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-rw-r--r--erts/emulator/beam/big.c102
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);
}
/*