interesting (but annoying) tidbit warning suppressed

This changeset is to suppress clang's -Wimplicit-int-float-conversion
warning.

In 64 bit signed long and IEEE 754 double combination (== almost
everyone these days), LONG_MAX is 9,223,372,036,854,775,807.  This
value is _not_ exactly representable by double.  The nearest value
that a double can represnt is 9,223,372,036,854,775,808. It is one
greater than LONG_MAX.  Let's call this value the "x".

The expression `LONG_MAX < yi` is a long versus double comparison.
According to ISO/IEC 9899:1999 Section 6.3.1.8 (that defines the
"usual rithmetic conversions"), The long value must first be casted
into double.  Because FLT_ROUNDS is typically 1 ("round to the
nearest" mode), the conversion yields the "x" value shown above.  So
the comparison is in fact `x < yi`.

This comparison is false for yi == x situation, i.e. yi is still
bigger than LONG_MAX.  On such situation the `yn = (long)yi;`
statement that appear several lines below renders underfined
behaviour, as per ISO/IEC 9899:1999 Section 6.3.1.3.

To remedy, we just change the comparison from `<` to `<=` so that
yi == x situation can properly be handled.

0 files changed, 0 insertions, 0 deletions