https://issues.dlang.org/show_bug.cgi?id=13474
--- Comment #19 from Илья Ярошенко <[email protected]> --- (In reply to yebblies from comment #18) > (In reply to Илья Ярошенко from comment #17) > > (In reply to yebblies from comment #15) > > > > Why you have changed the name of this issue? > > Bug is not only for return. Truncation should be during all calculations. > > > > I changed the title because the old one was not accurate. The optimizer is > working as designed, even if that design is not what you want. > > Please change the title if you want to request no extra intermediate > precision anywhere, I just kept it to the scope of the original report. > > > > > Yes. D is unique language in this question. > > In other other words D is not a system language because it can't compile > > correctly IEEE 754 standard. > > > > I'm not sure this counts as violating IEEE 754, though I'm not an expert. C > has the same problem, so I guess C isn't a system language either by that > logic. C has this problem only when special compiler flags enabled. All this algorithms are from Python source code (C) or Wikipedia(C, Pascal). > > I am disappointed. > > All D contributors explain me that "it is a feature for precise math". > > But this feature prohibits price math: > > https://github.com/D-Programming-Language/phobos/pull/2513. > > > > Maybe. The logic in here does seem sound, although again I'm not an expert. > > http://dlang.org/d-floating-point.html > > So the idea is that strict double rounding would be a big performance hit, > and > > > The problem is that value isn't "more price". The value is wrong because > > truncation should be performed during ALL calculation. > > Technically the value _is_ more precise. The way it interacts with rounding > is what produces the incorrect result. > > Under the current spec the rounding is not required. > > > > > > 3. Lobbying Walter for a language change enforcing this in some way. > > > > Can you help me to do it? > > > > I don't know enough about the algorithms you're using to be sure either you > or Walter is right here. You may want to comment on issue 9937 and see if > Don agrees with you. --
