diff options
Diffstat (limited to 'erts/emulator/beam/big.c')
| -rw-r--r-- | erts/emulator/beam/big.c | 102 |
1 files changed, 92 insertions, 10 deletions
diff --git a/erts/emulator/beam/big.c b/erts/emulator/beam/big.c index d18de9ae5d..5a5b162b9c 100644 --- a/erts/emulator/beam/big.c +++ b/erts/emulator/beam/big.c @@ -1,7 +1,7 @@ /* * %CopyrightBegin% * - * Copyright Ericsson AB 1996-2011. All Rights Reserved. + * Copyright Ericsson AB 1996-2012. All Rights Reserved. * * The contents of this file are subject to the Erlang Public License, * Version 1.1, (the "License"); you may not use this file except in @@ -310,12 +310,12 @@ #define DREM(a1,a0,b,r) do { \ ErtsDigit __a1 = (a1); \ ErtsDigit __b = (b); \ - ErtsDigit __q0; \ + ERTS_DECLARE_DUMMY(ErtsDigit __q0); \ DDIVREM((__a1 % __b), (a0), __b, __q0, r); \ } while(0) #define DDIV(a1,a0,b,q) do { \ - ErtsDigit _tmp; \ + ERTS_DECLARE_DUMMY(ErtsDigit _tmp); \ DDIVREM(a1,a0,b,q,_tmp); \ } while(0) @@ -413,8 +413,8 @@ } while(0) #define DDIV2(a1,a0,b1,b0,q) do { \ - ErtsDigit _tmp_r1; \ - ErtsDigit _tmp_r0; \ + ERTS_DECLARE_DUMMY(ErtsDigit _tmp_r1); \ + ERTS_DECLARE_DUMMY(ErtsDigit _tmp_r0); \ D2DIVREM(a1,a0,b1,b0,q,_tmp_r1,_tmp_r0); \ } while(0) @@ -810,7 +810,9 @@ static dsize_t D_div(ErtsDigit* x, dsize_t xl, ErtsDigit d, ErtsDigit* q, ErtsDi } do { - ErtsDigit q0, a0, b1, b0, b; + ErtsDigit q0, a0, b0; + ERTS_DECLARE_DUMMY(ErtsDigit b); + ERTS_DECLARE_DUMMY(ErtsDigit b1); if (d > a1) { a0 = *xp; @@ -1323,7 +1325,7 @@ static dsize_t I_lshift(ErtsDigit* x, dsize_t xl, Sint y, return 1; } else { - long ay = (y < 0) ? -y : y; + SWord ay = (y < 0) ? -y : y; int bw = ay / D_EXP; int sw = ay % D_EXP; dsize_t rl; @@ -1448,6 +1450,20 @@ erts_make_integer(Uint x, Process *p) return uint_to_big(x,hp); } } +/* + * As erts_make_integer, but from a whole UWord. + */ +Eterm +erts_make_integer_from_uword(UWord x, Process *p) +{ + Eterm* hp; + if (IS_USMALL(0,x)) + return make_small(x); + else { + hp = HAlloc(p, BIG_UWORD_HEAP_SIZE(x)); + return uword_to_big(x,hp); + } +} /* ** convert Uint to bigint @@ -1584,6 +1600,62 @@ big_to_double(Wterm x, double* resp) return 0; } +/* + * Logic has been copied from erl_bif_guard.c and slightly + * modified to use a static instead of dynamic heap + */ +Eterm +double_to_big(double x, Eterm *heap) +{ + int is_negative; + int ds; + ErtsDigit* xp; + Eterm res; + int i; + size_t sz; + Eterm* hp; + double dbase; + + if (x >= 0) { + is_negative = 0; + } else { + is_negative = 1; + x = -x; + } + + /* Unscale & (calculate exponent) */ + ds = 0; + dbase = ((double) (D_MASK) + 1); + while (x >= 1.0) { + x /= dbase; /* "shift" right */ + ds++; + } + sz = BIG_NEED_SIZE(ds); /* number of words including arity */ + + hp = heap; + res = make_big(hp); + xp = (ErtsDigit*) (hp + 1); + + for (i = ds - 1; i >= 0; i--) { + ErtsDigit d; + + x *= dbase; /* "shift" left */ + d = x; /* trunc */ + xp[i] = d; /* store digit */ + x -= d; /* remove integer part */ + } + while ((ds & (BIG_DIGITS_PER_WORD - 1)) != 0) { + xp[ds++] = 0; + } + + if (is_negative) { + *hp = make_neg_bignum_header(sz-1); + } else { + *hp = make_pos_bignum_header(sz-1); + } + return res; +} + /* ** Estimate the number of decimal digits (include sign) @@ -1772,6 +1844,7 @@ dsize_t big_bytes(Eterm x) /* ** Load a bignum from bytes ** xsz is the number of bytes in xp +** *r is untouched if number fits in small */ Eterm bytes_to_big(byte *xp, dsize_t xsz, int xsgn, Eterm *r) { @@ -1780,7 +1853,7 @@ Eterm bytes_to_big(byte *xp, dsize_t xsz, int xsgn, Eterm *r) ErtsDigit d; int i; - while(xsz >= sizeof(ErtsDigit)) { + while(xsz > sizeof(ErtsDigit)) { d = 0; for(i = sizeof(ErtsDigit); --i >= 0;) d = (d << 8) | xp[i]; @@ -1795,11 +1868,20 @@ Eterm bytes_to_big(byte *xp, dsize_t xsz, int xsgn, Eterm *r) d = 0; for(i = xsz; --i >= 0;) d = (d << 8) | xp[i]; + if (++rsz == 1 && IS_USMALL(xsgn,d)) { + if (xsgn) d = -d; + return make_small(d); + } *rwp = d; rwp++; - rsz++; } - return big_norm(r, rsz, (short) xsgn); + if (xsgn) { + *r = make_neg_bignum_header(rsz); + } + else { + *r = make_pos_bignum_header(rsz); + } + return make_big(r); } /* |