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 aedf65760ace7face8e45ff70dd1c016de4d00d7..d27cf8ad6cff845d6c2661a3bb64f944ee26db3b 100644 (file)
--- 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
-