https://issues.dlang.org/show_bug.cgi?id=14865
Issue ID: 14865
Summary: Elide calling invariant for classes with no invariant
defined
Product: D
Version: D2
Hardware: All
OS: All
Status: NEW
Severity: enhancement
Priority: P1
Component: dmd
Assignee: [email protected]
Reporter: [email protected]
See relevant discussion:
http://forum.dlang.org/thread/[email protected]?page=1
It's a common knowledge that class invariant stays injected as a call to some
internal routine even if there is no user-defined invariant for a given class.
It should be elided or at the very least inlined and carried on to all of the
usual optimizations to avoid redundant null checks (it seems to check for null
pointer only by default).
Citing the relevant part of discussion:
On 8/3/15 12:59 PM, Dmitry Olshansky wrote:
> On 03-Aug-2015 19:54, Steven Schveighoffer wrote:
>> ALSO, make SURE you are compiling in release mode, so you aren't calling
>> a virtual invariant function before/after every call.
>
> This one is critical. Actually why do we have an extra call for trivial
> null-check on any object that doesn't even have invariant?
Actually, that the call to the invariant should be avoidable if the object
doesn't have one. It should be easy to check the vtable pointer to see if it
points at the "default" invariant (which does nothing).
-Steve
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