Upsidedown MIPS Stack

Stack-like behavior is sometimes called "LIFO" for Last In First Out.

The data elements in our stacks are 32-bit words. In general, stacks can be used for all types of data. But in these chapters, stacks contain only 32-bit MIPS full words.

The picture shows a stack of MIPS full words. The stack pointer register $sp by convention points at the top item of the stack. The stack pointer is register $29 by software convention. The mnemonic register name $sp is used by the extended assembler.

In the usual way of drawing memory the stack is upside down. In the picture, the top item of the stack is 81. The bottom of the stack contains the integer -92.

Before the operating system starts your program it ensures that there is a range of memory for a stack and puts a suitable address into $sp.