[RFC] How to add vector math functions to Glibc

[Andrew Senkevich]

>> +# We need to install libm.so as linker script
>> +# for more comfortable use of vector math library.
>> +subdir_install: $(inst_libdir)/libm.so
>> +
>> +$(inst_libdir)/libm.so: $(common-objpfx)format.lds \
>> + $(common-objpfx)math/libm.so$(libm.so-version) \
>> + $(common-objpfx)mathvec/libmvec.so$(libmvec.so-version) \
>> + $(+force)
>> + (echo '/* GNU ld script */';\
>> + cat $<; \
>> + echo 'GROUP ( $(slibdir)/libm.so$(libm.so-version) ' \
>> + 'AS_NEEDED ( $(slibdir)/libmvec.so$(libmvec.so-version) ) )' \
>> + ) > $@.new
>> + mv -f $@.new $@
>
> Do you have ordering issues here?  It seems bad for math/ to install a
> direct symlink and then mathvec/ to change it to something else - all
> installation rules for libm should be in the math/ directory.

Inserted in math/Makefile this rule produces warning about overriding
recipe for target libm.so (as I see rule for libm.so was already
generated from o-iterator.mk).

If use temporary target:

+subdir_install: $(inst_libdir)/libm.so.tmp
+$(inst_libdir)/libm.so.tmp: $(common-objpfx)format.lds \
+       $(common-objpfx)math/libm.so$(libm.so-version) \
+       $(common-objpfx)mathvec/libmvec.so$(libmvec.so-version) \
+       $(+force)
+       (echo '/* GNU ld script */';\
+       cat $<; \
+       echo 'GROUP ( $(slibdir)/libm.so$(libm.so-version) ' \
+       'AS_NEEDED ( $(slibdir)/libmvec.so$(libmvec.so-version) ) )' \
+       ) > $@
+       mv -f $@ $(inst_libdir)/libm.so

$(inst_libdir)/libm.so became overwritten later.
So I have temporary file and need to move it to $(inst_libdir)/libm.so
at the end.

If would be great if someone can give me advice how to do it.


--
WBR,
Andrew