On 8/2/19 5:25 AM, Andrew Jones wrote:
> +/*
> + * SVE registers are encoded in KVM's memory in an endianness-invariant
> format.
> + * The byte at offset i from the start of the in-memory representation
> contains
> + * the bits [(7 + 8 * i) : (8 * i)] of the register value. As this means the
> + * lowest offsets are stored in the lowest memory addresses, then that nearly
> + * matches QEMU's representation, which is to use an array of host-endian
> + * uint64_t's, where the lower offsets are at the lower indices. To complete
> + * the translation we just need to byte swap the uint64_t's on big-endian
> hosts.
> + */
> +#ifdef HOST_WORDS_BIGENDIAN
> +static uint64_t *sve_bswap64(uint64_t *dst, uint64_t *src, int nr)
> +{
> + int i;
> +
> + for (i = 0; i < nr; ++i) {
> + dst[i] = bswap64(src[i]);
> + }
> +
> + return dst;
> +}
> +#endif
Maybe better as
static uint64_t *sve_bswap64(uint64_t *tmp, uint64_t *src, int nr)
{
#ifdef HOST_WORDS_BIGENDIAN
int i;
for (i = 0; i < nr; ++i) {
tmp[i] = bswap64(src[i]);
}
return tmp;
#else
return src;
#endif
}
and then the rest of the ifdefs can be removed.
Otherwise,
Reviewed-by: Richard Henderson <[email protected]>
r~
