Squelch HOST_FLOAT_WORDS_BIG_ENDIAN

Thu Mar 13 20:41:00 GMT 2003

Richard Henderson <rth@redhat.com> writes:
> On Thu, Mar 13, 2003 at 10:55:30AM -0800, Zack Weinberg wrote:
>> float qnan = __builtin_nanf(0);
>> 0 is not a valid argument. "0" is.

Bleh. real_nan() returns the result of get_canonical_[qs]nan if
passed a null pointer, and I mistakenly thought __builtin_nan would do
the same.
Changing it to "0" makes cc1 happy, but not cc1plus; I still get
test.cc:3: error: `double __builtin_nan(const char*)' cannot appear in a 
 constant-expression
from
class Double {
public:
 static const double NaN = __builtin_nan("0");
};
>> 0x1.0p+INF
>> 0x1.xxxxxxp+NAN (QNAN, SNAN)
>>>> which would require less fragile special-casing of builtin functions, etc.)
>> Doesn't that run afoul of p-numbers etc?

No. Arbitrary sequences of identifier-nondigits may appear at any
position in a pp-number except immediately before [+-] (where [eEpP]
is required). See C99 6.4.8p1,2.
zw