src/glsl/nir/nir_control_flow.h

   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  *    Connor Abbott (cwabbott0@gmail.com)
  25  *
  26  */
  27
  28 #include "nir.h"
  29
  30 #pragma once
  31
  32 #ifdef __cplusplus
  33 extern "C" {
  34 #endif
  35
  36 /** NIR Control Flow Modification
  37  *
  38  * This file contains various API's that make modifying control flow in NIR,
  39  * while maintaining the invariants checked by the validator, much easier.
  40  */
  41
  42 /* Helper struct for representing a point to extract/insert. Helps reduce the
  43  * combinatorial explosion of possible points to extract.
  44  */
  45
  46 typedef enum {
  47    nir_cursor_before_block,
  48    nir_cursor_after_block,
  49    nir_cursor_before_instr,
  50    nir_cursor_after_instr,
  51 } nir_cursor_option;
  52
  53 typedef struct {
  54    nir_cursor_option option;
  55    union {
  56       nir_block *block;
  57       nir_instr *instr;
  58    };
  59 } nir_cursor;
  60
  61 static inline nir_cursor
  62 nir_before_block(nir_block *block)
  63 {
  64    nir_cursor cursor;
  65    cursor.option = nir_cursor_before_block;
  66    cursor.block = block;
  67    return cursor;
  68 }
  69
  70 static inline nir_cursor
  71 nir_after_block(nir_block *block)
  72 {
  73    nir_cursor cursor;
  74    cursor.option = nir_cursor_after_block;
  75    cursor.block = block;
  76    return cursor;
  77 }
  78
  79 static inline nir_cursor
  80 nir_before_instr(nir_instr *instr)
  81 {
  82    nir_cursor cursor;
  83    cursor.option = nir_cursor_before_instr;
  84    cursor.instr = instr;
  85    return cursor;
  86 }
  87
  88 static inline nir_cursor
  89 nir_after_instr(nir_instr *instr)
  90 {
  91    nir_cursor cursor;
  92    cursor.option = nir_cursor_after_instr;
  93    cursor.instr = instr;
  94    return cursor;
  95 }
  96
  97 static inline nir_cursor
  98 nir_before_cf_node(nir_cf_node *node)
  99 {
 100    if (node->type == nir_cf_node_block)
 101       return nir_before_block(nir_cf_node_as_block(node));
 102
 103    return nir_after_block(nir_cf_node_as_block(nir_cf_node_prev(node)));
 104 }
 105
 106 static inline nir_cursor
 107 nir_after_cf_node(nir_cf_node *node)
 108 {
 109    if (node->type == nir_cf_node_block)
 110       return nir_after_block(nir_cf_node_as_block(node));
 111
 112    return nir_before_block(nir_cf_node_as_block(nir_cf_node_next(node)));
 113 }
 114
 115 static inline nir_cursor
 116 nir_before_cf_list(struct exec_list *cf_list)
 117 {
 118    nir_cf_node *first_node = exec_node_data(nir_cf_node,
 119                                             exec_list_get_head(cf_list), node);
 120    return nir_before_cf_node(first_node);
 121 }
 122
 123 static inline nir_cursor
 124 nir_after_cf_list(struct exec_list *cf_list)
 125 {
 126    nir_cf_node *last_node = exec_node_data(nir_cf_node,
 127                                            exec_list_get_tail(cf_list), node);
 128    return nir_after_cf_node(last_node);
 129 }
 130
 131 /** Control flow insertion. */
 132
 133 /** puts a control flow node where the cursor is */
 134 void nir_cf_node_insert(nir_cursor cursor, nir_cf_node *node);
 135
 136 /** puts a control flow node immediately after another control flow node */
 137 static inline void
 138 nir_cf_node_insert_after(nir_cf_node *node, nir_cf_node *after)
 139 {
 140    nir_cf_node_insert(nir_after_cf_node(node), after);
 141 }
 142
 143 /** puts a control flow node immediately before another control flow node */
 144 static inline void
 145 nir_cf_node_insert_before(nir_cf_node *node, nir_cf_node *before)
 146 {
 147    nir_cf_node_insert(nir_before_cf_node(node), before);
 148 }
 149
 150 /** puts a control flow node at the beginning of a list from an if, loop, or function */
 151 static inline void
 152 nir_cf_node_insert_begin(struct exec_list *list, nir_cf_node *node)
 153 {
 154    nir_cf_node_insert(nir_before_cf_list(list), node);
 155 }
 156
 157 /** puts a control flow node at the end of a list from an if, loop, or function */
 158 static inline void
 159 nir_cf_node_insert_end(struct exec_list *list, nir_cf_node *node)
 160 {
 161    nir_cf_node_insert(nir_after_cf_list(list), node);
 162 }
 163
 164 /** removes a control flow node, doing any cleanup necessary */
 165 void nir_cf_node_remove(nir_cf_node *node);
 166
 167 #ifdef __cplusplus
 168 }
 169 #endif