From 62aa952f34ef158d1a85970825959e281f9b28ff Mon Sep 17 00:00:00 2001
From: parrt <parrt@antlr.org>
Date: Wed, 5 May 2010 11:22:22 -0800
Subject: [PATCH] optimization: don't add intermediate closure addrs to
closure; we ignore them during reach anyway. saves time/space.
[git-p4: depot-paths = "//depot/code/antlr4/main/": change = 6840]
---
runtime/Java/src/org/antlr/v4/runtime/nfa/NFA.java | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/runtime/Java/src/org/antlr/v4/runtime/nfa/NFA.java b/runtime/Java/src/org/antlr/v4/runtime/nfa/NFA.java
index 3634e89d5..41a377a36 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/nfa/NFA.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/nfa/NFA.java
@@ -195,7 +195,6 @@ processOneChar:
ThreadState t = new ThreadState(ip, alt, context);
//System.out.println("add to closure "+ip+" "+closure);
if ( closure.contains(t) ) return;
- closure.add(t);
short opcode = code[ip];
ip++; // move to next instruction or first byte of operand
switch (opcode) {
@@ -207,6 +206,7 @@ processOneChar:
case Bytecode.LABEL :
case Bytecode.SAVE :
// see through them for closure ops
+ closure.add(t); // add to closure; need to execute during reach
ip += 2;
addToClosure(closure, ip, alt, context); // do closure past SAVE
break;
@@ -227,6 +227,7 @@ processOneChar:
// accept is just a ret if we have a stack;
// i.e., don't stop; someone called us and we need to use their
// accept, not this one
+ closure.add(t); // add to closure; need to execute during reach
case Bytecode.RET :
if ( context != NFAStack.EMPTY ) {
addToClosure(closure, context.returnAddr, alt, context.parent);
@@ -241,6 +242,11 @@ processOneChar:
addToClosure(closure, ip+4, alt, context);
}
break;
+ default :
+ // optimization: only add edges of closure to closure list; reduces what we walk later
+ // we don't want to have to ignore CALL, RET, etc... later
+ closure.add(t);
+ break;
}
}