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Re: GCC beaten by ICC in stupid trig test!
Paul Koning wrote:
I don't have a C standard, but my copy of Harbison & Steele says what
I expected about parentheses: "Parentheses do not necessarily force a
particular evaluation order".
Harbison and Steele, whether read carefully or not :-) should not be
considered a substitute for the standard.
So as far as I can tell, by the language rules, (a+b)+c and a+(b+c)
are the same -- they have the same ordering properties (or lack
thereof).
I am unaware of any authority for this statement.
Is the implication that if -fno-fast-math is in effect, parentheses
acquire an ADDITIONAL semantic (evaluation order) that goes beyond the
C language definition (forcing operand grouping)?
I an unaware of any authority for this statement.
Curious that C++ (at least as described in Stroustrup) *does* say that
parentheses force evaluation order...
Not curious at all, of course parentheses control the evaluation order,
e.g. in (a+b)*c.
paul