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Re: PATCH: PR rtl-optimization/39241: [4.4 Regression] ICE in subreg_get_info, at rtlanal.c:3104
> The original patch, which caused this regression, calls
> subreg_offset_representable_p and subreg_regno_offset.
> Both of them are wrappers for subreg_get_info. I don't
> see a reason to make 2 calls to subreg_get_info
> instead of one call. Why do we unnecessarily make
> gcc to run slower?
As you noted, this was the pre-existing idiom used in jump.c (true_regnum) so
the patch was consistent in this respect. We'll revisit that for 4.5.
> BTW, there are no regressions when 2 calls
> to subreg_offset_representable_p are removed.
>
> Can I check in the patch just to remove 2 calls
> to subreg_offset_representable_p?
Yes, the patch that just removes the 2nd and 4th calls is pre-approved for
mainline, assuming that it does fix the PR. Thanks for your patience.
--
Eric Botcazou