unary +

[Gregory Smith]

In article <1147 at lsuc.UUCP> msb at lsuc.UUCP (Mark Brader) writes:
>
>People who don't think (a+b)+c, a+(b+c), and a+b+c should be
>interchangeable with respect to optimization -- as they are and
>will continue to be -- should consider this toy example:
>
>	#define  C_TO_F(temp)		((temp)*1.8 + 32)
>	#define  JUST_ABOVE(temp)	((temp) + epsilon) /* extern epsilon */
>	#define  ROUND(real)		((long) .5 + (real))
>
>	scanf ("%d", &melt_pt);
>	desired_f_temp = ROUND (JUST_ABOVE (C_TO_F (melt_pt)));
>
>There are, of course, NO unnecessary parentheses in the example*.
[example deleted, illustrating why C should be allowed to ignore ()'s in
evaluating expressions]
-But- ROUND(real) should be ((long)(.5+(real))). Casts are more bindish than
+. So the example carries evan more weight.

-- 
"So this is it. We're going to die."	- Arthur Dent
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Greg Smith     University of Toronto       ..!decvax!utzoo!utcsri!greg