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Fix i386/x86_64 log2l (sNaN) (bug 20235) [committed]
- From: Joseph Myers <joseph at codesourcery dot com>
- To: <libc-alpha at sourceware dot org>
- Date: Thu, 9 Jun 2016 18:05:14 +0000
- Subject: Fix i386/x86_64 log2l (sNaN) (bug 20235) [committed]
- Authentication-results: sourceware.org; auth=none
The i386/x86_64 versions of log2l return sNaN for sNaN input. This
patch fixes them to add NaN inputs to themselves so that qNaN is
returned in this case.
Tested for x86_64 and x86. Committed.
2016-06-09 Joseph Myers <joseph@codesourcery.com>
[BZ #20235]
* sysdeps/i386/fpu/e_log2l.S (__ieee754_log2l): Add NaN input to
itself.
* sysdeps/x86_64/fpu/e_log2l.S (__ieee754_log2l): Likewise.
* math/libm-test.inc (log2_test_data): Add sNaN tests.
diff --git a/math/libm-test.inc b/math/libm-test.inc
index 4371c4c..2df6f29 100644
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -9076,6 +9076,8 @@ static const struct test_f_f_data log2_test_data[] =
TEST_f_f (log2, plus_infty, plus_infty, ERRNO_UNCHANGED),
TEST_f_f (log2, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
TEST_f_f (log2, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+ TEST_f_f (log2, snan_value, qnan_value, INVALID_EXCEPTION),
+ TEST_f_f (log2, -snan_value, qnan_value, INVALID_EXCEPTION),
AUTO_TESTS_f_f (log2),
};
diff --git a/sysdeps/i386/fpu/e_log2l.S b/sysdeps/i386/fpu/e_log2l.S
index 0f5f7e5..73e62ea 100644
--- a/sysdeps/i386/fpu/e_log2l.S
+++ b/sysdeps/i386/fpu/e_log2l.S
@@ -64,6 +64,7 @@ ENTRY(__ieee754_log2l)
3: jp 4b // in case x is ?Inf
fstp %st(1)
fstp %st(1)
+ fadd %st(0)
ret
END (__ieee754_log2l)
strong_alias (__ieee754_log2l, __log2l_finite)
diff --git a/sysdeps/x86_64/fpu/e_log2l.S b/sysdeps/x86_64/fpu/e_log2l.S
index a063255..023ec29 100644
--- a/sysdeps/x86_64/fpu/e_log2l.S
+++ b/sysdeps/x86_64/fpu/e_log2l.S
@@ -63,6 +63,7 @@ ENTRY(__ieee754_log2l)
jnz 4b // in case x is ?Inf
fstp %st(1)
fstp %st(1)
+ fadd %st(0)
ret
END (__ieee754_log2l)
--
Joseph S. Myers
joseph@codesourcery.com