Chapter 1 discussed the
difference between instructions that access memory (
stores) and instructions that do actual
computation (integer instructions, floating-point instructions, etc.).
Just like integer instructions are executed in the IUs and
floating-point instructions are executed in the FPUs, memory access
instructions have their own specialized execution units in the form of
one or more load-store units (LSUs).
Chapter 1 also discussed the
fact that in order to access memory via a
load or a
store, it’s usually necessary to perform an address calculation so the processor can figure out the location in memory that it should access. Even though such address calculations are just simple integer operations, they’re ...