From 0e57694745979286cda0cd414cc6d1f4efe5408b Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Wed, 21 Oct 2015 12:03:21 -0700 Subject: i965/gs: Do prog_data setup and other calculations in brw_compile_gs This commit moves the large pile of setup calculations we have to do for geometry shaders out of brw_gs_emit and into brw_compile_gs. This has a couple of nice implications. First, it's less work that the caller of brw_compile_gs has to do. Second, it's consistent with the vertex and fragment stages. Finally, it allows us to put brw_gs_compile back behind the API boundary where it belongs. v2 (Jason Ekstrand): - Pull the changes to use nir info into a separate patch - Put brw_gs_compile into brw_shader.h rather than brw_vec4_gs_visitor.h so that we can use it for scalar GS. Reviewed-by: Kenneth Graunke --- src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp | 211 +++++++++++++++++++++- 1 file changed, 207 insertions(+), 4 deletions(-) (limited to 'src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp') diff --git a/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp index faad1a8..9402489 100644 --- a/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp +++ b/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp @@ -601,7 +601,7 @@ vec4_gs_visitor::gs_end_primitive() extern "C" const unsigned * brw_compile_gs(const struct brw_compiler *compiler, void *log_data, void *mem_ctx, - struct brw_gs_compile *c, + const struct brw_gs_prog_key *key, struct brw_gs_prog_data *prog_data, const nir_shader *shader, struct gl_shader_program *shader_prog, @@ -609,6 +609,209 @@ brw_compile_gs(const struct brw_compiler *compiler, void *log_data, unsigned *final_assembly_size, char **error_str) { + struct brw_gs_compile c; + memset(&c, 0, sizeof(c)); + c.key = *key; + + prog_data->include_primitive_id = + (shader->info.inputs_read & VARYING_BIT_PRIMITIVE_ID) != 0; + + prog_data->invocations = shader->info.gs.invocations; + + if (compiler->devinfo->gen >= 8) + prog_data->static_vertex_count = nir_gs_count_vertices(shader); + + if (compiler->devinfo->gen >= 7) { + if (shader->info.gs.output_primitive == GL_POINTS) { + /* When the output type is points, the geometry shader may output data + * to multiple streams, and EndPrimitive() has no effect. So we + * configure the hardware to interpret the control data as stream ID. + */ + prog_data->control_data_format = GEN7_GS_CONTROL_DATA_FORMAT_GSCTL_SID; + + /* We only have to emit control bits if we are using streams */ + if (shader_prog && shader_prog->Geom.UsesStreams) + c.control_data_bits_per_vertex = 2; + else + c.control_data_bits_per_vertex = 0; + } else { + /* When the output type is triangle_strip or line_strip, EndPrimitive() + * may be used to terminate the current strip and start a new one + * (similar to primitive restart), and outputting data to multiple + * streams is not supported. So we configure the hardware to interpret + * the control data as EndPrimitive information (a.k.a. "cut bits"). + */ + prog_data->control_data_format = GEN7_GS_CONTROL_DATA_FORMAT_GSCTL_CUT; + + /* We only need to output control data if the shader actually calls + * EndPrimitive(). + */ + c.control_data_bits_per_vertex = + shader->info.gs.uses_end_primitive ? 1 : 0; + } + } else { + /* There are no control data bits in gen6. */ + c.control_data_bits_per_vertex = 0; + + /* If it is using transform feedback, enable it */ + if (shader->info.has_transform_feedback_varyings) + prog_data->gen6_xfb_enabled = true; + else + prog_data->gen6_xfb_enabled = false; + } + c.control_data_header_size_bits = + shader->info.gs.vertices_out * c.control_data_bits_per_vertex; + + /* 1 HWORD = 32 bytes = 256 bits */ + prog_data->control_data_header_size_hwords = + ALIGN(c.control_data_header_size_bits, 256) / 256; + + /* Compute the output vertex size. + * + * From the Ivy Bridge PRM, Vol2 Part1 7.2.1.1 STATE_GS - Output Vertex + * Size (p168): + * + * [0,62] indicating [1,63] 16B units + * + * Specifies the size of each vertex stored in the GS output entry + * (following any Control Header data) as a number of 128-bit units + * (minus one). + * + * Programming Restrictions: The vertex size must be programmed as a + * multiple of 32B units with the following exception: Rendering is + * disabled (as per SOL stage state) and the vertex size output by the + * GS thread is 16B. + * + * If rendering is enabled (as per SOL state) the vertex size must be + * programmed as a multiple of 32B units. In other words, the only time + * software can program a vertex size with an odd number of 16B units + * is when rendering is disabled. + * + * Note: B=bytes in the above text. + * + * It doesn't seem worth the extra trouble to optimize the case where the + * vertex size is 16B (especially since this would require special-casing + * the GEN assembly that writes to the URB). So we just set the vertex + * size to a multiple of 32B (2 vec4's) in all cases. + * + * The maximum output vertex size is 62*16 = 992 bytes (31 hwords). We + * budget that as follows: + * + * 512 bytes for varyings (a varying component is 4 bytes and + * gl_MaxGeometryOutputComponents = 128) + * 16 bytes overhead for VARYING_SLOT_PSIZ (each varying slot is 16 + * bytes) + * 16 bytes overhead for gl_Position (we allocate it a slot in the VUE + * even if it's not used) + * 32 bytes overhead for gl_ClipDistance (we allocate it 2 VUE slots + * whenever clip planes are enabled, even if the shader doesn't + * write to gl_ClipDistance) + * 16 bytes overhead since the VUE size must be a multiple of 32 bytes + * (see below)--this causes up to 1 VUE slot to be wasted + * 400 bytes available for varying packing overhead + * + * Worst-case varying packing overhead is 3/4 of a varying slot (12 bytes) + * per interpolation type, so this is plenty. + * + */ + unsigned output_vertex_size_bytes = prog_data->base.vue_map.num_slots * 16; + assert(compiler->devinfo->gen == 6 || + output_vertex_size_bytes <= GEN7_MAX_GS_OUTPUT_VERTEX_SIZE_BYTES); + prog_data->output_vertex_size_hwords = + ALIGN(output_vertex_size_bytes, 32) / 32; + + /* Compute URB entry size. The maximum allowed URB entry size is 32k. + * That divides up as follows: + * + * 64 bytes for the control data header (cut indices or StreamID bits) + * 4096 bytes for varyings (a varying component is 4 bytes and + * gl_MaxGeometryTotalOutputComponents = 1024) + * 4096 bytes overhead for VARYING_SLOT_PSIZ (each varying slot is 16 + * bytes/vertex and gl_MaxGeometryOutputVertices is 256) + * 4096 bytes overhead for gl_Position (we allocate it a slot in the VUE + * even if it's not used) + * 8192 bytes overhead for gl_ClipDistance (we allocate it 2 VUE slots + * whenever clip planes are enabled, even if the shader doesn't + * write to gl_ClipDistance) + * 4096 bytes overhead since the VUE size must be a multiple of 32 + * bytes (see above)--this causes up to 1 VUE slot to be wasted + * 8128 bytes available for varying packing overhead + * + * Worst-case varying packing overhead is 3/4 of a varying slot per + * interpolation type, which works out to 3072 bytes, so this would allow + * us to accommodate 2 interpolation types without any danger of running + * out of URB space. + * + * In practice, the risk of running out of URB space is very small, since + * the above figures are all worst-case, and most of them scale with the + * number of output vertices. So we'll just calculate the amount of space + * we need, and if it's too large, fail to compile. + * + * The above is for gen7+ where we have a single URB entry that will hold + * all the output. In gen6, we will have to allocate URB entries for every + * vertex we emit, so our URB entries only need to be large enough to hold + * a single vertex. Also, gen6 does not have a control data header. + */ + unsigned output_size_bytes; + if (compiler->devinfo->gen >= 7) { + output_size_bytes = + prog_data->output_vertex_size_hwords * 32 * shader->info.gs.vertices_out; + output_size_bytes += 32 * prog_data->control_data_header_size_hwords; + } else { + output_size_bytes = prog_data->output_vertex_size_hwords * 32; + } + + /* Broadwell stores "Vertex Count" as a full 8 DWord (32 byte) URB output, + * which comes before the control header. + */ + if (compiler->devinfo->gen >= 8) + output_size_bytes += 32; + + assert(output_size_bytes >= 1); + int max_output_size_bytes = GEN7_MAX_GS_URB_ENTRY_SIZE_BYTES; + if (compiler->devinfo->gen == 6) + max_output_size_bytes = GEN6_MAX_GS_URB_ENTRY_SIZE_BYTES; + if (output_size_bytes > max_output_size_bytes) + return false; + + + /* URB entry sizes are stored as a multiple of 64 bytes in gen7+ and + * a multiple of 128 bytes in gen6. + */ + if (compiler->devinfo->gen >= 7) + prog_data->base.urb_entry_size = ALIGN(output_size_bytes, 64) / 64; + else + prog_data->base.urb_entry_size = ALIGN(output_size_bytes, 128) / 128; + + prog_data->output_topology = + get_hw_prim_for_gl_prim(shader->info.gs.output_primitive); + + /* The GLSL linker will have already matched up GS inputs and the outputs + * of prior stages. The driver does extend VS outputs in some cases, but + * only for legacy OpenGL or Gen4-5 hardware, neither of which offer + * geometry shader support. So we can safely ignore that. + * + * For SSO pipelines, we use a fixed VUE map layout based on variable + * locations, so we can rely on rendezvous-by-location making this work. + * + * However, we need to ignore VARYING_SLOT_PRIMITIVE_ID, as it's not + * written by previous stages and shows up via payload magic. + */ + GLbitfield64 inputs_read = + shader->info.inputs_read & ~VARYING_BIT_PRIMITIVE_ID; + brw_compute_vue_map(compiler->devinfo, + &c.input_vue_map, inputs_read, + shader->info.separate_shader); + + /* GS inputs are read from the VUE 256 bits (2 vec4's) at a time, so we + * need to program a URB read length of ceiling(num_slots / 2). + */ + prog_data->base.urb_read_length = (c.input_vue_map.num_slots + 1) / 2; + + /* Now that prog_data setup is done, we are ready to actually compile the + * program. + */ + if (compiler->devinfo->gen >= 7) { /* Compile the geometry shader in DUAL_OBJECT dispatch mode, if we can do * so without spilling. If the GS invocations count > 1, then we can't use @@ -618,7 +821,7 @@ brw_compile_gs(const struct brw_compiler *compiler, void *log_data, likely(!(INTEL_DEBUG & DEBUG_NO_DUAL_OBJECT_GS))) { prog_data->base.dispatch_mode = DISPATCH_MODE_4X2_DUAL_OBJECT; - vec4_gs_visitor v(compiler, log_data, c, prog_data, shader, + vec4_gs_visitor v(compiler, log_data, &c, prog_data, shader, mem_ctx, true /* no_spills */, shader_time_index); if (v.run()) { vec4_generator g(compiler, log_data, &prog_data->base, mem_ctx, @@ -660,11 +863,11 @@ brw_compile_gs(const struct brw_compiler *compiler, void *log_data, const unsigned *ret = NULL; if (compiler->devinfo->gen >= 7) - gs = new vec4_gs_visitor(compiler, log_data, c, prog_data, + gs = new vec4_gs_visitor(compiler, log_data, &c, prog_data, shader, mem_ctx, false /* no_spills */, shader_time_index); else - gs = new gen6_gs_visitor(compiler, log_data, c, prog_data, shader_prog, + gs = new gen6_gs_visitor(compiler, log_data, &c, prog_data, shader_prog, shader, mem_ctx, false /* no_spills */, shader_time_index); -- cgit v1.1