
CPU Register File - peter_d_sherman
https://en.wikipedia.org/wiki/Register_file
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peter_d_sherman
A few selcted excerpts:

"In simpler CPUs, these _architectural registers_ correspond one-for-one to
the entries in a physical register file (PRF) within the CPU. More complicated
CPUs use register renaming, so that the mapping of which physical entry stores
a particular architectural register changes dynamically during execution.[1]"

"The Alpha 21264 (EV6), for instance, was the first large micro-architecture
to implement "Shadow Register File Architecture". It had two copies of the
integer register file and two copies of floating point register that locate in
its front end (future and scaled file, each contain 2 read and 2 write port),
and took an extra cycle to propagate data between the two during context
switch. The issue logic attempted to reduce the number of operations
forwarding data between the two and greatly improved its integer performance
and help reduce the impact of limited number of GPR in superscalar and
speculative execution. The design was later adapted by SPARC, MIPS and some
later x86 implementation."

Related: Architectural Registers Vs. Physical Registers

All truly open CPU designs would extensively document all Architectural
Registers, not merely Physical Registers, that the CPU's Instruction Set
Architecture (ISA) document usually documents...

And all of the microcode, and what it does, as well...

