1 /* 2 * Copyright 2010 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 21 * DEALINGS IN THE SOFTWARE. 22 */ 23 24 /** 25 * \file ir_basic_block.cpp 26 * 27 * Basic block analysis of instruction streams. 28 */ 29 30 #include "ir.h" 31 #include "ir_visitor.h" 32 #include "ir_basic_block.h" 33 #include "glsl_types.h" 34 35 /** 36 * Calls a user function for every basic block in the instruction stream. 37 * 38 * Basic block analysis is pretty easy in our IR thanks to the lack of 39 * unstructured control flow. We've got: 40 * 41 * ir_loop (for () {}, while () {}, do {} while ()) 42 * ir_loop_jump ( 43 * ir_if () {} 44 * ir_return 45 * ir_call() 46 * 47 * Note that the basic blocks returned by this don't encompass all 48 * operations performed by the program -- for example, if conditions 49 * don't get returned, nor do the assignments that will be generated 50 * for ir_call parameters. 51 */ 52 void call_for_basic_blocks(exec_list *instructions, 53 void (*callback)(ir_instruction *first, 54 ir_instruction *last, 55 void *data), 56 void *data) 57 { 58 ir_instruction *leader = NULL; 59 ir_instruction *last = NULL; 60 61 foreach_iter(exec_list_iterator, iter, *instructions) { 62 ir_instruction *ir = (ir_instruction *)iter.get(); 63 ir_if *ir_if; 64 ir_loop *ir_loop; 65 ir_function *ir_function; 66 67 if (!leader) 68 leader = ir; 69 70 if ((ir_if = ir->as_if())) { 71 callback(leader, ir, data); 72 leader = NULL; 73 74 call_for_basic_blocks(&ir_if->then_instructions, callback, data); 75 call_for_basic_blocks(&ir_if->else_instructions, callback, data); 76 } else if ((ir_loop = ir->as_loop())) { 77 callback(leader, ir, data); 78 leader = NULL; 79 call_for_basic_blocks(&ir_loop->body_instructions, callback, data); 80 } else if (ir->as_return() || ir->as_call()) { 81 callback(leader, ir, data); 82 leader = NULL; 83 } else if ((ir_function = ir->as_function())) { 84 /* A function definition doesn't interrupt our basic block 85 * since execution doesn't go into it. We should process the 86 * bodies of its signatures for BBs, though. 87 * 88 * Note that we miss an opportunity for producing more 89 * maximal BBs between the instructions that precede main() 90 * and the body of main(). Perhaps those instructions ought 91 * to live inside of main(). 92 */ 93 foreach_iter(exec_list_iterator, fun_iter, *ir_function) { 94 ir_function_signature *ir_sig; 95 96 ir_sig = (ir_function_signature *)fun_iter.get(); 97 98 call_for_basic_blocks(&ir_sig->body, callback, data); 99 } 100 } 101 last = ir; 102 } 103 if (leader) { 104 callback(leader, last, data); 105 } 106 } 107
