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.

2 files changed, 34 insertions, 4 deletions

diff --git a/manual/arith.texi b/manual/arith.texi
index eaaf2b7..a5c04e4 100644
--- a/manual/arith.texi
+++ b/manual/arith.texi
@@ -1857,6 +1857,36 @@ selects one.  On other systems it may do nothing.
 
 @comment math.h
 @comment ISO
+@deftypefun int canonicalize (double *@var{cx}, const double *@var{x})
+@comment math.h
+@comment ISO
+@deftypefunx int canonicalizef (float *@var{cx}, const float *@var{x})
+@comment math.h
+@comment ISO
+@deftypefunx int canonicalizel (long double *@var{cx}, const long double *@var{x})
+@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
+In some floating-point formats, some values have canonical (preferred)
+and noncanonical encodings (for IEEE interchange binary formats, all
+encodings are canonical).  These functions, defined by TS
+18661-1:2014, attempt to produce a canonical version of the
+floating-point value pointed to by @var{x}; if that value is a
+signaling NaN, they raise the invalid exception and produce a quiet
+NaN.  If a canonical value is produced, it is stored in the object
+pointed to by @var{cx}, and these functions return zero.  Otherwise
+(if a canonical value could not be produced because the object pointed
+to by @var{x} is not a valid representation of any floating-point
+value), the object pointed to by @var{cx} is unchanged and a nonzero
+value is returned.
+
+Note that some formats have multiple encodings of a value which are
+all equally canonical; when such an encoding is used as an input to
+this function, any such encoding of the same value (or of the
+corresponding quiet NaN, if that value is a signaling NaN) may be
+produced as output.
+@end deftypefun
+
+@comment math.h
+@comment ISO
 @deftypefun double getpayload (const double *@var{x})
 @comment math.h
 @comment ISO
diff --git a/manual/libm-err-tab.pl b/manual/libm-err-tab.pl
index 59c5372..18b8ca9 100755
--- a/manual/libm-err-tab.pl
+++ b/manual/libm-err-tab.pl
@@ -77,10 +77,10 @@ use vars qw (%results @all_floats %suffices @all_functions);
     "nextup", "pow", "remainder", "remquo", "rint", "round", "scalb",
     "scalbn", "sin", "sincos", "sinh", "sqrt", "tan", "tanh", "tgamma",
     "trunc", "y0", "y1", "yn" );
-# fpclassify, getpayload, iscanonical, isnormal, isfinite, isinf, isnan,
-# issignaling, issubnormal, iszero, signbit, iseqsig, isgreater,
-# isgreaterequal, isless, islessequal, islessgreater, isunordered,
-# totalorder, totalordermag
+# canonicalize, fpclassify, getpayload, iscanonical, isnormal,
+# isfinite, isinf, isnan, issignaling, issubnormal, iszero, signbit,
+# iseqsig, isgreater, isgreaterequal, isless, islessequal,
+# islessgreater, isunordered, totalorder, totalordermag
 # are not tabulated.
 
 if ($#ARGV == 0) {