LXR linux/arch/mips/math-emu/ieee754dp.h

   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 * IEEE754 floating point
   4 * double precision internal header file
   5 */
   6/*
   7 * MIPS floating point support
   8 * Copyright (C) 1994-2000 Algorithmics Ltd.
   9 */
  10
  11#include <linux/compiler.h>
  12
  13#include "ieee754int.h"
  14
  15#define assert(expr) ((void)0)
  16
  17#define DP_EBIAS        1023
  18#define DP_EMIN         (-1022)
  19#define DP_EMAX         1023
  20#define DP_FBITS        52
  21#define DP_MBITS        52
  22
  23#define DP_MBIT(x)      ((u64)1 << (x))
  24#define DP_HIDDEN_BIT   DP_MBIT(DP_FBITS)
  25#define DP_SIGN_BIT     DP_MBIT(63)
  26
  27#define DPSIGN(dp)      (dp.sign)
  28#define DPBEXP(dp)      (dp.bexp)
  29#define DPMANT(dp)      (dp.mant)
  30
  31static inline int ieee754dp_finite(union ieee754dp x)
  32{
  33        return DPBEXP(x) != DP_EMAX + 1 + DP_EBIAS;
  34}
  35
  36/* 3bit extended double precision sticky right shift */
  37#define XDPSRS(v,rs)    \
  38        ((rs > (DP_FBITS+3))?1:((v) >> (rs)) | ((v) << (64-(rs)) != 0))
  39
  40#define XDPSRSX1() \
  41        (xe++, (xm = (xm >> 1) | (xm & 1)))
  42
  43#define XDPSRS1(v)      \
  44        (((v) >> 1) | ((v) & 1))
  45
  46/* 32bit * 32bit => 64bit unsigned integer multiplication */
  47#define DPXMULT(x, y)   ((u64)(x) * (u64)y)
  48
  49/* convert denormal to normalized with extended exponent */
  50#define DPDNORMx(m,e) \
  51        while ((m >> DP_FBITS) == 0) { m <<= 1; e--; }
  52#define DPDNORMX        DPDNORMx(xm, xe)
  53#define DPDNORMY        DPDNORMx(ym, ye)
  54#define DPDNORMZ        DPDNORMx(zm, ze)
  55
  56static inline union ieee754dp builddp(int s, int bx, u64 m)
  57{
  58        union ieee754dp r;
  59
  60        assert((s) == 0 || (s) == 1);
  61        assert((bx) >= DP_EMIN - 1 + DP_EBIAS
  62               && (bx) <= DP_EMAX + 1 + DP_EBIAS);
  63        assert(((m) >> DP_FBITS) == 0);
  64
  65        r.sign = s;
  66        r.bexp = bx;
  67        r.mant = m;
  68
  69        return r;
  70}
  71
  72extern union ieee754dp __cold ieee754dp_nanxcpt(union ieee754dp);
  73extern union ieee754dp ieee754dp_format(int, int, u64);
  74