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