Re: [Qemu-devel] [PATCH] bitops: unify bitops_ffsl with the one in host-utils.h

[Richard Henderson]

On 01/30/2013 09:46 AM, Paolo Bonzini wrote:
> > >Nevertheless I wonder why you don't use gcc's __builtin_ffsl.
> Because I had no idea it existed until now. :)
> Do you know what version of GCC introduced it?

gcc 3.4.

> 2003-02-01  Falk Hueffner  <address@hidden>
>
>         * optabs.h (optab_index): Add OTI_clz, OTI_ctz, OTI_popcount and
>         OTI_parity.
>         (clz_optab, ctz_optab, popcount_optab, parity_optab): New.
>         * optabs.c (widen_clz, expand_parity): New.
>         (expand_unop): Handle clz and parity.  Hardcode SImode as outmode
>         for libcalls to clz, ctz, popcount, and parity.
>         (init_optabs): Init clz_optab, ctz_optab, popcount_optab and
>         parity_optab, and set up libfunc handlers.
>         * libgcc2.c (__clzsi2, __clzdi2, __ctzsi2, __ctzdi2,
>         __popcountsi2, __popcountdi2, __paritysi2 __paritydi2,
>         __popcount_tab): New.
>         * libgcc2.h: Declare them.
>         * libgcc-std.ver (GCC_3.4): Add new functions from libgcc2.c.
>         * genopinit.c (optabs): Add clz_optab, ctz_optab, popcount_optab
>         and parity_optab.
>         * builtin-types.def (BT_FN_INT_LONG, BT_FN_INT_LONGLONG): New.
>         * builtins.def (BUILT_IN_CLZ, BUILT_IN_CTZ, BUILT_IN_POPCOUNT,
>         BUILT_IN_PARITY, BUILT_IN_FFSL, BUILT_IN_CLZL, BUILT_IN_CTZL,
>         BUILT_IN_POPCOUNTL, BUILT_IN_PARITYL, BUILT_IN_FFSLL,
>         BUILT_IN_CLZLL, BUILT_IN_CTZLL, BUILT_IN_POPCOUNTLL,
>         BUILT_IN_PARITYLL): New.
...


r~