i965: Rename brw_vec4_gs.[ch] to brw_gs.[ch].

These source files support actual geometry shaders, so using "gs" for
the name makes a lot of sense.  We're going to be adding SIMD8 geometry
shader support as well, at which point "vec4_gs" will be a misnomer.

Signed-off-by: Kenneth Graunke <[email protected]>
Acked-by: Matt Turner <[email protected]>
Acked-by: Jason Ekstrand <[email protected]>
Acked-by: Iago Toral Quiroga <[email protected]>

1 files changed, 428 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_gs.c b/src/mesa/drivers/dri/i965/brw_gs.c
new file mode 100644
index 00000000000..f44ac26d580
--- /dev/null
+++ b/src/mesa/drivers/dri/i965/brw_gs.c
@@ -0,0 +1,428 @@
+/*
+ * Copyright © 2013 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.
+ */
+
+/**
+ * \file brw_vec4_gs.c
+ *
+ * State atom for client-programmable geometry shaders, and support code.
+ */
+
+#include "brw_gs.h"
+#include "brw_context.h"
+#include "brw_vec4_gs_visitor.h"
+#include "brw_state.h"
+#include "brw_ff_gs.h"
+
+
+static bool
+do_gs_prog(struct brw_context *brw,
+           struct gl_shader_program *prog,
+           struct brw_geometry_program *gp,
+           struct brw_gs_prog_key *key)
+{
+   struct brw_stage_state *stage_state = &brw->gs.base;
+   struct brw_gs_compile c;
+   memset(&c, 0, sizeof(c));
+   c.key = *key;
+   c.gp = gp;
+
+   c.prog_data.include_primitive_id =
+      (gp->program.Base.InputsRead & VARYING_BIT_PRIMITIVE_ID) != 0;
+
+   c.prog_data.invocations = gp->program.Invocations;
+
+   /* Allocate the references to the uniforms that will end up in the
+    * prog_data associated with the compiled program, and which will be freed
+    * by the state cache.
+    *
+    * Note: param_count needs to be num_uniform_components * 4, since we add
+    * padding around uniform values below vec4 size, so the worst case is that
+    * every uniform is a float which gets padded to the size of a vec4.
+    */
+   struct gl_shader *gs = prog->_LinkedShaders[MESA_SHADER_GEOMETRY];
+   int param_count = gs->num_uniform_components * 4;
+
+   /* We also upload clip plane data as uniforms */
+   param_count += MAX_CLIP_PLANES * 4;
+
+   c.prog_data.base.base.param =
+      rzalloc_array(NULL, const gl_constant_value *, param_count);
+   c.prog_data.base.base.pull_param =
+      rzalloc_array(NULL, const gl_constant_value *, param_count);
+   /* Setting nr_params here NOT to the size of the param and pull_param
+    * arrays, but to the number of uniform components vec4_visitor
+    * needs. vec4_visitor::setup_uniforms() will set it back to a proper value.
+    */
+   c.prog_data.base.base.nr_params = ALIGN(param_count, 4) / 4 + gs->num_samplers;
+
+   if (brw->gen >= 7) {
+      if (gp->program.OutputType == 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.
+          */
+         c.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 (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").
+          */
+         c.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 = gp->program.UsesEndPrimitive ? 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 (prog->TransformFeedback.NumVarying)
+         c.prog_data.gen6_xfb_enabled = true;
+      else
+         c.prog_data.gen6_xfb_enabled = false;
+   }
+   c.control_data_header_size_bits =
+      gp->program.VerticesOut * c.control_data_bits_per_vertex;
+
+   /* 1 HWORD = 32 bytes = 256 bits */
+   c.prog_data.control_data_header_size_hwords =
+      ALIGN(c.control_data_header_size_bits, 256) / 256;
+
+   GLbitfield64 outputs_written = gp->program.Base.OutputsWritten;
+
+   /* In order for legacy clipping to work, we need to populate the clip
+    * distance varying slots whenever clipping is enabled, even if the vertex
+    * shader doesn't write to gl_ClipDistance.
+    */
+   if (c.key.base.userclip_active) {
+      outputs_written |= BITFIELD64_BIT(VARYING_SLOT_CLIP_DIST0);
+      outputs_written |= BITFIELD64_BIT(VARYING_SLOT_CLIP_DIST1);
+   }
+
+   brw_compute_vue_map(brw, &c.prog_data.base.vue_map, outputs_written);
+
+   /* 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 = c.prog_data.base.vue_map.num_slots * 16;
+   assert(brw->gen == 6 ||
+          output_vertex_size_bytes <= GEN7_MAX_GS_OUTPUT_VERTEX_SIZE_BYTES);
+   c.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 (brw->gen >= 7) {
+      output_size_bytes =
+         c.prog_data.output_vertex_size_hwords * 32 * gp->program.VerticesOut;
+      output_size_bytes += 32 * c.prog_data.control_data_header_size_hwords;
+   } else {
+      output_size_bytes = c.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 (brw->gen >= 8)
+      output_size_bytes += 32;
+
+   assert(output_size_bytes >= 1);
+   int max_output_size_bytes = GEN7_MAX_GS_URB_ENTRY_SIZE_BYTES;
+   if (brw->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 (brw->gen >= 7)
+      c.prog_data.base.urb_entry_size = ALIGN(output_size_bytes, 64) / 64;
+   else
+      c.prog_data.base.urb_entry_size = ALIGN(output_size_bytes, 128) / 128;
+
+   c.prog_data.output_topology =
+      get_hw_prim_for_gl_prim(gp->program.OutputType);
+
+   brw_compute_vue_map(brw, &c.input_vue_map, c.key.input_varyings);
+
+   /* 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).
+    */
+   c.prog_data.base.urb_read_length = (c.input_vue_map.num_slots + 1) / 2;
+
+   void *mem_ctx = ralloc_context(NULL);
+   unsigned program_size;
+   const unsigned *program =
+      brw_gs_emit(brw, prog, &c, mem_ctx, &program_size);
+   if (program == NULL) {
+      ralloc_free(mem_ctx);
+      return false;
+   }
+
+   /* Scratch space is used for register spilling */
+   if (c.base.last_scratch) {
+      perf_debug("Geometry shader triggered register spilling.  "
+                 "Try reducing the number of live vec4 values to "
+                 "improve performance.\n");
+
+      c.prog_data.base.base.total_scratch
+         = brw_get_scratch_size(c.base.last_scratch*REG_SIZE);
+
+      brw_get_scratch_bo(brw, &stage_state->scratch_bo,
+			 c.prog_data.base.base.total_scratch *
+                         brw->max_gs_threads);
+   }
+
+   brw_upload_cache(&brw->cache, BRW_GS_PROG,
+                    &c.key, sizeof(c.key),
+                    program, program_size,
+                    &c.prog_data, sizeof(c.prog_data),
+                    &stage_state->prog_offset, &brw->gs.prog_data);
+   ralloc_free(mem_ctx);
+
+   return true;
+}
+
+
+static void
+brw_upload_gs_prog(struct brw_context *brw)
+{
+   struct gl_context *ctx = &brw->ctx;
+   struct brw_stage_state *stage_state = &brw->gs.base;
+   struct brw_gs_prog_key key;
+   /* BRW_NEW_GEOMETRY_PROGRAM */
+   struct brw_geometry_program *gp =
+      (struct brw_geometry_program *) brw->geometry_program;
+
+   if (gp == NULL) {
+      /* No geometry shader.  Vertex data just passes straight through. */
+      if (brw->state.dirty.brw & BRW_NEW_VUE_MAP_VS) {
+         brw->vue_map_geom_out = brw->vue_map_vs;
+         brw->state.dirty.brw |= BRW_NEW_VUE_MAP_GEOM_OUT;
+      }
+
+      if (brw->gen == 6 &&
+          (brw->state.dirty.brw & BRW_NEW_TRANSFORM_FEEDBACK)) {
+         gen6_brw_upload_ff_gs_prog(brw);
+         return;
+      }
+
+      /* Other state atoms had better not try to access prog_data, since
+       * there's no GS program.
+       */
+      brw->gs.prog_data = NULL;
+      brw->gs.base.prog_data = NULL;
+
+      return;
+   }
+
+   struct gl_program *prog = &gp->program.Base;
+
+   memset(&key, 0, sizeof(key));
+
+   key.base.program_string_id = gp->id;
+   brw_setup_vec4_key_clip_info(brw, &key.base,
+                                gp->program.Base.UsesClipDistanceOut);
+
+   /* _NEW_LIGHT | _NEW_BUFFERS */
+   key.base.clamp_vertex_color = ctx->Light._ClampVertexColor;
+
+   /* _NEW_TEXTURE */
+   brw_populate_sampler_prog_key_data(ctx, prog, stage_state->sampler_count,
+                                      &key.base.tex);
+
+   /* BRW_NEW_VUE_MAP_VS */
+   key.input_varyings = brw->vue_map_vs.slots_valid;
+
+   if (!brw_search_cache(&brw->cache, BRW_GS_PROG,
+                         &key, sizeof(key),
+                         &stage_state->prog_offset, &brw->gs.prog_data)) {
+      bool success =
+         do_gs_prog(brw, ctx->_Shader->CurrentProgram[MESA_SHADER_GEOMETRY], gp,
+                    &key);
+      assert(success);
+      (void)success;
+   }
+   brw->gs.base.prog_data = &brw->gs.prog_data->base.base;
+
+   if (memcmp(&brw->vs.prog_data->base.vue_map, &brw->vue_map_geom_out,
+              sizeof(brw->vue_map_geom_out)) != 0) {
+      brw->vue_map_geom_out = brw->gs.prog_data->base.vue_map;
+      brw->state.dirty.brw |= BRW_NEW_VUE_MAP_GEOM_OUT;
+   }
+}
+
+
+const struct brw_tracked_state brw_gs_prog = {
+   .dirty = {
+      .mesa  = (_NEW_LIGHT | _NEW_BUFFERS | _NEW_TEXTURE),
+      .brw   = (BRW_NEW_GEOMETRY_PROGRAM |
+                BRW_NEW_VUE_MAP_VS |
+                BRW_NEW_TRANSFORM_FEEDBACK),
+   },
+   .emit = brw_upload_gs_prog
+};
+
+
+bool
+brw_gs_precompile(struct gl_context *ctx, struct gl_shader_program *prog)
+{
+   struct brw_context *brw = brw_context(ctx);
+   struct brw_gs_prog_key key;
+   uint32_t old_prog_offset = brw->gs.base.prog_offset;
+   struct brw_gs_prog_data *old_prog_data = brw->gs.prog_data;
+   bool success;
+
+   if (!prog->_LinkedShaders[MESA_SHADER_GEOMETRY])
+      return true;
+
+   struct gl_geometry_program *gp = (struct gl_geometry_program *)
+      prog->_LinkedShaders[MESA_SHADER_GEOMETRY]->Program;
+   struct brw_geometry_program *bgp = brw_geometry_program(gp);
+
+   memset(&key, 0, sizeof(key));
+
+   brw_vec4_setup_prog_key_for_precompile(ctx, &key.base, bgp->id, &gp->Base);
+
+   /* Assume that the set of varyings coming in from the vertex shader exactly
+    * matches what the geometry shader requires.
+    */
+   key.input_varyings = gp->Base.InputsRead;
+
+   success = do_gs_prog(brw, prog, bgp, &key);
+
+   brw->gs.base.prog_offset = old_prog_offset;
+   brw->gs.prog_data = old_prog_data;
+
+   return success;
+}
+
+
+bool
+brw_gs_prog_data_compare(const void *in_a, const void *in_b)
+{
+   const struct brw_gs_prog_data *a = in_a;
+   const struct brw_gs_prog_data *b = in_b;
+
+   /* Compare the base structure. */
+   if (!brw_stage_prog_data_compare(&a->base.base, &b->base.base))
+      return false;
+
+   /* Compare the rest of the struct. */
+   const unsigned offset = sizeof(struct brw_stage_prog_data);
+   if (memcmp(((char *) a) + offset, ((char *) b) + offset,
+              sizeof(struct brw_gs_prog_data) - offset)) {
+      return false;
+   }
+
+   return true;
+}