh->Program->DualSlotInputs);
 
    shader->info.name = ralloc_asprintf(shader, "GLSL%d", shader_prog->Name);
    if (shader_prog->Label)

src/compiler/nir/nir.c

@@ -1854,34 +1854,32 @@ nir_system_value_from_intrinsic(nir_intrinsic_op intrin)
    }
 }
 
-uint64_t
-nir_get_dual_slot_attributes(nir_shader *shader)
-{
-   assert(shader->info.stage == MESA_SHADER_VERTEX);
-
-   uint64_t dual_slot = 0;
-   nir_foreach_variable(var, &shader->inputs) {
-      if (glsl_type_is_dual_slot(glsl_without_array(var->type))) {
-         unsigned slots = glsl_count_attribute_slots(var->type, true);
-         dual_slot |= BITFIELD64_MASK(slots) << var->data.location;
-      }
-   }
-
-   return dual_slot;
-}
-
 /* OpenGL utility method that remaps the location attributes if they are
  * doubles. Not needed for vulkan due the differences on the input location
  * count for doubles on vulkan vs OpenGL
+ *
+ * The bitfield returned in dual_slot is one bit for each double input slot in
+ * the original OpenGL single-slot input numbering.  The mapping from old
+ * locations to new locations is as follows:
+ *
+ *    new_loc = loc + _mesa_bitcount(dual_slot & BITFIELD64_MASK(loc))
  */
 void
-nir_remap_dual_slot_attributes(nir_shader *shader, uint64_t dual_slot)
+nir_remap_dual_slot_attributes(nir_shader *shader, uint64_t *dual_slot)
 {
    assert(shader->info.stage == MESA_SHADER_VERTEX);
 
+   *dual_slot = 0;
+   nir_foreach_variable(var, &shader->inputs) {
+      if (glsl_type_is_dual_slot(glsl_without_array(var->type))) {
+         unsigned slots = glsl_count_attribute_slots(var->type, true);
+         *dual_slot |= BITFIELD64_MASK(slots) << var->data.location;
+      }
+   }
+
    nir_foreach_variable(var, &shader->inputs) {
       var->data.location +=
-         _mesa_bitcount_64(dual_slot & BITFIELD64_MASK(var->data.location));
+         _mesa_bitcount_64(*dual_slot & BITFIELD64_MASK(var->data.location));
    }
 }
 

src/compiler/nir/nir.h

@@ -2119,12 +2119,6 @@ typedef struct nir_shader_compiler_options {
     */
    bool use_interpolated_input_intrinsics;
 
-   /**
-    * Do vertex shader double inputs use two locations? The Vulkan spec
-    * requires two locations to be used, OpenGL allows a single location.
-    */
-   bool vs_inputs_dual_locations;
-
    unsigned max_unroll_iterations;
 } nir_shader_compiler_options;
 
@@ -3039,9 +3033,8 @@ bool nir_opt_conditional_discard(nir_shader *shader);
 
 void nir_sweep(nir_shader *shader);
 
-uint64_t nir_get_dual_slot_attributes(nir_shader *shader);
 void nir_remap_dual_slot_attributes(nir_shader *shader,
-                                    uint64_t dual_slot);
+                                    uint64_t *dual_slot_inputs);
 uint64_t nir_get_single_slot_attribs_mask(uint64_t attribs, uint64_t dual_slot);
 
 nir_intrinsic_op nir_intrinsic_from_system_value(gl_system_value val);

src/compiler/nir/nir_gather_info.c

@@ -88,21 +88,15 @@ static void
 mark_whole_variable(nir_shader *shader, nir_variable *var, bool is_output_read)
 {
    const struct glsl_type *type = var->type;
-   bool is_vertex_input = false;
 
    if (nir_is_per_vertex_io(var, shader->info.stage)) {
       assert(glsl_type_is_array(type));
       type = glsl_get_array_element(type);
    }
 
-   if (!shader->options->vs_inputs_dual_locations &&
-       shader->info.stage == MESA_SHADER_VERTEX &&
-       var->data.mode == nir_var_shader_in)
-      is_vertex_input = true;
-
    const unsigned slots =
       var->data.compact ? DIV_ROUND_UP(glsl_get_length(type), 4)
-                        : glsl_count_attribute_slots(type, is_vertex_input);
+                        : glsl_count_attribute_slots(type, false);
 
    set_io_mask(shader, var, 0, slots, is_output_read);
 }
@@ -165,13 +159,7 @@ try_mask_partial_io(nir_shader *shader, nir_variable *var,
       return false;
    }
 
-   bool is_vertex_input = false;
-   if (!shader->options->vs_inputs_dual_locations &&
-       shader->info.stage == MESA_SHADER_VERTEX &&
-       var->data.mode == nir_var_shader_in)
-      is_vertex_input = true;
-
-   unsigned offset = get_io_offset(deref, is_vertex_input);
+   unsigned offset = get_io_offset(deref, false);
    if (offset == -1)
       return false;
 
@@ -187,10 +175,8 @@ try_mask_partial_io(nir_shader *shader, nir_variable *var,
    }
 
    /* double element width for double types that takes two slots */
-   if (!is_vertex_input &&
-       glsl_type_is_dual_slot(glsl_without_array(type))) {
+   if (glsl_type_is_dual_slot(glsl_without_array(type)))
       elem_width *= 2;
-   }
 
    if (offset >= num_elems * elem_width * mat_cols) {
       /* Constant index outside the bounds of the matrix/array.  This could

src/gallium/drivers/radeonsi/si_get.c

@@ -501,7 +501,6 @@ static const struct nir_shader_compiler_options nir_options = {
 	.lower_extract_word = true,
 	.max_unroll_iterations = 32,
 	.native_integers = true,
-	.vs_inputs_dual_locations = true,
 };
 
 static const void *

src/intel/compiler/brw_compiler.c

@@ -59,7 +59,6 @@
    .lower_unpack_snorm_4x8 = true,                                            \
    .lower_unpack_unorm_2x16 = true,                                           \
    .lower_unpack_unorm_4x8 = true,                                            \
-   .vs_inputs_dual_locations = true,                                          \
    .max_unroll_iterations = 32
 
 static const struct nir_shader_compiler_options scalar_nir_options = {
@@ -91,7 +90,6 @@ static const struct nir_shader_compiler_options vector_nir_options = {
    .lower_unpack_unorm_2x16 = true,
    .lower_extract_byte = true,
    .lower_extract_word = true,
-   .vs_inputs_dual_locations = true,
    .max_unroll_iterations = 32,
 };
 
@@ -110,7 +108,6 @@ static const struct nir_shader_compiler_options vector_nir_options_gen6 = {
    .lower_unpack_unorm_2x16 = true,
    .lower_extract_byte = true,
    .lower_extract_word = true,
-   .vs_inputs_dual_locations = true,
    .max_unroll_iterations = 32,
 };
 

src/mesa/main/glspirv.c

@@ -263,12 +263,8 @@ _mesa_spirv_to_nir(struct gl_context *ctx,
    NIR_PASS_V(nir, nir_split_var_copies);
    NIR_PASS_V(nir, nir_split_per_member_structs);
 
-   if (nir->info.stage == MESA_SHADER_VERTEX) {
-      uint64_t dual_slot_inputs = nir_get_dual_slot_attributes(nir);
-      if (options->vs_inputs_dual_locations)
-         nir_remap_dual_slot_attributes(nir, dual_slot_inputs);
-      linked_shader->Program->DualSlotInputs = dual_slot_inputs;
-   }
+   if (nir->info.stage == MESA_SHADER_VERTEX)
+      nir_remap_dual_slot_attributes(nir, &linked_shader->Program->DualSlotInputs);
 
    return nir;
 }