I'm compiling an Android kernel for my Xperia Z using Linaro GCC 4.9. My question is, which option gives better optimization -mcpu=cortex-a15 or -march=armv7ve? Or do they give the same results?
-mcpu tells it to generate code SPECIFICALLY for a certain chip.
-mcpu implies -mtune, but will also cause the compiler to emit instructions specific to the target processor.
This does not guarantee binary compatibility with other chips based on a different microarchitecture.
So, i think:
-mcpu=cortex-a15 gives a better optimization.