Commit Graph

3 Commits

Author SHA1 Message Date
Paul E. Murphy
e2239af353 Rename __LONG_DOUBLE_USES_FLOAT128 to __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI
Improve the commentary to aid future developers who will stumble
upon this novel, yet not always perfect, mechanism to support
alternative formats for long double.

Likewise, rename __LONG_DOUBLE_USES_FLOAT128 to
__LDOUBLE_REDIRECTS_TO_FLOAT128_ABI now that development work
has settled down.  The command used was

git grep -l __LONG_DOUBLE_USES_FLOAT128 ':!./ChangeLog*' | \
  xargs sed -i 's/__LONG_DOUBLE_USES_FLOAT128/__LDOUBLE_REDIRECTS_TO_FLOAT128_ABI/g'

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2020-04-30 08:52:08 -05:00
Paul E. Murphy
45ae17dd7e ldbl-128ibm-compat: PLT redirects for using ldbl redirects internally
Tweak the PLT bypass magic when building glibc with long double
redirects.  This is made more difficult by the fact we only get
one chance to redirect functions.  This happens via the public
headers.

There are roughly three classes of redirect we need to attend to
today:

 1. Simple redirects, redirected via cdef macro overrides and
    and new libc_hidden_ldbl_proto macro.
 2. Internal usage of internal API, e.g __snprintf, which has
    no direct analogue.  This is bypassed directly on case-by-
    case basis.
 3. Double redirects, e.g sscanf and related.  These require
    a heavier handed approach of macro renaming to existing
    symbols.

Most simple redirects are handled via 1.  Ideally, the libc_*
macro would live in libc-symbols.h, but in practice the macros
needed for it to do anything useful live in cdefs.h, so they
are defined in the local override.

Notably, the internal name of the asprintf generated for ieee ldbl
redirects is renamed to work with internal prefixed usage.

This resolves the local plt usage introduced when building glibc
with ldbl == ieee128 on ppc64le.

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2020-03-25 14:34:23 -05:00
Joseph Myers
eaf5ad0bc4 Add canonicalize, canonicalizef, canonicalizel.
TS 18661-1 defines canonicalize functions to produce a canonical
version of a floating-point representation.  This patch implements
these functions for glibc.

As with the iscanonical macro, these functions are oriented to the
decimal floating-point case, where some values have both canonical and
noncanonical representations.  However, the functions have a return
value that says whether they succeeded in storing a canonical result;
thus, they can fail for the case of an invalid representation (while
still not making any particular choice from among multiple equally
canonical valid representations of the same value).  Since no
floating-point formats in glibc actually have noncanonical valid
representations, a type-generic implementation of these functions can
be used that expects iscanonical to return 0 only for invalid
representations.  Now that iscanonical is used within libm.so,
libm_hidden_proto / libm_hidden_def are added for __iscanonicall.

The definition of these functions is intended to correspond to a
convertFormat operation to the same floating-point format.  Thus, they
convert signaling NaNs to quiet NaNs, raising the "invalid" exception.
Such a conversion "should" produce "the canonical version of that
signaling NaN made quiet".

libm-test.inc is made to check NaN payloads for the output of these
functions, a new feature (at some point manipulation functions such as
fabs and copysign should have tests added that verify payload
preservation for them).  As however some architectures may not follow
the recommended practice of preserving NaN payloads when converting a
signaling NaN to quiet, a new math-tests.h macro
SNAN_TESTS_PRESERVE_PAYLOAD is added, and defined to 0 for non-NAN2008
MIPS; any other architectures seeing test failures for lack of payload
preservation in this case should also define this macro to 0.  (If any
cases arise where the sign isn't preserved either, those should have a
similar macro added.)

The ldbl-96 and ldbl-128ibm tests of iscanonical are renamed and
adapted to test canonicalizel as well on the same representations.

Tested for x86_64, x86, mips64 and powerpc.

	* math/bits/mathcalls.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
	(canonicalize): New declaration.
	* math/Versions (canonicalize): New libm symbol at version
	GLIBC_2.25.
	(canonicalizef): Likewise.
	(canonicalizel): Likewise.
	* math/Makefile (gen-libm-calls): Add s_canonicalizeF.
	* math/s_canonicalize_template.c: New file.
	* math/libm-test.inc: Update comment on functions tested and
	testing of NaN payloads.
	(TEST_NAN_PAYLOAD): New macro.
	(NO_TEST_INLINE): Update value.
	(XFAIL_TEST): Likewise.
	(ERRNO_UNCHANGED): Likewise.
	(ERRNO_EDOM): Likewise.
	(ERRNO_ERANGE): Likewise.
	(IGNORE_RESULT): Likewise.
	(NON_FINITE): Likewise.
	(TEST_SNAN): Likewise.
	(NO_TEST_MATHVEC): Likewise.
	(TEST_NAN_PAYLOAD_CANONICALIZE): New macro.
	(check_float_internal): Check NaN payloads if TEST_NAN_PAYLOAD.
	(struct test_Ffp_b1_data): New type.
	(RUN_TEST_Ffp_b1): New macro.
	(RUN_TEST_LOOP_Ffp_b1): Likewise.
	(canonicalize_test_data): New array.
	(canonicalize_test): New function.
	(main): Call canonicalize_test.
	* manual/arith.texi (FP Bit Twiddling): Document canonicalize,
	canonicalizef and canonicalizel.
	* manual/libm-err-tab.pl: Update comment on interfaces without
	ulps tabulated.
	* sysdeps/ieee754/ldbl-opt/nldbl-canonicalize.c: New file.
	* sysdeps/ieee754/ldbl-opt/s_canonicalizel.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/Makefile (libnldbl-calls): Add
	canonicalize.
	(CFLAGS-nldbl-canonicalize.c): New variable.
	* sysdeps/ieee754/ldbl-128ibm/test-iscanonical-ldbl-128ibm.c: Move
	to ...
	* sysdeps/ieee754/ldbl-128ibm/test-canonical-ldbl-128ibm.c:
	... here.
	(do_test): Also test canonicalizel.
	* sysdeps/ieee754/ldbl-128ibm/Makefile (tests): Change
	test-iscanonical-ldbl-128ibm to test-canonical-ldbl-128ibm.
	* sysdeps/ieee754/ldbl-128ibm/include/bits/iscanonical.h: New
	file.
	* sysdeps/ieee754/ldbl-128ibm/s_iscanonicall.c (__iscanonicall):
	Use libm_hidden_def.
	* sysdeps/ieee754/ldbl-96/test-iscanonical-ldbl-96.c: Move to ...
	* sysdeps/ieee754/ldbl-96/test-canonical-ldbl-96.c: ... here.
	(do_test): Also test canonicalizel.
	* sysdeps/ieee754/ldbl-96/Makefile (tests): Change
	test-iscanonical-ldbl-96 to test-canonical-ldbl-96.
	* sysdeps/ieee754/ldbl-96/include/bits/iscanonical.h: New file.
	* sysdeps/ieee754/ldbl-96/s_iscanonicall.c (__iscanonicall): Use
	libm_hidden_def.
	* sysdeps/generic/math-tests.h (SNAN_TESTS_PRESERVE_PAYLOAD): New
	macro.
	* sysdeps/mips/math-tests.h [__mips_hard_float && !__mips_nan2008]
	(SNAN_TESTS_PRESERVE_PAYLOAD): Likewise.
	* sysdeps/nacl/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
2016-10-26 23:14:31 +00:00