diff options
Diffstat (limited to 'stdlib/strtod_l.c')
| -rw-r--r-- | stdlib/strtod_l.c | 70 |
1 files changed, 47 insertions, 23 deletions
diff --git a/stdlib/strtod_l.c b/stdlib/strtod_l.c index ccd117a9f1..95f13e40a2 100644 --- a/stdlib/strtod_l.c +++ b/stdlib/strtod_l.c @@ -61,6 +61,7 @@ extern unsigned long long int ____strtoull_l_internal (const char *, char **, #include <stdlib.h> #include <string.h> #include <stdint.h> +#include <rounding-mode.h> /* The gmp headers need some configuration frobs. */ #define HAVE_ALLOCA 1 @@ -126,6 +127,8 @@ extern unsigned long long int ____strtoull_l_internal (const char *, char **, #define MIN_EXP PASTE(FLT,_MIN_EXP) #define MAX_10_EXP PASTE(FLT,_MAX_10_EXP) #define MIN_10_EXP PASTE(FLT,_MIN_10_EXP) +#define MAX_VALUE PASTE(FLT,_MAX) +#define MIN_VALUE PASTE(FLT,_MIN) /* Extra macros required to get FLT expanded before the pasting. */ #define PASTE(a,b) PASTE1(a,b) @@ -172,6 +175,34 @@ extern const mp_limb_t _tens_in_limb[MAX_DIG_PER_LIMB + 1]; memcpy (dst, src, (dst##size = src##size) * sizeof (mp_limb_t)) +/* Set errno and return an overflowing value with sign specified by + NEGATIVE. */ +static FLOAT +overflow_value (int negative) +{ + __set_errno (ERANGE); +#if FLT_EVAL_METHOD != 0 + volatile +#endif + FLOAT result = (negative ? -MAX_VALUE : MAX_VALUE) * MAX_VALUE; + return result; +} + + +/* Set errno and return an underflowing value with sign specified by + NEGATIVE. */ +static FLOAT +underflow_value (int negative) +{ + __set_errno (ERANGE); +#if FLT_EVAL_METHOD != 0 + volatile +#endif + FLOAT result = (negative ? -MIN_VALUE : MIN_VALUE) * MIN_VALUE; + return result; +} + + /* Return a floating point number of the needed type according to the given multi-precision number after possible rounding. */ static FLOAT @@ -181,10 +212,7 @@ round_and_return (mp_limb_t *retval, intmax_t exponent, int negative, if (exponent < MIN_EXP - 1) { if (exponent < MIN_EXP - 1 - MANT_DIG) - { - __set_errno (ERANGE); - return negative ? -0.0 : 0.0; - } + return underflow_value (negative); mp_size_t shift = MIN_EXP - 1 - exponent; @@ -237,9 +265,14 @@ round_and_return (mp_limb_t *retval, intmax_t exponent, int negative, if (exponent > MAX_EXP) goto overflow; - if ((round_limb & (((mp_limb_t) 1) << round_bit)) != 0 - && (more_bits || (retval[0] & 1) != 0 - || (round_limb & ((((mp_limb_t) 1) << round_bit) - 1)) != 0)) + int mode = get_rounding_mode (); + + if (round_away (negative, + (retval[0] & 1) != 0, + (round_limb & (((mp_limb_t) 1) << round_bit)) != 0, + (more_bits + || (round_limb & ((((mp_limb_t) 1) << round_bit) - 1)) != 0), + mode)) { mp_limb_t cy = __mpn_add_1 (retval, retval, RETURN_LIMB_SIZE, 1); @@ -263,7 +296,7 @@ round_and_return (mp_limb_t *retval, intmax_t exponent, int negative, if (exponent > MAX_EXP) overflow: - return negative ? -FLOAT_HUGE_VAL : FLOAT_HUGE_VAL; + return overflow_value (negative); return MPN2FLOAT (retval, exponent, negative); } @@ -914,9 +947,9 @@ ____STRTOF_INTERNAL (nptr, endptr, group, loc) else { /* Overflow or underflow. */ - __set_errno (ERANGE); - result = (exp_negative ? (negative ? -0.0 : 0.0) : - negative ? -FLOAT_HUGE_VAL : FLOAT_HUGE_VAL); + result = (exp_negative + ? underflow_value (negative) + : overflow_value (negative)); } /* Accept all following digits as part of the exponent. */ @@ -1112,16 +1145,10 @@ ____STRTOF_INTERNAL (nptr, endptr, group, loc) } if (__builtin_expect (exponent > MAX_10_EXP + 1 - (intmax_t) int_no, 0)) - { - __set_errno (ERANGE); - return negative ? -FLOAT_HUGE_VAL : FLOAT_HUGE_VAL; - } + return overflow_value (negative); if (__builtin_expect (exponent < MIN_10_EXP - (DIG + 1), 0)) - { - __set_errno (ERANGE); - return negative ? -0.0 : 0.0; - } + return underflow_value (negative); if (int_no > 0) { @@ -1182,10 +1209,7 @@ ____STRTOF_INTERNAL (nptr, endptr, group, loc) /* Now we know the exponent of the number in base two. Check it against the maximum possible exponent. */ if (__builtin_expect (bits > MAX_EXP, 0)) - { - __set_errno (ERANGE); - return negative ? -FLOAT_HUGE_VAL : FLOAT_HUGE_VAL; - } + return overflow_value (negative); /* We have already the first BITS bits of the result. Together with the information whether more non-zero bits follow this is enough |