| /* FPU control word bits. Mips version. |
| Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Olaf Flebbe and Ralf Baechle. |
| |
| 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/>. */ |
| |
| #ifndef _FPU_CONTROL_H |
| #define _FPU_CONTROL_H |
| |
| /* MIPS FPU floating point control register bits. |
| * |
| * 31-25 -> floating point conditions code bits 7-1. These bits are only |
| * available in MIPS IV. |
| * 24 -> flush denormalized results to zero instead of |
| * causing unimplemented operation exception. This bit is only |
| * available for MIPS III and newer. |
| * 23 -> Condition bit |
| * 22-18 -> reserved (read as 0, write with 0) |
| * 17 -> cause bit for unimplemented operation |
| * 16 -> cause bit for invalid exception |
| * 15 -> cause bit for division by zero exception |
| * 14 -> cause bit for overflow exception |
| * 13 -> cause bit for underflow exception |
| * 12 -> cause bit for inexact exception |
| * 11 -> enable exception for invalid exception |
| * 10 -> enable exception for division by zero exception |
| * 9 -> enable exception for overflow exception |
| * 8 -> enable exception for underflow exception |
| * 7 -> enable exception for inexact exception |
| * 6 -> flag invalid exception |
| * 5 -> flag division by zero exception |
| * 4 -> flag overflow exception |
| * 3 -> flag underflow exception |
| * 2 -> flag inexact exception |
| * 1-0 -> rounding control |
| * |
| * |
| * Rounding Control: |
| * 00 - rounding to nearest (RN) |
| * 01 - rounding toward zero (RZ) |
| * 10 - rounding (up) toward plus infinity (RP) |
| * 11 - rounding (down)toward minus infinity (RM) |
| */ |
| |
| #include <features.h> |
| |
| /* masking of interrupts */ |
| #define _FPU_MASK_V 0x0800 /* Invalid operation */ |
| #define _FPU_MASK_Z 0x0400 /* Division by zero */ |
| #define _FPU_MASK_O 0x0200 /* Overflow */ |
| #define _FPU_MASK_U 0x0100 /* Underflow */ |
| #define _FPU_MASK_I 0x0080 /* Inexact operation */ |
| |
| /* flush denormalized numbers to zero */ |
| #define _FPU_FLUSH_TZ 0x1000000 |
| |
| /* rounding control */ |
| #define _FPU_RC_NEAREST 0x0 /* RECOMMENDED */ |
| #define _FPU_RC_ZERO 0x1 |
| #define _FPU_RC_UP 0x2 |
| #define _FPU_RC_DOWN 0x3 |
| |
| #define _FPU_RESERVED 0xfe3c0000 /* Reserved bits in cw */ |
| |
| |
| /* The fdlibm code requires strict IEEE double precision arithmetic, |
| and no interrupts for exceptions, rounding to nearest. */ |
| |
| #define _FPU_DEFAULT 0x00000000 |
| |
| /* IEEE: same as above, but exceptions */ |
| #define _FPU_IEEE 0x00000F80 |
| |
| /* Type of the control word. */ |
| typedef unsigned int fpu_control_t __attribute__ ((__mode__ (__SI__))); |
| |
| /* Macros for accessing the hardware control word. */ |
| #define _FPU_GETCW(cw) __asm__ ("cfc1 %0,$31" : "=r" (cw)) |
| #define _FPU_SETCW(cw) __asm__ ("ctc1 %0,$31" : : "r" (cw)) |
| |
| #if 0 |
| /* Default control word set at startup. */ |
| extern fpu_control_t __fpu_control; |
| #endif |
| |
| #endif /* fpu_control.h */ |