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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