On Wed, Dec 19, 2012 at 01:34:34PM -0800, Teresa Johnson wrote:
> +#if IN_LIBGCOV
> + /* When building libgcov we don't include system.h, which includes
> + hwint.h (where floor_log2 is declared). However, libgcov.a
> + is built by the bootstrapped compiler and therefore the builtins
> + are always available. */
> + r = 63 - __builtin_clzll (v);
Perhaps it would be more portable to use
r = sizeof (long long) * __CHAR_BIT__ - 1 - __builtin_clzll (v);
here.
> +#else
> + /* We use floor_log2 from hwint.c, which takes a HOST_WIDE_INT
> + that is either 32 or 64 bits, and gcov_type_unsigned may be 64 bits.
> + Need to check for the case where gcov_type_unsigned is 64 bits
> + and HOST_WIDE_INT is 32 bits and handle it specially. */
> +#if LONG_LONG_TYPE_SIZE <= HOST_BITS_PER_WIDE_INT
If not in libgcov.a, we have
typedef unsigned HOST_WIDEST_INT gcov_type_unsigned;
in gcov-io.h. LONG_LONG_TYPE_SIZE is target long long size, you are
interested about the size of host gcov_type_unsigned.
So perhaps test HOST_BITS_PER_WIDEST_INT instead of LONG_LONG_TYPE_SIZE?
> + r = floor_log2 (v);
> +#else
> +#if LONG_LONG_TYPE_SIZE == 2 * HOST_BITS_PER_WIDE_INT
Likewise. Can't you use #elif above and get rid of one of the #endif lines?
> + HOST_WIDE_INT hwi_v = v >> HOST_BITS_PER_WIDE_INT;
> + if (hwi_v)
> + r = floor_log2 (hwi_v) + HOST_BITS_PER_WIDE_INT;
> + else
> + r = floor_log2 ((HOST_WIDE_INT)v);
> +#else
> + gcc_unreachable ();
> +#endif
> +#endif
> +#endif
> + }
>
Jakub
