[patch tree-optimization]: Improve handling of conditional-branches on targets with high branch costs

[Michael Matz]

Hi,

On Wed, 12 Oct 2011, Kai Tietz wrote:

> > And I think it could use some overview of the transformation done like in
> > the initial patch, ala:
> >
> > "Transform ((A && B) && C) into (A && (B & C))."
> >
> > and
> >
> > "Or (A && B) into (A & B)." for this part:
> >
> > + Â  Â  /* Needed for sequence points to handle trappings, and side-effects. Â */
> > + Â  Â  else if (simple_operand_p_2 (arg0))
> > + Â  Â  Â  return fold_build2_loc (loc, ncode, type, arg0, arg1);
> 
> Well to use here binary form of operation seems to me misleading.

Hmm?  What do you mean?  Both operations are binary.  ANDIF is '&&', AND 
is '&'.  In fold-const.c comments we usually use the C notations of the 
operations.

> It is right that the non-IF AND/OR has finally the same behavior as the 
> binary form in gimple.  Nevertheless it isn't the same on AST level. But 
> sure I can Add comments for operations like (A OR/AND-IF B) OR/AND-IF C 
> -> (A OR/AND-IF (B OR/AND C and A OR/AND-IF C -> (A OR/AND C)

Too much noise, leave out the || variant, and just say once "Same for ||."


Ciao,
Michael.