Having many triggers still hits a bottleneck in LLVM leading to long
compile times.
Instead of setting triggers bit-wise, set them as a whole 64-bit word
when possible. This improves C++ compile times by ~4x on some large
designs and has minor run-time performance benefit.
Continuing the idea of decoupling the implementations of the various algorithms.
The main points:
-Move the former "processDomain" stuff, dealing with assigning combinational logic into the relevant sensitivity domains into V3OrderProcessDomains.cpp
-Move the parallel code construction in V3OrderParallel.cpp (Could combine this with some parts of V3Partition - those not called from V3Partition::finalize - but that's not for this patch).
-Move the serial code construction into V3OrderSerial.cpp
-Factored the very small common code between the parallel and serial code construction (processMoveOneLogic) into V3OrderCFuncEmitter.cpp
Again --prof-exec have bit-rotted a little with all the recent changes
to the structure of the generated code. This patch contains a few
improvements:
- Repalce the eval/evl_loop begin/end events with generic
section_push/section_pop events, that can be arbitrarily sprinkled
into the generate code (so long as they are matched correctly) to
measure various sections. The report then contains a nested profile
of the sections, and the VCD trace shows the section names.
- Better handling of exec graphs
- Clearer overall statistics
Pack the elements of VlTriggerVec as dense bits (instead of a 1 byte
bool per bit), and check whether they are set on a word granularity.
This effectively transforms conditions of the form `if (trig.at(0) |
trig.at(2) | trig.at(64))` into `if (trig.word(0) & 0x5 | trig.word(1) &
0x1)`. This improves OpenTitan ST by about 1%, worth more on some other
designs.
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