From: Joseph Myers Date: Sat, 29 Mar 2014 17:22:14 +0000 (+0000) Subject: Fix scalb spurious "invalid" exceptions (bug 16770). X-Git-Tag: glibc-2.20~671 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ea6029b19c6004c69a9074bf399091bbfbf58a0c;p=thirdparty%2Fglibc.git 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. --- diff --git a/ChangeLog b/ChangeLog index 081bf0b6d6c..5bb69dc0b26 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +2014-03-29 Joseph Myers + + [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 * benchtests/Makefile (DETAILED_OPT): New make option. diff --git a/NEWS b/NEWS index b34c9fc65ec..9597cbdb24d 100644 --- a/NEWS +++ b/NEWS @@ -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, diff --git a/math/e_scalb.c b/math/e_scalb.c index bddedfa0320..146d49e1c30 100644 --- a/math/e_scalb.c +++ b/math/e_scalb.c @@ -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); diff --git a/math/e_scalbf.c b/math/e_scalbf.c index 319752c993f..3f2e853353f 100644 --- a/math/e_scalbf.c +++ b/math/e_scalbf.c @@ -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); diff --git a/math/e_scalbl.c b/math/e_scalbl.c index 5815a0d67b9..739db7a188b 100644 --- a/math/e_scalbl.c +++ b/math/e_scalbl.c @@ -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); diff --git a/math/libm-test.inc b/math/libm-test.inc index cefcb9682af..0eff34a0cab 100644 --- a/math/libm-test.inc +++ b/math/libm-test.inc @@ -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), };