OpenE2K
/
glibc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Fix scalb spurious "invalid" exceptions (bug 16770). 

This patch fixes bug 16770, spurious "invalid" exceptions from scalb
when testing whether the second argument is an integer, by inserting
appropriate range checks to determine whether a cast to int is safe.
(Note that invalid_fn is a function that handles both nonintegers and
large integers, distinguishing them reliably using functions such as
__rint; note also that there are no issues with scalb needing to avoid
spurious "inexact" exceptions - it's an old-POSIX XSI function, not a
standard C function bound to an IEEE 754 operation - although the
return value is still fully determined.)

Tested x86_64 and x86.

	[BZ #16770]
	* math/e_scalb.c (__ieee754_scalb): Check second argument is not
	too large before casting to int.
	* math/e_scalbf.c (__ieee754_scalbf): Likewise.
	* math/e_scalbl.c (__ieee754_scalbl): Likewise.
	* math/libm-test.inc (scalb_test_data): Add more tests.
This commit is contained in:
Joseph Myers 2014-03-29 17:22:14 +00:00
parent 5673750800
commit ea6029b19c
6 changed files with 30 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
ChangeLog
View File

@ -1,3 +1,12 @@
2014-03-29 Joseph Myers <joseph@codesourcery.com>
[BZ #16770]
* math/e_scalb.c (__ieee754_scalb): Check second argument is not
too large before casting to int.
* math/e_scalbf.c (__ieee754_scalbf): Likewise.
* math/e_scalbl.c (__ieee754_scalbl): Likewise.
* math/libm-test.inc (scalb_test_data): Add more tests.
2014-03-29 Siddhesh Poyarekar <siddhesh@redhat.com>
* benchtests/Makefile (DETAILED_OPT): New make option.

2
NEWS
View File

@ -13,7 +13,7 @@ Version 2.20
16532, 16545, 16574, 16599, 16600, 16609, 16610, 16611, 16613, 16623,
16632, 16634, 16639, 16642, 16649, 16670, 16674, 16677, 16680, 16683,
16689, 16695, 16701, 16706, 16707, 16712, 16713, 16714, 16731, 16743,
16758, 16759, 16760.
16758, 16759, 16760, 16770.
* Running the testsuite no longer terminates as soon as a test fails.
Instead, a file tests.sum (xtests.sum from "make xcheck") is generated,

2
math/e_scalb.c
View File

@ -50,7 +50,7 @@ __ieee754_scalb (double x, double fn)
return x;
return x / -fn;
}
if (__glibc_unlikely ((double) (int) fn != fn))
if (__glibc_unlikely (fabs (fn) >= 0x1p31 || (double) (int) fn != fn))
return invalid_fn (x, fn);
return __scalbn (x, (int) fn);

2
math/e_scalbf.c
View File

@ -50,7 +50,7 @@ __ieee754_scalbf (float x, float fn)
return x;
return x / -fn;
}
if (__glibc_unlikely ((float) (int) fn != fn))
if (__glibc_unlikely (fabsf (fn) >= 0x1p31f || (float) (int) fn != fn))
return invalid_fn (x, fn);
return __scalbnf (x, (int) fn);

2
math/e_scalbl.c
View File

@ -50,7 +50,7 @@ __ieee754_scalbl (long double x, long double fn)
return x;
return x / -fn;
}
if (__glibc_unlikely ((long double) (int) fn != fn))
if (__glibc_unlikely (fabsl (fn) >= 0x1p31L || (long double) (int) fn != fn))
return invalid_fn (x, fn);
return __scalbnl (x, (int) fn);

17
math/libm-test.inc
View File

@ -9134,6 +9134,23 @@ static const struct test_ff_f_data scalb_test_data[] =
TEST_ff_f (scalb, plus_infty, qnan_value, qnan_value, NO_INEXACT_EXCEPTION),
TEST_ff_f (scalb, qnan_value, qnan_value, qnan_value, NO_INEXACT_EXCEPTION),
TEST_ff_f (scalb, max_value, max_value, plus_oflow, OVERFLOW_EXCEPTION),
TEST_ff_f (scalb, max_value, -max_value, plus_uflow, UNDERFLOW_EXCEPTION),
TEST_ff_f (scalb, 1, max_value, plus_oflow, OVERFLOW_EXCEPTION),
TEST_ff_f (scalb, 1, -max_value, plus_uflow, UNDERFLOW_EXCEPTION),
TEST_ff_f (scalb, min_value, max_value, plus_oflow, OVERFLOW_EXCEPTION),
TEST_ff_f (scalb, min_value, -max_value, plus_uflow, UNDERFLOW_EXCEPTION),
TEST_ff_f (scalb, min_subnorm_value, max_value, plus_oflow, OVERFLOW_EXCEPTION),
TEST_ff_f (scalb, min_subnorm_value, -max_value, plus_uflow, UNDERFLOW_EXCEPTION),
TEST_ff_f (scalb, -max_value, max_value, minus_oflow, OVERFLOW_EXCEPTION),
TEST_ff_f (scalb, -max_value, -max_value, minus_uflow, UNDERFLOW_EXCEPTION),
TEST_ff_f (scalb, -1, max_value, minus_oflow, OVERFLOW_EXCEPTION),
TEST_ff_f (scalb, -1, -max_value, minus_uflow, UNDERFLOW_EXCEPTION),
TEST_ff_f (scalb, -min_value, max_value, minus_oflow, OVERFLOW_EXCEPTION),
TEST_ff_f (scalb, -min_value, -max_value, minus_uflow, UNDERFLOW_EXCEPTION),
TEST_ff_f (scalb, -min_subnorm_value, max_value, minus_oflow, OVERFLOW_EXCEPTION),
TEST_ff_f (scalb, -min_subnorm_value, -max_value, minus_uflow, UNDERFLOW_EXCEPTION),
TEST_ff_f (scalb, 0.8L, 4, 12.8L),
TEST_ff_f (scalb, -0.854375L, 5, -27.34L),
};