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This patch makes the glibc build generate an additional header ldbl-compat-choose.h that defines LONG_DOUBLE_COMPAT_CHOOSE_* macros for each libc and libm symbol, which select one or the other of their arguments based on whether the symbol was added before a change to long double != double. The effect of this is that it is then possible to define a macro maybe_long_double_symbol that automatically acts as either long_double_symbol or weak_alias depending on when the symbol being defined was added. This can be used when building long double functions from type-generic templates. Thus, with this patch ldbl-opt no longer needs special long double implementations of each new libm function added using such a template, and the existing such implementations are removed. This is a step towards being able more generally to use common macros to create all the aliases needed for a libm function, so reducing the amount of special-case code needed in ldbl-opt and ldbl-64-128, and facilitating subsequently adding *f32 / *f64 / *f128 / *f32x / *f64x aliases to existing functions (where the set of aliases that a function should have may depend on the architecture in various ways). Tested with build-many-glibcs.py. Except for on powerpc64le-linux-gnu, installed stripped shared libraries are unchanged by the patch. powerpc64le-linux-gnu is the unique configuration which used ldbl-opt from the start rather than adding a new long double choice after originally only having had long double = double. The effect of the patch there is that various cases that previously used long_double_symbol unconditionally now use weak_alias instead, so .os files contain e.g. a symbol cabsl instead of cabsl@@GLIBC_2.17. The final dynamic symbols and versions in the resulting shared libraries are unchanged (ABI tests pass), as is the disassembly of the shared libraries, but the differences in the .os files still result in different .gnu_hash contents in libm.so; the differences are of no significance and logically using weak_alias is what's most appropriate in those cases. * scripts/versions.awk: Generate ldbl-compat-choose.h. * sysdeps/ieee754/ldbl-opt/math-type-macros-ldouble.h: Include <ldbl-compat-choose.h>. (maybe_long_double_symbol): New macro. [!declare_mgen_alias] (declare_mgen_alias): Use maybe_long_double_symbol. * sysdeps/ieee754/ldbl-opt/s_canonicalizel.c: Remove. * sysdeps/ieee754/ldbl-opt/s_fmaxmagl.c: Likewise. * sysdeps/ieee754/ldbl-opt/s_fminmagl.c: Likewise. * sysdeps/ieee754/ldbl-opt/s_nextdownl.c: Likewise. * sysdeps/ieee754/ldbl-opt/w_llogbl.c: Likewise. * Makerules [$(build-shared) = yes && !avoid-generated] (before-compile): Add $(common-objpfx)ldbl-compat-choose.h. [$(build-shared) = yes && !avoid-generated] ($(common-objpfx)ldbl-compat-choose.h): New target. |
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| .. | ||
| bits | ||
| dbl-64 | ||
| float128 | ||
| flt-32 | ||
| ldbl-64-128 | ||
| ldbl-96 | ||
| ldbl-128 | ||
| ldbl-128ibm | ||
| ldbl-opt | ||
| ieee754.h | ||
| k_standard.c | ||
| k_standardf.c | ||
| k_standardl.c | ||
| Makefile | ||
| s_lib_version.c | ||
| s_matherr.c | ||
| s_signgam.c | ||