[Mesa-dev] [PATCH] radv: fix scanning output_usage_mask with structs

[Samuel Pitoiset]

To fix a regression in:
dEQP-VK.spirv_assembly.instruction.graphics.variable_init.output.struct

Fixes: f3275ca01c ("ac/nir: only enable used channels when exporting parameters")
Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
---
 src/amd/vulkan/radv_shader_info.c | 47 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 45 insertions(+), 2 deletions(-)

diff --git a/src/amd/vulkan/radv_shader_info.c b/src/amd/vulkan/radv_shader_info.c
index 9c18791524..54c9b425a0 100644
--- a/src/amd/vulkan/radv_shader_info.c
+++ b/src/amd/vulkan/radv_shader_info.c
@@ -47,6 +47,46 @@ static void mark_tess_output(struct radv_shader_info *info,
 		info->tcs.outputs_written |= (mask << param);
 }
 
+static void get_deref_offset(nir_deref_var *deref, unsigned *const_out)
+{
+	nir_deref *tail = &deref->deref;
+	unsigned const_offset = 0;
+
+	if (deref->var->data.compact) {
+		assert(tail->child->deref_type == nir_deref_type_array);
+		assert(glsl_type_is_scalar(glsl_without_array(deref->var->type)));
+
+		nir_deref_array *deref_array = nir_deref_as_array(tail->child);
+		/* We always lower indirect dereferences for "compact" array vars. */
+		assert(deref_array->deref_array_type == nir_deref_array_type_direct);
+
+		*const_out = deref_array->base_offset;
+		return;
+	}
+
+	while (tail->child != NULL) {
+		const struct glsl_type *parent_type = tail->type;
+		tail = tail->child;
+
+		if (tail->deref_type == nir_deref_type_array) {
+			nir_deref_array *deref_array = nir_deref_as_array(tail);
+			unsigned size = glsl_count_attribute_slots(tail->type, false);
+
+			const_offset += size * deref_array->base_offset;
+		} else if (tail->deref_type == nir_deref_type_struct) {
+			nir_deref_struct *deref_struct = nir_deref_as_struct(tail);
+
+			for (unsigned i = 0; i < deref_struct->index; i++) {
+				const struct glsl_type *ft = glsl_get_struct_field(parent_type, i);
+				const_offset += glsl_count_attribute_slots(ft, false);
+			}
+		} else
+			unreachable("unsupported deref type");
+	}
+
+	*const_out = const_offset;
+}
+
 static void
 gather_intrinsic_info(const nir_shader *nir, const nir_intrinsic_instr *instr,
 		      struct radv_shader_info *info)
@@ -176,12 +216,15 @@ gather_intrinsic_info(const nir_shader *nir, const nir_intrinsic_instr *instr,
 		if (var->data.mode == nir_var_shader_out) {
 			unsigned idx = var->data.location;
 			unsigned comp = var->data.location_frac;
+			unsigned const_offset = 0;
+
+			get_deref_offset(dvar, &const_offset);
 
 			if (nir->info.stage == MESA_SHADER_VERTEX) {
-				info->vs.output_usage_mask[idx] |=
+				info->vs.output_usage_mask[idx + const_offset] |=
 					instr->const_index[0] << comp;
 			} else if (nir->info.stage == MESA_SHADER_TESS_EVAL) {
-				info->tes.output_usage_mask[idx] |=
+				info->tes.output_usage_mask[idx + const_offset] |=
 					instr->const_index[0] << comp;
 			} else if (nir->info.stage == MESA_SHADER_TESS_CTRL) {
 				unsigned param = shader_io_get_unique_index(idx);
-- 
2.16.2