diff options
Diffstat (limited to 'gcc/real.cc')
| -rw-r--r-- | gcc/real.cc | 48 |
1 files changed, 31 insertions, 17 deletions
diff --git a/gcc/real.cc b/gcc/real.cc index b64bad0..1f987d4 100644 --- a/gcc/real.cc +++ b/gcc/real.cc @@ -101,7 +101,7 @@ static int do_compare (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *, int); static void do_fix_trunc (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *); static unsigned long rtd_divmod (REAL_VALUE_TYPE *, REAL_VALUE_TYPE *); -static void decimal_from_integer (REAL_VALUE_TYPE *); +static void decimal_from_integer (REAL_VALUE_TYPE *, int); static void decimal_integer_string (char *, const REAL_VALUE_TYPE *, size_t); @@ -2230,7 +2230,6 @@ real_from_integer (REAL_VALUE_TYPE *r, format_helper fmt, { unsigned int len = val_in.get_precision (); int i, j, e = 0; - int maxbitlen = MAX_BITSIZE_MODE_ANY_INT + HOST_BITS_PER_WIDE_INT; const unsigned int realmax = (SIGNIFICAND_BITS / HOST_BITS_PER_WIDE_INT * HOST_BITS_PER_WIDE_INT); @@ -2238,12 +2237,6 @@ real_from_integer (REAL_VALUE_TYPE *r, format_helper fmt, r->cl = rvc_normal; r->sign = wi::neg_p (val_in, sgn); - /* We have to ensure we can negate the largest negative number. */ - wide_int val = wide_int::from (val_in, maxbitlen, sgn); - - if (r->sign) - val = -val; - /* Ensure a multiple of HOST_BITS_PER_WIDE_INT, ceiling, as elt won't work with precisions that are not a multiple of HOST_BITS_PER_WIDE_INT. */ @@ -2252,7 +2245,13 @@ real_from_integer (REAL_VALUE_TYPE *r, format_helper fmt, /* Ensure we can represent the largest negative number. */ len += 1; - len = len/HOST_BITS_PER_WIDE_INT * HOST_BITS_PER_WIDE_INT; + len = len / HOST_BITS_PER_WIDE_INT * HOST_BITS_PER_WIDE_INT; + + /* We have to ensure we can negate the largest negative number. */ + wide_int val = wide_int::from (val_in, len, sgn); + + if (r->sign) + val = -val; /* Cap the size to the size allowed by real.h. */ if (len > realmax) @@ -2260,14 +2259,18 @@ real_from_integer (REAL_VALUE_TYPE *r, format_helper fmt, HOST_WIDE_INT cnt_l_z; cnt_l_z = wi::clz (val); - if (maxbitlen - cnt_l_z > realmax) + if (len - cnt_l_z > realmax) { - e = maxbitlen - cnt_l_z - realmax; + e = len - cnt_l_z - realmax; /* This value is too large, we must shift it right to preserve all the bits we can, and then bump the - exponent up by that amount. */ - val = wi::lrshift (val, e); + exponent up by that amount, but or in 1 if any of + the shifted out bits are non-zero. */ + if (wide_int::from (val, e, UNSIGNED) != 0) + val = wi::set_bit (wi::lrshift (val, e), 0); + else + val = wi::lrshift (val, e); } len = realmax; } @@ -2306,7 +2309,9 @@ real_from_integer (REAL_VALUE_TYPE *r, format_helper fmt, } if (fmt.decimal_p ()) - decimal_from_integer (r); + /* We need at most one decimal digits for each 3 bits of input + precision. */ + decimal_from_integer (r, val_in.get_precision () / 3); if (fmt) real_convert (r, fmt, r); } @@ -2361,12 +2366,21 @@ decimal_integer_string (char *str, const REAL_VALUE_TYPE *r_orig, /* Convert a real with an integral value to decimal float. */ static void -decimal_from_integer (REAL_VALUE_TYPE *r) +decimal_from_integer (REAL_VALUE_TYPE *r, int digits) { char str[256]; - decimal_integer_string (str, r, sizeof (str) - 1); - decimal_real_from_string (r, str); + if (digits <= 256) + { + decimal_integer_string (str, r, sizeof (str) - 1); + decimal_real_from_string (r, str); + } + else + { + char *s = XALLOCAVEC (char, digits); + decimal_integer_string (s, r, digits - 1); + decimal_real_from_string (r, s); + } } /* Returns 10**2**N. */ |