Similarly to the earlier patch that defers constant folding on optimized
logic, now we also defer the variable substitutions as well. This again
eliminates a lot of traversals, and yields another ~10x speedup of V3Gate
on a design where V3Gate used to dominate while producing identical
results.
Rather than constant folding each logic block after every substitution,
only constant fold updated blocks when re-analysed, or at the end. This
removes a lot of invocations of V3Const on large blocks that can be
optimized well, and should yield the same result.
This speeds up V3Gate by ~4x on a design where V3Gate dominates.
Speed improvements:
- Use a direct, recursion-free implementation
- Improve pre-fetching
Functionality:
- Support remove/replace of currently iterated node
__gcov_flush was a private function and was removed from later GCC
versions (at least from 11.2.0, possibly earlier). Replace with the
documented public __gcov_dump.
Set default value of --comp-limit-parens to 240, to respect default
maximum nesting of parentheses in clang (which is controlled by
-fbracket-depth and defaults to 256). For code generation consistency,
also use the same default with gcc.
* Tests: Add a test to reproduce #3509
* Tests: Compile without tautological-compare check because bit op tree optimization is disabled in the test.
* Internals: Dedup code. No functional change is intended.
* Fix#3509.
"2'b10 == (2'b11 & {1'b0, val[0]})" and "2'b10 != (2'b11 & {1'b0, val[0]})" were
wrongly optimized to "!val[0]" and "val[0]" respectively.
Now properly optimize them to 1'b0 and 1'b1.
* Commentary
* Commentary: Update Changes
Associative arrays that specify a wildcard index type may be indexed by
integral expressions of any size, with leading zeros removed
automatically. A natural representation for such expressions is a
string, especially that the standard explicitly specifies automatic
casts from string indices to bit vectors of equivalent size.
The automatic cast part is done implicitly by the existing type system.
A simpler way to just make this work would be to convert wildcard index
type to a string type directly in the parser code, but several new AST
classes are needed to make sure illegal method calls are detected.
The verilated data structure implementation is reused, because there is
no need for differentiating the behavior on C++ side.
All remaining use of conditional compilation in the tracing
implementation of the run-time library are replaced with the use of
VerilatedModel::traceConfig, and is now done at run-time.
Step towards a proper run-time library. Reduce the amount of ifdefs in
the implementation of offloaded tracing. There are still a very small
number of ifdefs left, which will need more careful changes in order to
keep user API compatibility.
Using unlinkFrBackWithNext is O(n) in the size of the list if unlinking
from the middle, so addHereThisAsNext also had this complexity. This
patch implements addHereThisAsNext directly, which is always O(1).
Use std::partial_sort for the non-exhaustive case. This is O(n) instead
of O(n*log(n)) in the size of the candidate list being sorted. (It
actually is O(n*log(k)), but k is constant 6 in the non-exhaustive
case).
* Tests: Add a test to reproduce #3470
* Update LSB during return path of traversal. No functional change is intended.
* Introduce LeafInfo::m_msb
* Update LeafInfo::m_msb when visitin AstCCast
* Internals: Add comment, reorder. No functional change is intended.
* Delete explicit from copy constructor to fix build error.
* Update Changes
* Internals: Remove unused parameter. No functional change is intended.
* Tests: Add explanation to t_const_opt.
* Internals: Let LeafInfo class. No functional change is intended.
* Internals: Rename LeafInfo::width -> LeafInfo::varWidth(). No functional change is intende.
Geza Lore
Wilson Snyder
Yutetsu TAKATSUKASA
github action
Mostafa Gamal
Arkadiusz Kozdra
Todd Strader
William D. Jones
Mariusz Glebocki
Unai Martinez-Corral