From: Ulya Trofimovich <skvadrik@gmail.com>
Date: Fri, 7 Apr 2017 17:49:58 +0000 (+0100)
Subject: Don't forget histories when comparing right hand sides of tag commands.
X-Git-Tag: 1.0~39^2~72
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a43d840244ab31a22d0fe62c3feb87b2e041e14a;p=re2c

Don't forget histories when comparing right hand sides of tag commands.
---

diff --git a/re2c/src/dfa/cfg/interfere.cc b/re2c/src/dfa/cfg/interfere.cc
index aedf6576..d27cf8ad 100644
--- a/re2c/src/dfa/cfg/interfere.cc
+++ b/re2c/src/dfa/cfg/interfere.cc
@@ -5,53 +5,51 @@
 namespace re2c
 {
 
-static void interfere(const tcmd_t *cmd, const bool *live, bool *interf, bool *buf1, bool *buf2, size_t nver);
+static void interfere(const tcmd_t *cmd, const bool *live, bool *interf, bool *buf, size_t nver);
 
 void cfg_t::interference(const cfg_t &cfg, const bool *live, bool *interf)
 {
 	const size_t nver = static_cast<size_t>(cfg.dfa.maxtagver) + 1;
-	bool *buf1 = new bool[nver];
-	bool *buf2 = new bool[nver];
+	bool *buf = new bool[nver];
 	const cfg_bb_t *b = cfg.bblocks, *e = b + cfg.nbbfin;
 
 	memset(interf, 0, nver * nver * sizeof(bool));
 	for (; b < e; ++b, live += nver) {
-		interfere(b->cmd, live, interf, buf1, buf2, nver);
+		interfere(b->cmd, live, interf, buf, nver);
 	}
 
-	delete[] buf1;
-	delete[] buf2;
+	delete[] buf;
 }
 
 void interfere(const tcmd_t *cmd, const bool *live, bool *interf,
-	bool *buf1, bool *buf2, size_t nver)
+	bool *buf, size_t nver)
 {
 	// LHS of each command iterferes with all tags that are alive after
 	// this command except its RHS and tags that are are assigned to
 	// the same RHS by other commands in this block.
-	memcpy(buf1, live, nver * sizeof(bool));
 	for (const tcmd_t *p = cmd; p; p = p->next) {
-		const tagver_t r = p->rhs;
+		const tagver_t r = p->rhs, h = p->pred;
 
 		// alive after this command
-		memcpy(buf2, buf1, nver * sizeof(bool));
-		cfg_t::live_through_bblock(p->next, buf2);
+		memcpy(buf, live, nver * sizeof(bool));
+		cfg_t::live_through_bblock(p->next, buf);
 
 		// exclude RHS
-		if (tcmd_t::iscopy(r)) buf2[r] = false;
+		if (tcmd_t::iscopy(r)) buf[r] = false;
 
 		// exclude tags assigned to the same RHS
 		for (const tcmd_t *q = cmd; q; q = q->next) {
-			if (q->rhs == r) buf2[q->lhs] = false;
+			if (q->rhs == r && q->pred == h) {
+				buf[q->lhs] = false;
+			}
 		}
 
 		const size_t l = static_cast<size_t>(p->lhs);
 		for (size_t v = 0; v < nver; ++v) {
-			if (!buf2[v]) continue;
+			if (!buf[v]) continue;
 			interf[l * nver + v] = interf[v * nver + l] = true;
 		}
 	}
 }
 
 } // namespace re2c
-