This is the mail archive of the
newlib@sourceware.org
mailing list for the newlib project.
Re: libm -fno-builtin
- From: Joseph Myers <joseph at codesourcery dot com>
- To: "Richard Earnshaw (lists)" <Richard dot Earnshaw at arm dot com>
- Cc: Jon Beniston <jon at beniston dot com>, <newlib at sourceware dot org>
- Date: Tue, 26 Jun 2018 19:39:24 +0000
- Subject: Re: libm -fno-builtin
- References: <005301d407c1$b3a9a8b0$1afcfa10$@beniston.com> <2083f76d-7080-d31e-cd02-b4b8728feb31@arm.com>
On Mon, 25 Jun 2018, Richard Earnshaw (lists) wrote:
> The canonical example is something like memset. memset idioms are
> generally quite easy for the compiler to recognize and I've frequently
But -fno-builtin isn't what you want there (it's about recognising the
semantics of a call to a standard function, as opposed to generating a
call to a function not called in the source, and GCC always requires libc
to provide memcpy, memmove, memset and memcmp); to avoid converting loops
to mem* calls, you need -fno-tree-loop-distribute-patterns.
--
Joseph S. Myers
joseph@codesourcery.com