This saves about 5% memory. V3AstUserAllocator is appropriate for most use
cases, performance is marginally up as we are mostly D-cache bound on
large designs.
Multiple edge timing controls in class methods would cause compilation errors on
the generated C++ code. This is because the `SenExprBuilder` used for these
would get recreated per timing control, resulting in duplicate variable names.
The fix is to have a single `SenExprBuilder` per scope.
Multiple edge timing controls in class methods would cause compilation errors on the generated C++ code. This is because the `SenExprBuilder` used for these would get recreated per timing control, resulting in duplicate variable names. The fix is to have a single `SenExprBuilder` per scope.
Event-triggered coroutines live in two stages: 'uncommitted' and 'ready'. First
they land in 'uncommitted', meaning they can't be resumed yet. Only after
coroutines from the 'ready' queue are resumed, the 'uncommitted' ones are moved
to the 'ready' queue, and can be resumed. This is to avoid self-triggering in
situations like waiting for an event immediately after triggering it.
However, there is an issue with `wait` statements. If you have a `wait(b)`, it's
being translated into a loop that awaits a change in `b` as long as `b` is
false. If `b` is false at first, the coroutine is put into the `uncommitted`
queue. If `b` is set to true before it's committed, the coroutine won't get
resumed.
This patch fixes that by immediately committing event controls created from
`wait` statements. That means the coroutine from the example above will get
resumed from now on.
This makes the implementation of the detection and propagation of the
suspendable property simpler and easier to read. More importantly, there are no
more jumps around the AST with the `visit` functions, which in some cases could
result in incorrect visitor context while in the `visit` function. See the added
test, which would cause Verilator to segfault before this patch.
In testing, verilation performance was not shown to be affected by this change.
Though there is a slight performance improvement from this patch, due to adding
one more check before refreshing class member cache.
Signed-off-by: Krzysztof Bieganski <kbieganski@antmicro.com>
This patch fixes two cases where methods in base classes were not being marked
as coroutines, even though they were being overridden by coroutines.
- One case is the class member cache not getting refreshed for searched classes.
- The other is when the overriding methods are not declared as `virtual`. In
that case, the `isVirtual()` getter on such a method returns false, which led
to `V3Timing` skipping the step of searching for overridden methods.
Signed-off-by: Krzysztof Bieganski <kbieganski@antmicro.com>
Apart from the representational changes below, this patch renames
AstNodeMath to AstNodeExpr, and AstCMath to AstCExpr.
Now every expression (i.e.: those AstNodes that represent a [possibly
void] value, with value being interpreted in a very general sense) has
AstNodeExpr as a super class. This necessitates the introduction of an
AstStmtExpr, which represents an expression in statement position, e.g :
'foo();' would be represented as AstStmtExpr(AstCCall(foo)). In exchange
we can get rid of isStatement() in AstNodeStmt, which now really always
represent a statement
Peak memory consumption and verilation speed are not measurably changed.
Partial step towards #3420
In non-static contexts like class objects or stack frames, the use of
global trigger evaluation is not feasible. The concept of dynamic
triggers allows for trigger evaluation in such cases. These triggers are
simply local variables, and coroutines are themselves responsible for
evaluating them. They await the global dynamic trigger scheduler object,
which is responsible for resuming them during the trigger evaluation
step in the 'act' eval region. Once the trigger is set, they await the
dynamic trigger scheduler once again, and then get resumed during the
resumption step in the 'act' eval region.
Signed-off-by: Krzysztof Bieganski <kbieganski@antmicro.com>