Please note that as of October 24, 2014, the Nokia Developer Wiki will no longer be accepting user contributions, including new entries, edits and comments, as we begin transitioning to our new home, in the Windows Phone Development Wiki. We plan to move over the majority of the existing entries. Thanks for all your past and future contributions.

Enabling hardware floats on ARMV6 builds in Qt for Symbian projects

From Wiki
Jump to: navigation, search
Article Metadata
Tested with
Devices(s): Nokia N8-00, Nokia C6-00
Platform(s): Symbian^3
Keywords: floating point, float, double, hardware acceleration, math processor, armv6
Created: tuohirv (29 Apr 2015)
Last edited: hamishwillee (13 Jun 2012)


Floating point operations can be quite slow with Symbian^3 framework's default settings. Even though the ARMV6 processor is capable of hardware floating point calculations, by default the compiler provided with the SDK doesn't deploy them but uses software emulation instead.

The following snippet shows how you can enable the GCCE compiler to use its math processor when using floating point instructions within your Qt application for Symbian^3.

This can speed up the floating point operations up to 1000%.

The following code is to be placed under your project's .pro file's symbian {} section.


  • Qt 4.7 or higher is installed on your platform.


symbian: {
MMP_RULES += "OPTION gcce -march=armv6"
MMP_RULES += "OPTION gcce -mfpu=vfp"
MMP_RULES += "OPTION gcce -mfloat-abi=softfp"
MMP_RULES += "OPTION gcce -marm"
This page was last modified on 13 June 2012, at 04:47.
58 page views in the last 30 days.