Previously, the action table stores a reduce action for each lookahead
token it should allow. These tokens are the followSet(action.rule.target).
In practice, the follow sets are large, so we spend a bunch of time binary
searching around all these essentially-duplicates to check whether our lookahead
token is there.
However the number of reduces for a given state is very small, so we're
much better off linear scanning over them and performing a fast check for each.
D128318 was an attempt at this, storing a bitmap for each reduce.
However it's even more compact just to use the follow sets directly, as
there are fewer nonterminals than (state, rule) pairs. It's also faster.
This specialized approach means unbundling Reduce from other actions in
LRTable, so it's no longer useful to support it in Action. I suspect
Action will soon go away, as we store each kind of action separately.
This improves glrParse speed by 42% (3.30 -> 4.69 MB/s).
It also reduces LR table size by 59% (343 -> 142kB).
Differential Revision: https://reviews.llvm.org/D128472
As pointed out in the previous review section, having a dedicated accept
action doesn't seem to be necessary. This patch implements the the same behavior
without accept acction, which will save some code complexity.
Reviewed By: sammccall
Differential Revision: https://reviews.llvm.org/D125677
Reductions need to be performed in a careful order in GLR parser, to
make sure we gather all alternatives before creating an ambigous forest
node.
This patch encodes the nonterminal order into the rule id, so that we
can efficiently to determinal ordering of reductions in GLR parser.
This patch also abstracts to a TestGrammar, which is shared among tests.
This is a part of the GLR parser, https://reviews.llvm.org/D121368,
https://reviews.llvm.org/D121150
Differential Revision: https://reviews.llvm.org/D122303
This reverts commit 049f4e4eab.
The problem was a stray dependency in CLANG_TEST_DEPS which caused cmake
to fail if clang-pseudo wasn't built. This is now removed.
This should make clearer that:
- it's not part of clang proper
- there's no expectation to update it along with clang (beyond green tests)
- clang should not depend on it
This is intended to be expose a library, so unlike other tools has a split
between include/ and lib/.
The main renames are:
clang/lib/Tooling/Syntax/Pseudo/* => clang-tools-extra/pseudo/lib/*
clang/include/clang/Tooling/Syntax/Pseudo/* => clang-tools-extra/pseudo/include/clang-pseudo/*
clang/tools/clang/pseudo/* => clang-tools-extra/pseudo/tool/*
clang/test/Syntax/* => clang-tools-extra/pseudo/test/*
clang/unittests/Tooling/Syntax/Pseudo/* => clang-tools-extra/pseudo/unittests/*
#include "clang/Tooling/Syntax/Pseudo/*" => #include "clang-pseudo/*"
namespace clang::syntax::pseudo => namespace clang::pseudo
check-clang => check-clang-pseudo
clangToolingSyntaxPseudo => clangPseudo
The clang-pseudo and ClangPseudoTests binaries are not renamed.
See discussion around:
https://discourse.llvm.org/t/rfc-a-c-pseudo-parser-for-tooling/59217/50
Differential Revision: https://reviews.llvm.org/D121233
Sam McCall