Re: [Chicken-janitors] #823: arithmetic-shift fails in extreme cases (was: arithmetic-shift fails in exactly one edge case)

[Chicken Trac]

#823: arithmetic-shift fails in extreme cases
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  Reporter:  sjamaan         |       Owner:                                     
    
      Type:  defect          |      Status:  new                                
    
  Priority:  minor           |   Milestone:  4.9.0                              
    
 Component:  core libraries  |     Version:  4.7.x                              
    
Resolution:                  |    Keywords:  edge cases, numbers, shifting, 
overflow
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Comment(by sjamaan):

 Turns out there's also a bug when shifting more than C_WORD_SIZE
 positions.

 According to the [http://std.dkuug.dk/JTC1/SC22/WG14/www/docs/n843.htm C
 spec], shifting more than the number of bits in the type is undefined (#3
 in section 6.5.7, "bitwise shift operators").
 Shifting negative values is also pretty ill-defined (#4 and #5, final
 sentence in both).

 C: Don't you just ''love'' it?

-- 
Ticket URL: <http://bugs.call-cc.org/ticket/823#comment:1>
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