| 1 | /* This code in included by number.s.c to generate integer conversion |
| 2 | functions like scm_to_int and scm_from_int. It is only for |
| 3 | unsigned types, see conv-integer.i.c for the signed variant. |
| 4 | */ |
| 5 | |
| 6 | /* You need to define the following macros before including this |
| 7 | template. They are undefined at the end of this file to giove a |
| 8 | clean slate for the next inclusion. |
| 9 | |
| 10 | TYPE - the integral type to be converted |
| 11 | TYPE_MIN - the smallest representable number of TYPE, typically 0. |
| 12 | TYPE_MAX - the largest representable number of TYPE |
| 13 | SIZEOF_TYPE - the size of TYPE, equal to "sizeof (TYPE)" but |
| 14 | in a form that can be computed by the preprocessor. |
| 15 | When this number is 0, the preprocessor is not used |
| 16 | to select which code to compile; the most general |
| 17 | code is always used. |
| 18 | |
| 19 | SCM_TO_TYPE_PROTO(arg), SCM_FROM_TYPE_PROTO(arg) |
| 20 | - These two macros should expand into the prototype |
| 21 | for the two defined functions, without the return |
| 22 | type. |
| 23 | |
| 24 | */ |
| 25 | |
| 26 | TYPE |
| 27 | SCM_TO_TYPE_PROTO (SCM val) |
| 28 | { |
| 29 | if (SCM_I_INUMP (val)) |
| 30 | { |
| 31 | scm_t_signed_bits n = SCM_I_INUM (val); |
| 32 | if (n >= 0 |
| 33 | && ((scm_t_uintmax)n) >= TYPE_MIN && ((scm_t_uintmax)n) <= TYPE_MAX) |
| 34 | return n; |
| 35 | else |
| 36 | { |
| 37 | out_of_range: |
| 38 | scm_i_range_error (val, |
| 39 | scm_from_unsigned_integer (TYPE_MIN), |
| 40 | scm_from_unsigned_integer (TYPE_MAX)); |
| 41 | return 0; |
| 42 | } |
| 43 | } |
| 44 | else if (SCM_BIGP (val)) |
| 45 | { |
| 46 | if (TYPE_MAX <= SCM_MOST_POSITIVE_FIXNUM) |
| 47 | goto out_of_range; |
| 48 | else if (TYPE_MAX <= ULONG_MAX) |
| 49 | { |
| 50 | if (mpz_fits_ulong_p (SCM_I_BIG_MPZ (val))) |
| 51 | { |
| 52 | unsigned long n = mpz_get_ui (SCM_I_BIG_MPZ (val)); |
| 53 | #if SIZEOF_TYPE != 0 && SIZEOF_TYPE > SCM_SIZEOF_LONG |
| 54 | return n; |
| 55 | #else |
| 56 | |
| 57 | if (n >= TYPE_MIN && n <= TYPE_MAX) |
| 58 | return n; |
| 59 | else |
| 60 | goto out_of_range; |
| 61 | |
| 62 | #endif |
| 63 | } |
| 64 | else |
| 65 | goto out_of_range; |
| 66 | } |
| 67 | else |
| 68 | { |
| 69 | scm_t_uintmax n; |
| 70 | size_t count; |
| 71 | |
| 72 | if (mpz_sgn (SCM_I_BIG_MPZ (val)) < 0) |
| 73 | goto out_of_range; |
| 74 | |
| 75 | if (mpz_sizeinbase (SCM_I_BIG_MPZ (val), 2) |
| 76 | > CHAR_BIT*sizeof (TYPE)) |
| 77 | goto out_of_range; |
| 78 | |
| 79 | mpz_export (&n, &count, 1, sizeof (TYPE), 0, 0, SCM_I_BIG_MPZ (val)); |
| 80 | |
| 81 | if (n >= TYPE_MIN && n <= TYPE_MAX) |
| 82 | return n; |
| 83 | else |
| 84 | goto out_of_range; |
| 85 | |
| 86 | } |
| 87 | } |
| 88 | else |
| 89 | { |
| 90 | scm_wrong_type_arg_msg (NULL, 0, val, "exact integer"); |
| 91 | return 0; |
| 92 | } |
| 93 | } |
| 94 | |
| 95 | SCM |
| 96 | SCM_FROM_TYPE_PROTO (TYPE val) |
| 97 | { |
| 98 | #if SIZEOF_TYPE != 0 && SIZEOF_TYPE < SIZEOF_SCM_T_BITS |
| 99 | return SCM_I_MAKINUM (val); |
| 100 | #else |
| 101 | if (SCM_POSFIXABLE (val)) |
| 102 | return SCM_I_MAKINUM (val); |
| 103 | else if (val <= ULONG_MAX) |
| 104 | return scm_i_ulong2big (val); |
| 105 | else |
| 106 | { |
| 107 | SCM z = scm_double_cell (scm_tc16_big, 0, 0, 0); |
| 108 | mpz_init (SCM_I_BIG_MPZ (z)); |
| 109 | mpz_import (SCM_I_BIG_MPZ (z), 1, 1, sizeof (TYPE), 0, 0, &val); |
| 110 | return z; |
| 111 | } |
| 112 | #endif |
| 113 | } |
| 114 | |
| 115 | #undef TYPE |
| 116 | #undef TYPE_MIN |
| 117 | #undef TYPE_MAX |
| 118 | #undef SIZEOF_TYPE |
| 119 | #undef SCM_TO_TYPE_PROTO |
| 120 | #undef SCM_FROM_TYPE_PROTO |
| 121 | |