| /* FPU-related code for x86 and x86_64 processors. |
| Copyright 2005 Free Software Foundation, Inc. |
| Contributed by Francois-Xavier Coudert <coudert@clipper.ens.fr> |
| |
| This file is part of the GNU Fortran 95 runtime library (libgfortran). |
| |
| Libgfortran is free software; you can redistribute it and/or |
| modify it under the terms of the GNU General Public |
| License as published by the Free Software Foundation; either |
| version 2 of the License, or (at your option) any later version. |
| |
| In addition to the permissions in the GNU General Public License, the |
| Free Software Foundation gives you unlimited permission to link the |
| compiled version of this file into combinations with other programs, |
| and to distribute those combinations without any restriction coming |
| from the use of this file. (The General Public License restrictions |
| do apply in other respects; for example, they cover modification of |
| the file, and distribution when not linked into a combine |
| executable.) |
| |
| Libgfortran 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 General Public License for more details. |
| |
| You should have received a copy of the GNU General Public |
| License along with libgfortran; see the file COPYING. If not, |
| write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| Boston, MA 02110-1301, USA. */ |
| |
| #define SSE (1 << 25) |
| |
| static int |
| has_sse (void) |
| { |
| #ifdef __x86_64__ |
| return 1; |
| #else |
| unsigned int eax, ebx, ecx, edx; |
| |
| /* See if we can use cpuid. */ |
| asm volatile ("pushfl; pushfl; popl %0; movl %0,%1; xorl %2,%0;" |
| "pushl %0; popfl; pushfl; popl %0; popfl" |
| : "=&r" (eax), "=&r" (ebx) |
| : "i" (0x00200000)); |
| |
| if (((eax ^ ebx) & 0x00200000) == 0) |
| return 0; |
| |
| /* Check the highest input value for eax. */ |
| asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1" |
| : "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx) |
| : "0" (0)); |
| |
| if (eax == 0) |
| return 0; |
| |
| asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1" |
| : "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx) |
| : "0" (1)); |
| |
| if (edx & SSE) |
| return 1; |
| |
| return 0; |
| #endif |
| } |
| |
| void set_fpu (void) |
| { |
| unsigned short cw; |
| unsigned int cw_sse; |
| |
| /* i387 -- see linux <fpu_control.h> header file for details. */ |
| #define _FPU_MASK_IM 0x01 |
| #define _FPU_MASK_DM 0x02 |
| #define _FPU_MASK_ZM 0x04 |
| #define _FPU_MASK_OM 0x08 |
| #define _FPU_MASK_UM 0x10 |
| #define _FPU_MASK_PM 0x20 |
| asm volatile ("fnstcw %0" : "=m" (cw)); |
| cw |= _FPU_MASK_IM | _FPU_MASK_DM | _FPU_MASK_ZM | _FPU_MASK_OM | _FPU_MASK_UM | _FPU_MASK_PM; |
| if (options.fpe & GFC_FPE_INVALID) cw &= ~_FPU_MASK_IM; |
| if (options.fpe & GFC_FPE_DENORMAL) cw &= ~_FPU_MASK_DM; |
| if (options.fpe & GFC_FPE_ZERO) cw &= ~_FPU_MASK_ZM; |
| if (options.fpe & GFC_FPE_OVERFLOW) cw &= ~_FPU_MASK_OM; |
| if (options.fpe & GFC_FPE_UNDERFLOW) cw &= ~_FPU_MASK_UM; |
| if (options.fpe & GFC_FPE_PRECISION) cw &= ~_FPU_MASK_PM; |
| asm volatile ("fldcw %0" : : "m" (cw)); |
| |
| if (has_sse()) |
| { |
| /* SSE */ |
| asm volatile ("stmxcsr %0" : "=m" (cw_sse)); |
| cw_sse &= 0xFFFF0000; |
| cw_sse |= (_FPU_MASK_IM | _FPU_MASK_DM | _FPU_MASK_ZM | _FPU_MASK_OM |
| | _FPU_MASK_UM | _FPU_MASK_PM ) << 7; |
| if (options.fpe & GFC_FPE_INVALID) cw_sse &= ~(_FPU_MASK_IM << 7); |
| if (options.fpe & GFC_FPE_DENORMAL) cw_sse &= ~(_FPU_MASK_DM << 7); |
| if (options.fpe & GFC_FPE_ZERO) cw_sse &= ~(_FPU_MASK_ZM << 7); |
| if (options.fpe & GFC_FPE_OVERFLOW) cw_sse &= ~(_FPU_MASK_OM << 7); |
| if (options.fpe & GFC_FPE_UNDERFLOW) cw_sse &= ~(_FPU_MASK_UM << 7); |
| if (options.fpe & GFC_FPE_PRECISION) cw_sse &= ~(_FPU_MASK_PM << 7); |
| asm volatile ("ldmxcsr %0" : : "m" (cw_sse)); |
| } |
| } |