TASKING VX-toolset for ARM User Guide

TASKING VX-toolset for ARM User GuideRemove the exclusive lock created by __LDREXB, __LDREXH, or __LDREXW.1.10.4.1. Writing Your Own Intrinsic FunctionBecause you can use any assembly instruction with the __asm() keyword, you can use the __asm()keyword to create your own intrinsic functions. The essence of an intrinsic function is that it is inlined.1. First write a function with assembly in the body using the keyword __asm(). See Section 1.5, UsingAssembly in the C Source: __asm()2. Next make sure that the function is inlined rather than being called.You can do this with the functionqualifier inline.This qualifier is discussed in more detail in Section 1.10.2, Inlining Functions: inline.inline int __my_pow( int base, int power ){int result;__asm( "mov %0,%1\n""1:\n\t""subs %2,%2,#1\n\t""mulne %0,%0,%1\n\t""bne 1p\n\t", %2": "=&r"(result): "r"(base), "r"(power) );}return result;void main(void){int result;}// call to function __my_powresult = __my_pow(3,2);Generated assembly code:main: .type func; __my_pow code is inlined heremov r0,#2mov r1,#31:movr2,r1subs r0,r0,#1mulne r2,r2,r1bne 1pAs you can see, the generated assembly code for the function __my_pow is inlined rather than called.Numeric labels are used for the loop.34