1  /* FPU control word bits.
       2     Copyright (C) 2022-2023 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     <https://www.gnu.org/licenses/>.  */
      18  
      19  #ifndef _FPU_CONTROL_H
      20  #define _FPU_CONTROL_H
      21  
      22  /* LoongArch FPU floating point control register bits.
      23   *
      24   * 31-29  -> reserved (read as 0, can not changed by software)
      25   * 28     -> cause bit for invalid exception
      26   * 27     -> cause bit for division by zero exception
      27   * 26     -> cause bit for overflow exception
      28   * 25     -> cause bit for underflow exception
      29   * 24     -> cause bit for inexact exception
      30   * 23-21  -> reserved (read as 0, can not changed by software)
      31   * 20     -> flag invalid exception
      32   * 19     -> flag division by zero exception
      33   * 18     -> flag overflow exception
      34   * 17     -> flag underflow exception
      35   * 16     -> flag inexact exception
      36   *  9-8   -> rounding control
      37   *  7-5   -> reserved (read as 0, can not changed by software)
      38   *  4     -> enable exception for invalid exception
      39   *  3     -> enable exception for division by zero exception
      40   *  2     -> enable exception for overflow exception
      41   *  1     -> enable exception for underflow exception
      42   *  0     -> enable exception for inexact exception
      43   *
      44   *
      45   * Rounding Control:
      46   * 00 - rounding ties to even (RNE)
      47   * 01 - rounding toward zero (RZ)
      48   * 10 - rounding (up) toward plus infinity (RP)
      49   * 11 - rounding (down) toward minus infinity (RM)
      50   */
      51  
      52  #include <features.h>
      53  
      54  #ifdef __loongarch_soft_float
      55  
      56  #define _FPU_RESERVED 0xffffffff
      57  #define _FPU_DEFAULT 0x00000000
      58  typedef unsigned int fpu_control_t;
      59  #define _FPU_GETCW(cw) (cw) = 0
      60  #define _FPU_SETCW(cw) (void) (cw)
      61  extern fpu_control_t __fpu_control;
      62  
      63  #else /* __loongarch_soft_float */
      64  
      65  /* Masks for interrupts.  */
      66  #define _FPU_MASK_V 0x10 /* Invalid operation */
      67  #define _FPU_MASK_Z 0x08 /* Division by zero  */
      68  #define _FPU_MASK_O 0x04 /* Overflow */
      69  #define _FPU_MASK_U 0x02 /* Underflow */
      70  #define _FPU_MASK_I 0x01 /* Inexact operation */
      71  
      72  /* Flush denormalized numbers to zero.  */
      73  #define _FPU_FLUSH_TZ 0x1000000
      74  
      75  /* Rounding control.  */
      76  #define _FPU_RC_NEAREST 0x000 /* RECOMMENDED */
      77  #define _FPU_RC_ZERO 0x100
      78  #define _FPU_RC_UP 0x200
      79  #define _FPU_RC_DOWN 0x300
      80  /* Mask for rounding control.  */
      81  #define _FPU_RC_MASK 0x300
      82  
      83  #define _FPU_RESERVED 0x0
      84  
      85  #define _FPU_DEFAULT 0x0
      86  #define _FPU_IEEE 0x1F
      87  
      88  /* Type of the control word.  */
      89  typedef unsigned int fpu_control_t __attribute__ ((__mode__ (__SI__)));
      90  
      91  /* Macros for accessing the hardware control word.  */
      92  extern fpu_control_t __loongarch_fpu_getcw (void) __THROW;
      93  extern void __loongarch_fpu_setcw (fpu_control_t) __THROW;
      94  #define _FPU_GETCW(cw) __asm__ volatile ("movfcsr2gr %0,$r0" : "=r"(cw))
      95  #define _FPU_SETCW(cw) __asm__ volatile ("movgr2fcsr $r0,%0" : : "r"(cw))
      96  
      97  /* Default control word set at startup.  */
      98  extern fpu_control_t __fpu_control;
      99  
     100  # define _FCLASS_SNAN     (1 << 0)
     101  # define _FCLASS_QNAN     (1 << 1)
     102  # define _FCLASS_MINF     (1 << 2)
     103  # define _FCLASS_MNORM    (1 << 3)
     104  # define _FCLASS_MSUBNORM (1 << 4)
     105  # define _FCLASS_MZERO    (1 << 5)
     106  # define _FCLASS_PINF     (1 << 6)
     107  # define _FCLASS_PNORM    (1 << 7)
     108  # define _FCLASS_PSUBNORM (1 << 8)
     109  # define _FCLASS_PZERO    (1 << 9)
     110  
     111  # define _FCLASS_ZERO     (_FCLASS_MZERO | _FCLASS_PZERO)
     112  # define _FCLASS_SUBNORM  (_FCLASS_MSUBNORM | _FCLASS_PSUBNORM)
     113  # define _FCLASS_NORM     (_FCLASS_MNORM | _FCLASS_PNORM)
     114  # define _FCLASS_INF      (_FCLASS_MINF | _FCLASS_PINF)
     115  # define _FCLASS_NAN      (_FCLASS_SNAN | _FCLASS_QNAN)
     116  
     117  #endif /* __loongarch_soft_float */
     118  
     119  #endif /* fpu_control.h */