------------------------------------------------------------------ Sender:Richard Biener <richard.guent...@gmail.com> Sent At:2020 Mar. 3 (Tue.) 17:36 Recipient:Andrew Pinski <pins...@gmail.com> Cc:bin.cheng <bin.ch...@linux.alibaba.com>; GCC Patches <gcc-patches@gcc.gnu.org> Subject:Re: [PATCH PR93674]Avoid introducing IV of enumeral type in case of -fstrict-enums
On Mon, Mar 2, 2020 at 6:14 PM Andrew Pinski <pins...@gmail.com> wrote:
>
> On Mon, Mar 2, 2020 at 1:40 AM Richard Biener
> <richard.guent...@gmail.com> wrote:
> >
> > On Mon, Mar 2, 2020 at 9:07 AM bin.cheng <bin.ch...@linux.alibaba.com>
> > wrote:
> > >
> > > Hi,
> > > This is a simple fix for PR93674. It adds cand carefully for enumeral
> > > type iv_use in
> > > case of -fstrict-enums, it also avoids computing, replacing iv_use with
> > > the candidate
> > > so that no IV of enumeral type is introduced with -fstrict-enums option.
> > >
> > > Testcase is also added. Bootstrap and test on x86_64. Any comment?
> >
> > I think we should avoid enum-typed (or bool-typed) IVs in general, not just
> > with -fstrict-enums. That said, the ENUMERAL_TYPE checks should be
> > !(INTEGER_TYPE || POINTER_TYPE_P) checks.
>
> Maybe even check type_has_mode_precision_p or
> TYPE_MIN_VALUE/TYPE_MAX_VALUE have the same as the min/max for that
> precision/signedness.
Indeed we don't want non-mode precision INTEGER_TYPE IVs either. I wouldn't
check TYPE_MIN/MAX_VALUE here though.
Here is the updated patch with more checks. I also removed the
computation/elimination part for now.
Thanks,
bin
2020-03-19 Bin Cheng <bin.ch...@linux.alibaba.com>
PR tree-optimization/93674
* tree-ssa-loop-ivopts.c (add_iv_candidate_for_use): Don't add iv_cand
for iv_use which is not integer or pointer type, or non-mode precision
type. For such cases, add iv_cand for source operand if it's
converted from other one.
(get_computation_cost, may_eliminate_iv): Avoid compute, eliminate
iv_use with enumeral type iv_cand in case of -fstrict-enums.
gcc/testsuite
2020-03-19 Bin Cheng <bin.ch...@linux.alibaba.com>
PR tree-optimization/93674
* g++.dg/pr93674.C: New test.
0001-Don-t-add-iv_cand-for-iv_use-with-non-mode-precision.patch
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