IeeeFlags

IEEE exception status flags ('sticky bits')

These flags indicate that an exceptional floating-point condition has occurred. They indicate that a NaN or an infinity has been generated, that a result is inexact, or that a signalling NaN has been encountered. If floating-point exceptions are enabled (unmasked), a hardware exception will be generated instead of setting these flags.

version(IeeeFlagsSupport)

struct IeeeFlags {

bool inexact [@property getter];

bool underflow [@property getter];

bool overflow [@property getter];

bool divByZero [@property getter];

bool invalid [@property getter];

}

Members

Properties

divByZero bool divByZero [@property getter]: An infinity was generated by division by zero
inexact bool inexact [@property getter]: The result cannot be represented exactly, so rounding occurred.
invalid bool invalid [@property getter]: A machine NaN was generated.
overflow bool overflow [@property getter]: An infinity was generated by overflow
underflow bool underflow [@property getter]: A zero was generated by underflow

Examples

1 static void func() {
2     int a = 10 * 10;
3 }
4 pragma(inline, false) static void blockopt(ref real x) {}
5 real a = 3.5;
6 // Set all the flags to zero
7 resetIeeeFlags();
8 assert(!ieeeFlags.divByZero);
9 blockopt(a); // avoid constant propagation by the optimizer
10 // Perform a division by zero.
11 a /= 0.0L;
12 assert(a == real.infinity);
13 assert(ieeeFlags.divByZero);
14 blockopt(a); // avoid constant propagation by the optimizer
15 // Create a NaN
16 a *= 0.0L;
17 assert(ieeeFlags.invalid);
18 assert(isNaN(a));
19 
20 // Check that calling func() has no effect on the
21 // status flags.
22 IeeeFlags f = ieeeFlags;
23 func();
24 assert(ieeeFlags == f);

IeeeFlags

Members

Properties

Examples

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