- Allow reordering pure statements with DPI import calls iff no public
variables (including those read via a DPI export) are involved. This
ensures the DPI import can't observe the reordering
- Allow reordering of pure statements with AstDisplay and AstStop. This
requires an assumption that AstDisplay and AstStop will not read or
write model state other than via a VarRef explicitly present int the
Ast.
Overall this allows eliminating a lot of conditionals around assertions,
which were previously not possible.
Introduce new pass that converts impure expressions, or those with
function and method calls into simple assignment statements. Please see
the blurb at the top of the file why this is useful and how it works.
In particular currently it enables more Dfg optimization as functions
will be inlined without AstExprStmt.
Ideally we should enforce this lowering is applied to every procedural
statement (there are still a handful of exceptions). With that, long
term with this pass + #6820, there should be no need to ever use an
AstExprStmt past this new lowering pass, which should enable more easier
optimization down the line.
Also ideally this should be run earlier. Currently it's after V3Tristate
as that calls pinReconnectSimple so we don't have to touch Cell ports.
Currently disabled when code coverage is enabled due to #7119.
Rename AstSelLoopVars to AstForeachHeader, and make it a non-NodeExpr.
Tweak parser to always create an AstForeachHeader, so no need to fix it
up later.
AstCAwait is only ever uses in statement position, so model it as a
statement. We should never ever have a coroutine that returns a value.
There is no need for it in SV, nor should we rely on it for internals.
Also reworks the fix for V3Life incorrectly constant propagating the
beforeTrig functions (#7072). The property that upsets V3Life is that
a function:
1. Is called from multiple static call sites (multiple AstCCall)
2. Reads model state directly (AstVarRef to non-locals/arguments)
Such function can only be created internally after scheduling (V3Task
throws an unsupported error on a non-inlined function that reads model
state), so added a flag to AstCFunc to mark the dangerous ones for
V3Life.
The Syms class can contain a very large number of VeriltedScope
instances if `--vpi` is used, all of which need a call to the default
constructor in the constructor of the Syms class. This can lead to very
long compilation times, even without optimization on some compilers.
To avoid the constructor calls, hold VeriltedScope via pointers in the
Syms class, and explicitly new and delete them in the Syms
constructor/destructor. These explicit new/delte can then be
automatically split up into sub functions when the Syms
constructor/destructor become large.
Regarding run-time performance, this should have no significant effect,
most interactions are either during construction/destruction of the Syms
object, or are via pointers already. The one place where we used to
refer to VerilatedScope instances is when emitting an AstScopeName for
things like $display %m. For those there will be an extra load
instruction at run-time, which should not make a big difference.
Patch 3 of 3 to fix long compile times of the Syms module in some
scenarios.
Remove the large variety of ways raw "text" is represented in the Ast.
Particularly, the only thing that represents a string to be emitted in
the output is AstText.
There are 5 AstNodes that can contain AstText, and V3Emit will throw an
error if an AstText is encountered anywhere else:
- AstCStmt: Internally generated procedural statements involving raw
text.
- AstCStmtUser: This is the old AstUCStmt, renamed so it sorts next to
AstCStmt, as it's largely equivalent. We should never create this
internally unless used to represent user input. It is used for $c,
statements in the input, and for some 'systemc_* blocks.
- AstCExpr: Internally generaged expression involving raw text.
- AstCExprUser: This is the old AstUCFunc, renamed so it sorts next to
AstCExpr. It is largely equivalent, but also has more optimizations
disabled. This should never be created internally, it is only used for
$c expressions in the input.
- AstTextBlock: Use by V3ProtectLib only, to generate the hierarchical
wrappers.
Text "tracking" for indentation is always on for AstCStmt, AstCExpr, and
AstTextBlock, as these are always generated by us, and should always be
well formed.
Tracking is always off for AstCStmtUser and AstCExprUser, as these
contain arbitrary user input that might not be safe to parse for
indentation.
Remove subsequently redundant AstNodeSimpleText and AstNodeText types.
This patch also fixes incorrect indentation in emitted waveform tracing
functions, and makes the output more readable for hier block SV stubs.
With that, all raw text nodes are handled as a proper AstNodeStmt or
AstNodeExpr as required for #6280.
There was exactly one place in V3Task, handling DPI arguments when we
relied on cleanOut of AstCExpr being false for masking. Made that code
do the relevant masking via a few new run-time functions, which also
eliminates some special cases in the relevant V3Task functions.
Todd Strader
em2machine
Todd Strader
Geza Lore
Wilson Snyder
Srinivasan Venkataramanan
Geza Lore
Igor Zaworski
Pawel Kojma
Jose Drowne
Bartłomiej Chmiel
Artur Bieniek