From 161a72a3b197b7f1c84954475aac89a7b191745d Mon Sep 17 00:00:00 2001 From: brian Date: Thu, 3 Jun 2004 23:58:23 +0000 Subject: [PATCH 1/1] optimized constant pool darcs-hash:20040603235823-24bed-2fd8947dbf450150fa8d89923e142997e19289eb.gz --- src/org/ibex/classgen/CPGen.java | 115 +++++++++++++++++++++++----------- src/org/ibex/classgen/ClassGen.java | 11 ++-- src/org/ibex/classgen/MethodGen.java | 8 +-- 3 files changed, 90 insertions(+), 44 deletions(-) diff --git a/src/org/ibex/classgen/CPGen.java b/src/org/ibex/classgen/CPGen.java index 1919cae..c41d67d 100644 --- a/src/org/ibex/classgen/CPGen.java +++ b/src/org/ibex/classgen/CPGen.java @@ -5,13 +5,10 @@ import java.io.*; import org.ibex.classgen.util.*; -// FEATURE: Add a "hit count" to each entry and optimize the table - class CPGen { - private Hashtable entries = new Hashtable(); - private int nextIndex = 1; // 0 is reserved - private int count; - private int state; + private final Hashtable entries = new Hashtable(); + private int usedSlots = 1; // 0 is reserved + private int state = OPEN; private static final int OPEN = 0; private static final int STABLE = 1; // existing entries won't change private static final int SEALED = 2; // no new entries @@ -22,19 +19,18 @@ class CPGen { * Entries */ abstract static class Ent { - int index; + int n; // this is the refcount if state == OPEN, index if >= STABLE int tag; Ent(int tag) { this.tag = tag; } - int getIndex() { return index; } - void dump(DataOutput o) throws IOException { o.writeByte(tag); } + String debugToString() { return toString(); } // so we can remove this method when not debugging } - static class OneU4Ent extends Ent { + static class IntEnt extends Ent { int i; - OneU4Ent(int tag) { super(tag); } + IntEnt(int tag) { super(tag); } void dump(DataOutput o) throws IOException { super.dump(o); o.writeInt(i); } } @@ -48,16 +44,21 @@ class CPGen { Ent e1; Ent e2; CPRefEnt(int tag) { super(tag); } + + String debugToString() { return "[" + e1.n + ":" + e1.debugToString() + (e2 == null ? "" : " + " + e2.n + ":" + e2.debugToString()) + "]"; } + void dump(DataOutput o) throws IOException { super.dump(o); - o.writeShort(e1.index); - if(e2 != null) o.writeShort(e2.index); + if(e1.n == 6 || (e2!=null && e2.n == 6)) System.err.println(debugToString() + " refs 6"); + o.writeShort(e1.n); + if(e2 != null) o.writeShort(e2.n); } } static class Utf8Ent extends Ent { String s; Utf8Ent() { super(1); } + String debugToString() { return s; } void dump(DataOutput o) throws IOException { super.dump(o); o.writeUTF(s); } } @@ -86,20 +87,22 @@ class CPGen { /* * Methods */ - public void seal() { if(state > SEALED) throw new IllegalStateException(); state = SEALED; } - public void stable() { if(state > STABLE) throw new IllegalStateException(); state = STABLE; } public final Ent get(Object o) { return (Ent) entries.get(o); } public final Ent getUtf8(String s) { return get(new Utf8Key(s)); } public final int getIndex(Object o) { Ent e = get(o); if(e == null) throw new IllegalStateException("entry not found"); - return e.getIndex(); + return getIndex(e); } public final int getUtf8Index(String s) { Ent e = getUtf8(s); if(e == null) throw new IllegalStateException("entry not found"); - return e.getIndex(); + return getIndex(e); + } + public final int getIndex(Ent ent) { + if(state < STABLE) throw new IllegalStateException("constant pool is not stable"); + return ent.n; } public final Ent addNameAndType(String name, String descriptor) { return add(new NameAndTypeKey(name,descriptor)); } @@ -109,7 +112,10 @@ class CPGen { if(state == SEALED) throw new IllegalStateException("constant pool is sealed"); Ent ent = get(o); - if(ent != null) return ent; + if(ent != null) { + if(state == OPEN) ent.n++; + return ent; + } if(o instanceof Type.Object) { CPRefEnt ce = new CPRefEnt(7); @@ -120,11 +126,11 @@ class CPGen { ce.e1 = addUtf8((String)o); ent = ce; } else if(o instanceof Integer) { - OneU4Ent ue = new OneU4Ent(3); + IntEnt ue = new IntEnt(3); ue.i = ((Integer)o).intValue(); ent = ue; } else if(o instanceof Float) { - OneU4Ent ue = new OneU4Ent(4); + IntEnt ue = new IntEnt(4); ue.i = Float.floatToIntBits(((Float)o).floatValue()); ent = ue; } else if(o instanceof Long) { @@ -157,34 +163,73 @@ class CPGen { throw new IllegalArgumentException("Unknown type passed to add"); } - int spaces = ent instanceof LongEnt ? 2 : 1; + int spaces = ent instanceof LongEnt ? 2 : 1; + if(usedSlots + spaces > 65536) throw new ClassGen.Exn("constant pool full"); - if(nextIndex + spaces > 65536) throw new ClassGen.Exn("constant pool full"); - - ent.index = nextIndex; - nextIndex += spaces; - count++; + ent.n = state == OPEN ? 1 : usedSlots; // refcount or index + + usedSlots += spaces; entries.put(o,ent); return ent; } - public int size() { return nextIndex; } + public int slots() { return usedSlots; } + + public void seal() { state = SEALED; } - private static final Sort.CompareFunc compareFunc = new Sort.CompareFunc() { - public int compare(Object a_, Object b_) { - return ((Ent)a_).index - ((Ent)b_).index; - } - }; - public void dump(DataOutput o) throws IOException { + private Ent[] asArray() { + int count = entries.size(); Ent[] ents = new Ent[count]; int i=0; Enumeration e = entries.keys(); while(e.hasMoreElements()) ents[i++] = (Ent) entries.get(e.nextElement()); if(i != count) throw new Error("should never happen"); + return ents; + } + + private static void assignIndex(Ent[] ents) { + int index = 1; + for(int i=0;i " + ents[i].debugToString() + " (" + ents[i].n + ")"); + state = STABLE; + assignIndex(ents); + } + + public void dump(DataOutput o) throws IOException { + Ent[] ents = asArray(); Sort.sort(ents,compareFunc); - for(i=0;i= 256) this.op[i] = op = LDC_W; break; default: @@ -546,7 +546,7 @@ public class MethodGen implements CGConst { throw new Error("should never happen"); } } else if((opdata & OP_CPENT_FLAG) != 0) { - int v = ((CPGen.Ent)arg).getIndex(); + int v = cp.getIndex((CPGen.Ent)arg); if(argLength == 1) o.writeByte(v); else if(argLength == 2) o.writeShort(v); else throw new Error("should never happen"); @@ -585,7 +585,7 @@ public class MethodGen implements CGConst { baos.reset(); o.writeShort(thrownExceptions.size()); for(Enumeration e = thrownExceptions.keys();e.hasMoreElements();) - o.writeShort(((CPGen.Ent)thrownExceptions.get(e.nextElement())).getIndex()); + o.writeShort(cp.getIndex((CPGen.Ent)thrownExceptions.get(e.nextElement()))); attrs.add("Exceptions",baos.toByteArray()); size = capacity = FINISHED; -- 1.7.10.4