Compiler/MSP430FR6989: Could someone explain "intrinsics" to me?

Start reading here: http://www.ti.com/lit/ug/slau132u/slau132u.pdf

Chapter 6.8 Using Intrinsics to Access Assembly Language Statements.

From a programming perspective, intrinsics are very similar to function calls.  But they are not implemented by calling a function.  Instead, they are implemented by a few instructions, and often just one instruction.  They allow you to access features of the MSP430 which are difficult, and sometimes impossible, to express in C.

Bálint Garas said:

More specifically, whats the difference between these 2 lines of code:

__bis_SR_register(GIE);

__enable_interrupt();

Please search for those intrinsics in the MSP430 compiler manual.

Thanks and regards,

-George