Sticky bits after trap

Fred J. Tydeman tydemanatybor.com
Wed Jul 21 13:40:27 PDT 1999


If the user's program does:
  disable traps
  raise exceptions -- no trap implies flags are set
  enable traps  -- assume no trap happens
  raise exceptions -- now a trap happens
  return from trap handler (which did nothing to flags)
  test flags
Are the flags still set?  Or, are they undefined?

IEEE-754 8.1 Trap Handler:  "Similarly, the flag(s)
corresponding to the exceptions being signaled with their
associated traps enabled may be undefined unless set or
reset by the trap handler."  

IEEE-754 7. Exceptions: "It [status flag] shall be reset
only at the user's request."  

So, there appears to me to be a contradiction in IEEE-754.
What is the intent of the committee?
---
Fred J. Tydeman    +1 (512) 255-8696   Tydeman Consulting
3711 Del Robles    tydemanatybor.com   Programming, testing, numerics
Austin, Texas 78727                    Voting member of J11 (ANSI "C")
USA            Sample C9X+FPCE tests:  ftp://jump.net/pub/tybor/





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