lib/glibc
1
0
Fork 0
mirror of https://sourceware.org/git/glibc.git synced 2025-12-24 17:51:17 +03:00
Code Activity

Make strtod respect the rounding mode (bug 14518).

Browse Source
This commit is contained in:
Joseph Myers
2012-09-12 23:36:19 +00:00
parent 19fcedd5fc
commit 6c9b0f6826
12 changed files with 491 additions and 53 deletions
Download Patch File Download Diff File Expand all files Collapse all files

70
stdlib/strtod_l.c
View File

@@ -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