1 /* 2 * Copyright 2016 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 24 #pragma once 25 26 #include "nir.h" 27 28 /* Returns true if nir_cf_node contains a jump other than the expected_jump 29 * parameter. 30 */ 31 static inline bool 32 contains_other_jump(nir_cf_node *node, nir_instr *expected_jump) 33 { 34 switch (node->type) { 35 case nir_cf_node_block: { 36 nir_instr *lst_instr = nir_block_last_instr(nir_cf_node_as_block(node)); 37 38 /* dead_cf should have eliminated any instruction after the first break 39 */ 40 nir_foreach_instr(instr, nir_cf_node_as_block(node)) 41 assert(instr->type != nir_instr_type_jump || instr == lst_instr); 42 43 if (lst_instr && lst_instr->type == nir_instr_type_jump && 44 lst_instr != expected_jump) 45 return true; 46 else 47 return false; 48 } 49 case nir_cf_node_if: { 50 nir_if *if_stmt = nir_cf_node_as_if(node); 51 52 foreach_list_typed_safe(nir_cf_node, node, node, &if_stmt->then_list) { 53 if (contains_other_jump(node, expected_jump)) 54 return true; 55 } 56 57 foreach_list_typed_safe(nir_cf_node, node, node, &if_stmt->else_list) { 58 if (contains_other_jump(node, expected_jump)) 59 return true; 60 } 61 62 return false; 63 } 64 case nir_cf_node_loop: 65 return true; 66 67 default: 68 unreachable("Unhandled cf node type"); 69 } 70 } 71 72 /* Here we define a trivial if as containing only a single break that must be 73 * located at the end of either the then or else branch of the top level if, 74 * there must be no other breaks or any other type of jump. Or we pass NULL 75 * to break_block the if must contains no jumps at all. 76 */ 77 static inline bool 78 nir_is_trivial_loop_if(nir_if *nif, nir_block *break_block) 79 { 80 nir_instr *last_instr = NULL; 81 82 if (break_block) { 83 last_instr = nir_block_last_instr(break_block); 84 assert(last_instr && last_instr->type == nir_instr_type_jump && 85 nir_instr_as_jump(last_instr)->type == nir_jump_break); 86 } 87 88 if (contains_other_jump(&nif->cf_node, last_instr)) 89 return false; 90 91 return true; 92 } 93
