On 1/27/18 9:50 AM, ag0aep6g wrote:
Wow, that looks really bad.
Apparently, dmd implements `i < 0` as a `i >> 31`. I.e., it shifts the
bits to the right so far that only the sign bit is left. This is ok.
But it implements `i > 0` as `(-i) >> 31`. That would be correct if
negation would always flip the sign bit. But it doesn't for `int.min`.
`-int.min` is `int.min` again.
So dmd emits wrong code for `i > 0`. O_O
I've filed an issue:
https://issues.dlang.org/show_bug.cgi?id=18315
This is insane. i > 0 is used in so many places. The only saving grace
appears to be that int.min is just so uncommonly seen in the wild.
I tested all the way back to 2.040, still has the same behavior.
-Steve
