1 Commits

Author	SHA1	Message	Date
Joseph Myers	29cb929332	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.	2016-09-30 00:27:50 +00:00