From b9719b4b05b6aa5176e1a536ad948578f8a68fad Mon Sep 17 00:00:00 2001 From: Neil Roberts Date: Tue, 12 Dec 2017 17:27:44 +0100 Subject: nir/linker: Add the start of a pure-NIR linker for XFB MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit v2: ignore names on purpose, for consistency with other places where we are doing the same (Alejandro) v3: changes proposed by Timothy Arceri, implemented by Alejandro Piñeiro: * Remove redundant 'struct active_xfb_varying' * Update several comments, including spec quotes if needed * Rename struct 'active_xfb_varying_array' to 'active_xfb_varyings' * Rename variable 'array' to 'active_varyings' * Replace one if condition for an assert ( Signed-off-by: Alejandro Piñeiro Reviewed-by: Timothy Arceri --- src/compiler/glsl/gl_nir_link_xfb.c | 316 ++++++++++++++++++++++++++++++++++++ 1 file changed, 316 insertions(+) create mode 100644 src/compiler/glsl/gl_nir_link_xfb.c (limited to 'src/compiler/glsl/gl_nir_link_xfb.c') diff --git a/src/compiler/glsl/gl_nir_link_xfb.c b/src/compiler/glsl/gl_nir_link_xfb.c new file mode 100644 index 00000000000..bcef1e1863d --- /dev/null +++ b/src/compiler/glsl/gl_nir_link_xfb.c @@ -0,0 +1,316 @@ +/* + * 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.h" +#include "gl_nir_linker.h" +#include "ir_uniform.h" /* for gl_uniform_storage */ +#include "linker_util.h" +#include "main/context.h" + +/* + * This file does the linking of GLSL transform feedback using NIR. + * + * Note: This linking pass is currently tailored for ARB_gl_spirv needs and + * particularities. + */ + +struct active_xfb_buffer { + GLuint stride; + GLuint num_varyings; +}; + +struct active_xfb_varyings { + unsigned num_varyings; + unsigned num_outputs; + unsigned buffer_size; + struct nir_variable **varyings; + struct active_xfb_buffer buffers[MAX_FEEDBACK_BUFFERS]; +}; + +static unsigned +get_num_outputs(nir_variable *var) +{ + return glsl_count_attribute_slots(var->type, + false /* is_vertex_input */); +} + +static void +add_xfb_varying(struct active_xfb_varyings *active_varyings, + nir_variable *var) +{ + if (active_varyings->num_varyings >= active_varyings->buffer_size) { + if (active_varyings->buffer_size == 0) + active_varyings->buffer_size = 1; + else + active_varyings->buffer_size *= 2; + + active_varyings->varyings = realloc(active_varyings->varyings, + sizeof(nir_variable*) * + active_varyings->buffer_size); + } + + active_varyings->varyings[active_varyings->num_varyings++] = var; + + active_varyings->num_outputs += get_num_outputs(var); +} + +static int +cmp_xfb_offset(const void *x_generic, const void *y_generic) +{ + const nir_variable *const *x = x_generic; + const nir_variable *const *y = y_generic; + + if ((*x)->data.xfb_buffer != (*y)->data.xfb_buffer) + return (*x)->data.xfb_buffer - (*y)->data.xfb_buffer; + return (*x)->data.offset - (*y)->data.offset; +} + +static void +get_active_xfb_varyings(struct gl_shader_program *prog, + struct active_xfb_varyings *active_varyings) +{ + for (unsigned i = 0; i < MESA_SHADER_STAGES; ++i) { + struct gl_linked_shader *sh = prog->_LinkedShaders[i]; + if (sh == NULL) + continue; + + nir_shader *nir = sh->Program->nir; + + nir_foreach_variable(var, &nir->outputs) { + if (var->data.explicit_xfb_buffer && + var->data.explicit_xfb_stride) { + assert(var->data.xfb_buffer < MAX_FEEDBACK_BUFFERS); + active_varyings->buffers[var->data.xfb_buffer].stride = + var->data.xfb_stride; + } + + if (!var->data.explicit_xfb_buffer || + !var->data.explicit_offset) + continue; + + active_varyings->buffers[var->data.xfb_buffer].num_varyings++; + + add_xfb_varying(active_varyings, var); + } + } + + /* The xfb_offset qualifier does not have to be used in increasing order + * however some drivers expect to receive the list of transform feedback + * declarations in order so sort it now for convenience. + */ + qsort(active_varyings->varyings, + active_varyings->num_varyings, + sizeof(*active_varyings->varyings), + cmp_xfb_offset); +} + +static unsigned +add_varying_outputs(nir_variable *var, + const struct glsl_type *type, + unsigned location_offset, + unsigned dest_offset, + struct gl_transform_feedback_output *output) +{ + unsigned num_outputs = 0; + + 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); + unsigned component_slots = glsl_get_component_slots(child_type); + + for (unsigned i = 0; i < length; i++) { + unsigned child_outputs = add_varying_outputs(var, + child_type, + location_offset, + dest_offset, + output + num_outputs); + num_outputs += child_outputs; + location_offset += child_outputs; + dest_offset += component_slots; + } + } 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); + unsigned child_outputs = add_varying_outputs(var, + child_type, + location_offset, + dest_offset, + output + num_outputs); + num_outputs += child_outputs; + location_offset += child_outputs; + dest_offset += glsl_get_component_slots(child_type); + } + } else { + unsigned location = var->data.location + location_offset; + unsigned location_frac = var->data.location_frac; + unsigned num_components = glsl_get_component_slots(type); + + while (num_components > 0) { + unsigned output_size = MIN2(num_components, 4 - location_frac); + + output->OutputRegister = location; + output->OutputBuffer = var->data.xfb_buffer; + output->NumComponents = output_size; + output->StreamId = var->data.stream; + output->DstOffset = var->data.offset / 4 + dest_offset; + output->ComponentOffset = location_frac; + + dest_offset += output_size; + num_components -= output_size; + num_outputs++; + output++; + location++; + location_frac = 0; + } + } + + return num_outputs; +} + +void +gl_nir_link_assign_xfb_resources(struct gl_context *ctx, + struct gl_shader_program *prog) +{ + /* + * From ARB_gl_spirv spec: + * + * "- If the *Xfb* Execution Mode is set, any output variable that is at + * least partially captured: + * * must be decorated with an *XfbBuffer*, declaring the capturing buffer + * * must have at least one captured output variable in the capturing + * buffer decorated with an *XfbStride* (and all such *XfbStride* values + * for the capturing buffer must be equal) + * - If the *Xfb* Execution Mode is set, any captured output: + * * must be a non-structure decorated with *Offset* or a member of a + * structure whose type member is decorated with *Offset*" + * + * Note the "must be", meaning that explicit buffer, offset and stride are + * mandatory. So as this is intended to work with SPIR-V shaders we don't + * need to calculate the offset or the stride. + */ + + struct gl_program *xfb_prog = prog->last_vert_prog; + + if (xfb_prog == NULL) + return; + + /* free existing varyings, if any */ + for (unsigned i = 0; i < prog->TransformFeedback.NumVarying; i++) + free(prog->TransformFeedback.VaryingNames[i]); + free(prog->TransformFeedback.VaryingNames); + + struct active_xfb_varyings active_varyings = { 0 }; + + get_active_xfb_varyings(prog, &active_varyings); + + for (unsigned buf = 0; buf < MAX_FEEDBACK_BUFFERS; buf++) + prog->TransformFeedback.BufferStride[buf] = active_varyings.buffers[buf].stride; + + prog->TransformFeedback.NumVarying = active_varyings.num_varyings; + prog->TransformFeedback.VaryingNames = + malloc(sizeof(GLchar *) * active_varyings.num_varyings); + + struct gl_transform_feedback_info *linked_xfb = + rzalloc(xfb_prog, struct gl_transform_feedback_info); + xfb_prog->sh.LinkedTransformFeedback = linked_xfb; + + linked_xfb->Outputs = + rzalloc_array(xfb_prog, + struct gl_transform_feedback_output, + active_varyings.num_outputs); + linked_xfb->NumOutputs = active_varyings.num_outputs; + + linked_xfb->Varyings = + rzalloc_array(xfb_prog, + struct gl_transform_feedback_varying_info, + active_varyings.num_varyings); + linked_xfb->NumVarying = active_varyings.num_varyings; + + struct gl_transform_feedback_output *output = linked_xfb->Outputs; + for (unsigned i = 0; i < active_varyings.num_varyings; i++) { + struct nir_variable *var = active_varyings.varyings[i]; + + /* From ARB_gl_spirv spec: + * + * "19. How should the program interface query operations behave for + * program objects created from SPIR-V shaders? + * + * DISCUSSION: we previously said we didn't need reflection to work + * for SPIR-V shaders (at least for the first version), however we + * are left with specifying how it should "not work". The primary + * issue is that SPIR-V binaries are not required to have names + * associated with variables. They can be associated in debug + * information, but there is no requirement for that to be present, + * and it should not be relied upon." + * + * Options:" + * + * + * + * "RESOLVED. Pick (c), but also allow debug names to be returned + * if an implementation wants to." + * + * So names are considered optional debug info, so the linker needs to + * work without them, and returning them is optional. For simplicity at + * this point we are ignoring names + */ + prog->TransformFeedback.VaryingNames[i] = NULL; + + unsigned varying_outputs = add_varying_outputs(var, + var->type, + 0, /* location_offset */ + 0, /* dest_offset */ + output); + assert(varying_outputs == get_num_outputs(var)); + output = output + varying_outputs; + + struct gl_transform_feedback_varying_info *varying = + linked_xfb->Varyings + i; + + /* ARB_gl_spirv: see above. */ + varying->Name = NULL; + varying->Type = glsl_get_gl_type(var->type); + varying->BufferIndex = var->data.xfb_buffer; + varying->Size = glsl_get_length(var->type); + varying->Offset = var->data.offset; + } + + /* Make sure MaxTransformFeedbackBuffers is <= 32 so the bitmask for + * tracking the number of buffers doesn't overflow. + */ + unsigned buffers = 0; + assert(ctx->Const.MaxTransformFeedbackBuffers <= sizeof(buffers) * 8); + + for (unsigned buf = 0; buf < MAX_FEEDBACK_BUFFERS; buf++) { + if (active_varyings.buffers[buf].stride > 0) { + linked_xfb->Buffers[buf].Stride = active_varyings.buffers[buf].stride / 4; + linked_xfb->Buffers[buf].NumVaryings = active_varyings.buffers[buf].num_varyings; + buffers |= 1 << buf; + } + } + + linked_xfb->ActiveBuffers = buffers; + + free(active_varyings.varyings); +} -- cgit v1.2.3