src/mesa/drivers/dri/i965/brw_conditional_render.c

   1 /*
   2  * Copyright © 2014 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *    Neil Roberts <neil@linux.intel.com>
  25  */
  26
  27 /** @file brw_conditional_render.c
  28  *
  29  * Support for conditional rendering based on query objects
  30  * (GL_NV_conditional_render, GL_ARB_conditional_render_inverted) on Gen7+.
  31  */
  32
  33 #include "main/imports.h"
  34 #include "main/condrender.h"
  35
  36 #include "brw_context.h"
  37 #include "brw_defines.h"
  38 #include "intel_batchbuffer.h"
  39
  40 static void
  41 set_predicate_enable(struct brw_context *brw,
  42                      bool value)
  43 {
  44    if (value)
  45       brw->predicate.state = BRW_PREDICATE_STATE_RENDER;
  46    else
  47       brw->predicate.state = BRW_PREDICATE_STATE_DONT_RENDER;
  48 }
  49
  50 static void
  51 set_predicate_for_overflow_query(struct brw_context *brw,
  52                                  struct brw_query_object *query,
  53                                  int stream_start, int count)
  54 {
  55    if (!can_do_mi_math_and_lrr(brw->screen)) {
  56       brw->predicate.state = BRW_PREDICATE_STATE_STALL_FOR_QUERY;
  57       return;
  58    }
  59
  60    brw->predicate.state = BRW_PREDICATE_STATE_USE_BIT;
  61
  62    /* Needed to ensure the memory is coherent for the MI_LOAD_REGISTER_MEM
  63     * command when loading the values into the predicate source registers for
  64     * conditional rendering.
  65     */
  66    brw_emit_pipe_control_flush(brw, PIPE_CONTROL_FLUSH_ENABLE);
  67
  68    hsw_overflow_result_to_gpr0(brw, query, count);
  69    brw_load_register_reg64(brw, HSW_CS_GPR(0), MI_PREDICATE_SRC0);
  70    brw_load_register_imm64(brw, MI_PREDICATE_SRC1, 0ull);
  71 }
  72
  73 static void
  74 set_predicate_for_occlusion_query(struct brw_context *brw,
  75                                   struct brw_query_object *query)
  76 {
  77    if (!brw->predicate.supported) {
  78       brw->predicate.state = BRW_PREDICATE_STATE_STALL_FOR_QUERY;
  79       return;
  80    }
  81
  82    brw->predicate.state = BRW_PREDICATE_STATE_USE_BIT;
  83
  84    /* Needed to ensure the memory is coherent for the MI_LOAD_REGISTER_MEM
  85     * command when loading the values into the predicate source registers for
  86     * conditional rendering.
  87     */
  88    brw_emit_pipe_control_flush(brw, PIPE_CONTROL_FLUSH_ENABLE);
  89
  90    brw_load_register_mem64(brw,
  91                            MI_PREDICATE_SRC0,
  92                            query->bo,
  93                            I915_GEM_DOMAIN_INSTRUCTION,
  94                            0, /* write domain */
  95                            0 /* offset */);
  96    brw_load_register_mem64(brw,
  97                            MI_PREDICATE_SRC1,
  98                            query->bo,
  99                            I915_GEM_DOMAIN_INSTRUCTION,
 100                            0, /* write domain */
 101                            8 /* offset */);
 102 }
 103
 104 static void
 105 set_predicate_for_result(struct brw_context *brw,
 106                          struct brw_query_object *query,
 107                          bool inverted)
 108 {
 109    int load_op;
 110
 111    assert(query->bo != NULL);
 112
 113    switch (query->Base.Target) {
 114    case GL_TRANSFORM_FEEDBACK_STREAM_OVERFLOW_ARB:
 115       set_predicate_for_overflow_query(brw, query, 0, 1);
 116       break;
 117    case GL_TRANSFORM_FEEDBACK_OVERFLOW_ARB:
 118       set_predicate_for_overflow_query(brw, query, 0, MAX_VERTEX_STREAMS);
 119       break;
 120    default:
 121       set_predicate_for_occlusion_query(brw, query);
 122    }
 123
 124    if (brw->predicate.state == BRW_PREDICATE_STATE_USE_BIT) {
 125       if (inverted)
 126          load_op = MI_PREDICATE_LOADOP_LOAD;
 127       else
 128          load_op = MI_PREDICATE_LOADOP_LOADINV;
 129
 130       BEGIN_BATCH(1);
 131       OUT_BATCH(GEN7_MI_PREDICATE |
 132                 load_op |
 133                 MI_PREDICATE_COMBINEOP_SET |
 134                 MI_PREDICATE_COMPAREOP_SRCS_EQUAL);
 135       ADVANCE_BATCH();
 136    }
 137 }
 138
 139 static void
 140 brw_begin_conditional_render(struct gl_context *ctx,
 141                              struct gl_query_object *q,
 142                              GLenum mode)
 143 {
 144    struct brw_context *brw = brw_context(ctx);
 145    struct brw_query_object *query = (struct brw_query_object *) q;
 146    bool inverted;
 147
 148    switch (mode) {
 149    case GL_QUERY_WAIT:
 150    case GL_QUERY_NO_WAIT:
 151    case GL_QUERY_BY_REGION_WAIT:
 152    case GL_QUERY_BY_REGION_NO_WAIT:
 153       inverted = false;
 154       break;
 155    case GL_QUERY_WAIT_INVERTED:
 156    case GL_QUERY_NO_WAIT_INVERTED:
 157    case GL_QUERY_BY_REGION_WAIT_INVERTED:
 158    case GL_QUERY_BY_REGION_NO_WAIT_INVERTED:
 159       inverted = true;
 160       break;
 161    default:
 162       unreachable("Unexpected conditional render mode");
 163    }
 164
 165    /* If there are already samples from a BLT operation or if the query object
 166     * is ready then we can avoid looking at the values in the buffer and just
 167     * decide whether to draw using the CPU without stalling.
 168     */
 169    if (query->Base.Result || query->Base.Ready)
 170       set_predicate_enable(brw, (query->Base.Result != 0) ^ inverted);
 171    else
 172       set_predicate_for_result(brw, query, inverted);
 173 }
 174
 175 static void
 176 brw_end_conditional_render(struct gl_context *ctx,
 177                            struct gl_query_object *q)
 178 {
 179    struct brw_context *brw = brw_context(ctx);
 180
 181    /* When there is no longer a conditional render in progress it should
 182     * always render.
 183     */
 184    brw->predicate.state = BRW_PREDICATE_STATE_RENDER;
 185 }
 186
 187 void
 188 brw_init_conditional_render_functions(struct dd_function_table *functions)
 189 {
 190    functions->BeginConditionalRender = brw_begin_conditional_render;
 191    functions->EndConditionalRender = brw_end_conditional_render;
 192 }
 193
 194 bool
 195 brw_check_conditional_render(struct brw_context *brw)
 196 {
 197    if (brw->predicate.state == BRW_PREDICATE_STATE_STALL_FOR_QUERY) {
 198       perf_debug("Conditional rendering is implemented in software and may "
 199                  "stall.\n");
 200       return _mesa_check_conditional_render(&brw->ctx);
 201    }
 202
 203    return brw->predicate.state != BRW_PREDICATE_STATE_DONT_RENDER;
 204 }