henry@utzoo.UUCP (Henry Spencer) (07/24/84)
Has anybody got yacc up on a machine which has distinct 0 and -0?
If so, did you have any fun? I just noticed that yacc actually
generates code using -0 as a subscript.
--
Henry Spencer @ U of Toronto Zoology
{allegra,ihnp4,linus,decvax}!utzoo!henrygwyn@brl-tgr.ARPA (Doug Gwyn <gwyn>) (07/26/84)
I don't think "-0" at the source code level will cause any problem. I used to use ones' complement machines and the only way you could get a -0 out of an arithmetic expression was by having ones for an operand. In particular, negating 0 would give (normal) 0.
louie@cvl.UUCP (07/26/84)
<for all you do, this one's for you>
We run UNIX on our Sperry 1100/80 system from time to time, and it has
one's compliment hardware. The -0 subscript shouldn't be a problem,
because the hardware treats -0 the same as +0 as far as arithmetic
operations are concerned.
Here's for UNIX on the big guys....
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Louis A. Mamakos - Computer Science Center (Systems Staff) - Univ. of Maryland
Internet: louie@cvl.ARPA uucp: ...!{seismo,ihnp4,allegra}!rlgvax!cvl!louie
Why would you even think that the opinions expressed are those of my employer?gwyn@BRL-VLD.ARPA (07/28/84)
From: Doug Gwyn (VLD/VMB) <gwyn@BRL-VLD.ARPA> Upon further reflection, I realize that a C implementer on a 1's-complemenet machine may have made a mistake and implemented negation (unary minus) by ones'-complementing the (integer) value instead of correctly subtracting it from zero, so Henry's query amounts to asking whether any C implementer on a 1's-complement machine was so foolish.