I warn anybody before using ARM Keil 4.13a. It generates defective code. I have spent several hours with debugging a code that has been already worked. The problem affects local variables of functions and passing arguments. Code has been wrongly compiled without any optimization. I have no courage and time to test optimizations.
I also encourage Keil not to publish Keil 4.13a any more.
Keil 4.12 seems to be OK.
Jaroslav Fojtík,
Please don't give up! This is the only way to improve the Keil/our products!