On Tue, Apr 30, 2013 at 11:46 PM, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Mon, 29 Apr 2013 09:20:25 +0200 Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote: >> On Mon, Apr 29, 2013 at 7:40 AM, Chanho Min <chanho.min@xxxxxxx> wrote: >> > Some architectures need __clzsi2() or __clzdi2() for __builtin_clz and >> > It causes build failure. They can be implemented using the fls() and >> > overridden by linking arch-specific versions may not be implemented yet. >> > >> > Reference: https://lkml.org/lkml/2013/4/18/603 >> > Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> >> > Signed-off-by: Chanho Min <chanho.min@xxxxxxx> >> >> Thanks, this fixes the link error on m68k, so >> >> Acked-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> > > It doesn't work for alpha (gcc-4.4.4): > > ERROR: "__ctzdi2" [lib/lz4/lz4hc_compress.ko] undefined! > ERROR: "__ctzdi2" [lib/lz4/lz4_compress.ko] undefined! > > akpm3:/usr/src/25> nm vmlinux|grep ctzd > akpm3:/usr/src/25> > > I assume the linker threw the code away. No, the link errors are for __ctzdi2, not __clzdi2. __ctzdi2 can be implemented using __ffs(). > How's about we stop using __builtin_ctz[ll]() altogether? Use N-fls()? That was my first suggestion ;-) > btw, this: > > int __weak __clzsi2(int val) > { > return BITS_PER_LONG - fls(val); > } > > looks wrong. It will give a different result for 32- and 64-bit. Indeed. It should be hardcoded 32. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
