After detecting a corrupted BTB, don't speculatively update it until
the next non-speculative fetch. This prevents the frontend from replaying
forever.
The reason for the :=? operator was for when you have an adapter chain
whose direction of cardinality you could not know. We used explicit
directives to tell these compositions which way to go.
Unfortunately, that makes the API leaky. You think the chain of adapters
is just one adapter, but you have to use strange Cardinality scopes to
use it. That's just bad.
The new :*=* just automagically figures it out from the graph.
This removes the mostly obsolete 'numIn/Out' range restrictions on nodes.
It also makes it possible to connect optional crossbars that disappear.
val x = TLXbar()
x := master
slave := x
val y = TLXbar()
x :=* y // only connect y if it gets used
This will create crossbar x, but crossbar y will disappear.
RegField.bytes updates only those bytes which are written every cycle.
However, there was a bug that it would try to return the updated value on reads.
This led to another TL-spec violating combinational path, just like the Debug module.
When passed a Wire, WNotify outputs that wire on reads wire => d_bits.
Furthermore, it updates the Wire when a write occures d_ready => wire.
These registers should be returning undefined value on read, anyway.
This esoteric bug manifests if a tag-read error occurs when a FENCE.I is
executed, even if the error was correctable. Subsequently, an attempt to
flush a dirty line may flush the wrong line's data.
This esoteric bug manifests if a tag-read error occurs when a FENCE.I is
executed, even if the error was correctable. Subsequently, an attempt to
flush a dirty line may flush the wrong line's data.
Putting the common DTS nodes into a shared object makes them get
emitted only one time. Plus it's better style.
timebase-frequency should really have been in the cpu nodes in the
first place according to the spec anyway. I was foolishly trying to
save bytes. However, now we really want it there in case it differs.
Deallocation can change repl_way, which violates the assumption that it
remains constant throughout refill.
The workaround described in commit 3db066303b
still suffices, provided only the hart that owns the ITIM changes the ITIM
allocation.
This subsumes commit 3db066303b.
