Commit Graph

15 Commits

Author SHA1 Message Date
Joseph Myers
04277e02d7 Update copyright dates with scripts/update-copyrights.
* All files with FSF copyright notices: Update copyright dates
	using scripts/update-copyrights.
	* locale/programs/charmap-kw.h: Regenerated.
	* locale/programs/locfile-kw.h: Likewise.
2019-01-01 00:11:28 +00:00
Joseph Myers
fcd6b5ac36 Fix strtod overflow detection (bug 23279).
As shown by bug 23279, strtod's round_and_return has an off-by-one
error in its overflow detection, only counting an exponent greater
than MAX_EXP as overflowing when an exponent of MAX_EXP also means
overflow (recall the ISO C definition of DBL_MAX_EXP etc. is based on
a floating-point model where 2^exp is multiplied by a value in the
interval [0.5, 1), so 2^MAX_EXP is not representable).

For decimal arguments to strtod, a separate overflow check in the main
implementation covers the case where the integer part of the argument
(truncated to the nearest integer towards zero) has more than MAX_EXP
bits, meaning that this issue in round_and_return only affects cases
(arguments with absolute value strictly between the maximum
representable value and 2^MAX_EXP) where overflow depends on the
rounding mode; in such cases, the returned value would still have been
correct on overflow but without the overflow exception being raised or
errno being set to ERANGE.  For hex float arguments, however, other
cases can arise, as shown in bug 23279, where a value with exponent
already set to MAX_EXP is passed into round_and_return and a result
can wrongly end up being NaN, or infinity instead of the largest
finite value.

This patch fixes the off-by-one error, adds testing of overflow
exceptions to the tst-strtod-round framework, and adds tests of these
issues.

Tested for x86_64.  Also ran the tst-strtod-round tests for powerpc to
make sure the new tests didn't introduce any new failures for IBM long
double.

	[BZ ]
	* stdlib/strtod_l.c (round_and_return): Handle an exponent of
	MAX_EXP as overflowing.
	* stdlib/gen-tst-strtod-round.c (string_to_fp): Clear MPFR
	overflow flag.
	(round_str): Output also whether result overflows in each rounding
	mode.
	* stdlib/tst-strtod-round-data: Add more tests.
	* stdlib/tst-strtod-round-data.h: Regenerated.
	* stdlib/tst-strtod-round-skeleton.c (_XNTRY): Update comment.
	(TEST): Handle extra arguments for overflow flags.
	(struct test_overflow): New type.
	[!FE_OVERFLOW] (FE_OVERFLOW): Define to 0.
	(GEN_ONE_TEST): Clear all exceptions.  Test overflow flag.
	(test_in_one_mode): Take argument with overflow information.
	(do_test): Update calls to test_in_one_mode.
2018-06-13 16:06:14 +00:00
Joseph Myers
688903eb3e Update copyright dates with scripts/update-copyrights.
* All files with FSF copyright notices: Update copyright dates
	using scripts/update-copyrights.
	* locale/programs/charmap-kw.h: Regenerated.
	* locale/programs/locfile-kw.h: Likewise.
2018-01-01 00:32:25 +00:00
Joseph Myers
bfff8b1bec Update copyright dates with scripts/update-copyrights. 2017-01-01 00:14:16 +00:00
Joseph Myers
4725d33eed Make strtod raise "inexact" exceptions (bug 19380).
The strtod function should raise the "inexact" exception when its
result is inexact, but fails to do so except in the case of underflow
or overflow.  This patch fixes it to do so for all inexact results.

tst-strtod-round is extended to test for this exception; the generator
is fixed to properly mark inexact results as such in the case where
the inexactness is from the mpfr_subnormalize step.

Tested for x86_64, x86 and powerpc.

	[BZ ]
	* stdlib/strtod_l.c (round_and_return): Force "inexact" exception
	for inexact results.
	* stdlib/gen-tst-strtod-round.c (string_to_fp): Return indication
	of inexact result where mpfr_subnormalize is the only inexact
	step.
	* stdlib/tst-strtod-round-data.h: Regenerated.
	* stdlib/tst-strtod-round-skeleton.c [!FE_INEXACT] (FE_INEXACT):
	Define to 0.
	(GEN_ONE_TEST): Test inexact exceptions raised are as expected.
2016-10-28 00:40:23 +00:00
Paul E. Murphy
1ced34c00a Refactor tst-strtod-round.c for type-generic-ness
Reduce much of the redundancy in this file, and attempt
to coral the type specific stuff to ease adding an new type.
2016-05-25 13:33:36 -05:00
Paul E. Murphy
118fbf0e1c Refactor tst-strtod-round.c
This file is partially generated.  To make updates a little
simpler, I have moved the generated code into a partially
contained header to simplify regeneration.

gen-tst-strtod-round.c now takes two, mandatory arguments.
These arguments specify the input test data and the output
destination, respectively.
2016-05-24 14:39:57 -05:00
Joseph Myers
f7a9f785e5 Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
Joseph Myers
b168057aaa Update copyright dates with scripts/update-copyrights. 2015-01-02 16:29:47 +00:00
Allan McRae
d4697bc93d Update copyright notices with scripts/update-copyrights 2014-01-01 22:00:23 +10:00
Joseph Myers
1f24b9ad0f Rework tst-strtod-round handling of inexact results. 2013-06-13 15:41:58 +00:00
Joseph Myers
568035b787 Update copyright notices with scripts/update-copyrights. 2013-01-02 19:05:09 +00:00
Joseph Myers
ed8c2ecd21 Fix strtod test for values above maximum for IBM long double. 2012-09-06 15:33:06 +00:00
Andreas Schwab
e1343020fb Correctly handle Motorola extended float format in tst-strtod-round 2012-09-05 12:40:45 +02:00
Joseph Myers
af92131a8e Fix strtod rounding (bug 3479). 2012-08-27 16:02:07 +00:00