--- /dev/null
+/*
+ * Copyright © 2018 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "nir_xfb_info.h"
+
+#include <util/u_math.h>
+
+static void
+add_var_xfb_outputs(nir_xfb_info *xfb,
+ nir_variable *var,
+ unsigned *location,
+ unsigned *offset,
+ const struct glsl_type *type)
+{
+ if (glsl_type_is_array(type) || glsl_type_is_matrix(type)) {
+ unsigned length = glsl_get_length(type);
+ const struct glsl_type *child_type = glsl_get_array_element(type);
+ for (unsigned i = 0; i < length; i++)
+ add_var_xfb_outputs(xfb, var, location, offset, child_type);
+ } else if (glsl_type_is_struct(type)) {
+ unsigned length = glsl_get_length(type);
+ for (unsigned i = 0; i < length; i++) {
+ const struct glsl_type *child_type = glsl_get_struct_field(type, i);
+ add_var_xfb_outputs(xfb, var, location, offset, child_type);
+ }
+ } else {
+ assert(var->data.xfb_buffer < NIR_MAX_XFB_BUFFERS);
+ if (xfb->buffers_written & (1 << var->data.xfb_buffer)) {
+ assert(xfb->strides[var->data.xfb_buffer] == var->data.xfb_stride);
+ assert(xfb->buffer_to_stream[var->data.xfb_buffer] == var->data.stream);
+ } else {
+ xfb->buffers_written |= (1 << var->data.xfb_buffer);
+ xfb->strides[var->data.xfb_buffer] = var->data.xfb_stride;
+ xfb->buffer_to_stream[var->data.xfb_buffer] = var->data.stream;
+ }
+
+ assert(var->data.stream < NIR_MAX_XFB_STREAMS);
+ xfb->streams_written |= (1 << var->data.stream);
+
+ unsigned comp_slots = glsl_get_component_slots(type);
+ unsigned attrib_slots = DIV_ROUND_UP(comp_slots, 4);
+ assert(attrib_slots == glsl_count_attribute_slots(type, false));
+
+ /* Ensure that we don't have, for instance, a dvec2 with a location_frac
+ * of 2 which would make it crass a location boundary even though it
+ * fits in a single slot. However, you can have a dvec3 which crosses
+ * the slot boundary with a location_frac of 2.
+ */
+ assert(DIV_ROUND_UP(var->data.location_frac + comp_slots, 4) == attrib_slots);
+
+ assert(var->data.location_frac + comp_slots <= 8);
+ uint8_t comp_mask = ((1 << comp_slots) - 1) << var->data.location_frac;
+
+ assert(attrib_slots <= 2);
+ for (unsigned s = 0; s < attrib_slots; s++) {
+ nir_xfb_output_info *output = &xfb->outputs[xfb->output_count++];
+
+ output->buffer = var->data.xfb_buffer;
+ output->offset = *offset;
+ output->location = *location;
+ output->component_mask = (comp_mask >> (s * 4)) & 0xf;
+
+ (*location)++;
+ *offset += comp_slots * 4;
+ }
+ }
+}
+
+static int
+compare_xfb_output_offsets(const void *_a, const void *_b)
+{
+ const nir_xfb_output_info *a = _a, *b = _b;
+ return a->offset - b->offset;
+}
+
+nir_xfb_info *
+nir_gather_xfb_info(const nir_shader *shader, void *mem_ctx)
+{
+ assert(shader->info.stage == MESA_SHADER_VERTEX ||
+ shader->info.stage == MESA_SHADER_TESS_EVAL ||
+ shader->info.stage == MESA_SHADER_GEOMETRY);
+
+ /* Compute the number of outputs we have. This is simply the number of
+ * cumulative locations consumed by all the variables. If a location is
+ * represented by multiple variables, then they each count separately in
+ * number of outputs.
+ */
+ unsigned num_outputs = 0;
+ nir_foreach_variable(var, &shader->outputs) {
+ if (var->data.explicit_xfb_buffer ||
+ var->data.explicit_xfb_stride) {
+ assert(var->data.explicit_xfb_buffer &&
+ var->data.explicit_xfb_stride &&
+ var->data.explicit_offset);
+ num_outputs += glsl_count_attribute_slots(var->type, false);
+ }
+ }
+ if (num_outputs == 0)
+ return NULL;
+
+ nir_xfb_info *xfb = rzalloc_size(mem_ctx, nir_xfb_info_size(num_outputs));
+
+ /* Walk the list of outputs and add them to the array */
+ nir_foreach_variable(var, &shader->outputs) {
+ if (var->data.explicit_xfb_buffer ||
+ var->data.explicit_xfb_stride) {
+ unsigned location = var->data.location;
+ unsigned offset = var->data.offset;
+ add_var_xfb_outputs(xfb, var, &location, &offset, var->type);
+ }
+ }
+ assert(xfb->output_count == num_outputs);
+
+ /* Everything is easier in the state setup code if the list is sorted in
+ * order of output offset.
+ */
+ qsort(xfb->outputs, xfb->output_count, sizeof(xfb->outputs[0]),
+ compare_xfb_output_offsets);
+
+ /* Finally, do a sanity check */
+ unsigned max_offset[NIR_MAX_XFB_BUFFERS] = { };
+ for (unsigned i = 0; i < xfb->output_count; i++) {
+ assert(xfb->outputs[i].offset >= max_offset[xfb->outputs[i].buffer]);
+ assert(xfb->outputs[i].component_mask != 0);
+ unsigned slots = util_bitcount(xfb->outputs[i].component_mask);
+ max_offset[xfb->outputs[i].buffer] = xfb->outputs[i].offset + slots * 4;
+ }
+
+ return xfb;
+}
--- /dev/null
+/*
+ * Copyright © 2018 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef NIR_XFB_INFO_H
+#define NIR_XFB_INFO_H
+
+#include "nir.h"
+
+#define NIR_MAX_XFB_BUFFERS 4
+#define NIR_MAX_XFB_STREAMS 4
+
+typedef struct {
+ uint8_t buffer;
+ uint16_t offset;
+ uint8_t location;
+ uint8_t component_mask;
+} nir_xfb_output_info;
+
+typedef struct {
+ uint8_t buffers_written;
+ uint8_t streams_written;
+
+ uint16_t strides[NIR_MAX_XFB_BUFFERS];
+ uint8_t buffer_to_stream[NIR_MAX_XFB_STREAMS];
+
+ uint16_t output_count;
+ nir_xfb_output_info outputs[0];
+} nir_xfb_info;
+
+static inline size_t
+nir_xfb_info_size(uint16_t output_count)
+{
+ return sizeof(nir_xfb_info) + sizeof(nir_xfb_output_info) * output_count;
+}
+
+nir_xfb_info *
+nir_gather_xfb_info(const nir_shader *shader, void *mem_ctx);
+
+#endif /* NIR_XFB_INFO_H */