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 21 * DEALINGS IN THE SOFTWARE. 22 */ 23 24 #ifndef OPT_ADD_NEG_TO_SUB_H 25 #define OPT_ADD_NEG_TO_SUB_H 26 27 #include "ir.h" 28 #include "ir_hierarchical_visitor.h" 29 30 class add_neg_to_sub_visitor : public ir_hierarchical_visitor { 31 public: add_neg_to_sub_visitor()32 add_neg_to_sub_visitor() 33 { 34 /* empty */ 35 } 36 visit_leave(ir_expression * ir)37 ir_visitor_status visit_leave(ir_expression *ir) 38 { 39 if (ir->operation != ir_binop_add) 40 return visit_continue; 41 42 for (unsigned i = 0; i < 2; i++) { 43 ir_expression *const op = ir->operands[i]->as_expression(); 44 45 if (op != NULL && op->operation == ir_unop_neg) { 46 ir->operation = ir_binop_sub; 47 48 /* This ensures that -a + b becomes b - a. */ 49 if (i == 0) 50 ir->operands[0] = ir->operands[1]; 51 52 ir->operands[1] = op->operands[0]; 53 break; 54 } 55 } 56 57 return visit_continue; 58 } 59 }; 60 61 #endif /* OPT_ADD_NEG_TO_SUB_H */ 62