* net/loveruby/cflat/asm/PeepholeOptimizer.java: unify insn optimization and jump elimination.

* net/loveruby/cflat/utils/ClonableIterator.java -> Cursor.java
* net/loveruby/cflat/compiler/Options.java: use default optimization rule set for -O.


git-svn-id: file:///Users/aamine/c/gitwork/public/cbc/trunk@4052 1b9489fe-b721-0410-924e-b54b9192deb8

ChangeLog

@@ -1,3 +1,13 @@
+Wed Sep 24 00:48:37 2008  Minero Aoki  <aamine@loveruby.net>
+
+	* net/loveruby/cflat/asm/PeepholeOptimizer.java: unify insn
+	  optimization and jump elimination.
+
+	* net/loveruby/cflat/utils/ClonableIterator.java -> Cursor.java
+
+	* net/loveruby/cflat/compiler/Options.java: use default
+	  optimization rule set for -O.
+
 Tue Sep 23 22:50:52 2008  Minero Aoki  <aamine@loveruby.net>
 
 	* net/loveruby/cflat/compiler/CodeGenerator.java: apply jump

net/loveruby/cflat/asm/PeepholeOptimizer.java

@@ -1,26 +1,75 @@
 package net.loveruby.cflat.asm;
-import net.loveruby.cflat.utils.ClonableIterator;
+import net.loveruby.cflat.utils.Cursor;
 import java.util.*;
 
 public class PeepholeOptimizer implements AsmOptimizer {
-    protected List filters;
+    protected Map filterSet;   // Map<String, List<Filter>>
 
     public PeepholeOptimizer() {
-        this.filters = defaultFilterSet();
+        this.filterSet = new HashMap();
+    }
+
+    public void add(Filter filter) {
+        String[] heads = filter.patternHeads();
+        for (int i = 0; i < heads.length; i++) {
+            String head = heads[i];
+            List list = (List)filterSet.get(head);
+            if (list == null) {
+                list = new ArrayList();
+                list.add(filter);
+                filterSet.put(head, list);
+            }
+            else {
+                list.add(filter);
+            }
+        }
     }
 
     public List optimize(List assemblies) {
-        return jumpElimination(insnOptimization(assemblies));
+        List result = new ArrayList();
+        Cursor cursor = new Cursor(assemblies);
+        while (cursor.hasNext()) {
+            Assembly asm = (Assembly)cursor.next();
+            if (asm.isInstruction()) {
+                Filter matched = matchFilter(cursor);
+                if (matched != null) {
+                    matched.optimize(cursor, result);
+                    continue;
+                }
+            }
+            result.add(asm);
+        }
+        return result;
     }
 
-    // List<Filter>
+    protected Filter matchFilter(Cursor asms) {
-    protected List defaultFilterSet() {
+        Instruction insn = (Instruction)asms.current();
-        List set = new ArrayList();
+        List filters = (List)filterSet.get(insn.mnemonic());
+        if (filters == null) return null;
+        if (filters.isEmpty()) return null;
+        Iterator it = filters.iterator();
+        while (it.hasNext()) {
+            Filter filter = (Filter)it.next();
+            if (filter.match(asms)) {
+                return filter;
+            }
+        }
+        return null;
+    }
+
+    static public PeepholeOptimizer defaultSet() {
+        PeepholeOptimizer set = new PeepholeOptimizer();
+        set.loadDefaultFilters();
+        return set;
+    }
+
+    protected void loadDefaultFilters() {
+        PeepholeOptimizer set = this;
 
         // mov
-        set.add(new Filter(
+        set.add(new SingleInsnFilter(
             new InsnPattern("mov", imm(0), reg()),
-            new InsnTemplate() {
+            new InsnTransform() {
                 public Instruction apply(Instruction insn) {
                     return insn.build("xor", insn.operand2(), insn.operand2());
                 }
@@ -28,21 +77,21 @@ public class PeepholeOptimizer implements AsmOptimizer {
         ));
 
         // add
-        set.add(new Filter(
+        set.add(new SingleInsnFilter(
             new InsnPattern("add", imm(-1), reg()),
-            new InsnTemplate() {
+            new InsnTransform() {
                 public Instruction apply(Instruction insn) {
                     return insn.build("dec", insn.operand2());
                 }
             }
         ));
-        set.add(new Filter(
+        set.add(new SingleInsnFilter(
             new InsnPattern("add", imm(0), reg()),
             null
         ));
-        set.add(new Filter(
+        set.add(new SingleInsnFilter(
             new InsnPattern("add", imm(1), reg()),
-            new InsnTemplate() {
+            new InsnTransform() {
                 public Instruction apply(Instruction insn) {
                     return insn.build("inc", insn.operand2());
                 }
@@ -50,21 +99,21 @@ public class PeepholeOptimizer implements AsmOptimizer {
         ));
 
         // sub
-        set.add(new Filter(
+        set.add(new SingleInsnFilter(
             new InsnPattern("sub", imm(-1), reg()),
-            new InsnTemplate() {
+            new InsnTransform() {
                 public Instruction apply(Instruction insn) {
                     return insn.build("inc", insn.operand2());
                 }
             }
         ));
-        set.add(new Filter(
+        set.add(new SingleInsnFilter(
             new InsnPattern("sub", imm(0), reg()),
             null
         ));
-        set.add(new Filter(
+        set.add(new SingleInsnFilter(
             new InsnPattern("sub", imm(1), reg()),
-            new InsnTemplate() {
+            new InsnTransform() {
                 public Instruction apply(Instruction insn) {
                     return insn.build("dec", insn.operand2());
                 }
@@ -72,52 +121,53 @@ public class PeepholeOptimizer implements AsmOptimizer {
         ));
 
         // imul
-        set.add(new Filter(
+        set.add(new SingleInsnFilter(
             new InsnPattern("imul", imm(0), reg()),
-            new InsnTemplate() {
+            new InsnTransform() {
                 public Instruction apply(Instruction insn) {
                     return insn.build("xorl", insn.operand2(), insn.operand2());
                 }
             }
         ));
-        set.add(new Filter(
+        set.add(new SingleInsnFilter(
             new InsnPattern("imul", imm(1), reg()),
             null
         ));
-        set.add(new Filter(
+        set.add(new SingleInsnFilter(
             new InsnPattern("imul", imm(2), reg()),
-            new InsnTemplate() {
+            new InsnTransform() {
                 public Instruction apply(Instruction insn) {
                     return insn.build("sal", imm(1), insn.operand2());
                 }
             }
         ));
-        set.add(new Filter(
+        set.add(new SingleInsnFilter(
             new InsnPattern("imul", imm(4), reg()),
-            new InsnTemplate() {
+            new InsnTransform() {
                 public Instruction apply(Instruction insn) {
                     return insn.build("sal", imm(2), insn.operand2());
                 }
             }
         ));
-        set.add(new Filter(
+        set.add(new SingleInsnFilter(
             new InsnPattern("imul", imm(8), reg()),
-            new InsnTemplate() {
+            new InsnTransform() {
                 public Instruction apply(Instruction insn) {
                     return insn.build("sal", imm(3), insn.operand2());
                 }
             }
         ));
-        set.add(new Filter(
+        set.add(new SingleInsnFilter(
             new InsnPattern("imul", imm(16), reg()),
-            new InsnTemplate() {
+            new InsnTransform() {
                 public Instruction apply(Instruction insn) {
                     return insn.build("sal", imm(4), insn.operand2());
                 }
             }
         ));
 
-        return set;
+        // jmp
+        set.add(new JumpEliminationFilter());
     }
 
     protected ImmediateValue imm(long n) {
@@ -128,57 +178,40 @@ public class PeepholeOptimizer implements AsmOptimizer {
         return new AnyRegisterPattern();
     }
 
-    public List insnOptimization(List assemblies) {
+    abstract class Filter {
-        List result = new ArrayList();
+        abstract public String[] patternHeads();
-        Iterator asms = assemblies.iterator();
+        abstract public boolean match(Cursor asms);
-        while (asms.hasNext()) {
+        abstract public void optimize(Cursor src, List dest);
-            Assembly asm = (Assembly)asms.next();
-            if (! asm.isInstruction()) {
-                result.add(asm);
-            }
-            else {
-                Assembly optAsm = optimizeInstruction((Instruction)asm);
-                if (optAsm == null) {
-                    // remove instruction
-                }
-                else {
-                    result.add(optAsm);
-                }
-            }
-        }
-        return result;
     }
 
-    protected Assembly optimizeInstruction(Instruction insn) {
+    //
-        Iterator it = filters.iterator();
+    // single instruction optimization
-        while (it.hasNext()) {
+    //
-            Filter filter = (Filter)it.next();
-            if (filter.match(insn)) {
-                return filter.optimize(insn);
-            }
-        }
-        return insn;
-    }
 
-    class Filter {
+    class SingleInsnFilter extends Filter {
         protected InsnPattern pattern;
-        protected InsnTemplate template;
+        protected InsnTransform transform;
 
-        public Filter(InsnPattern pattern, InsnTemplate template) {
+        public SingleInsnFilter(InsnPattern pattern, InsnTransform transform) {
             this.pattern = pattern;
-            this.template = template;
+            this.transform = transform;
         }
 
-        public boolean match(Instruction insn) {
+        /** Matching mnemonic of InstructionPattern */
-            return pattern.match(insn);
+        public String[] patternHeads() {
+            return new String[] { pattern.name };
         }
 
-        public Instruction optimize(Instruction insn) {
+        public boolean match(Cursor asms) {
-            if (template == null) {
+            return pattern.match((Instruction)asms.current());
-                return null;
+        }
+
+        public void optimize(Cursor src, List dest) {
+            if (transform == null) {
+                ;   // remove instruction
             }
             else {
-                return template.apply(insn);
+                dest.add(transform.apply((Instruction)src.current()));
             }
         }
     }
@@ -207,7 +240,7 @@ public class PeepholeOptimizer implements AsmOptimizer {
         }
     }
 
-    interface InsnTemplate {
+    interface InsnTransform {
         abstract public Instruction apply(Instruction insn);
     }
 
@@ -215,59 +248,60 @@ public class PeepholeOptimizer implements AsmOptimizer {
     // jumpElimination
     //
 
-    public List jumpElimination(List assemblies) {
+    class JumpEliminationFilter extends Filter {
-        List result = new ArrayList();
+        public JumpEliminationFilter() {
-        ClonableIterator asms = new ClonableIterator(assemblies);
-        while (asms.hasNext()) {
-            Assembly asm = (Assembly)asms.next();
-            if (isUselessJump(asm, asms)) {
-                ;  // remove useless jump
-            }
-            else {
-                result.add(asm);
-            }
         }
-        return result;
-    }
 
-    protected boolean isUselessJump(Assembly asm, ClonableIterator asms) {
+        protected String[] jmpInsns() {
-        if (! asm.isInstruction()) return false;
+            return new String[] { "jmp", "jz", "jne", "je", "jne" };
-        Instruction insn = (Instruction)asm;
+        }
-        if (! insn.isJumpInstruction()) return false;
-        return doesLabelFollows(asms.dup(), insn.jmpDestination());
-    }
 
-    /**
+        public String[] patternHeads() {
-     * Returns true if jmpDest is found in asms before any instruction
+            return jmpInsns();
-     * or directives.  For example, this method returns true if contents
+        }
-     * of asms are:
+
-     *
+        public void optimize(Cursor src, List dest) {
-     *    if_end3:
+            ;   // remove jump
-     *          # comment
+        }
-     *    jmpDest:
+
-     *          mov
+        public boolean match(Cursor asms) {
-     *          mov
+            Instruction insn = (Instruction)asms.current();
-     *          add
+            return doesLabelFollows(asms.dup(), insn.jmpDestination());
-     */
+        }
-    protected boolean doesLabelFollows(ClonableIterator asms, Label jmpDest) {
+
-        while (asms.hasNext()) {
+        /**
-            Assembly asm = (Assembly)asms.next();
+         * Returns true if jmpDest is found in asms before any instruction
-            if (asm.isLabel()) {
+         * or directives.  For example, this method returns true if contents
-                Label label = (Label)asm;
+         * of asms are:
-                if (label.equals(jmpDest)) {
+         *
-                    return true;
+         *    if_end3:
+         *          # comment
+         *    jmpDest:
+         *          mov
+         *          mov
+         *          add
+         */
+        protected boolean doesLabelFollows(Cursor asms, Label jmpDest) {
+            while (asms.hasNext()) {
+                Assembly asm = (Assembly)asms.next();
+                if (asm.isLabel()) {
+                    Label label = (Label)asm;
+                    if (label.equals(jmpDest)) {
+                        return true;
+                    }
+                    else {
+                        continue;
+                    }
                 }
-                else {
+                else if (asm.isComment()) {
                     continue;
                 }
+                else {
+                    // instructions or directives
+                    return false;
+                }
             }
-            else if (asm.isComment()) {
+            return false;
-                continue;
-            }
-            else {
-                return false;
-            }
         }
-        return false;
     }
 }

net/loveruby/cflat/compiler/Options.java

@@ -119,7 +119,7 @@ class Options {
             return new NullAsmOptimizer();
         }
         else {
-            return new PeepholeOptimizer();
+            return PeepholeOptimizer.defaultSet();
         }
     }
 

net/loveruby/cflat/utils/Cursor.java

@@ -1,25 +1,25 @@
 package net.loveruby.cflat.utils;
 import java.util.*;
 
-public class ClonableIterator implements Iterator {
+public class Cursor implements Iterator {
     protected List list;
     protected int index;
 
-    public ClonableIterator(List list) {
+    public Cursor(List list) {
         this(list, 0);
     }
 
-    protected ClonableIterator(List list, int index) {
+    protected Cursor(List list, int index) {
         this.list = list;
         this.index = index;
     }
 
     public Object clone() {
-        return new ClonableIterator(list, index);
+        return new Cursor(list, index);
     }
 
-    public ClonableIterator dup() {
+    public Cursor dup() {
-        return new ClonableIterator(list, index);
+        return new Cursor(list, index);
     }
 
     public boolean hasNext() {
@@ -30,11 +30,18 @@ public class ClonableIterator implements Iterator {
         return list.get(index++);
     }
 
+    public Object current() {
+        if (index == 0) {
+            throw new Error("must not happen: Cursor#current");
+        }
+        return list.get(index - 1);
+    }
+
     public void remove() {
         list.remove(index);
     }
 
     public String toString() {
-        return "#<ClonableIterator list=" + list + " index=" + index + ">";
+        return "#<Cursor list=" + list + " index=" + index + ">";
     }
 }