MSP430 IAR C/C++ Compiler reference guide - Rice University

Descriptions of intrinsic functions__set_R4_registerSyntaxDescriptionvoid __set_R4_register(unsigned short);Writes a specific value to the R4 register. This intrinsic function is only available whenR4 is locked.See also --lock_r4, page 154__set_R5_registerSyntaxDescriptionvoid __set_R5_register(unsigned short);Writes a specific value to the R5 register. This intrinsic function is only available whenR5 is locked.See also --lock_r5, page 154__set_SP_registerSyntaxDescriptionvoid __set_SP_register(unsigned short);Writes a specific value to the SP stack pointer register. A warning message is issued ifthe compiler has used the stack in any way at the location where this intrinsic functionis used.__swap_bytesSyntaxDescriptionExampleunsigned short __swap_bytes(unsigned short);Inserts an SWAPB instruction and returns the argument with the upper and lower partsinterchanged.__swap_bytes(0x1234)returns 0x3412.224MSP430 IAR C/C++ CompilerReference Guide