From: Ulya Trofimovich <skvadrik@gmail.com>
Date: Tue, 4 Oct 2016 16:05:20 +0000 (+0100)
Subject: Fixed tags comparison in table minimization.
X-Git-Tag: 1.0~39^2~265
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=71e94f3e4ebac528c7dd22e43121b8aac797cc02;p=re2c

Fixed tags comparison in table minimization.

Bug was introduced in commit 5958a2366cdb1361b5158076924014a36ff19dcc
"Bind contexts (a.k.a. tags) to DFA transitions, not states.":
instead of comparing tags of single transition on one particular
symbol, we compared tags for all outgoing transitions at once
(probably copy-paste from Moore minimization).

The bug was revealed by multiple tests (including '--skeleton' ones)
as soon as I ran testsute with '--dfa-determinization table'.
---

diff --git a/re2c/src/ir/dfa/minimization.cc b/re2c/src/ir/dfa/minimization.cc
index c742f786..2dcffcb6 100644
--- a/re2c/src/ir/dfa/minimization.cc
+++ b/re2c/src/ir/dfa/minimization.cc
@@ -67,11 +67,11 @@ static void minimization_table(
 						{
 							std::swap(oi, oj);
 						}
-						if (oi != oj &&
-							(oi == dfa_t::NIL
-							|| oj == dfa_t::NIL
-							|| tbl[oi][oj]
-							|| memcmp(states[i]->tags, states[j]->tags, nchars * sizeof(size_t)) != 0))
+						if (states[i]->tags[k] != states[j]->tags[k]
+							|| (oi != oj
+								&& (oi == dfa_t::NIL
+								|| oj == dfa_t::NIL
+								|| tbl[oi][oj])))
 						{
 							tbl[i][j] = true;
 							loop = true;
@@ -188,8 +188,10 @@ static void minimization_moore(
 					if (memcmp(&out[j * nchars],
 						&out[k * nchars],
 						nchars * sizeof(size_t)) == 0
-						&& memcmp(states[j]->tags, states[k]->tags, nchars * sizeof(size_t)) == 0)
-					{
+					 && memcmp(states[j]->tags,
+						states[k]->tags,
+						nchars * sizeof(size_t)) == 0
+					 ) {
 						part[j] = k;
 						next[j] = next[k];
 						next[k] = j;