fetch 4 i/c
5 units
32 slots for instruction window

This introduces one branch bubble
cycle, during which the RlOOOO decodes no instructions.

/!\ aux integer mul / div => compte comme '2' instructions

 Whenever
an instruction modifies a register, the processor assigns a
new physical register to the logical destination register and
stores these assignments in register map tables

When an exception occurs, however, subsequent instructions
never graduate. Instead, the processor restores old mappings
from the active list. The RlOOOO unmaps four
in:jtructions per cycle-in reverse order, in case it renamed
thme same logical register twice. Although this is slower than
restoring a branch, exceptions are much rarer than mispredicted
branches. The processor returns new physical registers
to the free lists by restoring their read pointers. 