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Re: flow patch for condexec
On Wed, Feb 21, 2001 at 09:04:53PM -0500, Michael Meissner wrote:
> ... having undefined makes nested IF-THEN statements easier.
Not really. "Undefined" is a horrible model.
> 3) CR2 = TEST2 if (CR1)
> 4) CR2 = CR2 & CR1
> In instruction #3, CR2 gets undefined if CR1 is false or undefined.
Much better is ia64's .unc tests. E.g.
(p5) cmp.lt.unc p6, p7 = r5, r6
p6 <= p5 & (r5 < r6)
p7 <= p5 & ! (r5 < r6)
A definite "and" is better, imo, than a mushy "undefined".