Commit Graph

125 Commits

Author SHA1 Message Date
Joseph Myers
f6987f5aa4 Fix hypot missing underflows (bug 18803).
Similar to various other bugs in this area, hypot functions can fail
to raise the underflow exception when the result is tiny and inexact
but one or more low bits of the intermediate result that is scaled
down (or, in the i386 case, converted from a wider evaluation format)
are zero.  This patch forces the exception in a similar way to
previous fixes.

Note that this issue cannot arise for implementations of hypotf using
double (or wider) for intermediate evaluation (if hypotf should
underflow, that means the double square root is being computed of some
number of the form N*2^-298, for 0 < N < 2^46, which is exactly
represented as a double, and whatever the rounding mode such a square
root cannot have a mantissa with all zeroes after the initial 23
bits).  Thus no changes are made to hypotf implementations in this
patch, only to hypot and hypotl.

Tested for x86_64, x86, mips64 and powerpc.

	[BZ #18803]
	* sysdeps/i386/fpu/e_hypot.S: Use DEFINE_DBL_MIN.
	(MO): New macro.
	(__ieee754_hypot) [PIC]: Load PIC register.
	(__ieee754_hypot): Use DBL_NARROW_EVAL_UFLOW_NONNEG instead of
	DBL_NARROW_EVAL.
	* sysdeps/ieee754/dbl-64/e_hypot.c (__ieee754_hypot): Use
	math_check_force_underflow_nonneg in case where result might be
	tiny.
	* sysdeps/ieee754/ldbl-128/e_hypotl.c (__ieee754_hypotl):
	Likewise.
	* sysdeps/ieee754/ldbl-128ibm/e_hypotl.c (__ieee754_hypotl):
	Likewise.
	* sysdeps/ieee754/ldbl-96/e_hypotl.c (__ieee754_hypotl): Likewise.
	* sysdeps/powerpc/fpu/e_hypot.c (__ieee754_hypot): Likewise.
	* math/auto-libm-test-in: Add more tests of hypot.
	* math/auto-libm-test-out: Regenerated.
2015-09-24 23:43:57 +00:00
Joseph Myers
46f74e1dee Fix tgamma missing underflows (bug 18951).
Similar to various other bugs in this area, tgamma functions can fail
to raise the underflow exception when the result is tiny and inexact
but one or more low bits of the intermediate result that is scaled
down are zero.  This patch forces the exception in a similar way to
previous fixes.

Tested for x86_64, x86, mips64 and powerpc.

	[BZ #18951]
	* sysdeps/ieee754/dbl-64/e_gamma_r.c (__ieee754_gamma_r): Force
	underflow exception for small results.
	* sysdeps/ieee754/flt-32/e_gammaf_r.c (__ieee754_gammaf_r):
	Likewise.
	* sysdeps/ieee754/ldbl-128/e_gammal_r.c (__ieee754_gammal_r):
	Likewise.
	* sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c (__ieee754_gammal_r):
	Likewise.
	* sysdeps/ieee754/ldbl-96/e_gammal_r.c (__ieee754_gammal_r):
	Likewise.
	* math/auto-libm-test-in: Add more tests of tgamma.
	* math/auto-libm-test-out: Regenerated.
2015-09-17 15:51:54 +00:00
Joseph Myers
0b87419b69 Fix ctan, ctanh missing underflows (bug 18595).
Similar to various other bugs in this area, ctan and ctanh can fail to
raise the underflow exception for some cases of results that are tiny
and inexact.  This patch forces the exception in a similar way to
previous fixes.

Tested for x86_64 and x86.

	[BZ #18595]
	* math/s_ctan.c (__ctan): Force underflow exception for results
	whose real or imaginary part has small absolute value.
	* math/s_ctanf.c (__ctanf): Likewise.
	* math/s_ctanh.c (__ctanh): Likewise.
	* math/s_ctanhf.c (__ctanhf): Likewise.
	* math/s_ctanhl.c (__ctanhl): Likewise.
	* math/s_ctanl.c (__ctanl): Likewise.
	* math/auto-libm-test-in: Do not allow missing underflow for ctan
	and ctanh.  Add more tests of ctan and ctanh.
2015-09-15 17:46:08 +00:00
Joseph Myers
828bf6828b Fix i386 exp10 missing underflows (bug 18966).
On i386, the double version of exp10 can miss underflow exceptions if
the result is in the subnormal range for double but the last 11 bits
of the 64-bit extended-precision mantissa happen to be zero.  This
patch forces the exception in a similar way to previous fixes.

As with the exp2 and exp fixes, the exp10f changes may in fact not be
needed to ensure underflow exceptions, but are included for
consistency and to fix the exp10 part of bug 18875 by ensuring that
excess range and precision is removed from underflowing return values.

Tested for x86_64 and x86.

	[BZ #18875]
	[BZ #18966]
	* sysdeps/i386/fpu/e_exp10.S (dbl_min): New object.
	(MO): New macro.
	(__ieee754_exp10): For small results, force underflow exception
	and remove excess range and precision from return value.
	* sysdeps/i386/fpu/e_exp10f.S (flt_min): New object.
	(MO): New macro.
	(__ieee754_exp10f): For small results, force underflow exception
	and remove excess range and precision from return value.
	* math/auto-libm-test-in: Add more tests of exp10.
	* math/auto-libm-test-out: Regenerated.
2015-09-15 16:50:02 +00:00
Joseph Myers
de5e81691c Fix i386 exp missing underflows (bug 18961).
On i386, the double version of exp can miss underflow exceptions if
the result is in the subnormal range for double but the last 11 bits
of the 64-bit extended-precision mantissa happen to be zero.  This
patch forces the exception in a similar way to previous fixes.

As with the exp2 fixes, the expf changes may in fact not be needed to
ensure underflow exceptions, but are included for consistency and to
fix the exp part of bug 18875 by ensuring that excess range and
precision is removed from underflowing return values.

Tested for x86_64 and x86.

	[BZ #18875]
	[BZ #18961]
	* sysdeps/i386/fpu/e_exp.S (dbl_min): New object.
	(MO): New macro.
	(__ieee754_exp): For small results, force underflow exception and
	remove excess range and precision from return value.
	(__exp_finite): Likewise.
	* sysdeps/i386/fpu/e_expf.S (flt_min): New object.
	(MO): New macro.
	(__ieee754_expf): For small results, force underflow exception and
	remove excess range and precision from return value.
	(__expf_finite): Likewise.
	* math/auto-libm-test-in: Add more tests of exp.
	* math/auto-libm-test-out: Regenerated.
2015-09-14 22:40:05 +00:00
Joseph Myers
903af5af9a Fix exp2 missing underflows (bug 16521).
Various exp2 implementations in glibc can miss underflow exceptions
when the scaling down part of the calculation is exact (or, in the x86
case, when the conversion from extended precision to the target
precision is exact).  This patch forces the exception in a similar way
to previous fixes.

The x86 exp2f changes may in fact not be needed for this purpose -
it's likely to be the case that no argument of type float has an exp2
result so close to an exact subnormal float value that it equals that
value when rounded to 64 bits (even taking account of variation
between different x86 implementations).  However, they are included
for consistency with the changes to exp2 and so as to fix the exp2f
part of bug 18875 by ensuring that excess range and precision is
removed from underflowing return values.

Tested for x86_64, x86 and mips64.

	[BZ #16521]
	[BZ #18875]
	* math/e_exp2l.c (__ieee754_exp2l): Force underflow exception for
	small results.
	* sysdeps/i386/fpu/e_exp2.S (dbl_min): New object.
	(MO): New macro.
	(__ieee754_exp2): For small results, force underflow exception and
	remove excess range and precision from return value.
	* sysdeps/i386/fpu/e_exp2f.S (flt_min): New object.
	(MO): New macro.
	(__ieee754_exp2f): For small results, force underflow exception
	and remove excess range and precision from return value.
	* sysdeps/i386/fpu/e_exp2l.S (ldbl_min): New object.
	(MO): New macro.
	(__ieee754_exp2l): Force underflow exception for small results.
	* sysdeps/ieee754/dbl-64/e_exp2.c (__ieee754_exp2): Likewise.
	* sysdeps/ieee754/flt-32/e_exp2f.c (__ieee754_exp2f): Likewise.
	* sysdeps/x86_64/fpu/e_exp2l.S (ldbl_min): New object.
	(MO): New macro.
	(__ieee754_exp2l): Force underflow exception for small results.
	* math/auto-libm-test-in: Add more tests or exp2.
	* math/auto-libm-test-out: Regenerated.
2015-09-14 22:00:12 +00:00
Joseph Myers
a1f99ba28b Add more random libm test inputs (mainly for ldbl-128).
This patch adds more libm test inputs found through random test
generation to increase previously known ulps.  This particular test
generation was run for mips64, so most of the increased ulps are for
ldbl-128 (float and double having been fairly well covered by such
testing for x86_64), but there's the odd ulps increase for other
formats.

Tested for x86_64, x86 and mips64.

	* math/auto-libm-test-in: Add more tests of acos, acosh, asin,
	asinh, atan, atan2, atanh, cabs, carg, cos, csqrt, erfc, exp,
	exp10, exp2, log, log1p, log2, pow, sin, sincos, sinh, tan and
	tanh.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/mips/mips32/libm-test-ulps: Likewise.
	* sysdeps/mips/mips64/libm-test-ulps: Likewise.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2015-09-12 00:01:38 +00:00
Joseph Myers
9bb69b60fa Fix ldbl-128/ldbl-128ibm lgamma spurious "invalid", incorrect signgam (bug 18952).
The ldbl-128 / ldbl-128ibm implementation of lgammal converts (the
floor of minus) non-integer negative arguments to int to determine the
value of signgam.  When those values are outside the range of int,
this produces spurious "invalid" exceptions and incorrect values of
signgam.  This patch fixes this by instead determining signgam through
comparing half the integer in question to floor of half the integer.

Tested for mips64, x86_64 and x86.

	[BZ #18952]
	* sysdeps/ieee754/ldbl-128/e_lgammal_r.c (__ieee754_lgammal_r): Do
	not convert non-integer negative arguments to int to determine the
	value of signgam.
	* math/auto-libm-test-in: Add more tests of lgamma.
	* math/auto-libm-test-out: Regenerated.
2015-09-11 15:34:25 +00:00
Joseph Myers
00a7073c38 Add more randomly-generated libm tests.
This patch adds more libm test inputs found through random test
generation to increase observed ulps on x86_64.

Tested for x86_64 and x86.

	* math/auto-libm-test-in: Add more tests of acosh, atanh, cbrt,
	cosh, csqrt, erfc, expm1 and lgamma.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2015-09-11 15:03:10 +00:00
Joseph Myers
050f29c188 Fix lgamma (negative) inaccuracy (bug 2542, bug 2543, bug 2558).
The existing implementations of lgamma functions (except for the ia64
versions) use the reflection formula for negative arguments.  This
suffers large inaccuracy from cancellation near zeros of lgamma (near
where the gamma function is +/- 1).

This patch fixes this inaccuracy.  For arguments above -2, there are
no zeros and no large cancellation, while for sufficiently large
negative arguments the zeros are so close to integers that even for
integers +/- 1ulp the log(gamma(1-x)) term dominates and cancellation
is not significant.  Thus, it is only necessary to take special care
about cancellation for arguments around a limited number of zeros.

Accordingly, this patch uses precomputed tables of relevant zeros,
expressed as the sum of two floating-point values.  The log of the
ratio of two sines can be computed accurately using log1p in cases
where log would lose accuracy.  The log of the ratio of two gamma(1-x)
values can be computed using Stirling's approximation (the difference
between two values of that approximation to lgamma being computable
without computing the two values and then subtracting), with
appropriate adjustments (which don't reduce accuracy too much) in
cases where 1-x is too small to use Stirling's approximation directly.

In the interval from -3 to -2, using the ratios of sines and of
gamma(1-x) can still produce too much cancellation between those two
parts of the computation (and that interval is also the worst interval
for computing the ratio between gamma(1-x) values, which computation
becomes more accurate, while being less critical for the final result,
for larger 1-x).  Because this can result in errors slightly above
those accepted in glibc, this interval is instead dealt with by
polynomial approximations.  Separate polynomial approximations to
(|gamma(x)|-1)(x-n)/(x-x0) are used for each interval of length 1/8
from -3 to -2, where n (-3 or -2) is the nearest integer to the
1/8-interval and x0 is the zero of lgamma in the relevant half-integer
interval (-3 to -2.5 or -2.5 to -2).

Together, the two approaches are intended to give sufficient accuracy
for all negative arguments in the problem range.  Outside that range,
the previous implementation continues to be used.

Tested for x86_64, x86, mips64 and powerpc.  The mips64 and powerpc
testing shows up pre-existing problems for ldbl-128 and ldbl-128ibm
with large negative arguments giving spurious "invalid" exceptions
(exposed by newly added tests for cases this patch doesn't affect the
logic for); I'll address those problems separately.

	[BZ #2542]
	[BZ #2543]
	[BZ #2558]
	* sysdeps/ieee754/dbl-64/e_lgamma_r.c (__ieee754_lgamma_r): Call
	__lgamma_neg for arguments from -28.0 to -2.0.
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c (__ieee754_lgammaf_r): Call
	__lgamma_negf for arguments from -15.0 to -2.0.
	* sysdeps/ieee754/ldbl-128/e_lgammal_r.c (__ieee754_lgammal_r):
	Call __lgamma_negl for arguments from -48.0 or -50.0 to -2.0.
	* sysdeps/ieee754/ldbl-96/e_lgammal_r.c (__ieee754_lgammal_r):
	Call __lgamma_negl for arguments from -33.0 to -2.0.
	* sysdeps/ieee754/dbl-64/lgamma_neg.c: New file.
	* sysdeps/ieee754/dbl-64/lgamma_product.c: Likewise.
	* sysdeps/ieee754/flt-32/lgamma_negf.c: Likewise.
	* sysdeps/ieee754/flt-32/lgamma_productf.c: Likewise.
	* sysdeps/ieee754/ldbl-128/lgamma_negl.c: Likewise.
	* sysdeps/ieee754/ldbl-128/lgamma_productl.c: Likewise.
	* sysdeps/ieee754/ldbl-128ibm/lgamma_negl.c: Likewise.
	* sysdeps/ieee754/ldbl-128ibm/lgamma_productl.c: Likewise.
	* sysdeps/ieee754/ldbl-96/lgamma_negl.c: Likewise.
	* sysdeps/ieee754/ldbl-96/lgamma_product.c: Likewise.
	* sysdeps/ieee754/ldbl-96/lgamma_productl.c: Likewise.
	* sysdeps/generic/math_private.h (__lgamma_negf): New prototype.
	(__lgamma_neg): Likewise.
	(__lgamma_negl): Likewise.
	(__lgamma_product): Likewise.
	(__lgamma_productl): Likewise.
	* math/Makefile (libm-calls): Add lgamma_neg and lgamma_product.
	* math/auto-libm-test-in: Add more tests of lgamma.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2015-09-10 22:27:58 +00:00
Joseph Myers
948e12a238 Fix csqrt missing underflows (bug 18370).
The csqrt implementations in glibc can miss underflow exceptions when
the real or imaginary part of the result becomes tiny in the course of
scaling down (in particular, multiplication by 0.5) and that scaling
is exact although the relevant part of the mathematical result isn't.
This patch forces the exception in a similar way to previous fixes.

Tested for x86_64 and x86.

	[BZ #18370]
	* math/s_csqrt.c (__csqrt): Force underflow exception for results
	whose real or imaginary part has small absolute value.
	* math/s_csqrtf.c (__csqrtf): Likewise.
	* math/s_csqrtl.c (__csqrtl): Likewise.
	* math/auto-libm-test-in: Add more tests of csqrt.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
2015-08-19 22:42:01 +00:00
Joseph Myers
3fb4cfaf1f Fix csqrt spurious underflows (bug 18823).
The csqrt functions scale up small arguments to avoid underflows when
calling hypot functions.  However, even when hypot does not underflow,
a subsequent calculation of 0.5 * hypot can underflow.  This patch
duly increases the threshold and scale factor to avoid such underflows
as well.

Tested for x86_64, x86 and mips64.

	[BZ #18823]
	* math/s_csqrt.c (__csqrt): Increase threshold and scale factor
	for scaling up small arguments.
	* math/s_csqrtf.c (__csqrtf): Likewise.
	* math/s_csqrtl.c (__csqrtl): Likewise.
	* math/auto-libm-test-in: Add more tests of csqrt.
	* math/auto-libm-test-out: Regenerated.
2015-08-17 23:02:54 +00:00
Joseph Myers
739babd775 Fix fma spurious underflows (bug 18824).
Various fma implementations have logic that, when computing fma (x, y,
z) where z is large (so care needs taking to avoid internal overflow)
but x * y is small, scale x * y up instead of down to avoid internal
underflows resulting from scaling down.  (In these cases, x * y is
small enough that only its sign actually matters rather than the exact
value.)

The threshold for scaling up instead of down was correct for "if the
unscaled values were multiplied, the low part of the multiplication
could underflow", and the scaling was sufficient to ensure that the
low part of the multiplication did not underflow (given that cases of
very small x * y - less than half the least subnormal - were
previously dealt with).  However, the choice in the functions wasn't
between scaling up or no scaling, but between scaling up and scaling
down (scaling down actually being needed when x * y isn't so small
compared to z and so the exact value does matter).  Thus a larger
threshold is needed to ensure that scaling down doesn't produce values
the multiplication of whose low parts underflows.  This patch
increases the thresholds accordingly.

Tested for x86_64, x86 and mips64 (with the MIPS version of s_fmal.c
removed so that the ldbl-128 version gets tested instead of the
soft-fp one).

	[BZ #18824]
	* sysdeps/ieee754/dbl-64/s_fma.c (__fma): Increase threshold for
	scaling x * y up instead of down.
	* sysdeps/ieee754/ldbl-128/s_fmal.c (__fmal): Likewise.
	* sysdeps/ieee754/ldbl-96/s_fmal.c (__fmal): Likewise.
	* math/auto-libm-test-in: Add more tests of fma.
	* math/auto-libm-test-out: Regenerated.
2015-08-14 17:15:06 +00:00
Joseph Myers
3ba0ac10fa Add more random libm-test inputs.
This patch adds more test inputs to various libm functions found
through random generation to have larger ulps errors than previously
listed in libm-test-ulp, on at least one of x86_64 and x86.

Tested for x86_64 and x86.

	* math/auto-libm-test-in: Add more tests of acos, acosh, asin,
	asinh, atan, atan2, atanh, cabs, cbrt, cosh, csqrt, erf, erfc,
	exp, exp2, lgamma, log, log1p, log2, pow, sin, sincos, tan, tanh
	and tgamma.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2015-08-13 23:23:23 +00:00
Joseph Myers
37d83a089d Fix tanh missing underflows (bug 16520).
Similar to various other bugs in this area, some tanh implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact.  This patch forces the exception in a
similar way to previous fixes.

Tested for x86_64, x86, mips64 and powerpc.

	[BZ #16520]
	* sysdeps/ieee754/dbl-64/s_tanh.c: Include <float.h>.
	(__tanh): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/flt-32/s_tanhf.c: Include <float.h>.
	(__tanhf): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/ldbl-128/s_tanhl.c: Include <float.h>.
	(__tanhl): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/ldbl-128ibm/s_tanhl.c: Include <float.h>.
	(__tanhl): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/ldbl-96/s_tanhl.c: Include <float.h>.
	(__tanhl): Force underflow exception for arguments with small
	absolute value.
	* math/auto-libm-test-in: Add more tests of tanh.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
2015-08-13 16:40:39 +00:00
Joseph Myers
4afe4b20ce Add more tests of various libm functions.
This patch adds more tests of various libm functions found through
random test generation to give increased ulps on 32-bit x86.

Tested for x86_64 and x86.

	* math/auto-libm-test-in: Add more tests of acosh, asin, asinh,
	atanh, cabs, carg, cbrt, cosh, csqrt, erf, erfc, exp, exp10,
	expm1, hypot, log, log10, log1p, log2, pow, sinh, tan and tgamma.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2015-08-11 00:58:28 +00:00
Joseph Myers
7ee06ef158 Fix ldbl-128ibm tanhl inaccuracy (bug 18790).
ldbl-128ibm tanhl uses a too-small threshold to decide when to return
+/-1, resulting in large errors.  This patch changes it to a more
appropriate threshold (the requirement is for 2*exp(-2|x|) to be small
in terms of ulps of 1).

Tested for x86_64, x86 and powerpc.

	[BZ #18790]
	* sysdeps/ieee754/ldbl-128ibm/s_tanhl.c (__tanhl): Increase
	threshold for returning +/- 1.
	* math/auto-libm-test-in: Add more tests of tanh.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
2015-08-10 20:35:30 +00:00
Joseph Myers
d0649b2d8e Fix ldbl-128ibm sinhl inaccuracy near 0 (bug 18789).
ldbl-128ibm sinhl uses a too-big threshold to decide when to return
the argument, resulting in large errors.  This patch fixes it to use a
more appropriate threshold.

Tested for x86_64, x86 and powerpc.

	[BZ #18789]
	* sysdeps/ieee754/ldbl-128ibm/e_sinhl.c (__ieee754_sinhl): Use
	smaller threshold for returning the argument.
	* math/auto-libm-test-in: Add more tests of sinh.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
2015-08-10 15:25:10 +00:00
Joseph Myers
37550cb3d6 Fix tan missing underflows (bug 16517).
Similar to various other bugs in this area, some tan implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact.  This patch forces the exception in a
similar way to previous fixes.

Tested for x86_64, x86, mips64 and powerpc.

	[BZ #16517]
	* sysdeps/ieee754/dbl-64/s_tan.c: Include <float.h>.
	(tan): Force underflow exception for arguments with small absolute
	value.
	* sysdeps/ieee754/flt-32/k_tanf.c: Include <float.h>.
	(__kernel_tanf): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/ldbl-128/k_tanl.c: Include <float.h>.
	(__kernel_tanl): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/ldbl-128ibm/k_tanl.c: Include <float.h>.
	(__kernel_tanl): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/ldbl-96/k_tanl.c: Include <float.h>.
	(__kernel_tanl): Force underflow exception for arguments with
	small absolute value.
	* math/auto-libm-test-in: Add more tests of tan.
	* math/auto-libm-test-out: Regenerated.
2015-08-07 23:10:35 +00:00
Joseph Myers
5e29dd5737 Fix sinh missing underflows (bug 16519).
Similar to various other bugs in this area, some sinh implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact.  This patch forces the exception in a
similar way to previous fixes.

Tested for x86_64, x86, mips64 and powerpc.

	[BZ #16519]
	* sysdeps/ieee754/dbl-64/e_sinh.c: Include <float.h>.
	(__ieee754_sinh): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/flt-32/e_sinhf.c: Include <float.h>.
	(__ieee754_sinhf): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/ldbl-128/e_sinhl.c: Include <float.h>.
	(__ieee754_sinhl): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/ldbl-128ibm/e_sinhl.c: Include <float.h>.
	(__ieee754_sinhl): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/ldbl-96/e_sinhl.c: Include <float.h>.
	(__ieee754_sinhl): Force underflow exception for arguments with
	small absolute value.
	* math/auto-libm-test-in: Add more tests of sinh.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
2015-08-06 23:01:09 +00:00
Joseph Myers
cf36e5034f Fix powf (close to -1, large) (bug 18647).
The flt-32 implementation of powf wrongly uses x-1 instead of |x|-1
when computing log (x) for the case where |x| is close to 1 and y is
large.  This patch fixes the logic accordingly.  Relevant tests
existed for x close to 1, and corresponding tests are added for x
close to -1, as well as for some new variant cases.

Tested for x86_64 and x86.

	[BZ #18647]
	* sysdeps/ieee754/flt-32/e_powf.c (__ieee754_powf): For large y
	and |x| close to 1, use absolute value of x when computing log.
	* math/auto-libm-test-in: Add more tests of pow.
	* math/auto-libm-test-out: Regenerated.
2015-08-05 15:01:58 +00:00
Joseph Myers
e02920bc02 Improve tgamma accuracy (bug 18613).
In non-default rounding modes, tgamma can be slightly less accurate
than permitted by glibc's accuracy goals.

Part of the problem is error accumulation, addressed in this patch by
setting round-to-nearest for internal computations.  However, there
was also a bug in the code dealing with computing pow (x + n, x + n)
where x + n is not exactly representable, providing another source of
error even in round-to-nearest mode; it was necessary to address both
bugs to get errors for all testcases within glibc's accuracy goals.
Given this second fix, accuracy in round-to-nearest mode is also
improved (hence regeneration of ulps for tgamma should be from scratch
- truncate libm-test-ulps or at least remove existing tgamma entries -
so that the expected ulps can be reduced).

Some additional complications also arose.  Certain tgamma tests should
strictly, according to IEEE semantics, overflow or not depending on
the rounding mode; this is beyond the scope of glibc's accuracy goals
for any function without exactly-determined results, but
gen-auto-libm-tests doesn't handle being lax there as it does for
underflow.  (libm-test.inc also doesn't handle being lax about whether
the result in cases very close to the overflow threshold is infinity
or a finite value close to overflow, but that doesn't cause problems
in this case though I've seen it cause problems with random test
generation for some functions.)  Thus, spurious-overflow markings,
with a comment, are added to auto-libm-test-in (no bug in Bugzilla
because the issue is with the testsuite, not a user-visible bug in
glibc).  And on x86, after the patch I saw ERANGE issues as previously
reported by Carlos (see my commentary in
<https://sourceware.org/ml/libc-alpha/2015-01/msg00485.html>), which
needed addressing by ensuring excess range and precision were
eliminated at various points if FLT_EVAL_METHOD != 0.

I also noticed and fixed a cosmetic issue where 1.0f was used in long
double functions and should have been 1.0L.

This completes the move of all functions to testing in all rounding
modes with ALL_RM_TEST, so gen-libm-have-vector-test.sh is updated to
remove the workaround for some functions not using ALL_RM_TEST.

Tested for x86_64, x86, mips64 and powerpc.

	[BZ #18613]
	* sysdeps/ieee754/dbl-64/e_gamma_r.c (gamma_positive): Take log of
	X_ADJ not X when adjusting exponent.
	(__ieee754_gamma_r): Do intermediate computations in
	round-to-nearest then adjust overflowing and underflowing results
	as needed.
	* sysdeps/ieee754/flt-32/e_gammaf_r.c (gammaf_positive): Take log
	of X_ADJ not X when adjusting exponent.
	(__ieee754_gammaf_r): Do intermediate computations in
	round-to-nearest then adjust overflowing and underflowing results
	as needed.
	* sysdeps/ieee754/ldbl-128/e_gammal_r.c (gammal_positive): Take
	log of X_ADJ not X when adjusting exponent.
	(__ieee754_gammal_r): Do intermediate computations in
	round-to-nearest then adjust overflowing and underflowing results
	as needed.  Use 1.0L not 1.0f as numerator of division.
	* sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c (gammal_positive): Take
	log of X_ADJ not X when adjusting exponent.
	(__ieee754_gammal_r): Do intermediate computations in
	round-to-nearest then adjust overflowing and underflowing results
	as needed.  Use 1.0L not 1.0f as numerator of division.
	* sysdeps/ieee754/ldbl-96/e_gammal_r.c (gammal_positive): Take log
	of X_ADJ not X when adjusting exponent.
	(__ieee754_gammal_r): Do intermediate computations in
	round-to-nearest then adjust overflowing and underflowing results
	as needed.  Use 1.0L not 1.0f as numerator of division.
	* math/libm-test.inc (tgamma_test_data): Remove one test.  Moved
	to auto-libm-test-in.
	(tgamma_test): Use ALL_RM_TEST.
	* math/auto-libm-test-in: Add one test of tgamma.  Mark some other
	tests of tgamma with spurious-overflow.
	* math/auto-libm-test-out: Regenerated.
	* math/gen-libm-have-vector-test.sh: Do not check for START.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2015-06-29 23:29:35 +00:00
Joseph Myers
4aa10d01b6 Fix ldbl-128 j1l spurious underflows (bug 18612).
The ldbl-128 implementation of j1l produces spurious underflow
exceptions for some small arguments, as a result of squaring the
argument.  This patch fixes it just to use a linear approximation for
sufficiently small arguments, and then to force an underflow exception
only in the cases where it is required.

Tested for mips64.

	[BZ #18612]
	* sysdeps/ieee754/ldbl-128/e_j1l.c (__ieee754_j1l): For small
	arguments, just return 0.5 times the argument, with underflow
	forced as needed.
	* math/auto-libm-test-in: Add more tests of j1.
	* math/auto-libm-test-out: Regenerated.
2015-06-29 17:51:32 +00:00
Joseph Myers
63dbe5f322 Fix j1, jn missing underflows (bug 16559).
Similar to various other bugs in this area, j1 and jn implementations
can fail to raise the underflow exception when the internal
computation is exact although the actual function is inexact.  This
patch forces the exception in a similar way to other such fixes.  (The
ldbl-128 / ldbl-128ibm j1l implementation is different and doesn't
need a change for this until spurious underflows in it are fixed.)

Tested for x86_64, x86, mips64 and powerpc.

	[BZ #16559]
	* sysdeps/ieee754/dbl-64/e_j1.c: Include <float.h>.
	(__ieee754_j1): Force underflow exception for small results.
	* sysdeps/ieee754/dbl-64/e_jn.c (__ieee754_jn): Likewise.
	* sysdeps/ieee754/flt-32/e_j1f.c: Include <float.h>.
	(__ieee754_j1f): Force underflow exception for small results.
	* sysdeps/ieee754/flt-32/e_jnf.c (__ieee754_jnf): Likewise.
	* sysdeps/ieee754/ldbl-128/e_jnl.c (__ieee754_jnl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/e_jnl.c (__ieee754_jnl): Likewise.
	* sysdeps/ieee754/ldbl-96/e_j1l.c: Include <float.h>.
	(__ieee754_j1l): Force underflow exception for small results.
	* sysdeps/ieee754/ldbl-96/e_jnl.c (__ieee754_jnl): Likewise.
	* math/auto-libm-test-in: Add more tests of j1 and jn.
	* math/auto-libm-test-out: Regenerated.
2015-06-29 16:52:16 +00:00
Joseph Myers
a67894c505 Fix cexp, ccos, ccosh, csin, csinh spurious underflows (bug 18594).
cexp, ccos, ccosh, csin and csinh have spurious underflows in cases
where they compute sin of the smallest normal, that produces an
underflow exception (depending on which sin implementation is in use)
but the final result does not underflow.  ctan and ctanh may also have
such underflows, or they may be latent (the issue there is that
e.g. ctan (DBL_MIN) should, rounded upwards, be the next double value
above DBL_MIN, which under glibc's accuracy goals may not have an
underflow exception, but the intermediate computation of sin (DBL_MIN)
would legitimately underflow on before-rounding architectures).

This patch fixes all those functions so they use plain comparisons (>
DBL_MIN etc.) instead of comparing the result of fpclassify with
FP_SUBNORMAL (in all these cases, we already know the number being
compared is finite).  Note that in the case of csin / csinf / csinl,
there is no need for fabs calls in the comparison because the real
part has already been reduced to its absolute value.

As the patch fixes the failures that previously obstructed moving
tests of cexp to use ALL_RM_TEST, those tests are moved to ALL_RM_TEST
by the patch (two functions remain yet to be converted).

Tested for x86_64 and x86 and ulps updated accordingly.

	[BZ #18594]
	* math/s_ccosh.c (__ccosh): Compare with least normal value
	instead of comparing class with FP_SUBNORMAL.
	* math/s_ccoshf.c (__ccoshf): Likewise.
	* math/s_ccoshl.c (__ccoshl): Likewise.
	* math/s_cexp.c (__cexp): Likewise.
	* math/s_cexpf.c (__cexpf): Likewise.
	* math/s_cexpl.c (__cexpl): Likewise.
	* math/s_csin.c (__csin): Likewise.
	* math/s_csinf.c (__csinf): Likewise.
	* math/s_csinh.c (__csinh): Likewise.
	* math/s_csinhf.c (__csinhf): Likewise.
	* math/s_csinhl.c (__csinhl): Likewise.
	* math/s_csinl.c (__csinl): Likewise.
	* math/s_ctan.c (__ctan): Likewise.
	* math/s_ctanf.c (__ctanf): Likewise.
	* math/s_ctanh.c (__ctanh): Likewise.
	* math/s_ctanhf.c (__ctanhf): Likewise.
	* math/s_ctanhl.c (__ctanhl): Likewise.
	* math/s_ctanl.c (__ctanl): Likewise.
	* math/auto-libm-test-in: Add more tests of ccos, ccosh, cexp,
	csin, csinh, ctan and ctanh.
	* math/auto-libm-test-out: Regenerated.
	* math/libm-test.inc (cexp_test): Use ALL_RM_TEST.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2015-06-24 21:04:51 +00:00
Joseph Myers
6f874bd4d4 Move csin, csinh tests to auto-libm-test-in.
This patch moves most tests of csin and csinh with finite inputs from
libm-test.inc to auto-libm-test-in.  The remaining two tests of each
function with small arguments are not moved because moving them causes
the time required by gen-auto-libm-tests to go up from under 8 seconds
to over 11 minutes for me.  (The current development version of MPC
has had speed improvements for mpc_sin for some time, but there hasn't
been a release containing those improvements yet.)

Tested for x86_64 and x86.

	* math/auto-libm-test-in: Add more tests of csin and csinh.
	* math/auto-libm-test-out: Regenerated.
	* math/libm-test.inc (csin_test_data): Remove tests moved to
	auto-libm-test-in.
	(csinh_test_data): Likewise.
2015-06-24 16:37:44 +00:00
Joseph Myers
ac831b362a Fix csin, csinh overflow in directed rounding modes (bug 18593).
csin and csinh can produce bad results when overflowing in directed
rounding modes, because a multiplication that can overflow is followed
by a possible negation.  This patch fixes this by negating one of the
arguments of the multiplication before the multiplication instead of
negating the result.

The new tests for this issue are added to auto-libm-test-in, starting
use of that file for csin and csinh.  The issue was found in the
course of moving existing tests for csin and csinh (existing tests, by
being enabled in more cases than previously, showed the issue for
float and double but not for long double); that move will now be done
separately.

Tested for x86_64 and x86 and ulps updated accordingly.

	[BZ #18593]
	* math/s_csin.c (__csin): Negate before rather than after possibly
	overflowing multiplication.
	* math/s_csinf.c (__csinf): Likewise.
	* math/s_csinh.c (__csinh): Likewise.
	* math/s_csinhf.c (__csinhf): Likewise.
	* math/s_csinhl.c (__csinhl): Likewise.
	* math/s_csinl.c (__csinl): Likewise.
	* math/auto-libm-test-in: Add some tests of csin and csinh.
	* math/auto-libm-test-out: Regenerated.
	* math/libm-test.inc (csin_test_data): Use AUTO_TESTS_c_c.
	(csinh_test_data): Likewise.
	* sysdeps/x86_64/fpu/libm-test-ulps: Update.
2015-06-24 16:20:48 +00:00
Joseph Myers
ad39cce0da Fix sin, sincos missing underflows (bug 16526, bug 16538).
Similar to various other bugs in this area, some sin and sincos
implementations do not raise the underflow exception for subnormal
arguments, when the result is tiny and inexact.  This patch forces the
exception in a similar way to previous fixes.

Tested for x86_64, x86, mips64 and powerpc.

	[BZ #16526]
	[BZ #16538]
	* sysdeps/ieee754/dbl-64/s_sin.c: Include <float.h>.
	(__sin): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/flt-32/k_sinf.c: Include <float.h>.
	(__kernel_sinf): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/ldbl-128/k_sincosl.c: Include <float.h>.
	(__kernel_sincosl): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/ldbl-128/k_sinl.c: Include <float.h>.
	(__kernel_sinl): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/ldbl-128ibm/k_sincosl.c: Include <float.h>.
	(__kernel_sincosl): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/ldbl-128ibm/k_sinl.c: Include <float.h>.
	(__kernel_sinl): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/ieee754/ldbl-96/k_sinl.c: Include <float.h>.
	(__kernel_sinl): Force underflow exception for arguments with
	small absolute value.
	* sysdeps/powerpc/fpu/k_sinf.c: Include <float.h>.
	(__kernel_sinf): Force underflow exception for arguments with
	small absolute value.
	* math/auto-libm-test-in: Add more tests of sin and sincos.
	* math/auto-libm-test-out: Regenerated.
2015-06-23 22:24:20 +00:00
Joseph Myers
718d34a309 Fix csqrt spurious underflows (bug 18371).
The csqrt implementations in glibc can cause spurious underflows in
some cases as a side-effect of the scaling for large arguments (when
underflow is correct for the square root of the argument that was
scaled down to avoid overflow, but not for the original argument).
This patch arranges to avoid the underflowing intermediate computation
(eliminating a multiplication in 0.5 in the problem cases where a
subsequent scaling by 2 would follow).

Tested for x86_64 and x86 and ulps updated accordingly (only needed
for x86).

	[BZ #18371]
	* math/s_csqrt.c (__csqrt): Avoid multiplication by 0.5 where
	intermediate but not final result might underflow.
	* math/s_csqrtf.c (__csqrtf): Likewise.
	* math/s_csqrtl.c (__csqrtl): Likewise.
	* math/auto-libm-test-in: Add more tests of csqrt.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
2015-06-23 16:01:54 +00:00
Joseph Myers
b59549574e Fix exp2, exp2f spurious underflows (bug 18219).
The dbl-64 and flt-32 implementations of exp2 functions produce
spurious underflow exceptions.  The underlying reason is the same in
both cases: the computation works as (2^a - 1)*2^b + 2^b for suitably
chosen a and b, where a has small magnitude so 2^a - 1 can be computed
with a low-degree polynomial approximation, and (2^a - 1)*2^b can
underflow even when the final result does not.  This patch fixes this
by adjusting the threshold for when scaling is used to avoid
intermediate underflow so it works for any possible value of a where
the final result would not underflow.

Tested for x86_64 and x86.

	[BZ #18219]
	* sysdeps/ieee754/dbl-64/e_exp2.c (__ieee754_exp2): Reduce
	threshold on absolute value of exponent for which scaling is used.
	* sysdeps/ieee754/flt-32/e_exp2f.c (__ieee754_exp2f): Likewise.
	* math/auto-libm-test-in: Add more tests of exp2.
	* math/auto-libm-test-out: Regenerated.
2015-06-23 14:35:18 +00:00
Joseph Myers
554edb23ff Fix expm1 missing underflows (bug 16353).
Similar to various other bugs in this area, some expm1 implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact.  This patch forces the exception in a
similar way to previous fixes.

(The issue does not apply to the ldbl-* implementations or to those
for x86 / x86_64 long double.  The change to
sysdeps/ieee754/dbl-64/wordsize-64/e_cosh.c is one I missed when
previously fixing bug 16354; the bug in that implementation was
previously latent, but the expm1 fixes stopped it being latent and so
required it to be fixed to avoid spurious underflows from cosh.)

Tested for x86_64 and x86.

	[BZ #16353]
	* sysdeps/i386/fpu/s_expm1.S (dbl_min): New object.
	(__expm1): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/i386/fpu/s_expm1f.S (flt_min): New object.
	(__expm1f): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/dbl-64/s_expm1.c: Include <float.h>.
	(__expm1): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/flt-32/s_expm1f.c: Include <float.h>.
	(__expm1f): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/dbl-64/wordsize-64/e_cosh.c (__ieee754_cosh):
	Check for small arguments before calling __expm1.
	* math/auto-libm-test-in: Do not mark underflow exceptions as
	possibly missing for bug 16353.
	* math/auto-libm-test-out: Regenerated.
2015-06-22 21:06:19 +00:00
Joseph Myers
cb0937b299 Fix x86_64 / x86 expm1l (-min_subnorm) result sign (bug 18569).
In the x86 / x86_64 implementations of expm1l, when expm1l's result
should underflow to 0 (argument minus the least subnormal, in some
rounding modes), it can be a zero of the wrong sign.  This patch fixes
this by returning the argument with underflow forced in that case
(this is a 1ulp error relative to the correctly rounded result of -0,
which is OK in terms of the documented accuracy goals, whereas a
result with the wrong sign never is).

Tested for x86_64 and x86.

	[BZ #18569]
	* sysdeps/i386/fpu/e_expl.S (IEEE754_EXPL) [USE_AS_EXPM1L]: Force
	underflow and return argument in case of subnormal argument.
	* sysdeps/x86_64/fpu/e_expl.S (IEEE754_EXPL) [USE_AS_EXPM1L]:
	Likewise.
	* math/auto-libm-test-in: Add more tests of expm1.
	* math/auto-libm-test-out: Regenerated.
2015-06-21 18:43:10 +00:00
Joseph Myers
7540cfc5a8 Fix x86 / x86_64 expl, exp10l missing underflows (bug 16361).
Similar to various other bugs in this area, the x86 and x86_64
implementations of expl / exp10l can fail to produce underflow
exceptions when the unscaled result has trailing 0 bits so the scaling
down to subnormal precision is exact.  This patch fixes this by
forcing the exception in the case of tiny results.

Tested for x86_64 and x86.

	[BZ #16361]
	* sysdeps/i386/fpu/e_expl.S [!USE_AS_EXPM1L] (cmin): New object.
	[!USE_AS_EXPM1L] (IEEE754_EXPL): Force underflow exception for
	tiny results.
	* sysdeps/x86_64/fpu/e_expl.S [!USE_AS_EXPM1L] (cmin): New object.
	[!USE_AS_EXPM1L] (IEEE754_EXPL): Force underflow exception for
	tiny results.
	* math/auto-libm-test-in: Add more tests of exp and exp10.  Do not
	mark underflow exceptions as possibly missing for bug 16361.
	* math/auto-libm-test-out: Regenerated.
2015-06-21 17:48:04 +00:00
Joseph Myers
8db3cdefef Fix asinh missing underflows (bug 16350).
Similar to various other bugs in this area, some asinh implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact.  This patch forces the exception in a
similar way to previous fixes.

Tested for x86_64, x86 and mips64.

	[BZ #16350]
	* sysdeps/i386/fpu/s_asinh.S (__asinh): Force underflow exception
	for arguments with small absolute value.
	* sysdeps/i386/fpu/s_asinhf.S (__asinhf): Likewise.
	* sysdeps/i386/fpu/s_asinhl.S (__asinhl): Likewise.
	* sysdeps/ieee754/dbl-64/s_asinh.c: Include <float.h>.
	(__asinh): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/flt-32/s_asinhf.c: Include <float.h>.
	(__asinhf): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/ldbl-128/s_asinhl.c: Include <float.h>.
	(__asinhl): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/ldbl-128ibm/s_asinhl.c: Include <float.h>.
	(__asinhl): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/ldbl-96/s_asinhl.c: Include <float.h>.
	(__asinhl): Force underflow exception for arguments with small
	absolute value.
	* math/auto-libm-test-in: Do not mark underflow exceptions as
	possibly missing for bug 16350.
	* math/auto-libm-test-out: Regenerated.
2015-06-18 23:27:41 +00:00
Joseph Myers
a1ee4fd106 Remove stray spurious-underflow markings from cexp test.
I noticed that I'd left a spurious-underflow allowance behind in
auto-libm-test-in for a bug that was fixed some time ago.  This patch
removes it.

Tested for x86_64 and x86.

	* math/auto-libm-test-in: Remove spurious underflow allowance for
	tests of cexp.
	* math/auto-libm-test-out: Regenerated.
2015-06-18 20:51:17 +00:00
Joseph Myers
526af54142 Fix i386 atanhl spurious underflows (bug 18049).
The i386 implementation of atanhl, for small arguments, does a
calculation that involves computing twice the square of the argument,
resulting in spurious underflows for some arguments.  This patch fixes
this by just returning the argument when its exponent is below -32,
with underflow being forced as needed for subnormal arguments.

Tested for x86 and x86_64.

	[BZ #18049]
	* sysdeps/i386/fpu/e_atanhl.S (__ieee754_atanhl): For exponents
	below -32, return the argument, with underflow if subnormal.
	* math/auto-libm-test-in: Add more tests of atanh.
	* math/auto-libm-test-out: Regenerated.
2015-05-19 23:05:22 +00:00
Joseph Myers
8020a80887 Fix atanhl missing underflows (bug 16352).
Similar to various other bugs in this area, some atanh implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact.  This patch forces the exception in a
similar way to previous fixes.  (No change in this regard is needed
for the i386 implementation; special handling to force underflows in
these cases will only be needed there when the spurious underflows,
bug 18049, get fixed.)

Tested for x86_64, x86, powerpc and mips64.

	[BZ #16352]
	* sysdeps/i386/fpu/e_atanh.S (dbl_min): New object.
	(__ieee754_atanh): Force underflow exception for results with
	small absolute value.
	* sysdeps/i386/fpu/e_atanhf.S (flt_min): New object.
	(__ieee754_atanhf): Force underflow exception for results with
	small absolute value.
	* sysdeps/ieee754/dbl-64/e_atanh.c: Include <float.h>.
	(__ieee754_atanh): Force underflow exception for results with
	small absolute value.
	* sysdeps/ieee754/flt-32/e_atanhf.c: Include <float.h>.
	(__ieee754_atanhf): Force underflow exception for results with
	small absolute value.
	* sysdeps/ieee754/ldbl-128/e_atanhl.c: Include <float.h>.
	(__ieee754_atanhl): Force underflow exception for results with
	small absolute value.
	* sysdeps/ieee754/ldbl-128ibm/e_atanhl.c: Include <float.h>.
	(__ieee754_atanhl): Force underflow exception for results with
	small absolute value.
	* sysdeps/ieee754/ldbl-96/e_atanhl.c: Include <float.h>.
	(__ieee754_atanhl): Force underflow exception for results with
	small absolute value.
	* math/auto-libm-test-in: Do not allow missing underflow
	exceptions from atanh.
	* math/auto-libm-test-out: Regenerated.
2015-05-15 22:07:57 +00:00
Joseph Myers
5a608ccc2d Fix tanf spurious underflows (bug 18221).
The flt-32 implementation of tanf produces spurious underflow
exceptions for some small arguments, through computing values on the
order of x^5.  This patch fixes this by adjusting the threshold for
returning x (or, as applicable, +/- 1/x) to 2**-13 (the next term in
the power series being x^3/3).

Tested for x86_64 and x86.

	[BZ #18221]
	* sysdeps/ieee754/flt-32/k_tanf.c (__kernel_tanf): Use 2**-13 not
	2**-28 as threshold for returning x or +/- 1/x.
	* math/auto-libm-test-in: Add more tests of tan.
	* math/auto-libm-test-out: Regenerated.
2015-05-15 17:47:29 +00:00
Joseph Myers
ff069f024a Fix lgammaf spurious underflows (bug 18220).
The flt-32 implementation of lgammaf produces spurious underflow
exceptions for some large arguments, because of calculations involving
x^-2 multiplied by small constants.  This patch fixes this by
adjusting the threshold for a simpler computation to 2**26 (the error
in the simpler computation is on the order of 0.5 * log (x), for a
result on the order of x * log (x)).

Tested for x86_64 and x86.

	[BZ #18220]
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c (__ieee754_lgammaf_r): Use
	2**26 not 2**58 as threshold for returning x * (log (x) - 1).
	* math/auto-libm-test-in: Add another test of lgamma.
	* math/auto-libm-test-out: Regenerated.
2015-05-15 17:21:08 +00:00
Joseph Myers
fbc68f03b0 Fix erfcf spurious underflows (bug 18217).
The flt-32 implementation of erfcf produces spurious underflow
exceptions for some arguments close to 0, because of calculations
squaring the argument and then multiplying by small constants.  This
patch fixes this by adjusting the threshold for arguments for which
the result is so close to 1 that 1 - x will give the right result from
2**-56 to 2**-26.  (If 1 - x * 2/sqrt(pi) were used, the errors would be
on the order of x^3 and a much larger threshold could be used.)

Tested for x86_64 and x86.

	[BZ #18217]
	* sysdeps/ieee754/flt-32/s_erff.c (__erfcf): Use 2**-26 not 2**-56
	as threshold for returning 1 - x.
	* math/auto-libm-test-in: Add more tests of erfc.
	* math/auto-libm-test-out: Regenerated.
2015-05-15 00:16:10 +00:00
Joseph Myers
9a71f1fcf5 Fix atanf spurious underflows (bug 18196).
The sysdeps/ieee754/flt-32 version of atanf produces spurious
underflow exceptions for some large arguments, because of computations
that compute x^-4.  This patch fixes this by adjusting the threshold
for large arguments (for which +/- pi/2 can just be returned, the
correct result being roughly +/- pi/2 - 1/x) from 2^34 to 2^25.

Tested for x86_64 and x86.

	[BZ #18196]
	* sysdeps/ieee754/flt-32/s_atanf.c (__atanf): Use 2^25 not 2^34 as
	threshold for large arguments.
	* math/auto-libm-test-in: Add another test of atan.
	* math/auto-libm-test-out: Regenerated.
2015-05-14 23:51:09 +00:00
Joseph Myers
0b7a5f9201 Fix log1p missing underflows (bug 16339).
Similar to various other bugs in this area, some log1p implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact.  This patch forces the exception in a
similar way to previous fixes.  (The ldbl-128ibm implementation
doesn't currently need any change as it already generates this
exception, albeit through code that would generate spurious exceptions
in other cases; special code for this issue will only be needed there
when fixing the spurious exceptions.)

Tested for x86_64, x86, powerpc and mips64.

	[BZ #16339]
	* sysdeps/i386/fpu/s_log1p.S (dbl_min): New object.
	(__log1p): Force underflow exception for results with small
	absolute value.
	* sysdeps/i386/fpu/s_log1pf.S (flt_min): New object.
	(__log1pf): Force underflow exception for results with small
	absolute value.
	* sysdeps/ieee754/dbl-64/s_log1p.c: Include <float.h>.
	(__log1p): Force underflow exception for results with small
	absolute value.
	* sysdeps/ieee754/flt-32/s_log1pf.c: Include <float.h>.
	(__log1pf): Force underflow exception for results with small
	absolute value.
	* sysdeps/ieee754/ldbl-128/s_log1pl.c: Include <float.h>.
	(__log1pl): Force underflow exception for results with small
	absolute value.
	* math/auto-libm-test-in: Do not allow missing underflow
	exceptions from log1p.
	* math/auto-libm-test-out: Regenerated.
2015-05-14 23:38:07 +00:00
Joseph Myers
14f36098f2 Add more tests of csqrt, lgamma, log10, sinh.
This patch adds more randomly-generated tests of various libm
functions that are observed to increase ulps on x86_64.

Tested for x86_64 and x86 and ulps updated accordingly.

	* math/auto-libm-test-in: Add more tests of csqrt, lgamma, log10
	and sinh.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2015-05-08 17:55:11 +00:00
Joseph Myers
471dffa12c Add more tests of acosh, atanh, cos, csqrt, erfc, sin, sincos.
This patch adds more randomly-generated tests of various libm
functions that are observed to increase ulps on x86_64.

Tested for x86_64 and x86 and ulps updated accordingly.

	* math/auto-libm-test-in: Add more tests of acosh, atanh, cos,
	csqrt, erfc, sin and sincos.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2015-05-06 17:30:18 +00:00
Joseph Myers
31450d9a87 Add further tests of libm functions.
This patch adds more randomly-generated tests of various libm
functions that are observed to increase ulps on x86_64.  (This process
must eventually converge, when my random test generation stops finding
inputs that increase the listed ulps, except maybe for any cases
uncovered where the errors exceed the maximum allowed 9ulp error and
so indicate actual libm bugs needing fixing.)

Tested for x86_64 and x86 and ulps updated accordingly.

	* math/auto-libm-test-in: Add more tests of acosh, atanh, clog,
	clog10, csqrt, erfc, exp2, expm1, log10, log2 and sinh.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2015-05-05 22:59:41 +00:00
Joseph Myers
305392eaca Add more tests of libm functions.
This patch adds more randomly-generated tests of various libm
functions that are observed to increase ulps on x86_64.

Tested for x86_64 and x86 and ulps updated accordingly.

	* math/auto-libm-test-in: Add more tests of atan, clog, clog10,
	cos, csqrt, erf, erfc, exp2, lgamma, log1p, sin, sincos, tanh and
	tgamma.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2015-05-02 21:06:33 +00:00
Joseph Myers
51e15247c3 Add more tests of tgamma.
This patch adds some randomly-generated tests of tgamma that are
observed to increase ulps on x86_64.

Tested for x86_64 and x86 and ulps updated accordingly.

	* math/auto-libm-test-in: Add more tests of tgamma.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2015-05-01 23:15:07 +00:00
Joseph Myers
5ffb9a53d7 Add more tests of tanh.
This patch adds some randomly-generated tests of tanh that are
observed to increase ulps on x86_64.

Tested for x86_64 and x86 and ulps updated accordingly.

	* math/auto-libm-test-in: Add more tests of tanh.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2015-05-01 23:06:44 +00:00
Joseph Myers
0957e15d0a Add more tests of tan.
This patch adds some randomly-generated tests of tan that are observed
to increase ulps on x86_64.

Tested for x86_64 and x86 and ulps updated accordingly.

	* math/auto-libm-test-in: Add more tests of tan.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2015-05-01 22:54:39 +00:00
Joseph Myers
827bb5859c Add more tests of cos, sin, sincos.
This patch adds some randomly-generated tests of cos, sin and sincos
that are observed to increase ulps on x86_64.

Tested for x86_64 and x86 and ulps updated accordingly.

	* math/auto-libm-test-in: Add more tests of cos, sin and sincos.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2015-05-01 22:41:00 +00:00