Re: [PATCH v3 3/4] perf annotate: add powerpc support

[Michael Ellerman <mpe@ellerman.id.au>]

On Thu, 2016-06-30 at 11:44 +0530, Ravi Bangoria wrote:
> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> index 36a5825..b87eac7 100644
> --- a/tools/perf/util/annotate.c
> +++ b/tools/perf/util/annotate.c
> @@ -476,6 +481,125 @@ static int ins__cmp(const void *a, const void *b)
...
> +
> +static struct ins *ins__find_powerpc(const char *name)
> +{
> +	int i;
> +	struct ins *ins;
> +	struct ins_ops *ops;
> +	static struct instructions_powerpc head;
> +	static bool list_initialized;
> +
> +	/*
> +	 * - Interested only if instruction starts with 'b'.
> +	 * - Few start with 'b', but aren't branch instructions.
> +	 * - Let's also ignore instructions involving 'ctr' and
> +	 *   'tar' since target branch addresses for those can't
> +	 *   be determined statically.
> +	 */
> +	if (name[0] != 'b'             ||
> +	    !strncmp(name, "bcd", 3)   ||
> +	    !strncmp(name, "brinc", 5) ||
> +	    !strncmp(name, "bper", 4)  ||
> +	    strstr(name, "ctr")        ||
> +	    strstr(name, "tar"))
> +		return NULL;

It would be good if 'bctr' was at least recognised as a branch, even if we
can't determine the target. They are very common.

It doesn't look like we have the opcode handy here? Could we get it somehow?
That would make this a *lot* more robust.

cheers