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authorJoseph Myers <joseph@codesourcery.com>2014-03-29 17:22:14 +0000
committerJoseph Myers <joseph@codesourcery.com>2014-03-29 17:22:14 +0000
commitea6029b19c6004c69a9074bf399091bbfbf58a0c (patch)
treea3f2488c38c5d4438f4dc08166a287825ffb60b1
parent56737508002f1759da8d4d9944a8e98e58dce917 (diff)
downloadglibc-ea6029b19c6004c69a9074bf399091bbfbf58a0c.tar.gz
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.
-rw-r--r--ChangeLog9
-rw-r--r--NEWS2
-rw-r--r--math/e_scalb.c2
-rw-r--r--math/e_scalbf.c2
-rw-r--r--math/e_scalbl.c2
-rw-r--r--math/libm-test.inc17
6 files changed, 30 insertions, 4 deletions
diff --git a/ChangeLog b/ChangeLog
index 081bf0b6d6..5bb69dc0b2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -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.
diff --git a/NEWS b/NEWS
index b34c9fc65e..9597cbdb24 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 bddedfa032..146d49e1c3 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 319752c993..3f2e853353 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 5815a0d67b..739db7a188 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 cefcb9682a..0eff34a0ca 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),
};