Function Calls and Returns: Stack Frames, call, and ret

To the CPU, a function call is a small set of agreed-upon moves: call jumps in, the prologue sets the stage, the epilogue cleans up, and ret jumps back. This topic walks each move instruction by instruction; what leaf functions save, which way the stack grows, and what -O2 rewrites are all settled by assembly.

STARTFINISHOne Function Call, as the CPU Sees It→STARTFINISHLeaf Functions, Stack Direction, and Call Sites at -O2→STARTFINISHFunctions That Keep Their Stack Frames, and Recursion That Fills the Stack→