Moved do_list_to_integer from bif.c to big.c

1 files changed, 153 insertions, 0 deletions

diff --git a/erts/emulator/beam/big.c b/erts/emulator/beam/big.c
index 02d37e24df..29e677d2e5 100644
--- a/erts/emulator/beam/big.c
+++ b/erts/emulator/beam/big.c
@@ -2732,3 +2732,156 @@ bytebuf_to_integer_1_done:
     return res;
 
 }
+
+int do_list_to_integer(Process *p, Eterm orig_list,
+                       Eterm *integer, Eterm *rest)
+{
+     Sint i = 0;
+     Uint ui = 0;
+     int skip = 0;
+     int neg = 0;
+     Sint n = 0;
+     int m;
+     int lg2;
+     Eterm res;
+     Eterm* hp;
+     Eterm *hp_end;
+     Eterm lst = orig_list;
+     Eterm tail = lst;
+     int error_res = LTI_BAD_STRUCTURE;
+
+     if (is_nil(lst)) {
+       error_res = LTI_NO_INTEGER;
+     error:
+         *rest = tail;
+         *integer = make_small(0);
+         return error_res;
+     }
+     if (is_not_list(lst))
+       goto error;
+
+     /* if first char is a '-' then it is a negative integer */
+     if (CAR(list_val(lst)) == make_small('-')) {
+          neg = 1;
+          skip = 1;
+          lst = CDR(list_val(lst));
+          if (is_not_list(lst)) {
+              tail = lst;
+              error_res = LTI_NO_INTEGER;
+              goto error;
+          }
+     } else if (CAR(list_val(lst)) == make_small('+')) {
+         /* ignore plus */
+         skip = 1;
+         lst = CDR(list_val(lst));
+         if (is_not_list(lst)) {
+             tail = lst;
+             error_res = LTI_NO_INTEGER;
+             goto error;
+         }
+     }
+
+     /* Calculate size and do type check */
+
+     while(1) {
+         if (is_not_small(CAR(list_val(lst)))) {
+             break;
+         }
+         if (unsigned_val(CAR(list_val(lst))) < '0' ||
+             unsigned_val(CAR(list_val(lst))) > '9') {
+             break;
+         }
+         ui = ui * 10;
+         ui = ui + unsigned_val(CAR(list_val(lst))) - '0';
+         n++;
+         lst = CDR(list_val(lst));
+         if (is_nil(lst)) {
+             break;
+         }
+         if (is_not_list(lst)) {
+             break;
+         }
+     }
+
+     tail = lst;
+     if (!n) {
+         error_res = LTI_NO_INTEGER;
+         goto error;
+     }
+
+
+      /* If n <= 8 then we know it's a small int
+      ** since 2^27 = 134217728. If n > 8 then we must
+      ** construct a bignum and let that routine do the checking
+      */
+
+     if (n <= SMALL_DIGITS) {  /* It must be small */
+         if (neg) i = -(Sint)ui;
+         else i = (Sint)ui;
+         res = make_small(i);
+     } else {
+         /* Convert from log10 to log2 by multiplying with 1/log10(2)=3.3219
+            which we round up to (3 + 1/3) */
+         lg2 = (n+1)*3 + (n+1)/3 + 1;
+         m  = (lg2+D_EXP-1)/D_EXP; /* number of digits */
+         m  = BIG_NEED_SIZE(m);    /* number of words + thing */
+
+         hp = HAlloc(p, m);
+         hp_end = hp + m;
+
+         lst = orig_list;
+         if (skip)
+             lst = CDR(list_val(lst));
+
+         /* load first digits (at least one digit) */
+         if ((i = (n % D_DECIMAL_EXP)) == 0)
+             i = D_DECIMAL_EXP;
+         n -= i;
+         m = 0;
+         while(i--) {
+             m = 10*m + (unsigned_val(CAR(list_val(lst))) - '0');
+             lst = CDR(list_val(lst));
+         }
+         res = small_to_big(m, hp);  /* load first digits */
+
+         while(n) {
+             i = D_DECIMAL_EXP;
+             n -= D_DECIMAL_EXP;
+             m = 0;
+             while(i--) {
+                 m = 10*m + (unsigned_val(CAR(list_val(lst))) - '0');
+                 lst = CDR(list_val(lst));
+             }
+             if (is_small(res))
+                 res = small_to_big(signed_val(res), hp);
+             res = big_times_small(res, D_DECIMAL_BASE, hp);
+             if (is_small(res))
+                 res = small_to_big(signed_val(res), hp);
+             res = big_plus_small(res, m, hp);
+         }
+
+         if (neg) {
+             if (is_small(res))
+                 res = make_small(-signed_val(res));
+             else {
+                 Uint *big = big_val(res); /* point to thing */
+                 *big = bignum_header_neg(*big);
+             }
+         }
+
+         if (is_not_small(res)) {
+             res = big_plus_small(res, 0, hp); /* includes conversion to small */
+
+             if (is_not_small(res)) {
+                 hp += (big_arity(res)+1);
+             }
+         }
+         HRelease(p,hp_end,hp);
+     }
+     *integer = res;
+     *rest = tail;
+     if (tail != NIL) {
+         return LTI_SOME_INTEGER;
+     }
+     return LTI_ALL_INTEGER;
+}