[Mono-bugs] [Bug 655380] String switch statement 2x slower if compared to simple list of if statements

bugzilla_noreply at novell.com bugzilla_noreply at novell.com
Tue Nov 23 06:28:30 EST 2010


https://bugzilla.novell.com/show_bug.cgi?id=655380

https://bugzilla.novell.com/show_bug.cgi?id=655380#c12


Paolo Molaro <lupus at novell.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|String switch statement     |String switch statement 2x
                   |runs 5x slower on iPhone if |slower if compared to
                   |compared to simple list of  |simple list of if
                   |if statements               |statements

--- Comment #12 from Paolo Molaro <lupus at novell.com> 2010-11-23 11:28:29 UTC ---
This is not an iphone issue: this is a bug about gmcs producing slow code for
no good reason on all the architectures and all the existing runtimes. You try
to push the blame when you give credit to sub millisecond benchmark numbers,
measure yourself that the code gmcs produces is always slow and still insist
that this is someone else problem ("I could implement if/else for smaller
counts but it makes sense only when our if comparison becomes as fast as .net
one").

We currently have no indication that on arm/iphone the code is significantly
slower than on other platforms: someone with an iphone needs to run the test
with reasonable repetition counts. If and when that happens, we'll open a
separate bug about dictionary lookups being slower with arm/aot code.

-- 
Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the QA contact for the bug.


More information about the mono-bugs mailing list