This patch makes more dbl-64 functions use libm_alias_double to define
function aliases. Specifically, it makes the change for functions
with dbl-64/wordsize-64 versions, changing both the dbl-64 and
dbl-64/wordsize-64 versions and removing the ldbl-opt wrappers.
Functions are excluded from this patch if there are complications
because of versions of those functions also present in libc, or
architecture-specific wrappers round these files.
Tested for x86_64, and with build-many-glibcs.py. Installed stripped
shared libraries are unchanged except for alpha (where increased use
of dbl-64/wordsize-64 files, where previously ldbl-opt files that
wrapped dbl-64 files were used, was expected to result in different,
better code).
* sysdeps/ieee754/dbl-64/s_ceil.c: Include <libm-alias-double.h>.
(ceil): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/s_floor.c: Include <libm-alias-double.h>.
(floor): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/s_llround.c: Include
<libm-alias-double.h>.
(llround): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/s_lround.c: Include
<libm-alias-double.h>.
(lround): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/s_nearbyint.c: Include
<libm-alias-double.h>.
(nearbyint): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/s_remquo.c: Include
<libm-alias-double.h>.
(remquo): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/s_rint.c: Include <libm-alias-double.h>.
(rint): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/s_round.c: Include <libm-alias-double.h>.
(round): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/s_trunc.c: Include <libm-alias-double.h>.
(trunc): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/wordsize-64/s_ceil.c: Include
<libm-alias-double.h>.
(ceil): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/wordsize-64/s_floor.c: Include
<libm-alias-double.h>.
(floor): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/wordsize-64/s_llround.c: Include
<libm-alias-double.h>.
(llround): Define using libm_alias_double.
[_LP64] (lround): Likewise.
* sysdeps/ieee754/dbl-64/wordsize-64/s_lround.c: Include
<libm-alias-double.h>.
[!_LP64] (lround): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/wordsize-64/s_nearbyint.c: Include
<libm-alias-double.h>.
(nearbyint): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/wordsize-64/s_remquo.c: Include
<libm-alias-double.h>.
(remquo): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/wordsize-64/s_rint.c: Include
<libm-alias-double.h>.
(rint): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/wordsize-64/s_round.c: Include
<libm-alias-double.h>.
(round): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/wordsize-64/s_trunc.c: Include
<libm-alias-double.h>.
(trunc): Define using libm_alias_double.
* sysdeps/ieee754/ldbl-opt/s_ceil.c: Remove file.
* sysdeps/ieee754/ldbl-opt/s_floor.c: Likewise.
* sysdeps/ieee754/ldbl-opt/s_llround.c: Likewise.
* sysdeps/ieee754/ldbl-opt/s_lround.c: Likewise.
* sysdeps/ieee754/ldbl-opt/s_nearbyint.c: Likewise.
* sysdeps/ieee754/ldbl-opt/s_remquo.c: Likewise.
* sysdeps/ieee754/ldbl-opt/s_rint.c: Likewise.
* sysdeps/ieee754/ldbl-opt/s_round.c: Likewise.
* sysdeps/ieee754/ldbl-opt/s_trunc.c: Likewise.
In <https://sourceware.org/ml/libc-alpha/2013-05/msg00722.html> I
remarked on the possibility of arithmetic in various nearbyint
implementations being scheduled before feholdexcept calls, resulting
in spurious "inexact" exceptions.
I'm now actually observing this occurring in glibc built for ARM with
GCC 7 (in fact, both copies of the same addition/subtraction sequence
being combined and moved out before the conditionals and
feholdexcept/fesetenv pairs), resulting in test failures.
This patch makes the nearbyint implementations with this particular
feholdexcept / arithmetic / fesetenv pattern consistently use
math_opt_barrier on the function argument when first used in
arithmetic, and also consistently use math_force_eval before fesetenv
(the latter was generally already done, but the dbl-64/wordsize-64
implementation used math_opt_barrier instead, and as
math_opt_barrier's intended effect is through its output value being
used, such a use that doesn't use the return value is suspect).
Tested for x86_64 (--disable-multi-arch so more of these
implementations get used), and for ARM in a configuration where I saw
the problem scheduling.
[BZ #22225]
* sysdeps/ieee754/dbl-64/s_nearbyint.c (__nearbyint): Use
math_opt_barrier on argument when doing arithmetic on it.
* sysdeps/ieee754/dbl-64/wordsize-64/s_nearbyint.c (__nearbyint):
Likewise. Use math_force_eval not math_opt_barrier after
arithmetic.
* sysdeps/ieee754/flt-32/s_nearbyintf.c (__nearbyintf): Use
math_opt_barrier on argument when doing arithmetic on it.
* sysdeps/ieee754/ldbl-128/s_nearbyintl.c (__nearbyintl):
Likewise.
