By default, registers are the size of RegVal, the type often used to
store them. For some types of registers, like vector or vector predicate
registers, the size of each individual register is larger, and can't fit
in a primitive type.
To help facilitate storing even these outliers in a generalized way,
this change adds two fields to RegClassInfo to track the size of
individual registers. One tracks the raw size of the registers
themselves, and the other tracks the minimal shift necessary to find the
offset of a register in a contiguous(ish) array of bytes. By forcing
each register to be aligned to a power of two boundary, we avoid having
to do a multiplication to find their address even if the registers are
oddly sized. We can instead do a shift with a precomputed shift amount
which should be faster.
Change-Id: I035f1b4cb00ece4e8306d7953ea358af75a0d1de
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/49104
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
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