Re: [PATCH] Fix PR30338, ICE in fold_comparison

[Roger Sayle <roger at eyesopen dot com>]

Hi Richard,

On Sun, 31 Dec 2006, Richard Guenther wrote:
>       /* Convert -1 - A to ~A.  */
>       if (INTEGRAL_TYPE_P (type)
>           && integer_all_onesp (arg0))
>         return fold_build1 (BIT_NOT_EXPR, type, arg1);

Historically, the better fix and prevalent idiom in fold-const.c would
be to use "fold_convert (type, arg1)" instead of "op1".  There was a time
when "op1" couldn't be guaranteed to be of type "type" (but things are
improving), and the utility of stripping NON_LVALUE_EXPR and other junk
nodes is becoming less significant with my plans to obsolete/deprecate
that tree code (once the C front-end is actively maintained).  So in the
near future, the benefits of avoiding allocating a new tree node and
leaking the old one, will probably outweigh traditional usage.

What do you think?

Roger
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