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Re: [PATCH] Gimplify builtin_expect on short-circuiting conditionals


Paolo Bonzini writes:
> Adam Nemet wrote:
> > The gimplifier treats __builtin_expect as a regular function call.
> > This does not seem to work well if the argument is a logical
> > expression with short-circuit semantics.
> 
> This is PR21513:
> 
> http://gcc.gnu.org/ml/gcc-bugs/2005-12/msg01775.html

I also thought of doing this in fold_builtin_expect but then I
convinced myself that folding in the call expression is too late for
shortcutting so we need to look ahead.  I of course forgot about the
folding in the front-end.  I quickly tried and adding the
transformation into fold seems to achieve the same thing so I will
reimplement the patch along your ideas.  Thanks.

Adam


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