| /* Raise given exceptions. |
| Copyright (C) 2004-2016 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <fpu_control.h> |
| #include <fenv.h> |
| #include <float.h> |
| #include <arm-features.h> |
| |
| |
| int |
| __feraiseexcept (int excepts) |
| { |
| /* Fail if a VFP unit isn't present unless nothing needs to be done. */ |
| if (!ARM_HAVE_VFP) |
| return (excepts != 0); |
| else |
| { |
| fpu_control_t fpscr; |
| const float fp_zero = 0.0, fp_one = 1.0, fp_max = FLT_MAX, |
| fp_min = FLT_MIN, fp_1e32 = 1.0e32f, fp_two = 2.0, |
| fp_three = 3.0; |
| |
| /* Raise exceptions represented by EXPECTS. But we must raise only |
| one signal at a time. It is important that if the overflow/underflow |
| exception and the inexact exception are given at the same time, |
| the overflow/underflow exception follows the inexact exception. After |
| each exception we read from the fpscr, to force the exception to be |
| raised immediately. */ |
| |
| /* There are additional complications because this file may be compiled |
| without VFP support enabled, and we also can't assume that the |
| assembler has VFP instructions enabled. To get around this we use the |
| generic coprocessor mnemonics and avoid asking GCC to put float values |
| in VFP registers. */ |
| |
| /* First: invalid exception. */ |
| if (FE_INVALID & excepts) |
| __asm__ __volatile__ ( |
| "ldc p10, cr0, %1\n\t" /* flds s0, %1 */ |
| "cdp p10, 8, cr0, cr0, cr0, 0\n\t" /* fdivs s0, s0, s0 */ |
| "mrc p10, 7, %0, cr1, cr0, 0" : "=r" (fpscr) /* fmrx %0, fpscr */ |
| : "m" (fp_zero) |
| : "s0"); |
| |
| /* Next: division by zero. */ |
| if (FE_DIVBYZERO & excepts) |
| __asm__ __volatile__ ( |
| "ldc p10, cr0, %1\n\t" /* flds s0, %1 */ |
| "ldcl p10, cr0, %2\n\t" /* flds s1, %2 */ |
| "cdp p10, 8, cr0, cr0, cr0, 1\n\t" /* fdivs s0, s0, s1 */ |
| "mrc p10, 7, %0, cr1, cr0, 0" : "=r" (fpscr) /* fmrx %0, fpscr */ |
| : "m" (fp_one), "m" (fp_zero) |
| : "s0", "s1"); |
| |
| /* Next: overflow. */ |
| if (FE_OVERFLOW & excepts) |
| /* There's no way to raise overflow without also raising inexact. */ |
| __asm__ __volatile__ ( |
| "ldc p10, cr0, %1\n\t" /* flds s0, %1 */ |
| "ldcl p10, cr0, %2\n\t" /* flds s1, %2 */ |
| "cdp p10, 3, cr0, cr0, cr0, 1\n\t" /* fadds s0, s0, s1 */ |
| "mrc p10, 7, %0, cr1, cr0, 0" : "=r" (fpscr) /* fmrx %0, fpscr */ |
| : "m" (fp_max), "m" (fp_1e32) |
| : "s0", "s1"); |
| |
| /* Next: underflow. */ |
| if (FE_UNDERFLOW & excepts) |
| __asm__ __volatile__ ( |
| "ldc p10, cr0, %1\n\t" /* flds s0, %1 */ |
| "ldcl p10, cr0, %2\n\t" /* flds s1, %2 */ |
| "cdp p10, 8, cr0, cr0, cr0, 1\n\t" /* fdivs s0, s0, s1 */ |
| "mrc p10, 7, %0, cr1, cr0, 0" : "=r" (fpscr) /* fmrx %0, fpscr */ |
| : "m" (fp_min), "m" (fp_three) |
| : "s0", "s1"); |
| |
| /* Last: inexact. */ |
| if (FE_INEXACT & excepts) |
| __asm__ __volatile__ ( |
| "ldc p10, cr0, %1\n\t" /* flds s0, %1 */ |
| "ldcl p10, cr0, %2\n\t" /* flds s1, %2 */ |
| "cdp p10, 8, cr0, cr0, cr0, 1\n\t" /* fdivs s0, s0, s1 */ |
| "mrc p10, 7, %0, cr1, cr0, 0" : "=r" (fpscr) /* fmrx %0, fpscr */ |
| : "m" (fp_two), "m" (fp_three) |
| : "s0", "s1"); |
| |
| /* Success. */ |
| return 0; |
| } |
| } |
| libm_hidden_def (__feraiseexcept) |
| weak_alias (__feraiseexcept, feraiseexcept) |
| libm_hidden_weak (feraiseexcept) |