diff options
Diffstat (limited to 'sysdeps/wordsize-32')
| -rw-r--r-- | sysdeps/wordsize-32/divdi3.c | 327 |
1 files changed, 327 insertions, 0 deletions
diff --git a/sysdeps/wordsize-32/divdi3.c b/sysdeps/wordsize-32/divdi3.c new file mode 100644 index 0000000000..7929e3019c --- /dev/null +++ b/sysdeps/wordsize-32/divdi3.c @@ -0,0 +1,327 @@ +/* 64-bit multiplication and division + Copyright (C) 1989, 1992-1999, 2000, 2001, 2002 + 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <endian.h> +#include <stdlib.h> +#include <bits/wordsize.h> + +#if __WORDSIZE != 32 +#error This is for 32-bit targets only +#endif + +typedef unsigned int UQItype __attribute__ ((mode (QI))); +typedef int SItype __attribute__ ((mode (SI))); +typedef unsigned int USItype __attribute__ ((mode (SI))); +typedef int DItype __attribute__ ((mode (DI))); +typedef unsigned int UDItype __attribute__ ((mode (DI))); +#define Wtype SItype +#define HWtype SItype +#define DWtype DItype +#define UWtype USItype +#define UHWtype USItype +#define UDWtype UDItype +#define W_TYPE_SIZE 32 + +#include <stdlib/longlong.h> + +#if __BYTE_ORDER == __BIG_ENDIAN +struct DWstruct { Wtype high, low;}; +#elif __BYTE_ORDER == __LITTLE_ENDIAN +struct DWstruct { Wtype low, high;}; +#else +#error Unhandled endianity +#endif +typedef union { struct DWstruct s; DWtype ll; } DWunion; + +static UDWtype +__udivmoddi4 (UDWtype n, UDWtype d, UDWtype *rp) +{ + DWunion ww; + DWunion nn, dd; + DWunion rr; + UWtype d0, d1, n0, n1, n2; + UWtype q0, q1; + UWtype b, bm; + + nn.ll = n; + dd.ll = d; + + d0 = dd.s.low; + d1 = dd.s.high; + n0 = nn.s.low; + n1 = nn.s.high; + +#if !UDIV_NEEDS_NORMALIZATION + if (d1 == 0) + { + if (d0 > n1) + { + /* 0q = nn / 0D */ + + udiv_qrnnd (q0, n0, n1, n0, d0); + q1 = 0; + + /* Remainder in n0. */ + } + else + { + /* qq = NN / 0d */ + + if (d0 == 0) + d0 = 1 / d0; /* Divide intentionally by zero. */ + + udiv_qrnnd (q1, n1, 0, n1, d0); + udiv_qrnnd (q0, n0, n1, n0, d0); + + /* Remainder in n0. */ + } + + if (rp != 0) + { + rr.s.low = n0; + rr.s.high = 0; + *rp = rr.ll; + } + } + +#else /* UDIV_NEEDS_NORMALIZATION */ + + if (d1 == 0) + { + if (d0 > n1) + { + /* 0q = nn / 0D */ + + count_leading_zeros (bm, d0); + + if (bm != 0) + { + /* Normalize, i.e. make the most significant bit of the + denominator set. */ + + d0 = d0 << bm; + n1 = (n1 << bm) | (n0 >> (W_TYPE_SIZE - bm)); + n0 = n0 << bm; + } + + udiv_qrnnd (q0, n0, n1, n0, d0); + q1 = 0; + + /* Remainder in n0 >> bm. */ + } + else + { + /* qq = NN / 0d */ + + if (d0 == 0) + d0 = 1 / d0; /* Divide intentionally by zero. */ + + count_leading_zeros (bm, d0); + + if (bm == 0) + { + /* From (n1 >= d0) /\ (the most significant bit of d0 is set), + conclude (the most significant bit of n1 is set) /\ (the + leading quotient digit q1 = 1). + + This special case is necessary, not an optimization. + (Shifts counts of W_TYPE_SIZE are undefined.) */ + + n1 -= d0; + q1 = 1; + } + else + { + /* Normalize. */ + + b = W_TYPE_SIZE - bm; + + d0 = d0 << bm; + n2 = n1 >> b; + n1 = (n1 << bm) | (n0 >> b); + n0 = n0 << bm; + + udiv_qrnnd (q1, n1, n2, n1, d0); + } + + /* n1 != d0... */ + + udiv_qrnnd (q0, n0, n1, n0, d0); + + /* Remainder in n0 >> bm. */ + } + + if (rp != 0) + { + rr.s.low = n0 >> bm; + rr.s.high = 0; + *rp = rr.ll; + } + } +#endif /* UDIV_NEEDS_NORMALIZATION */ + + else + { + if (d1 > n1) + { + /* 00 = nn / DD */ + + q0 = 0; + q1 = 0; + + /* Remainder in n1n0. */ + if (rp != 0) + { + rr.s.low = n0; + rr.s.high = n1; + *rp = rr.ll; + } + } + else + { + /* 0q = NN / dd */ + + count_leading_zeros (bm, d1); + if (bm == 0) + { + /* From (n1 >= d1) /\ (the most significant bit of d1 is set), + conclude (the most significant bit of n1 is set) /\ (the + quotient digit q0 = 0 or 1). + + This special case is necessary, not an optimization. */ + + /* The condition on the next line takes advantage of that + n1 >= d1 (true due to program flow). */ + if (n1 > d1 || n0 >= d0) + { + q0 = 1; + sub_ddmmss (n1, n0, n1, n0, d1, d0); + } + else + q0 = 0; + + q1 = 0; + + if (rp != 0) + { + rr.s.low = n0; + rr.s.high = n1; + *rp = rr.ll; + } + } + else + { + UWtype m1, m0; + /* Normalize. */ + + b = W_TYPE_SIZE - bm; + + d1 = (d1 << bm) | (d0 >> b); + d0 = d0 << bm; + n2 = n1 >> b; + n1 = (n1 << bm) | (n0 >> b); + n0 = n0 << bm; + + udiv_qrnnd (q0, n1, n2, n1, d1); + umul_ppmm (m1, m0, q0, d0); + + if (m1 > n1 || (m1 == n1 && m0 > n0)) + { + q0--; + sub_ddmmss (m1, m0, m1, m0, d1, d0); + } + + q1 = 0; + + /* Remainder in (n1n0 - m1m0) >> bm. */ + if (rp != 0) + { + sub_ddmmss (n1, n0, n1, n0, m1, m0); + rr.s.low = (n1 << b) | (n0 >> bm); + rr.s.high = n1 >> bm; + *rp = rr.ll; + } + } + } + } + + ww.s.low = q0; + ww.s.high = q1; + return ww.ll; +} + +DWtype +__divdi3 (DWtype u, DWtype v) +{ + Wtype c = 0; + DWtype w; + + if (u < 0) + { + c = ~c; + u = -u; + } + if (v < 0) + { + c = ~c; + v = -v; + } + w = __udivmoddi4 (u, v, NULL); + if (c) + w = -w; + return w; +} + +DWtype +__moddi3 (DWtype u, DWtype v) +{ + Wtype c = 0; + DWtype w; + + if (u < 0) + { + c = ~c; + u = -u; + } + if (v < 0) + { + c = ~c; + v = -v; + } + __udivmoddi4 (u, v, &w); + if (c) + w = -w; + return w; +} + +UDWtype +__udivdi3 (UDWtype u, UDWtype v) +{ + return __udivmoddi4 (u, v, NULL); +} + +UDWtype +__umoddi3 (UDWtype u, UDWtype v) +{ + UDWtype w; + + __udivmoddi4 (u, v, &w); + return w; +} |