| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame^] | 1 | /* Raise given exceptions. |
| 2 | Copyright (C) 2004-2016 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 | #include <fpu_control.h> |
| 20 | #include <fenv.h> |
| 21 | #include <float.h> |
| 22 | #include <arm-features.h> |
| 23 | |
| 24 | |
| 25 | int |
| 26 | __feraiseexcept (int excepts) |
| 27 | { |
| 28 | /* Fail if a VFP unit isn't present unless nothing needs to be done. */ |
| 29 | if (!ARM_HAVE_VFP) |
| 30 | return (excepts != 0); |
| 31 | else |
| 32 | { |
| 33 | fpu_control_t fpscr; |
| 34 | const float fp_zero = 0.0, fp_one = 1.0, fp_max = FLT_MAX, |
| 35 | fp_min = FLT_MIN, fp_1e32 = 1.0e32f, fp_two = 2.0, |
| 36 | fp_three = 3.0; |
| 37 | |
| 38 | /* Raise exceptions represented by EXPECTS. But we must raise only |
| 39 | one signal at a time. It is important that if the overflow/underflow |
| 40 | exception and the inexact exception are given at the same time, |
| 41 | the overflow/underflow exception follows the inexact exception. After |
| 42 | each exception we read from the fpscr, to force the exception to be |
| 43 | raised immediately. */ |
| 44 | |
| 45 | /* There are additional complications because this file may be compiled |
| 46 | without VFP support enabled, and we also can't assume that the |
| 47 | assembler has VFP instructions enabled. To get around this we use the |
| 48 | generic coprocessor mnemonics and avoid asking GCC to put float values |
| 49 | in VFP registers. */ |
| 50 | |
| 51 | /* First: invalid exception. */ |
| 52 | if (FE_INVALID & excepts) |
| 53 | __asm__ __volatile__ ( |
| 54 | "ldc p10, cr0, %1\n\t" /* flds s0, %1 */ |
| 55 | "cdp p10, 8, cr0, cr0, cr0, 0\n\t" /* fdivs s0, s0, s0 */ |
| 56 | "mrc p10, 7, %0, cr1, cr0, 0" : "=r" (fpscr) /* fmrx %0, fpscr */ |
| 57 | : "m" (fp_zero) |
| 58 | : "s0"); |
| 59 | |
| 60 | /* Next: division by zero. */ |
| 61 | if (FE_DIVBYZERO & excepts) |
| 62 | __asm__ __volatile__ ( |
| 63 | "ldc p10, cr0, %1\n\t" /* flds s0, %1 */ |
| 64 | "ldcl p10, cr0, %2\n\t" /* flds s1, %2 */ |
| 65 | "cdp p10, 8, cr0, cr0, cr0, 1\n\t" /* fdivs s0, s0, s1 */ |
| 66 | "mrc p10, 7, %0, cr1, cr0, 0" : "=r" (fpscr) /* fmrx %0, fpscr */ |
| 67 | : "m" (fp_one), "m" (fp_zero) |
| 68 | : "s0", "s1"); |
| 69 | |
| 70 | /* Next: overflow. */ |
| 71 | if (FE_OVERFLOW & excepts) |
| 72 | /* There's no way to raise overflow without also raising inexact. */ |
| 73 | __asm__ __volatile__ ( |
| 74 | "ldc p10, cr0, %1\n\t" /* flds s0, %1 */ |
| 75 | "ldcl p10, cr0, %2\n\t" /* flds s1, %2 */ |
| 76 | "cdp p10, 3, cr0, cr0, cr0, 1\n\t" /* fadds s0, s0, s1 */ |
| 77 | "mrc p10, 7, %0, cr1, cr0, 0" : "=r" (fpscr) /* fmrx %0, fpscr */ |
| 78 | : "m" (fp_max), "m" (fp_1e32) |
| 79 | : "s0", "s1"); |
| 80 | |
| 81 | /* Next: underflow. */ |
| 82 | if (FE_UNDERFLOW & excepts) |
| 83 | __asm__ __volatile__ ( |
| 84 | "ldc p10, cr0, %1\n\t" /* flds s0, %1 */ |
| 85 | "ldcl p10, cr0, %2\n\t" /* flds s1, %2 */ |
| 86 | "cdp p10, 8, cr0, cr0, cr0, 1\n\t" /* fdivs s0, s0, s1 */ |
| 87 | "mrc p10, 7, %0, cr1, cr0, 0" : "=r" (fpscr) /* fmrx %0, fpscr */ |
| 88 | : "m" (fp_min), "m" (fp_three) |
| 89 | : "s0", "s1"); |
| 90 | |
| 91 | /* Last: inexact. */ |
| 92 | if (FE_INEXACT & excepts) |
| 93 | __asm__ __volatile__ ( |
| 94 | "ldc p10, cr0, %1\n\t" /* flds s0, %1 */ |
| 95 | "ldcl p10, cr0, %2\n\t" /* flds s1, %2 */ |
| 96 | "cdp p10, 8, cr0, cr0, cr0, 1\n\t" /* fdivs s0, s0, s1 */ |
| 97 | "mrc p10, 7, %0, cr1, cr0, 0" : "=r" (fpscr) /* fmrx %0, fpscr */ |
| 98 | : "m" (fp_two), "m" (fp_three) |
| 99 | : "s0", "s1"); |
| 100 | |
| 101 | /* Success. */ |
| 102 | return 0; |
| 103 | } |
| 104 | } |
| 105 | libm_hidden_def (__feraiseexcept) |
| 106 | weak_alias (__feraiseexcept, feraiseexcept) |
| 107 | libm_hidden_weak (feraiseexcept) |