[Interest] Compiler optimisation flags on Android

[Thiago Macieira]

On segunda-feira, 2 de maio de 2016 22:07:03 PDT Nuno Santos wrote:
> Hi,
> 
> Below are the CFLAGS for Android
> (Qt/5.6/android_armv7/mkspecs/android-g++/qmake.conf)
> 
> I’m wondering why there are no optimisation settings for arm rather than
> size. Is there any specific reason?

Why should there be?

> } else { # arm
>     QMAKE_CFLAGS_RELEASE                   = -Os -fomit-frame-pointer
> -fno-strict-aliasing -finline-limit=64 
>     QMAKE_CFLAGS_RELEASE_WITH_DEBUGINFO   = -g -Os -fomit-frame-pointer 
>     -fno-strict-aliasing -finline-limit=64
>     QMAKE_CFLAGS_DEBUG                     = -g -marm -O0 -fno-omit-frame-
>     pointer 
>     equals(ANDROID_TARGET_ARCH, armeabi):if(equals(NDK_TOOLCHAIN_VERSION,
> 4.8)|equals(NDK_TOOLCHAIN_VERSION, 4.9)) {
>         DEFINES += QT_OS_ANDROID_GCC_48_WORKAROUND
>     } else {
>         QMAKE_CFLAGS_RELEASE += -mthumb
>         QMAKE_CFLAGS_RELEASE_WITH_DEBUGINFO += -mthumb
>     }
> }

This section you pasted contradicts your statement. There are more 
optimisation flags besides -Os.

-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center