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98e903e7a0
bison, keeping full compatibility with our previous yacc implementation. Also bring the ability to create reentrant parser This fix bin/140309 [1] PR: bin/140309 [1] Submitted by: Philippe Pepiot <ksh@philpep.org> [1] Approved by: des (mentor) MFC after: 1 month
10 lines
504 B
Plaintext
10 lines
504 B
Plaintext
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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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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