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RE: libm -fno-builtin
- From: Wilco Dijkstra <Wilco dot Dijkstra at arm dot com>
- To: Jon Beniston <jon at beniston dot com>
- Cc: nd <nd at arm dot com>, "newlib at sourceware dot org" <newlib at sourceware dot org>
- Date: Fri, 17 Aug 2018 13:49:24 +0000
- Subject: RE: libm -fno-builtin
Hi,
Yes -fno-builtin should not be used indeed as it disables lots of useful optimizations.
Removing -fno-builtin should have no negative effects except for eg. memcpy where
compilers can recognize an overly simplistic implementation and optimize it to a
call to memcpy... I think you will need a -fno-builtin-memcpy when building the size
optimized version of libc/string/memcpy.c given it is marked with restrict.
I think a config option is overkill.
Wilco