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 "util/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, MI_PREDICATE_SRC0, HSW_CS_GPR(0));
  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, MI_PREDICATE_SRC0, query->bo, 0 /* offset */);
  91    brw_load_register_mem64(brw, MI_PREDICATE_SRC1, query->bo, 8 /* offset */);
  92 }
  93
  94 static void
  95 set_predicate_for_result(struct brw_context *brw,
  96                          struct brw_query_object *query,
  97                          bool inverted)
  98 {
  99    int load_op;
 100
 101    assert(query->bo != NULL);
 102
 103    switch (query->Base.Target) {
 104    case GL_TRANSFORM_FEEDBACK_STREAM_OVERFLOW_ARB:
 105       set_predicate_for_overflow_query(brw, query, 0, 1);
 106       break;
 107    case GL_TRANSFORM_FEEDBACK_OVERFLOW_ARB:
 108       set_predicate_for_overflow_query(brw, query, 0, MAX_VERTEX_STREAMS);
 109       break;
 110    default:
 111       set_predicate_for_occlusion_query(brw, query);
 112    }
 113
 114    if (brw->predicate.state == BRW_PREDICATE_STATE_USE_BIT) {
 115       if (inverted)
 116          load_op = MI_PREDICATE_LOADOP_LOAD;
 117       else
 118          load_op = MI_PREDICATE_LOADOP_LOADINV;
 119
 120       BEGIN_BATCH(1);
 121       OUT_BATCH(GEN7_MI_PREDICATE |
 122                 load_op |
 123                 MI_PREDICATE_COMBINEOP_SET |
 124                 MI_PREDICATE_COMPAREOP_SRCS_EQUAL);
 125       ADVANCE_BATCH();
 126    }
 127 }
 128
 129 static void
 130 brw_begin_conditional_render(struct gl_context *ctx,
 131                              struct gl_query_object *q,
 132                              GLenum mode)
 133 {
 134    struct brw_context *brw = brw_context(ctx);
 135    struct brw_query_object *query = (struct brw_query_object *) q;
 136    bool inverted;
 137
 138    switch (mode) {
 139    case GL_QUERY_WAIT:
 140    case GL_QUERY_NO_WAIT:
 141    case GL_QUERY_BY_REGION_WAIT:
 142    case GL_QUERY_BY_REGION_NO_WAIT:
 143       inverted = false;
 144       break;
 145    case GL_QUERY_WAIT_INVERTED:
 146    case GL_QUERY_NO_WAIT_INVERTED:
 147    case GL_QUERY_BY_REGION_WAIT_INVERTED:
 148    case GL_QUERY_BY_REGION_NO_WAIT_INVERTED:
 149       inverted = true;
 150       break;
 151    default:
 152       unreachable("Unexpected conditional render mode");
 153    }
 154
 155    /* If there are already samples from a BLT operation or if the query object
 156     * is ready then we can avoid looking at the values in the buffer and just
 157     * decide whether to draw using the CPU without stalling.
 158     */
 159    if (query->Base.Result || query->Base.Ready)
 160       set_predicate_enable(brw, (query->Base.Result != 0) ^ inverted);
 161    else
 162       set_predicate_for_result(brw, query, inverted);
 163 }
 164
 165 static void
 166 brw_end_conditional_render(struct gl_context *ctx,
 167                            struct gl_query_object *q)
 168 {
 169    struct brw_context *brw = brw_context(ctx);
 170
 171    /* When there is no longer a conditional render in progress it should
 172     * always render.
 173     */
 174    brw->predicate.state = BRW_PREDICATE_STATE_RENDER;
 175 }
 176
 177 void
 178 brw_init_conditional_render_functions(struct dd_function_table *functions)
 179 {
 180    functions->BeginConditionalRender = brw_begin_conditional_render;
 181    functions->EndConditionalRender = brw_end_conditional_render;
 182 }
 183
 184 bool
 185 brw_check_conditional_render(struct brw_context *brw)
 186 {
 187    if (brw->predicate.state == BRW_PREDICATE_STATE_STALL_FOR_QUERY) {
 188       perf_debug("Conditional rendering is implemented in software and may "
 189                  "stall.\n");
 190       return _mesa_check_conditional_render(&brw->ctx);
 191    }
 192
 193    return brw->predicate.state != BRW_PREDICATE_STATE_DONT_RENDER;
 194 }