On April 13, 2018 12:35:54 AM GMT+02:00, Jakub Jelinek <ja...@redhat.com> wrote: >On Thu, Apr 12, 2018 at 07:37:22PM +0200, Jakub Jelinek wrote: >> On Thu, Apr 12, 2018 at 05:29:35PM +0000, Wilco Dijkstra wrote: >> > > Depending on what you mean old, I see e.g. in 2010 power7 mempcpy >got added, >> > > in 2013 other power versions, in 2016 s390*, etc. Doing a decent >mempcpy >> > > isn't hard if you have asm version of memcpy and one spare >register. >> > >> > More mempcpy implementations have been added in recent years >indeed, but almost all >> > add an extra copy of the memcpy code rather than using a single >combined implementation. >> > That means it is still better to call memcpy (which is frequently >used and thus likely in L1/L2) >> > rather than mempcpy (which is more likely to be cold and thus not >cached). >> >> That really depends, usually when some app uses mempcpy, it uses it >very >> heavily. And all the proposed patches do is honor what the user >asked, if >> you use memcpy () + n, we aren't transforming that into mempcpy >behind the >> user's back. >> >> Anyway, here is what I think Richard was asking for, that I'm >currently >> bootstrapping/regtesting. It can be easily combined with Martin's >target >> hook if needed, or do it only for >> endp == 1 && target != const0_rtx && CALL_EXPR_TAILCALL (exp) >> etc. >> >> 2018-04-12 Martin Liska <mli...@suse.cz> >> Jakub Jelinek <ja...@redhat.com> >> >> PR middle-end/81657 >> * expr.h (enum block_op_methods): Add BLOCK_OP_NO_LIBCALL_RET. >> * expr.c (emit_block_move_hints): Handle BLOCK_OP_NO_LIBCALL_RET. >> * builtins.c (expand_builtin_memory_copy_args): Use >> BLOCK_OP_NO_LIBCALL_RET method for mempcpy with non-ignored target, >> handle dest_addr == pc_rtx. >> >> * gcc.dg/string-opt-1.c: Remove bogus comment. Expect a mempcpy >> call. > >Successfully bootstrapped/regtested on x86_64-linux and i686-linux.
OK. Thanks, Richard. > Jakub
