Messages in this thread | | | Date | Fri, 10 Jun 2016 19:36:06 +0530 | From | "Naveen N. Rao" <> | Subject | Re: [PATCH 1/2] perf annotate: generalize handling of ret instructions |
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On 2016/06/10 10:30AM, Arnaldo Carvalho de Melo wrote: > Em Fri, Jun 10, 2016 at 06:32:50PM +0530, Naveen N. Rao escreveu: > > Introduce helper to detect ret instructions and use the same in the tui.
Hi Arnaldo, Thanks for the review.
> > Humm, I think this is simpler and equivalent, since so far we didn't had > any need for special handling of "retq"/"ret" instructions: > > diff --git a/tools/perf/ui/browsers/annotate.c b/tools/perf/ui/browsers/annotate.c > index 4fc208e82c6f..29cef599a091 100644 > --- a/tools/perf/ui/browsers/annotate.c > +++ b/tools/perf/ui/browsers/annotate.c > @@ -226,11 +226,11 @@ static void annotate_browser__write(struct ui_browser *browser, void *entry, int > ui_browser__write_nstring(browser, " ", 2); > } > } else { > - if (strcmp(dl->name, "retq")) { > - ui_browser__write_nstring(browser, " ", 2); > - } else { > + if (strcmp(dl->name, "retq") == 0 || strcmp(dl->name, "ret") == 0) {
This won't work on powerpc since we don't have a "ret" instruction. Returning from a function is *usually* done through some variant of a branch to LR (Link Register) instruction. This logic is encoded in the powerpc-specific ins__find() in the next patch.
That was the motivation in introducing a helper for handling return instructions in the tui.
- Naveen
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