glibc/bits/iscanonical.h

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Add iscanonical. TS 18661-1 adds an iscanonical classification macro to <math.h>. The motivation for this is decimal floating-point, where some values have both canonical and noncanonical encodings. For IEEE binary interchange formats, all encodings are canonical. For x86/m68k ldbl-96, and for ldbl-128ibm, there are encodings that do not represent any valid value of the type; although formally iscanonical does not need to handle trap representations (and so could just always return 1), it seems useful, and in line with the description in the TS of "representations that are extraneous to the floating-point model" as being non-canonical (as well as "redundant representations of some or all of its values"), for it to detect those representations and return 0 for them. This patch adds iscanonical to glibc. It goes in a header <bits/iscanonical.h>, included under appropriate conditions in <math.h>. The default header version just evaluates the argument (converted to its semantic type, though current GCC will probably discard that conversion and any exceptions resulting from it) and returns 1. ldbl-96 and ldbl-128ibm then have versions of the header that call a function __iscanonicall for long double (the sizeof-based tests will of course need updating for float128 support, like other such type-generic macro implementations). The ldbl-96 version of __iscanonicall has appropriate conditionals to reflect the differences in the m68k version of that format (where the high mantissa bit may be either 0 or 1 when the exponent is 0 or 0x7fff). Corresponding tests for those formats are added as well. Other architectures do not have any new functions added because just returning 1 is correct for all their floating-point formats. Tested for x86_64, x86, mips64 (to test the default macro version) and powerpc. * math/math.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Include <bits/iscanonical.h>. * bits/iscanonical.h: New file. * math/s_iscanonicall.c: Likewise. * math/Versions (__iscanonicall): New libm symbol at version GLIBC_2.25. * math/libm-test.inc (iscanonical_test_data): New array. (iscanonical_test): New function. (main): Call iscanonical_test. * math/Makefile (headers): Add bits/iscanonical.h. (type-ldouble-routines): Add s_iscanonicall. * manual/arith.texi (Floating Point Classes): Document iscanonical. * manual/libm-err-tab.pl: Update comment on interfaces without ulps tabulated. * sysdeps/ieee754/ldbl-128ibm/bits/iscanonical.h: New file. * sysdeps/ieee754/ldbl-128ibm/s_iscanonicall.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/test-iscanonical-ldbl-128ibm.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/Makefile (tests): Add test-iscanonical-ldbl-128ibm. * sysdeps/ieee754/ldbl-96/bits/iscanonical.h: New file. * sysdeps/ieee754/ldbl-96/s_iscanonicall.c: Likewise. * sysdeps/ieee754/ldbl-96/test-iscanonical-ldbl-96.c: Likewise. * sysdeps/ieee754/ldbl-96/Makefile: Likewise. * sysdeps/unix/sysv/linux/i386/libm.abilist: Update. * sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/m680x0/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/x86_64/64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
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/* Define iscanonical macro.
Copyright (C) 2016-2024 Free Software Foundation, Inc.
Add iscanonical. TS 18661-1 adds an iscanonical classification macro to <math.h>. The motivation for this is decimal floating-point, where some values have both canonical and noncanonical encodings. For IEEE binary interchange formats, all encodings are canonical. For x86/m68k ldbl-96, and for ldbl-128ibm, there are encodings that do not represent any valid value of the type; although formally iscanonical does not need to handle trap representations (and so could just always return 1), it seems useful, and in line with the description in the TS of "representations that are extraneous to the floating-point model" as being non-canonical (as well as "redundant representations of some or all of its values"), for it to detect those representations and return 0 for them. This patch adds iscanonical to glibc. It goes in a header <bits/iscanonical.h>, included under appropriate conditions in <math.h>. The default header version just evaluates the argument (converted to its semantic type, though current GCC will probably discard that conversion and any exceptions resulting from it) and returns 1. ldbl-96 and ldbl-128ibm then have versions of the header that call a function __iscanonicall for long double (the sizeof-based tests will of course need updating for float128 support, like other such type-generic macro implementations). The ldbl-96 version of __iscanonicall has appropriate conditionals to reflect the differences in the m68k version of that format (where the high mantissa bit may be either 0 or 1 when the exponent is 0 or 0x7fff). Corresponding tests for those formats are added as well. Other architectures do not have any new functions added because just returning 1 is correct for all their floating-point formats. Tested for x86_64, x86, mips64 (to test the default macro version) and powerpc. * math/math.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Include <bits/iscanonical.h>. * bits/iscanonical.h: New file. * math/s_iscanonicall.c: Likewise. * math/Versions (__iscanonicall): New libm symbol at version GLIBC_2.25. * math/libm-test.inc (iscanonical_test_data): New array. (iscanonical_test): New function. (main): Call iscanonical_test. * math/Makefile (headers): Add bits/iscanonical.h. (type-ldouble-routines): Add s_iscanonicall. * manual/arith.texi (Floating Point Classes): Document iscanonical. * manual/libm-err-tab.pl: Update comment on interfaces without ulps tabulated. * sysdeps/ieee754/ldbl-128ibm/bits/iscanonical.h: New file. * sysdeps/ieee754/ldbl-128ibm/s_iscanonicall.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/test-iscanonical-ldbl-128ibm.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/Makefile (tests): Add test-iscanonical-ldbl-128ibm. * sysdeps/ieee754/ldbl-96/bits/iscanonical.h: New file. * sysdeps/ieee754/ldbl-96/s_iscanonicall.c: Likewise. * sysdeps/ieee754/ldbl-96/test-iscanonical-ldbl-96.c: Likewise. * sysdeps/ieee754/ldbl-96/Makefile: Likewise. * sysdeps/unix/sysv/linux/i386/libm.abilist: Update. * sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/m680x0/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/x86_64/64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
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This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
Prefer https to http for gnu.org and fsf.org URLs Also, change sources.redhat.com to sourceware.org. This patch was automatically generated by running the following shell script, which uses GNU sed, and which avoids modifying files imported from upstream: sed -ri ' s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g ' \ $(find $(git ls-files) -prune -type f \ ! -name '*.po' \ ! -name 'ChangeLog*' \ ! -path COPYING ! -path COPYING.LIB \ ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \ ! -path manual/texinfo.tex ! -path scripts/config.guess \ ! -path scripts/config.sub ! -path scripts/install-sh \ ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \ ! -path INSTALL ! -path locale/programs/charmap-kw.h \ ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \ ! '(' -name configure \ -execdir test -f configure.ac -o -f configure.in ';' ')' \ ! '(' -name preconfigure \ -execdir test -f preconfigure.ac ';' ')' \ -print) and then by running 'make dist-prepare' to regenerate files built from the altered files, and then executing the following to cleanup: chmod a+x sysdeps/unix/sysv/linux/riscv/configure # Omit irrelevant whitespace and comment-only changes, # perhaps from a slightly-different Autoconf version. git checkout -f \ sysdeps/csky/configure \ sysdeps/hppa/configure \ sysdeps/riscv/configure \ sysdeps/unix/sysv/linux/csky/configure # Omit changes that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines git checkout -f \ sysdeps/powerpc/powerpc64/ppc-mcount.S \ sysdeps/unix/sysv/linux/s390/s390-64/syscall.S # Omit change that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 05:40:42 +00:00
<https://www.gnu.org/licenses/>. */
Add iscanonical. TS 18661-1 adds an iscanonical classification macro to <math.h>. The motivation for this is decimal floating-point, where some values have both canonical and noncanonical encodings. For IEEE binary interchange formats, all encodings are canonical. For x86/m68k ldbl-96, and for ldbl-128ibm, there are encodings that do not represent any valid value of the type; although formally iscanonical does not need to handle trap representations (and so could just always return 1), it seems useful, and in line with the description in the TS of "representations that are extraneous to the floating-point model" as being non-canonical (as well as "redundant representations of some or all of its values"), for it to detect those representations and return 0 for them. This patch adds iscanonical to glibc. It goes in a header <bits/iscanonical.h>, included under appropriate conditions in <math.h>. The default header version just evaluates the argument (converted to its semantic type, though current GCC will probably discard that conversion and any exceptions resulting from it) and returns 1. ldbl-96 and ldbl-128ibm then have versions of the header that call a function __iscanonicall for long double (the sizeof-based tests will of course need updating for float128 support, like other such type-generic macro implementations). The ldbl-96 version of __iscanonicall has appropriate conditionals to reflect the differences in the m68k version of that format (where the high mantissa bit may be either 0 or 1 when the exponent is 0 or 0x7fff). Corresponding tests for those formats are added as well. Other architectures do not have any new functions added because just returning 1 is correct for all their floating-point formats. Tested for x86_64, x86, mips64 (to test the default macro version) and powerpc. * math/math.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Include <bits/iscanonical.h>. * bits/iscanonical.h: New file. * math/s_iscanonicall.c: Likewise. * math/Versions (__iscanonicall): New libm symbol at version GLIBC_2.25. * math/libm-test.inc (iscanonical_test_data): New array. (iscanonical_test): New function. (main): Call iscanonical_test. * math/Makefile (headers): Add bits/iscanonical.h. (type-ldouble-routines): Add s_iscanonicall. * manual/arith.texi (Floating Point Classes): Document iscanonical. * manual/libm-err-tab.pl: Update comment on interfaces without ulps tabulated. * sysdeps/ieee754/ldbl-128ibm/bits/iscanonical.h: New file. * sysdeps/ieee754/ldbl-128ibm/s_iscanonicall.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/test-iscanonical-ldbl-128ibm.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/Makefile (tests): Add test-iscanonical-ldbl-128ibm. * sysdeps/ieee754/ldbl-96/bits/iscanonical.h: New file. * sysdeps/ieee754/ldbl-96/s_iscanonicall.c: Likewise. * sysdeps/ieee754/ldbl-96/test-iscanonical-ldbl-96.c: Likewise. * sysdeps/ieee754/ldbl-96/Makefile: Likewise. * sysdeps/unix/sysv/linux/i386/libm.abilist: Update. * sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/m680x0/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/x86_64/64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
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#ifndef _MATH_H
# error "Never use <bits/iscanonical.h> directly; include <math.h> instead."
#endif
/* Return nonzero value if X is canonical. By default, we only have
IEEE interchange binary formats, in which all values are canonical,
but the argument must still be converted to its semantic type for
any exceptions arising from the conversion, before being
discarded. */
#define iscanonical(x) ((void) (__typeof (x)) (x), 1)