| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* Determine floating-point rounding mode within libc. Generic version. |
| 2 | Copyright (C) 2012-2015 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | The GNU C Library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library; if not, see |
| 17 | <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #ifndef _GET_ROUNDING_MODE_H |
| 20 | #define _GET_ROUNDING_MODE_H 1 |
| 21 | |
| 22 | #include <fpu_control.h> |
| 23 | #include <stdlib.h> |
| 24 | |
| 25 | /* Define values for FE_* modes not defined for this architecture. */ |
| 26 | #ifdef FE_DOWNWARD |
| 27 | # define ORIG_FE_DOWNWARD FE_DOWNWARD |
| 28 | #else |
| 29 | # define ORIG_FE_DOWNWARD 0 |
| 30 | #endif |
| 31 | #ifdef FE_TONEAREST |
| 32 | # define ORIG_FE_TONEAREST FE_TONEAREST |
| 33 | #else |
| 34 | # define ORIG_FE_TONEAREST 0 |
| 35 | #endif |
| 36 | #ifdef FE_TOWARDZERO |
| 37 | # define ORIG_FE_TOWARDZERO FE_TOWARDZERO |
| 38 | #else |
| 39 | # define ORIG_FE_TOWARDZERO 0 |
| 40 | #endif |
| 41 | #ifdef FE_UPWARD |
| 42 | # define ORIG_FE_UPWARD FE_UPWARD |
| 43 | #else |
| 44 | # define ORIG_FE_UPWARD 0 |
| 45 | #endif |
| 46 | #define FE_CONSTRUCT_DISTINCT_VALUE(X, Y, Z) \ |
| 47 | ((((X) & 1) | ((Y) & 2) | ((Z) & 4)) ^ 7) |
| 48 | #ifndef FE_DOWNWARD |
| 49 | # define FE_DOWNWARD FE_CONSTRUCT_DISTINCT_VALUE (ORIG_FE_TONEAREST, \ |
| 50 | ORIG_FE_TOWARDZERO, \ |
| 51 | ORIG_FE_UPWARD) |
| 52 | #endif |
| 53 | #ifndef FE_TONEAREST |
| 54 | # define FE_TONEAREST FE_CONSTRUCT_DISTINCT_VALUE (FE_DOWNWARD, \ |
| 55 | ORIG_FE_TOWARDZERO, \ |
| 56 | ORIG_FE_UPWARD) |
| 57 | #endif |
| 58 | #ifndef FE_TOWARDZERO |
| 59 | # define FE_TOWARDZERO FE_CONSTRUCT_DISTINCT_VALUE (FE_DOWNWARD, \ |
| 60 | FE_TONEAREST, \ |
| 61 | ORIG_FE_UPWARD) |
| 62 | #endif |
| 63 | #ifndef FE_UPWARD |
| 64 | # define FE_UPWARD FE_CONSTRUCT_DISTINCT_VALUE (FE_DOWNWARD, \ |
| 65 | FE_TONEAREST, \ |
| 66 | FE_TOWARDZERO) |
| 67 | #endif |
| 68 | |
| 69 | /* Return the floating-point rounding mode. */ |
| 70 | |
| 71 | static inline int |
| 72 | get_rounding_mode (void) |
| 73 | { |
| 74 | #if (defined _FPU_RC_DOWN \ |
| 75 | || defined _FPU_RC_NEAREST \ |
| 76 | || defined _FPU_RC_ZERO \ |
| 77 | || defined _FPU_RC_UP) |
| 78 | fpu_control_t fc; |
| 79 | const fpu_control_t mask = (0 |
| 80 | # ifdef _FPU_RC_DOWN |
| 81 | | _FPU_RC_DOWN |
| 82 | # endif |
| 83 | # ifdef _FPU_RC_NEAREST |
| 84 | | _FPU_RC_NEAREST |
| 85 | # endif |
| 86 | # ifdef _FPU_RC_ZERO |
| 87 | | _FPU_RC_ZERO |
| 88 | # endif |
| 89 | # ifdef _FPU_RC_UP |
| 90 | | _FPU_RC_UP |
| 91 | # endif |
| 92 | ); |
| 93 | |
| 94 | _FPU_GETCW (fc); |
| 95 | switch (fc & mask) |
| 96 | { |
| 97 | # ifdef _FPU_RC_DOWN |
| 98 | case _FPU_RC_DOWN: |
| 99 | return FE_DOWNWARD; |
| 100 | # endif |
| 101 | |
| 102 | # ifdef _FPU_RC_NEAREST |
| 103 | case _FPU_RC_NEAREST: |
| 104 | return FE_TONEAREST; |
| 105 | # endif |
| 106 | |
| 107 | # ifdef _FPU_RC_ZERO |
| 108 | case _FPU_RC_ZERO: |
| 109 | return FE_TOWARDZERO; |
| 110 | # endif |
| 111 | |
| 112 | # ifdef _FPU_RC_UP |
| 113 | case _FPU_RC_UP: |
| 114 | return FE_UPWARD; |
| 115 | # endif |
| 116 | |
| 117 | default: |
| 118 | abort (); |
| 119 | } |
| 120 | #else |
| 121 | return FE_TONEAREST; |
| 122 | #endif |
| 123 | } |
| 124 | |
| 125 | #endif /* get-rounding-mode.h */ |