2012-06-06 15:25:48 +02:00
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$NetBSD: NOTES,v 1.2 2009/10/29 00:56:19 christos Exp $
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2010-05-12 18:28:54 +02:00
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Berkeley Yacc reflects its origins. The reason so many routines
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use exactly six register variables is that Berkeley Yacc was
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developed on a VAX using PCC. PCC placed at most six variables
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in registers. I went to considerable effort to find which six
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variables most belonged in registers. Changes in machines and
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compilers make that effort worthless, perhaps even harmful.
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[Given the previous paragraph, and the fact that GCC does not respect
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register declarations, and the fact that much of the rest of the
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4.4lite2 release had "register" declarations extirpated, I've removed
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most of the register declarations from the code. I left them in the
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generated skeleton code "for the hell of it" but they probably should
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go from there, too. -- pm, July 1997]
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[I totally removed the register stuff; we've deprecated it elsewhere
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in the tree now -- lukem, October 1997]
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The code contains many instances where address calculations are
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performed in particular ways to optimize the code for the VAX.
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