Register allocation is an important method in the final phase of the compiler .
Registers are faster to access than cache memory .
Registers are available in small size up to few hundred Kb .
Thus it is necessary to use minimum number of registers for variable allocation .Dec 29, 2020.
The computer can quickly read and write registers in the CPU, so the computer program runs faster when more variables can be in the CPU's registers.
Also, sometimes code accessing registers is more compact, so the code is smaller, and can be fetched faster if it uses registers rather than memory..
Optimized register usage is the responsibility of the compiler.
HLL programs have no explicit references to registers.
The objective of compiler is to keep the operands for as many computations as possible in registers to minimize load-and-store operations..
Register allocation consists therefore of choosing where to store the variables at runtime, i.e. inside or outside registers.
If the variable is to be stored in registers, then the allocator needs to determine in which register(s) this variable will be stored..
The key areas of code optimization in compiler design are instruction scheduling, register allocation, loop unrolling, dead code elimination, constant propagation, and function inlining.
These techniques aim to make code faster, more efficient, and smaller while preserving its functionality..
In computing, an optimizing compiler is a compiler that tries to minimize or maximize some attributes of an executable computer program.
Common requirements are to minimize a program's execution time, memory footprint, storage size, and power consumption (the last three being popular for portable computers)..
