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Remove unnecessary duplicate conditions

This commit is contained in:
Sam Harwell 2013-04-18 12:35:15 -05:00
parent 3defe6a2b1
commit 74f4938033
1 changed files with 23 additions and 31 deletions
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54
runtime/Java/src/org/antlr/v4/runtime/atn/ParserATNSimulator.java
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@ -328,16 +328,13 @@ public class ParserATNSimulator extends ATNSimulator {
// Now we are certain to have a specific decision's DFA
// But, do we still need an initial state?
if ( dfa.s0==null ) { // recheck
if ( dfa.s0==null ) { // recheck
try {
return predictATN(dfa, input, outerContext);
}
finally {
mergeCache = null; // wack cache after each prediction
}
if ( dfa.s0==null ) {
try {
return predictATN(dfa, input, outerContext);
}
finally {
mergeCache = null; // wack cache after each prediction
}
// fall through; another thread set dfa.s0 while we waited for lock
}
// We can start with an existing DFA
@ -467,30 +464,25 @@ public class ParserATNSimulator extends ATNSimulator {
" at DFA state "+s.stateNumber);
}
//TODO: recheck synchronization here. don't need if no sync
// recheck; another thread might have added edge
if ( s.edges == null || t >= s.edges.length || t < -1 || s.edges[t+1] == null ) {
alt = execATN(dfa, s, input, startIndex, outerContext);
// this adds edge even if next state is accept for
// same alt; e.g., s0-A->:s1=>2-B->:s2=>2
// TODO: This next stuff kills edge, but extra states remain. :(
if ( s.isAcceptState && alt!=ATN.INVALID_ALT_NUMBER ) {
DFAState d = s.edges[input.LA(1)+1];
if ( d.isAcceptState && d.prediction==s.prediction ) {
// we can carve it out.
s.edges[input.LA(1)+1] = ERROR; // IGNORE really not error
}
alt = execATN(dfa, s, input, startIndex, outerContext);
// this adds edge even if next state is accept for
// same alt; e.g., s0-A->:s1=>2-B->:s2=>2
// TODO: This next stuff kills edge, but extra states remain. :(
if ( s.isAcceptState && alt!=ATN.INVALID_ALT_NUMBER ) {
DFAState d = s.edges[input.LA(1)+1];
if ( d.isAcceptState && d.prediction==s.prediction ) {
// we can carve it out.
s.edges[input.LA(1)+1] = ERROR; // IGNORE really not error
}
if ( dfa_debug ) {
System.out.println("back from DFA update, alt="+alt+", dfa=\n"+dfa.toString(parser.getTokenNames()));
//dump(dfa);
}
// action already executed
if ( dfa_debug ) System.out.println("DFA decision "+dfa.decision+
" predicts "+alt);
return alt; // we've updated DFA, exec'd action, and have our deepest answer
}
// fall through; another thread gave us the edge
if ( dfa_debug ) {
System.out.println("back from DFA update, alt="+alt+", dfa=\n"+dfa.toString(parser.getTokenNames()));
//dump(dfa);
}
// action already executed
if ( dfa_debug ) System.out.println("DFA decision "+dfa.decision+
" predicts "+alt);
return alt; // we've updated DFA, exec'd action, and have our deepest answer
}
DFAState target = s.edges[t+1];
if ( target == ERROR ) {