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.
Added by shyouhei (Shyouhei Urabe) about 6 years ago
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 < yiis 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 thatyi == x situation can properly be handled.