ieeeFlags do not work properly

[Torben Hagerup]

Run under D version 2.037, the program below runs through without raising any 
assert exceptions. This shows an erratic behavior with respect to ieeeFlags 
that is hardly intended. Other ieeeFlags also work (or, rather, do not work) in 
unexpected ways.



import std.math;

void main() {
// The execution leads to no assert errors
 real a,b=3.5;
 resetIeeeFlags();
 assert(!ieeeFlags.divByZero); // so far no zero division
 a=3.5/0.0L; // but now ...
 assert(a==real.infinity); // yes, exactly
 assert(!ieeeFlags.divByZero); // perhaps not, after all
 b/=0.0L; // once more, the same, really
 assert(b==real.infinity); // yes, the same
 assert(ieeeFlags.divByZero); // oops, not the same after all?
}

Re: ieeeFlags do not work properly

[Lars T. Kyllingstad]

Torben Hagerup wrote:

Run under D version 2.037, the program below runs through without raising any 
assert exceptions. This shows an erratic behavior with respect to ieeeFlags 
that is hardly intended. Other ieeeFlags also work (or, rather, do not work) in 
unexpected ways.



import std.math;

void main() {
// The execution leads to no assert errors
 real a,b=3.5;
 resetIeeeFlags();
 assert(!ieeeFlags.divByZero); // so far no zero division
 a=3.5/0.0L; // but now ...
 assert(a==real.infinity); // yes, exactly
 assert(!ieeeFlags.divByZero); // perhaps not, after all
 b/=0.0L; // once more, the same, really
 assert(b==real.infinity); // yes, the same
 assert(ieeeFlags.divByZero); // oops, not the same after all?
}


Hi!

Please report bugs in Bugzilla:

  http://d.puremagic.com/issues/index.cgi

This newsgroup is just a feed from Bugzilla.

-Lars

Re: ieeeFlags do not work properly

[Don]

Torben Hagerup wrote:

Run under D version 2.037, the program below runs through without raising any 
assert exceptions. This shows an erratic behavior with respect to ieeeFlags 
that is hardly intended. Other ieeeFlags also work (or, rather, do not work) in 
unexpected ways.




This isn't a bug.


import std.math;

void main() {
// The execution leads to no assert errors
 real a,b=3.5;
 resetIeeeFlags();
 assert(!ieeeFlags.divByZero); // so far no zero division
 a=3.5/0.0L; // but now ...


This occurred at compile time. At runtime, this became:
a = real.infinity;


 assert(a==real.infinity); // yes, exactly
 assert(!ieeeFlags.divByZero); // perhaps not, after all
 b/=0.0L; // once more, the same, really


It's not the same. This is a runtime division by zero.


 assert(b==real.infinity); // yes, the same
 assert(ieeeFlags.divByZero); // oops, not the same after all?
}