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authorJoseph Myers <joseph@codesourcery.com>2016-12-02 01:42:49 +0000
committerJoseph Myers <joseph@codesourcery.com>2016-12-02 01:42:49 +0000
commit55a38f82369669e181a05bcf2ac6c647dcd9b261 (patch)
tree5ecf72dbb2673caa4e87a91b46fdc9a3af66db7d /manual
parent6dc07416777012947152edaf5b7848c9e62c2fc8 (diff)
downloadglibc-55a38f82369669e181a05bcf2ac6c647dcd9b261.tar.gz
Add llogb, llogbf, llogbl.
TS 18661-1 defines llogb functions that are like ilogb except that they return long int instead of int. Corresponding FP_LLOGB* macros are defined, whose values are required to have the obvious correspondence to those of the FP_ILOGB* macros. This patch implements these functions and macros for glibc. llogb uses the type-generic infrastructure, with an implementation similar to the wrapper for ilogb but with additional conversion from FP_ILOGB* to FP_LLOGB*; this approach avoids needing to modify or duplicate any of the architecture-specific ilogb implementations. Tests are also based on those for ilogb. Ideally the llogb functions would alias the ilogb ones when long is 32-bit, but such aliasing requires the associated header declarations of the different-type alias to be hidden, typically by defining macros before including the header (see e.g. how sysdeps/ieee754/dbl-64/wordsize-64/s_llround.c defines lround to __hidden_lround before including <math.h>). The infrastructure for type-generic function implementations does not support defining such macros at present (since C code can't define a macro whose name is determined by other macros). So this patch leaves them as separate functions (similar to e.g. scalbln and scalbn being separate in such a case as well), but with the remapping of FP_ILOGB* to FP_LLOGB* conditioned out in the case where it would be the identity map. Tested for x86_64, x86, mips64 and powerpc. * math/bits/mathcalls.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (llogb): New declaration. * math/tgmath.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (llogb): New macro. * math/math.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (__FP_LONG_MAX): New macro. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FP_LLOGB0): Likewise. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FP_LLOGBNAN): Likewise. * math/Versions (llogb): New libm symbol at version GLIBC_2.25. (llogbf): Likewise. (llogbl): Likewise. * math/Makefile (gen-libm-calls): Add w_llogbF. (tests): Add test-fp-llogb-constants. * math/w_llogb_template.c: New file. Based on math/w_ilogb_template.c. * math/libm-test.inc (llogb_test_data): New array. (llogb_test): New function. (main): Call llogb_test. * math/test-fp-llogb-constants.c: New file. Based on math/test-fp-ilogb-constants.c. * math/test-tgmath-ret.c (llogb): New CHECK_RET_CONST call. (do_test): Call check_return_llogb. * math/test-tgmath.c (NCALLS): Increase to 126. (F(compile_test)): Call llogb. (F(llogb)): New function. * manual/math.texi (Exponents and Logarithms): Document llogb, llogbf, llogbl, FP_LLOGB0 and FP_LLOGBNAN. * manual/libm-err-tab.pl (@all_functions): Add llogb. * sysdeps/ieee754/ldbl-opt/nldbl-llogb.c: New file. * sysdeps/ieee754/ldbl-opt/w_llogbl.c: Likewise. * sysdeps/ieee754/ldbl-opt/Makefile (libnldbl-calls): Add llogb. (CFLAGS-nldbl-llogb.c): New variable. * 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.
Diffstat (limited to 'manual')
-rwxr-xr-xmanual/libm-err-tab.pl2
-rw-r--r--manual/math.texi31
2 files changed, 31 insertions, 2 deletions
diff --git a/manual/libm-err-tab.pl b/manual/libm-err-tab.pl
index 6d0bffc372..0e83853949 100755
--- a/manual/libm-err-tab.pl
+++ b/manual/libm-err-tab.pl
@@ -58,7 +58,7 @@ use vars qw (%results @all_floats %suffices @all_functions);
"creal", "csin", "csinh", "csqrt", "ctan", "ctanh", "erf", "erfc",
"exp", "exp10", "exp2", "expm1", "fabs", "fdim", "floor", "fma",
"fmax", "fmin", "fmod", "frexp", "gamma", "hypot",
- "ilogb", "j0", "j1", "jn", "lgamma", "lrint",
+ "ilogb", "j0", "j1", "jn", "lgamma", "llogb", "lrint",
"llrint", "log", "log10", "log1p", "log2", "logb", "lround",
"llround", "modf", "nearbyint", "nextafter", "nextdown", "nexttoward",
"nextup", "pow", "remainder", "remquo", "rint", "round", "scalb",
diff --git a/manual/math.texi b/manual/math.texi
index b4bb32345e..5ad8732eca 100644
--- a/manual/math.texi
+++ b/manual/math.texi
@@ -584,9 +584,20 @@ negative), @code{logb} returns @math{@infinity{}}. If @var{x} is zero,
@comment math.h
@comment ISO
@deftypefunx int ilogbl (long double @var{x})
+@comment math.h
+@comment ISO
+@deftypefunx {long int} llogb (double @var{x})
+@comment math.h
+@comment ISO
+@deftypefunx {long int} llogbf (float @var{x})
+@comment math.h
+@comment ISO
+@deftypefunx {long int} llogbl (long double @var{x})
@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
These functions are equivalent to the corresponding @code{logb}
-functions except that they return signed integer values.
+functions except that they return signed integer values. The
+@code{ilogb} functions are from ISO C99; the @code{llogb} functions
+are from TS 18661-1:2014.
@end deftypefun
@noindent
@@ -605,6 +616,15 @@ This macro is defined in @w{ISO C99}.
@comment math.h
@comment ISO
+@deftypevr Macro {long int} FP_LLOGB0
+@code{llogb} returns this value if its argument is @code{0}. The
+numeric value is either @code{LONG_MIN} or @code{-LONG_MAX}.
+
+This macro is defined in TS 18661-1:2014.
+@end deftypevr
+
+@comment math.h
+@comment ISO
@deftypevr Macro int FP_ILOGBNAN
@code{ilogb} returns this value if its argument is @code{NaN}. The
numeric value is either @code{INT_MIN} or @code{INT_MAX}.
@@ -612,6 +632,15 @@ numeric value is either @code{INT_MIN} or @code{INT_MAX}.
This macro is defined in @w{ISO C99}.
@end deftypevr
+@comment math.h
+@comment ISO
+@deftypevr Macro {long int} FP_LLOGBNAN
+@code{llogb} returns this value if its argument is @code{NaN}. The
+numeric value is either @code{LONG_MIN} or @code{LONG_MAX}.
+
+This macro is defined in TS 18661-1:2014.
+@end deftypevr
+
These values are system specific. They might even be the same. The
proper way to test the result of @code{ilogb} is as follows: