On Sunday, 9 April 2017 at 07:12:51 UTC, Patrick Schluter wrote:
32 bit modes support for PIC is painful because the RIP
relative addressing mode does not exist. AMD introduced it when
they added 64 bit support in the Opteron processors. In 32 bit
mode it was possible to generate PIC code but it required some
ugly hacks (CALL 0) which broke some hardware optimization (the
return address target cache) and adds a layer of indirection
for shared libraries (GOT), which had the consequence of
breaking the sharing, i.e. .so and .dll weren't really shared
in 32 bit mode.
Here an in depth article that I haven't yet read but seem to be
interesting on the subject
https://www.technovelty.org/c/position-independent-code-and-x86-64-libraries.html
Of course, this has nothing to do with D per se.
Thanks for the explanation. TBH I find myself wondering whether
`-fPIC` should be in the flags defined in dmd.conf _at all_ (even
for 64-bit environments); surely that should be on request of
individual project builds ... ?
