From a5f3e7ae3a27259353e903d2a60ec7cb9faf3640 Mon Sep 17 00:00:00 2001
From: Ulya Trofimovich <skvadrik@gmail.com>
Date: Sat, 30 Apr 2016 16:47:06 +0100
Subject: [PATCH] Rule contexts are consecutive, so we only need to store
 bounds.

---
 re2c/src/codegen/emit_action.cc          | 4 ++--
 re2c/src/ir/dfa/context_deduplication.cc | 8 ++++++--
 re2c/src/ir/nfa/nfa.cc                   | 8 ++++----
 re2c/src/ir/rule.h                       | 6 ++++--
 4 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/re2c/src/codegen/emit_action.cc b/re2c/src/codegen/emit_action.cc
index 4384c11c..1708b3ec 100644
--- a/re2c/src/codegen/emit_action.cc
+++ b/re2c/src/codegen/emit_action.cc
@@ -233,8 +233,8 @@ static void subst_contexts(
 	const Rule &rule,
 	const std::vector<CtxVar> &contexts)
 {
-	for (size_t i = 0; i < rule.ctxvar.size(); ++i) {
-		const CtxVar &ctx = contexts[rule.ctxvar[i]];
+	for (size_t i = rule.ltag; i < rule.htag; ++i) {
+		const CtxVar &ctx = contexts[i];
 		strrreplace(action, "@" + *ctx.codename,
 			opts->input_api.expr_ctx(ctx.expr()));
 	}
diff --git a/re2c/src/ir/dfa/context_deduplication.cc b/re2c/src/ir/dfa/context_deduplication.cc
index 96098857..99a4f225 100644
--- a/re2c/src/ir/dfa/context_deduplication.cc
+++ b/re2c/src/ir/dfa/context_deduplication.cc
@@ -32,7 +32,9 @@ static void calc_live(
 
 		if (s->rule != Rule::NONE) {
 			const Rule &rule = dfa.rules[s->rule];
-			live[i].insert(rule.ctxvar.begin(), rule.ctxvar.end());
+			for (size_t j = rule.ltag; j < rule.htag; ++j) {
+				live[i].insert(j);
+			}
 			if (rule.trail.type == Trail::VAR) {
 				live[i].insert(rule.trail.pld.var);
 			}
@@ -55,7 +57,9 @@ size_t deduplicate_contexts(dfa_t &dfa,
 	std::set<size_t> fbctxs;
 	for (size_t i = 0; i < fallback.size(); ++i) {
 		const Rule &rule = dfa.rules[dfa.states[fallback[i]]->rule];
-		fbctxs.insert(rule.ctxvar.begin(), rule.ctxvar.end());
+		for (size_t j = rule.ltag; j < rule.htag; ++j) {
+			fbctxs.insert(j);
+		}
 		if (rule.trail.type == Trail::VAR) {
 			fbctxs.insert(rule.trail.pld.var);
 		}
diff --git a/re2c/src/ir/nfa/nfa.cc b/re2c/src/ir/nfa/nfa.cc
index b4646094..33f802e8 100644
--- a/re2c/src/ir/nfa/nfa.cc
+++ b/re2c/src/ir/nfa/nfa.cc
@@ -156,7 +156,7 @@ static nfa_state_t *compile_rule(
 	nfa_state_t *t = &nfa.states[nfa.size++];
 	t->fin(nrule);
 
-	std::vector<size_t> &ctxvar = r.ctxvar;
+	r.ltag = nfa.contexts.size();
 	std::vector<CtxFix> &ctxfix = r.ctxfix;
 	Trail &trail = r.trail;
 	// base2var is filled in right-to-left, this is crucial
@@ -168,9 +168,8 @@ static nfa_state_t *compile_rule(
 			const size_t idx = nfa.contexts.size();
 			base2var[i - 1] = idx;
 			nfa.contexts.push_back(CtxVar(name, nrule));
-			if (name != NULL) {
-				ctxvar.push_back(idx);
-			} else {
+			if (name == NULL) {
+				++r.ltag;
 				trail.make_var(idx);
 			}
 			nfa_state_t *q = &nfa.states[nfa.size++];
@@ -185,6 +184,7 @@ static nfa_state_t *compile_rule(
 			}
 		}
 	}
+	r.htag = nfa.contexts.size();
 	t = compile(rs[0], nfa, t);
 
 	bool null = nullable(rs[0]);
diff --git a/re2c/src/ir/rule.h b/re2c/src/ir/rule.h
index 9fb7ff7e..f5500533 100644
--- a/re2c/src/ir/rule.h
+++ b/re2c/src/ir/rule.h
@@ -35,7 +35,8 @@ struct Rule
 
 	const RuleInfo *info;
 
-	std::vector<size_t> ctxvar;
+	size_t ltag;
+	size_t htag;
 	std::vector<CtxFix> ctxfix;
 	Trail trail;
 	bool nullable;
@@ -45,7 +46,8 @@ struct Rule
 
 	Rule()
 		: info(NULL)
-		, ctxvar()
+		, ltag(0)
+		, htag(0)
 		, ctxfix()
 		, trail()
 		, nullable(false)
-- 
2.40.0