http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56888
--- Comment #23 from rguenther at suse dot de <rguenther at suse dot de> --- On Wed, 2 Oct 2013, bernd.edlinger at hotmail dot de wrote: > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56888 > > --- Comment #22 from Bernd Edlinger <bernd.edlinger at hotmail dot de> --- > (In reply to Richard Biener from comment #21) > > -fno-tree-loop-distribute-patterns is the reliable way to not transform > > loops > > into library calls. > > Thanks! > > Adding this fixed the generated code: > > #pragma GCC optimize ("no-tree-loop-distribute-patterns") > > BTW their memset.c looks like this: > > externC void * > memset( void *s, int c, size_t n ) __attribute__ ((weak, alias("_memset"))); > > void * > _memset( void *s, int c, size_t n ) > { > while (...) > } I suspect this is the most common form - glibc also uses aliases but IIRC they are using global asms for them :/ The above would be still detectable with the new symbol table / alias handling in GCC 4.9 (and maybe 4.8, I'm not sure). So it may be worth special-casing the "direct recursion" case as a QOI measure.
