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Subject: Re: [PATCH] Fortran: fix simplification of intrinsics IBCLR and IBSET
 [PR106557]
To: Harald Anlauf <anlauf@gmx.de>, fortran <fortran@gcc.gnu.org>,
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From: Mikael Morin <morin-mikael@orange.fr>
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Le 20/08/2022 à 21:11, Harald Anlauf via Fortran a écrit :
> Dear all,
> 
> the simplification of the TRANSFER intrinsic produces a
> redundant representation of the result, one in expr->value
> and another in expr->representation.string.  This is done
> to ensure a safe "round-trip" for nested TRANSFER.
> 
> In a subsequent use of this result we either need to make
> sure that both parts stay consistent, or drop the latter
> part.
> 
> The simplifications of IBCLR and IBSET do a gfc_copy_expr
> of their argument x and modify only the former part.
> Depending on context, either value.integer or
> representation.string (if non-NULL) are used later,
> leading to surprising results.
> 
> A conservative approach to fix this PR is to simply
> drop the unneeded representation.string in the
> simplification of the intrinsics IBCLR and IBSET,
> see attached patch.  (A quick glance did not turn up
> other intrinsics affected the same way.)
> 
> Regtested on x86_64-pc-linux-gnu.  OK for mainline?
> 
Yes, thanks.