projects / thirdparty / gcc.git / blame
| Commit | Line | Data |
|---|---|---|
| 3d2cf79f RB |
1 | /* Match-and-simplify patterns for shared GENERIC and GIMPLE folding. |
| 2 | This file is consumed by genmatch which produces gimple-match.c | |
| 3 | and generic-match.c from it. | |
| 4 | ||
| 5 | Copyright (C) 2014 Free Software Foundation, Inc. | |
| 6 | Contributed by Richard Biener <rguenther@suse.de> | |
| 7 | and Prathamesh Kulkarni <bilbotheelffriend@gmail.com> | |
| 8 | ||
| 9 | This file is part of GCC. | |
| 10 | ||
| 11 | GCC is free software; you can redistribute it and/or modify it under | |
| 12 | the terms of the GNU General Public License as published by the Free | |
| 13 | Software Foundation; either version 3, or (at your option) any later | |
| 14 | version. | |
| 15 | ||
| 16 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
| 17 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 18 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 19 | for more details. | |
| 20 | ||
| 21 | You should have received a copy of the GNU General Public License | |
| 22 | along with GCC; see the file COPYING3. If not see | |
| 23 | <http://www.gnu.org/licenses/>. */ | |
| 24 | ||
| 25 | ||
| 26 | /* Generic tree predicates we inherit. */ | |
| 27 | (define_predicates | |
| 28 | integer_onep integer_zerop integer_all_onesp | |
| 29 | real_zerop real_onep | |
| 30 | CONSTANT_CLASS_P) | |
| e0ee10ed RB |
31 | |
| 32 | ||
| 33 | /* Simplifications of operations with one constant operand and | |
| 34 | simplifications to constants. */ | |
| 35 | ||
| 36 | (for op (plus pointer_plus minus bit_ior bit_xor) | |
| 37 | (simplify | |
| 38 | (op @0 integer_zerop) | |
| 39 | (non_lvalue @0))) | |
| 40 | ||
| 41 | /* Simplify x - x. | |
| 42 | This is unsafe for certain floats even in non-IEEE formats. | |
| 43 | In IEEE, it is unsafe because it does wrong for NaNs. | |
| 44 | Also note that operand_equal_p is always false if an operand | |
| 45 | is volatile. */ | |
| 46 | (simplify | |
| 47 | (minus @0 @0) | |
| 48 | (if (!FLOAT_TYPE_P (type) || !HONOR_NANS (TYPE_MODE (type))) | |
| 49 | { build_zero_cst (type); })) | |
| 50 | ||
| 51 | (simplify | |
| 52 | (mult @0 integer_zerop@1) | |
| 53 | @1) | |
| 54 | ||
| 55 | /* Make sure to preserve divisions by zero. This is the reason why | |
| 56 | we don't simplify x / x to 1 or 0 / x to 0. */ | |
| 57 | (for op (mult trunc_div ceil_div floor_div round_div exact_div) | |
| 58 | (simplify | |
| 59 | (op @0 integer_onep) | |
| 60 | (non_lvalue @0))) | |
| 61 | ||
| 62 | /* Same applies to modulo operations, but fold is inconsistent here | |
| 63 | and simplifies 0 % x to 0, only preserving literal 0 % 0. */ | |
| 64 | (for op (ceil_mod floor_mod round_mod trunc_mod) | |
| 65 | /* 0 % X is always zero. */ | |
| 66 | (simplify | |
| 60e09045 | 67 | (op integer_zerop@0 @1) |
| e0ee10ed RB |
68 | /* But not for 0 % 0 so that we can get the proper warnings and errors. */ |
| 69 | (if (!integer_zerop (@1)) | |
| 70 | @0)) | |
| 71 | /* X % 1 is always zero. */ | |
| 72 | (simplify | |
| 60e09045 | 73 | (op @0 integer_onep) |
| e0ee10ed RB |
74 | { build_zero_cst (type); })) |
| 75 | ||
| 76 | /* x | ~0 -> ~0 */ | |
| 77 | (simplify | |
| 78 | (bit_ior @0 integer_all_onesp@1) | |
| 79 | @1) | |
| 80 | ||
| 81 | /* x & 0 -> 0 */ | |
| 82 | (simplify | |
| 83 | (bit_and @0 integer_zerop@1) | |
| 84 | @1) | |
| 85 | ||
| 86 | /* x ^ x -> 0 */ | |
| 87 | (simplify | |
| 88 | (bit_xor @0 @0) | |
| 89 | { build_zero_cst (type); }) | |
| 90 |