compiler: Move double_inputs to gl_program::DualSlotInputs

Previously, we had two field in shader_info: double_inputs_read and
double_inputs.  Presumably, the one was for all double inputs that are
read and the other is all that exist.  However, because nir_gather_info
regenerates these two values, there is a possibility, if a variable gets
deleted, that the value of double_inputs could change over time.  This
is a problem because double_inputs is used to remap the input locations
to a two-slot-per-dvec3/4 scheme for i965.  If that mapping were to
change between glsl_to_nir and back-end state setup, we would fall over
when trying to map the NIR outputs back onto the GL location space.

This commit changes the way slot re-mapping works.  Instead of the
double_inputs field in shader_info, it adds a DualSlotInputs bitfield to
gl_program.  By having it in gl_program, we more easily guarantee that
NIR passes won't touch it after it's been set.  It also makes more sense
to put it in a GL data structure since it's really a mapping from GL
slots to back-end and/or NIR slots and not really a NIR shader thing.

Tested-by: Alejandro Piñeiro <[email protected]> (ARB_gl_spirv tests)
Reviewed-by: Alejandro Piñeiro <[email protected]>
Reviewed-by: Timothy Arceri <[email protected]>

1 files changed, 4 insertions, 16 deletions

diff --git a/src/mesa/main/glspirv.c b/src/mesa/main/glspirv.c
index 1c5b7dd17f3..c53fe0bd07c 100644
--- a/src/mesa/main/glspirv.c
+++ b/src/mesa/main/glspirv.c
@@ -182,20 +182,6 @@ _mesa_spirv_link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
       prog->last_vert_prog = prog->_LinkedShaders[last_vert_stage - 1]->Program;
 }
 
-static void
-nir_compute_double_inputs(nir_shader *shader,
-                          const nir_shader_compiler_options *options)
-{
-   nir_foreach_variable(var, &shader->inputs) {
-      if (glsl_type_is_dual_slot(glsl_without_array(var->type))) {
-         for (unsigned i = 0; i < glsl_count_attribute_slots(var->type, true); i++) {
-            uint64_t bitfield = BITFIELD64_BIT(var->data.location + i);
-            shader->info.vs.double_inputs |= bitfield;
-         }
-      }
-   }
-}
-
 nir_shader *
 _mesa_spirv_to_nir(struct gl_context *ctx,
                    const struct gl_shader_program *prog,
@@ -278,8 +264,10 @@ _mesa_spirv_to_nir(struct gl_context *ctx,
    NIR_PASS_V(nir, nir_split_per_member_structs);
 
    if (nir->info.stage == MESA_SHADER_VERTEX) {
-      nir_compute_double_inputs(nir, options);
-      nir_remap_attributes(nir, options);
+      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;
    }
 
    return nir;