glibc/sysdeps/loongarch/fpu_control.h
2022-09-01 09:10:08 +08:00

103 lines
3.4 KiB
C

/* FPU control word bits.
Copyright (C) 2022 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
<https://www.gnu.org/licenses/>. */
#ifndef _FPU_CONTROL_H
#define _FPU_CONTROL_H
/* LoongArch FPU floating point control register bits.
*
* 31-29 -> reserved (read as 0, can not changed by software)
* 28 -> cause bit for invalid exception
* 27 -> cause bit for division by zero exception
* 26 -> cause bit for overflow exception
* 25 -> cause bit for underflow exception
* 24 -> cause bit for inexact exception
* 23-21 -> reserved (read as 0, can not changed by software)
* 20 -> flag invalid exception
* 19 -> flag division by zero exception
* 18 -> flag overflow exception
* 17 -> flag underflow exception
* 16 -> flag inexact exception
* 9-8 -> rounding control
* 7-5 -> reserved (read as 0, can not changed by software)
* 4 -> enable exception for invalid exception
* 3 -> enable exception for division by zero exception
* 2 -> enable exception for overflow exception
* 1 -> enable exception for underflow exception
* 0 -> enable exception for inexact exception
*
*
* Rounding Control:
* 00 - rounding ties to even (RNE)
* 01 - rounding toward zero (RZ)
* 10 - rounding (up) toward plus infinity (RP)
* 11 - rounding (down) toward minus infinity (RM)
*/
#include <features.h>
#ifdef __loongarch_soft_float
#define _FPU_RESERVED 0xffffffff
#define _FPU_DEFAULT 0x00000000
typedef unsigned int fpu_control_t;
#define _FPU_GETCW(cw) (cw) = 0
#define _FPU_SETCW(cw) (void) (cw)
extern fpu_control_t __fpu_control;
#else /* __loongarch_soft_float */
/* Masks for interrupts. */
#define _FPU_MASK_V 0x10 /* Invalid operation */
#define _FPU_MASK_Z 0x08 /* Division by zero */
#define _FPU_MASK_O 0x04 /* Overflow */
#define _FPU_MASK_U 0x02 /* Underflow */
#define _FPU_MASK_I 0x01 /* Inexact operation */
/* Flush denormalized numbers to zero. */
#define _FPU_FLUSH_TZ 0x1000000
/* Rounding control. */
#define _FPU_RC_NEAREST 0x000 /* RECOMMENDED */
#define _FPU_RC_ZERO 0x100
#define _FPU_RC_UP 0x200
#define _FPU_RC_DOWN 0x300
/* Mask for rounding control. */
#define _FPU_RC_MASK 0x300
#define _FPU_RESERVED 0x0
#define _FPU_DEFAULT 0x0
#define _FPU_IEEE 0x1F
/* Type of the control word. */
typedef unsigned int fpu_control_t __attribute__ ((__mode__ (__SI__)));
/* Macros for accessing the hardware control word. */
extern fpu_control_t __loongarch_fpu_getcw (void) __THROW;
extern void __loongarch_fpu_setcw (fpu_control_t) __THROW;
#define _FPU_GETCW(cw) __asm__ volatile ("movfcsr2gr %0,$r0" : "=r"(cw))
#define _FPU_SETCW(cw) __asm__ volatile ("movgr2fcsr $r0,%0" : : "r"(cw))
/* Default control word set at startup. */
extern fpu_control_t __fpu_control;
#endif /* __loongarch_soft_float */
#endif /* fpu_control.h */