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f280fa6d17
glibc/sysdeps/ieee754/dbl-64
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Joseph Myers f280fa6d17 Use __builtin_fma more in dbl-64 code. 
sysdeps/ieee754/dbl-64/dla.h can use a macro DLA_FMS for more
efficient double-width operations when fused multiply-subtract is
supported.  However, this macro is only defined for x86_64,
conditional on architecture-specific __FMA4__.  This patch makes the
code use __builtin_fma conditional on __FP_FAST_FMA, as used elsewhere
in glibc.

Tested for x86_64, x86 and powerpc.  On powerpc (where this is causing
fused operations to be used where they weren't previously) I see an
increase from 1ulp to 2ulp in the imaginary part of clog10:

testing double (without inline functions)
Failure: Test: Imaginary part of: clog10 (0x1.7a858p+0 - 0x6.d940dp-4 i)
Result:
 is:         -1.2237865208199886e-01  -0x1.f5435146bb61ap-4
 should be:  -1.2237865208199888e-01  -0x1.f5435146bb61cp-4
 difference:  2.7755575615628914e-17   0x1.0000000000000p-55
 ulp       :  2.0000
 max.ulp   :  1.0000
Maximal error of real part of: clog10
 is      : 3 ulp
 accepted: 3 ulp
Maximal error of imaginary part of: clog10
 is      : 2 ulp
 accepted: 1 ulp

This is actually resulting from atan2 becoming *more* accurate (atan2
(-0x6.d940dp-4, 0x1.7a858p+0) should ideally be -0x1.208cd6e841554p-2
but was -0x1.208cd6e841555p-2 from a powerpc libm built before this
change, and is -0x1.208cd6e841554p-2 from a powerpc libm built after
this change).  Since these functions are not expected to be correctly
rounding by glibc's accuracy goals, neither result is a problem, but
this does imply that some of this code, although designed to be
correctly rounding, is not in fact correctly rounding (possibly
because of GCC creating fused operations where the code does not
expect it, something we've only disabled for specific functions where
it was found to cause large errors).  (Of course as previously
discussed I think we should remove the slow cases where an error
analysis shows this wouldn't increase the errors much above 0.5ulp;
it's only functions such as cratan2 that are expected to be correctly
rounding, not atan2.)

	* sysdeps/ieee754/dbl-64/dla.h [__FP_FAST_FMA] (DLA_FMS): Define
	macro to use __builtin_fma.
	* sysdeps/x86_64/fpu/dla.h: Remove file.
2016-09-30 15:49:51 +00:00
..
wordsize-64 sparc64: add a VIS3 version of ceil, floor and trunc 2016-08-03 13:35:22 +02:00
asincos.tbl Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
atnat2.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
atnat.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
branred.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
branred.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
dbl2mpn.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
dla.h Use __builtin_fma more in dbl-64 code. 2016-09-30 15:49:51 +00:00
doasin.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
doasin.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
dosincos.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
dosincos.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
e_acos.c Update. 2001-03-12 00:04:52 +00:00
e_acosh.c Format floating routines. 2013-10-17 16:03:24 +02:00
e_asin.c Fix dbl-64 asin (sNaN) (bug 20213). 2016-06-06 22:21:11 +00:00
e_atan2.c Fix dbl-64 atan2 (sNaN, qNaN) (bug 20252). 2016-06-13 21:43:22 +00:00
e_atanh.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
e_cosh.c Avoid excess range overflowing results from cosh, sinh, lgamma (bug 18980). 2015-09-18 20:00:48 +00:00
e_exp2.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
e_exp10.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
e_exp.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
e_fmod.c Use glibc_likely instead __builtin_expect. 2014-02-10 15:07:12 +01:00
e_gamma_r.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
e_hypot.c Fix hypot missing underflows (bug 18803). 2015-09-24 23:43:57 +00:00
e_ilogb.c Format floating routines. 2013-10-17 16:03:24 +02:00
e_j0.c Avoid uninitialized warnings in Bessel functions. 2015-02-26 21:49:19 +00:00
e_j1.c Fix j1, jn missing errno setting on underflow (bug 18611). 2015-10-23 21:37:33 +00:00
e_jn.c Fix j1, jn missing errno setting on underflow (bug 18611). 2015-10-23 21:37:33 +00:00
e_lgamma_r.c Remove GCC version conditionals on -Wmaybe-uninitialized pragmas. 2015-10-27 23:42:20 +00:00
e_log2.c Work around powerpc32 integer 0 converting to -0 (bug 887, bug 19049, bug 19050). 2015-10-05 17:46:50 +00:00
e_log10.c Work around powerpc32 integer 0 converting to -0 (bug 887, bug 19049, bug 19050). 2015-10-05 17:46:50 +00:00
e_log.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
e_pow.c Eliminate redundant sign extensions in pow() 2016-01-04 14:55:38 -02:00
e_rem_pio2.c Format floating routines. 2013-10-17 16:03:24 +02:00
e_remainder.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
e_sinh.c Refactor code forcing underflow exceptions. 2015-09-23 22:42:30 +00:00
e_sqrt.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
gamma_product.c Merge common usage of mul_split function 2016-08-19 11:29:43 -05:00
gamma_productf.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
halfulp.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
k_cos.c Update. 2001-03-12 00:04:52 +00:00
k_rem_pio2.c Get rid of array-bounds warning in __kernel_rem_pio2[f] with gcc 6.1 -O3. 2016-08-18 12:20:35 +02:00
k_sin.c Update. 2001-03-12 00:04:52 +00:00
k_tan.c Replace sysdeps/ieee754/dbl-64/k_tan.c with empty file 2012-02-26 16:10:46 +01:00
lgamma_neg.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
lgamma_product.c Merge common usage of mul_split function 2016-08-19 11:29:43 -05:00
Makefile powerpc: Fix incorrect results for pow when using FMA 2015-03-10 09:38:54 -04:00
MathLib.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
mpa-arch.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
mpa.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
mpa.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
mpatan2.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
mpatan.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
mpatan.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
mpexp.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
mplog.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
mpn2dbl.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
mpsqrt.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
mpsqrt.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
mptan.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
mydefs.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
powtwo.tbl Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
root.tbl Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
s_asinh.c Refactor code forcing underflow exceptions. 2015-09-23 22:42:30 +00:00
s_atan.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
s_cbrt.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
s_ceil.c Do not raise "inexact" from generic ceil (bug 15479). 2016-05-24 17:42:10 +00:00
s_copysign.c Format floating routines. 2013-10-17 16:03:24 +02:00
s_cos.c Update. 2001-03-12 00:04:52 +00:00
s_erf.c Work around powerpc32 integer 0 converting to -0 (bug 887, bug 19049, bug 19050). 2015-10-05 17:46:50 +00:00
s_expm1.c Refactor code forcing underflow exceptions. 2015-09-23 22:42:30 +00:00
s_fabs.c 2015-05-28 Wilco Dijkstra <wdijkstr@arm.com> 2015-05-28 11:42:55 +01:00
s_finite.c Fix __finitel libm compat symbol version. 2016-01-20 19:04:43 +00:00
s_floor.c Do not raise "inexact" from generic floor (bug 15479). 2016-05-24 17:44:46 +00:00
s_fma.c Call math_opt_barrier inside if 2016-01-15 05:23:20 -08:00
s_fmaf.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
s_fpclassify.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
s_frexp.c Fix frexp (NaN) (bug 20250). 2016-06-13 17:27:19 +00:00
s_isinf.c math: add LDBL_CLASSIFY_COMPAT support 2015-12-03 13:00:46 -05:00
s_isnan.c math: add LDBL_CLASSIFY_COMPAT support 2015-12-03 13:00:46 -05:00
s_issignaling.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
s_llrint.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
s_llround.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
s_log1p.c Refactor code forcing underflow exceptions. 2015-09-23 22:42:30 +00:00
s_logb.c Work around powerpc32 integer 0 converting to -0 (bug 887, bug 19049, bug 19050). 2015-10-05 17:46:50 +00:00
s_lrint.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
s_lround.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
s_modf.c Use glibc_likely instead __builtin_expect. 2014-02-10 15:07:12 +01:00
s_nearbyint.c Format floating routines. 2013-10-17 16:03:24 +02:00
s_nexttoward.c Update. 1999-07-14 00:54:57 +00:00
s_nextup.c Add nextup and nextdown math functions 2016-06-16 21:37:45 +05:30
s_remquo.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
s_rint.c Format floating routines. 2013-10-17 16:03:24 +02:00
s_round.c Do not raise "inexact" from generic round (bug 15479). 2016-05-24 17:46:55 +00:00
s_scalbln.c [BZ #6803] Set errno for scalbln, scalbn 2014-06-20 07:48:20 +05:30
s_scalbn.c Make scalbn set errno (bug 6803). 2015-09-16 21:11:00 +00:00
s_signbit.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
s_sin.c Use copysign instead of ternary for some sin/cos input ranges 2016-09-30 05:19:05 +05:30
s_sincos.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
s_tan.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
s_tanh.c Refactor code forcing underflow exceptions. 2015-09-23 22:42:30 +00:00
s_trunc.c sparc64: add a VIS3 version of ceil, floor and trunc 2016-08-03 13:35:22 +02:00
sincos32.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
sincos32.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
sincostab.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
slowexp.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
slowpow.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
t_exp2.h Update. 1999-07-14 00:54:57 +00:00
t_exp.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
uasncs.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
uatan.tbl Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
uexp.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
uexp.tbl Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
ulog.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
ulog.tbl Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
upow.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
upow.tbl Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
urem.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
usncs.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
utan.h Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
utan.tbl Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
w_exp.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
x2y2m1.c Merge common usage of mul_split function 2016-08-19 11:29:43 -05:00
x2y2m1f.c Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00