Opened 10 years ago

Closed 10 years ago

#152 closed task (fixed)

Apply performance options

Reported by: rudi Owned by:
Priority: minor Milestone: Qt 4.6.2
Component: General Version: 4.5.1 GA
Severity: low Keywords:
Cc:

Description

Since we need to use any piece of performance we can get and we don't have to support i386 CPUs, I suggest to let qmake generate the compiler options (for GCC4.x):

-march=i486 -mtune=generic

Don't expect wonders from that, but a small speed gain can be measured. The down side is, that the created code grows a bit in size.

Change History (6)

comment:1 Changed 10 years ago by Dmitry A. Kuminov

This needs to be tested using the BLIT test (see the test result table in #101). Once I get numbers and these numbers demonstrate a noticeable performance boost, I will enable it.

comment:2 Changed 10 years ago by Silvan Scherrer

speed w/o the above options:

driver/mode NO_DIVEDIVE=BLITDIVE=FBDIVE=FBSWM
Panorama/32bit (16M) 30258 41744 47460 44459

speed with the above options:

driver/mode NO_DIVEDIVE=BLITDIVE=FBDIVE=FBSWM
Panorama/32bit (16M) 31032 43670 48940 47789

comment:3 Changed 10 years ago by Dmitry A. Kuminov

Not that bad. (The FBSWM test is probably not in the line because it depends on where your mouse is and how intensively you move it). I think it's worth doing it. I don't think there is anybody running an i386 PC and wanting to use Qt4.

comment:4 Changed 10 years ago by Silvan Scherrer

Milestone: Qt EnhancedQt 4.6.2

i agree with the above and moved the ticket to 4.6.2 milestone.

comment:5 Changed 10 years ago by Dmitry A. Kuminov

Done in r720.

comment:6 Changed 10 years ago by Dmitry A. Kuminov

Resolution: fixed
Status: newclosed
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