newlib/libc/machine/riscv/sys/fenv.h

   1 /* Copyright (c) 2017  SiFive Inc. All rights reserved.
   2
   3    This copyrighted material is made available to anyone wishing to use,
   4    modify, copy, or redistribute it subject to the terms and conditions
   5    of the FreeBSD License.   This program is distributed in the hope that
   6    it will be useful, but WITHOUT ANY WARRANTY expressed or implied,
   7    including the implied warranties of MERCHANTABILITY or FITNESS FOR
   8    A PARTICULAR PURPOSE.  A copy of this license is available at
   9    http://www.opensource.org/licenses.
  10 */
  11
  12 #ifndef _SYS_FENV_H
  13 #define _SYS_FENV_H
  14
  15 #include <stddef.h>
  16
  17 #if defined(__riscv_flen) || defined(__riscv_zfinx)
  18
  19 /* Per "The RISC-V Instruction Set Manual: Volume I: User-Level ISA:
  20  * Version 2.1", Section 8.2, "Floating-Point Control and Status
  21  * Register":
  22  *
  23  * Flag Mnemonic Flag Meaning
  24  * ------------- -----------------
  25  * NV            Invalid Operation
  26  * DZ            Divide by Zero
  27  * OF            Overflow
  28  * UF            Underflow
  29  * NX            Inexact
  30  */
  31
  32 #define FE_INVALID   0x00000010
  33 #define FE_DIVBYZERO 0x00000008
  34 #define FE_OVERFLOW  0x00000004
  35 #define FE_UNDERFLOW 0x00000002
  36 #define FE_INEXACT   0x00000001
  37
  38 #define FE_ALL_EXCEPT (FE_INVALID|FE_DIVBYZERO|FE_OVERFLOW|FE_UNDERFLOW|FE_INEXACT)
  39
  40 /* Per "The RISC-V Instruction Set Manual: Volume I: User-Level ISA:
  41  * Version 2.1", Section 8.2, "Floating-Point Control and Status
  42  * Register":
  43  *
  44  * Rounding Mode  Mnemonic Meaning  Meaning
  45  * -------------  ----------------  -------
  46  * 000            RNE               Round to Nearest, ties to Even
  47  * 001            RTZ               Round towards Zero
  48  * 010            RDN               Round Down (towards −∞)
  49  * 011            RUP               Round Up (towards +∞)
  50  * 100            RMM               Round to Nearest, ties to Max Magnitude
  51  * 101                              Invalid. Reserved for future use.
  52  * 110                              Invalid. Reserved for future use.
  53  * 111                              In instruction’s rm field, selects dynamic rounding mode;
  54  *                                  In Rounding Mode register, Invalid
  55  */
  56
  57 #define FE_TONEAREST_MM 0x00000004
  58 #define FE_UPWARD       0x00000003
  59 #define FE_DOWNWARD     0x00000002
  60 #define FE_TOWARDZERO   0x00000001
  61 #define FE_TONEAREST    0x00000000
  62
  63 #define FE_RMODE_MASK   0x7
  64
  65 /* Per "The RISC-V Instruction Set Manual: Volume I: User-Level ISA:
  66  * Version 2.1":
  67  *
  68  * "The F extension adds 32 floating-point registers, f0–f31, each 32
  69  * bits wide, and a floating-point control and status register fcsr,
  70  * which contains the operating mode and exception status of the
  71  * floating-point unit."
  72  */
  73
  74 #else /* !__riscv_flen */
  75
  76 #define FE_ALL_EXCEPT   0x00000000
  77 #define FE_TONEAREST    0x00000000
  78
  79 #endif /* !__riscv_flen */
  80
  81 typedef size_t fenv_t;
  82 typedef size_t fexcept_t;
  83 extern const fenv_t fe_dfl_env;
  84 extern const fenv_t *fe_dfl_env_p;
  85
  86 #define FE_DFL_ENV fe_dfl_env_p
  87
  88 #endif /* _SYS_FENV_H */