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-rw-r--r--chapter18/src/main/java/com/seaofnodes/simple/CodeGen.java10
-rw-r--r--chapter18/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java6
-rw-r--r--chapter18/src/main/java/com/seaofnodes/simple/node/CFGNode.java24
-rw-r--r--chapter18/src/main/java/com/seaofnodes/simple/node/CallEndNode.java2
-rw-r--r--chapter18/src/main/java/com/seaofnodes/simple/node/FunNode.java4
-rw-r--r--chapter18/src/main/java/com/seaofnodes/simple/node/LoopNode.java2
-rw-r--r--chapter18/src/main/java/com/seaofnodes/simple/node/RegionNode.java13
-rw-r--r--chapter18/src/main/java/com/seaofnodes/simple/node/ReturnNode.java6
-rw-r--r--chapter18/src/main/java/com/seaofnodes/simple/node/StopNode.java4
9 files changed, 46 insertions, 25 deletions
diff --git a/chapter18/src/main/java/com/seaofnodes/simple/CodeGen.java b/chapter18/src/main/java/com/seaofnodes/simple/CodeGen.java
index 47616b51..1586b3c5 100644
--- a/chapter18/src/main/java/com/seaofnodes/simple/CodeGen.java
+++ b/chapter18/src/main/java/com/seaofnodes/simple/CodeGen.java
@@ -6,6 +6,16 @@ import java.util.HashMap;
public class CodeGen {
+ // Inlining can insert CFG edges and invalidate cached depth ordering.
+ private char _iDepthVersion;
+ public char iDepthVersion() { return _iDepthVersion; }
+ public void invalidateIDepthCaches() {
+ assert _iDepthVersion < Character.MAX_VALUE : "Dominator cache version exceeds 65535";
+ ++_iDepthVersion;
+ }
+
+
+
public enum Phase {
Parse, Opto, TypeCheck, Schedule, LocalSched, RegAlloc;
}
diff --git a/chapter18/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java b/chapter18/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java
index d3ee62c3..f68043c4 100644
--- a/chapter18/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java
+++ b/chapter18/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java
@@ -140,7 +140,7 @@ public abstract class GlobalCodeMotion {
CFGNode lca = null;
for( Node use : n._outputs )
if( use != null )
- lca = use_block(n,use, late)._idom(lca,null);
+ lca = use_block(n,use, late).domLCA(lca,null);
// Loads may need anti-dependencies, raising their LCA
if( n instanceof LoadNode load )
@@ -167,7 +167,7 @@ public abstract class GlobalCodeMotion {
CFGNode found=null;
for( int i=1; i<phi.nIns(); i++ )
if( phi.in(i)==n )
- found = phi.region().cfg(i)._idom(found,null);
+ found = phi.region().cfg(i).domLCA(found,null);
assert found!=null;
return found;
@@ -220,7 +220,7 @@ public abstract class GlobalCodeMotion {
for( ; stblk != defblk.idom(); stblk = stblk.idom() ) {
// Store and Load overlap, need anti-dependence
if( stblk._anti==load._nid ) {
- lca = stblk._idom(lca,null); // Raise Loads LCA
+ lca = stblk.domLCA(lca,null); // Raise Loads LCA
if( lca == stblk && st != null && st._inputs.find(load) == -1 ) // And if something moved,
st.addDef(load); // Add anti-dep as well
return lca; // Cap this stores' anti-dep to here
diff --git a/chapter18/src/main/java/com/seaofnodes/simple/node/CFGNode.java b/chapter18/src/main/java/com/seaofnodes/simple/node/CFGNode.java
index b051b3ce..dc486549 100644
--- a/chapter18/src/main/java/com/seaofnodes/simple/node/CFGNode.java
+++ b/chapter18/src/main/java/com/seaofnodes/simple/node/CFGNode.java
@@ -1,5 +1,6 @@
package com.seaofnodes.simple.node;
+import com.seaofnodes.simple.CodeGen;
import com.seaofnodes.simple.Parser;
import com.seaofnodes.simple.type.*;
import com.seaofnodes.simple.Utils;
@@ -47,21 +48,32 @@ public abstract class CFGNode extends Node {
* <p>
* See {@link <a href="https://en.wikipedia.org/wiki/Dominator_(graph_theory)">...</a>}
*/
- public int _idepth;
- public int idepth() { return _idepth==0 ? (_idepth=idom().idepth()+1) : _idepth; }
+ public char _idepth;
+ public char _idepthVersion;
+ public int idepth() { return validIDepth() ? _idepth : cacheIDepth(idom().idepth()+1); }
+ // Zero depth means uncached. Check before narrowing so overflow cannot wrap.
+ final int cacheIDepth(int depth) {
+ assert 0 <= depth && depth <= Character.MAX_VALUE : "Dominator depth exceeds 65535";
+ _idepthVersion = CodeGen.CODE.iDepthVersion();
+ return _idepth = (char)depth;
+ }
+
+ final boolean validIDepth() { return _idepth!=0 && _idepthVersion==CodeGen.CODE.iDepthVersion(); }
+
// Return the immediate dominator of this Node and compute dom tree depth.
public CFGNode idom(Node dep) { return cfg(0); }
public final CFGNode idom() { return idom(null); }
// Return the LCA of two idoms
- public CFGNode _idom(CFGNode rhs, Node dep) {
+ public CFGNode domLCA(CFGNode rhs, Node dep) {
if( rhs==null ) return this;
CFGNode lhs = this;
while( lhs != rhs ) {
- var comp = lhs.idepth() - rhs.idepth();
- if( comp >= 0 ) lhs = ((CFGNode)lhs.addDep(dep)).idom();
- if( comp <= 0 ) rhs = ((CFGNode)rhs.addDep(dep)).idom();
+ if( lhs==null || rhs==null ) return null;
+ int comp = lhs.idepth() - rhs.idepth();
+ if( comp >= 0 ) lhs = (dep==null ? lhs : (CFGNode)lhs.addDep(dep)).idom();
+ if( comp <= 0 ) rhs = (dep==null ? rhs : (CFGNode)rhs.addDep(dep)).idom();
}
return lhs;
}
diff --git a/chapter18/src/main/java/com/seaofnodes/simple/node/CallEndNode.java b/chapter18/src/main/java/com/seaofnodes/simple/node/CallEndNode.java
index 07a2b5a3..6d7aa323 100644
--- a/chapter18/src/main/java/com/seaofnodes/simple/node/CallEndNode.java
+++ b/chapter18/src/main/java/com/seaofnodes/simple/node/CallEndNode.java
@@ -1,5 +1,6 @@
package com.seaofnodes.simple.node;
+import com.seaofnodes.simple.CodeGen;
import com.seaofnodes.simple.IterPeeps;
import com.seaofnodes.simple.Parser;
import com.seaofnodes.simple.Utils;
@@ -73,6 +74,7 @@ public class CallEndNode extends CFGNode implements MultiNode {
fun.setDef(2,call.ctrl()); // Bypass the Call;
fun.ret().setDef(3,null); // Return is folding also
IterPeeps.addAll(fun._outputs);
+ CodeGen.CODE.invalidateIDepthCaches();
return this;
}
} else {
diff --git a/chapter18/src/main/java/com/seaofnodes/simple/node/FunNode.java b/chapter18/src/main/java/com/seaofnodes/simple/node/FunNode.java
index 1f0c76eb..5873f6b6 100644
--- a/chapter18/src/main/java/com/seaofnodes/simple/node/FunNode.java
+++ b/chapter18/src/main/java/com/seaofnodes/simple/node/FunNode.java
@@ -78,8 +78,8 @@ public class FunNode extends RegionNode {
return progress;
}
- // Bypass Region idom, always assume depth == 1, one more than Start
- @Override public int idepth() { return (_idepth=1); }
+ // Unfolded functions are roots; inlining reconnects their depth to the caller.
+ @Override public int idepth() { return _folding ? super.idepth() : 1; }
// Bypass Region idom, always assume idom is Start
@Override public CFGNode idom(Node dep) { return cfg(1); }
diff --git a/chapter18/src/main/java/com/seaofnodes/simple/node/LoopNode.java b/chapter18/src/main/java/com/seaofnodes/simple/node/LoopNode.java
index f70a1012..097ddea7 100644
--- a/chapter18/src/main/java/com/seaofnodes/simple/node/LoopNode.java
+++ b/chapter18/src/main/java/com/seaofnodes/simple/node/LoopNode.java
@@ -24,7 +24,7 @@ public class LoopNode extends RegionNode {
}
// Bypass Region idom, same as the default idom() using use in(1) instead of in(0)
- @Override public int idepth() { return _idepth==0 ? (_idepth=idom().idepth()+1) : _idepth; }
+ @Override public int idepth() { return validIDepth() ? _idepth : cacheIDepth(entry().idepth()+1); }
// Bypass Region idom, same as the default idom() using use in(1) instead of in(0)
@Override public CFGNode idom(Node dep) { return entry(); }
diff --git a/chapter18/src/main/java/com/seaofnodes/simple/node/RegionNode.java b/chapter18/src/main/java/com/seaofnodes/simple/node/RegionNode.java
index ea053c02..9a076dea 100644
--- a/chapter18/src/main/java/com/seaofnodes/simple/node/RegionNode.java
+++ b/chapter18/src/main/java/com/seaofnodes/simple/node/RegionNode.java
@@ -100,20 +100,19 @@ public class RegionNode extends CFGNode {
// Immediate dominator of Region is a little more complicated.
@Override public int idepth() {
- if( _idepth!=0 ) return _idepth;
- int d=0;
+ if( validIDepth() ) return _idepth;
+ int depth=0;
for( Node n : _inputs )
if( n!=null )
- d = Math.max(d,((CFGNode)n).idepth()+1);
- return _idepth=d;
+ depth = Math.max(depth,((CFGNode)n).idepth()+1);
+ return cacheIDepth(depth);
}
@Override public CFGNode idom(Node dep) {
CFGNode lca = null;
- // Walk the LHS & RHS idom trees in parallel until they match, or either fails.
- // Because this does not cache, it can be linear in the size of the program.
+ // Recompute from predecessors: CFG edits can change the dominator.
for( int i=1; i<nIns(); i++ )
- lca = cfg(i)._idom(lca,dep);
+ lca = cfg(i).domLCA(lca,dep);
return lca;
}
diff --git a/chapter18/src/main/java/com/seaofnodes/simple/node/ReturnNode.java b/chapter18/src/main/java/com/seaofnodes/simple/node/ReturnNode.java
index e543f9ea..e516859b 100644
--- a/chapter18/src/main/java/com/seaofnodes/simple/node/ReturnNode.java
+++ b/chapter18/src/main/java/com/seaofnodes/simple/node/ReturnNode.java
@@ -77,8 +77,7 @@ public class ReturnNode extends CFGNode {
return ctrl().getClass() == RegionNode.class && ((RegionNode)ctrl()).inProgress();
}
- // Gather parse-time return types for error reporting
- private Type mt = Type.TOP;
+ // Remember parsed type kinds for diagnostics; the optimized expression decides validity.
private boolean ti=false, tf=false, tp=false, tn=false;
// Add a return exit to the current parsing function
@@ -87,7 +86,6 @@ public class ReturnNode extends CFGNode {
// Gather parse-time return types for error reporting
Type t = expr._type;
- mt = mt.meet(t);
ti |= t instanceof TypeInteger x;
tf |= t instanceof TypeFloat x;
tp |= t instanceof TypeMemPtr x;
@@ -113,7 +111,7 @@ public class ReturnNode extends CFGNode {
}
@Override public Parser.ParseException err() {
- return mt==Type.BOTTOM ? mixerr(ti,tf,tp,tn,_fun._loc) : null;
+ return expr()._type==Type.BOTTOM ? mixerr(ti,tf,tp,tn,_fun._loc) : null;
}
static Parser.ParseException mixerr( boolean ti, boolean tf, boolean tp, boolean tn, Parser.Lexer loc ) {
diff --git a/chapter18/src/main/java/com/seaofnodes/simple/node/StopNode.java b/chapter18/src/main/java/com/seaofnodes/simple/node/StopNode.java
index feb8347f..cabb7393 100644
--- a/chapter18/src/main/java/com/seaofnodes/simple/node/StopNode.java
+++ b/chapter18/src/main/java/com/seaofnodes/simple/node/StopNode.java
@@ -54,10 +54,10 @@ public class StopNode extends CFGNode {
}
@Override public int idepth() {
- if( _idepth!=0 ) return _idepth;
+ if( validIDepth() ) return _idepth;
int d=0;
for( Node ret : _inputs )
d = Math.max(d,((ReturnNode)ret).idepth()+1);
- return _idepth=d;
+ return cacheIDepth(d);
}
}