Messages in this thread | | | Date | Sun, 30 May 1999 21:18:24 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: linux-2.3.4pre1: Adjustments for using gcc builtins |
| |
On Fri, 28 May 1999, Horst von Brand wrote: > > After the recent problems with egcs snapshots, it was suggested that the > kernel don't use handcrafted mem* and str* functions, it better use the gcc > builtins. This gives rise to the first patch below: It just blows away the > redundant definitions in include/asm-i386/string.h and adds the symbols for > the functions to kernel/ksyms.c (gcc doesn't allways inline them for some > reason, falling back on the library functions).
Thcc gcc "builtins" are generally noticeably worse than the kernel headers.
Anyway, there is a really simple choice when it comes to compilers: we will choose the one that generates better code. For a long time it _seemed_ that egcs would be the choice, but if we have to disable the new alias code and/or use ugly tricks like the above then the choice is fairly clear - gcc-2.7.2 will still continue to generate better code.
I've asked the egcs people to give us some way to tell the compiler what's going on, but at least so far I haven't had any replies. As I know how gcc-2.7.2 can be made to generate the code I want, and nobody so far has told me how to get egcs to do the same, I know which compiler _I_ will recommend.
Linus
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |