Commit Graph

7 Commits

Author SHA1 Message Date
Geza Lore
8681861be9 Improve bitop tree optimization
- Remove redundant casting
- Cheaper final XOR parity flip (~/^1 instead of != 0)
- Support XOR reduction of ~XOR nodes
- Don't add redundant masking of terms
- Support unmasked terms
- Add cheaper implementation for single bit only terms
- Ensure result is clean under all circumstances (this fixes current bugs)
2021-08-18 22:00:13 +01:00
Yutetsu TAKATSUKASA
4ec8bc3589
Fix op count and wrong optimization in bitop tree (#3099)
- Fix op calculation.
- Fix wrong optimization revealed by changing the op calculation:
  Not(CCast(And(a, b))) must be frozen.
2021-08-14 12:28:47 +01:00
Yutetsu TAKATSUKASA
ec4eb18846
Fiix incorrect result by bit tree opt (#3023) (#3030)
* Add a test to reproduce #3023. Also applied verilog-mode formatting.

* use unique_ptr. No functional change is intended.

* Introduce restorer that reverts changes during iterate() if failed.
2021-06-21 07:28:39 +09:00
Yutetsu TAKATSUKASA
8624ce6a84
Stop checking dtype for better optimization chance in BitOpTree (#2909)
* Tests: Add more case that does not match native C++ width (8, 16, 32 or 64).

* Use AstVarRef::same() instead of AstNode::sameGateTree() because the latter checks dtype in addition to scope.

AstVarRef may have different minWidth in some cases,
but the difference should be ignored in the context of bitOpTree optimization.
2021-05-04 10:40:16 +09:00
Yutetsu TAKATSUKASA
bb5384bc50
Optimize bit op tree #2186, #2632, and #2633 (#2751)
* Tests:Add some more signals to t_const_opt_red.v

* Optimize bit op trees such as ~a[2] & a[1] & ~a[0] to 3'b010 == (3'111 & a)

* Update src/V3Const.cpp

Co-authored-by: Wilson Snyder <wsnyder@wsnyder.org>

* Update src/V3Const.cpp

Co-authored-by: Wilson Snyder <wsnyder@wsnyder.org>

* Update src/V3Const.cpp

Co-authored-by: Wilson Snyder <wsnyder@wsnyder.org>

* Apply clang-format

* Don't edit and-or tree.

* Call matchBitOpTree() after V3Expand does its job.

* Internals: Rename newNodep -> newp. No functional change is intended.

* Internals: Remove m_sels. No functional change is intended.

* Internals: Remove stringstream. No functional change is intended.

* Internals: Use V3Number::bitIs1(). No functional change is intended.

* Internals: Use V3Number instead of std::map. Resolved laek. Result should be same.

* Internals: Resolve overload of setPolarity. No functional change is intended.

* Internals: Pass failure reason. No functional change is intended.

* Internals: Add VNUser::toPtr(). No functional change is intended.

* Internals: Use user4 instead of std::map. No functional change is intended.

* Catch up with the AST style aftre V3Expand

* Internals: Rename Context to VarInfo. No functional change is intended.

* Add some more test case

* tests:Add stats to tests
Update stats in t_merge_cond.pl as matchBitopTree does some of them.

* insert CCast if necessary

* small optimization to remove redundant bit mask

* No quick exit even when unoptimizable node is found.

* Simplify removing redundant And

* simplify

* Revert "Internals: Add VNUser::toPtr(). No functional change is intended."

This reverts commit f98dce10db.

* Consider AstWordSel and cleanup

* Update test

* Update src/V3Const.cpp

Co-authored-by: Wilson Snyder <wsnyder@wsnyder.org>

* Update src/V3Const.cpp

Co-authored-by: Wilson Snyder <wsnyder@wsnyder.org>

* Update src/V3Const.cpp

Co-authored-by: Wilson Snyder <wsnyder@wsnyder.org>

* Update src/V3Const.cpp

Co-authored-by: Wilson Snyder <wsnyder@wsnyder.org>

* Update src/V3Const.cpp

Co-authored-by: Wilson Snyder <wsnyder@wsnyder.org>

* Update src/V3Const.cpp

Co-authored-by: Wilson Snyder <wsnyder@wsnyder.org>

* Apply clang-format

* Internals: rename variables. No functional change is intended.

Co-authored-by: Wilson Snyder <wsnyder@wsnyder.org>
Co-authored-by: github action <action@example.com>
2021-02-21 18:11:33 +09:00
Wilson Snyder
9655e287ab Tests: Travis regression fix 2020-11-08 17:06:03 -05:00
Wilson Snyder
917ca2bad7 Tests: Add t_const_opt_red (#2632) (#2633) 2020-11-08 16:39:28 -05:00