421165 - Replace all users of NS_round with NS_floor(x+0.5)

Status: NEW

(Core :: Layout: Text and Fonts, defect)

Description

[Alfred Kayser]

Spin off from bug 405308:
Should we not at least create a bug to check all uses of NS_round and replace them with NS_floor(x+0.5) where possible? 
Any be add NS_roundup(x) { return floor(x + 0.5); } to nsMathUtils.h ?
All current users seems to work with positive numbers, and NS_round is more expensive than NS_floor, but the same for positive numbers, and is 'wrong' for negative numbers...

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

It should definitely be its own function (not putting the +0.5 in at all the callsites), as roc points out in bug 405308 comment 21.

Comment 2

[Robert O'Callahan (:roc) (email my personal email if necessary)]

In bug 413787 I asked Michael Moy to add the appropriate function to nsMathUtils.h. Let's do that and then use this bug to convert various call sites to use the new function.