From 5b2468c41a335bb210fae7a2a605a42ccb5441ce Mon Sep 17 00:00:00 2001
From: Cliff Click <cliffc@acm.org>
Date: Tue, 14 Jan 2025 11:08:36 -0800
Subject: Minor fuzzer bugs

Missing SubF
Missing progress dep
Missing null check
Different fuzzer errors if peeps on/off
---
 chapter18/src/main/java/com/seaofnodes/simple/node/IfNode.java       | 1 +
 chapter18/src/main/java/com/seaofnodes/simple/node/LoadNode.java     | 5 +++--
 chapter18/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java | 5 ++---
 chapter18/src/main/java/com/seaofnodes/simple/node/PhiNode.java      | 2 +-
 4 files changed, 7 insertions(+), 6 deletions(-)

(limited to 'chapter18/src/main/java/com')

diff --git a/chapter18/src/main/java/com/seaofnodes/simple/node/IfNode.java b/chapter18/src/main/java/com/seaofnodes/simple/node/IfNode.java
index c49ee662..eafcdf5b 100644
--- a/chapter18/src/main/java/com/seaofnodes/simple/node/IfNode.java
+++ b/chapter18/src/main/java/com/seaofnodes/simple/node/IfNode.java
@@ -34,6 +34,7 @@ public class IfNode extends CFGNode implements MultiNode {
         // If the If node is not reachable then neither is any following Proj
         if (ctrl()._type != Type.CONTROL && ctrl()._type != Type.BOTTOM )
             return TypeTuple.IF_NEITHER;
+        if( _disablePeephole ) return TypeTuple.IF_BOTH;
         Node pred = pred();
         Type t = pred._type;
         // High types mean NEITHER side is reachable.
diff --git a/chapter18/src/main/java/com/seaofnodes/simple/node/LoadNode.java b/chapter18/src/main/java/com/seaofnodes/simple/node/LoadNode.java
index 7c5a0e66..eee5169d 100644
--- a/chapter18/src/main/java/com/seaofnodes/simple/node/LoadNode.java
+++ b/chapter18/src/main/java/com/seaofnodes/simple/node/LoadNode.java
@@ -166,8 +166,9 @@ public class LoadNode extends MemOpNode {
     private boolean profit(PhiNode phi, int idx) {
         Node px = phi.in(idx);
         if( px==null ) return false;
-        if( px._type instanceof TypeMem mem && mem._t.isHighOrConst() ) { px.addDep(this); return true; }
-        if( px instanceof StoreNode st1 && ptr()==st1.ptr() && off()==st1.off() ) { px.addDep(this); return true; }
+        if( px._type instanceof TypeMem mem && mem._t.isHighOrConst() ) return true;
+        if( px instanceof StoreNode st1 && ptr()==st1.ptr() && off()==st1.off() ) return true;
+        px.addDep(this);
         return false;
     }
 
diff --git a/chapter18/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java b/chapter18/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java
index 61d99ed1..8a08853c 100644
--- a/chapter18/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java
+++ b/chapter18/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java
@@ -113,8 +113,7 @@ public class MemMergeNode extends Node {
         for( int i = 2; i < len; i++)
             if( alias(i) != that.alias(i) ) { // No need for redundant Phis
                 // If we are in lazy phi mode we need to a lookup
-                // by name as it will trigger a phi creation
-                //Var v = _vars.at(i);
+                // by alias as it will trigger a phi creation
                 Node lhs = this._mem(i,null);
                 Node rhs = that._mem(i,null);
                 alias(i, new PhiNode(Parser.memName(i), lhs._type.glb().meet(rhs._type.glb()), r, lhs, rhs).peephole());
@@ -124,7 +123,7 @@ public class MemMergeNode extends Node {
     // Fill in the backedge of any inserted Phis
     void _endLoopMem( ScopeNode scope, MemMergeNode back, MemMergeNode exit ) {
         Node exit_def = exit.alias(1);
-        for( int i=1; i<back.nIns(); i++ ) {
+        for( int i=1; i<nIns(); i++ ) {
             if( in(i) instanceof PhiNode phi && phi.region()==scope.ctrl() ) {
                 assert phi.in(2)==null;
                 phi.setDef(2,back.in(i)==scope ? phi : back.in(i)); // Fill backedge
diff --git a/chapter18/src/main/java/com/seaofnodes/simple/node/PhiNode.java b/chapter18/src/main/java/com/seaofnodes/simple/node/PhiNode.java
index 4dae6f36..9aed8287 100644
--- a/chapter18/src/main/java/com/seaofnodes/simple/node/PhiNode.java
+++ b/chapter18/src/main/java/com/seaofnodes/simple/node/PhiNode.java
@@ -124,7 +124,7 @@ public class PhiNode extends Node {
                 if( r.idom(this).addDep(this) instanceof IfNode iff && iff.pred().addDep(this)==val ) {
                     // Must walk the idom on the null side to make sure we hit False.
                     CFGNode idom = (CFGNode)r.in(nullx);
-                    while( idom.nIns() > 0 && idom.in(0) != iff ) idom = idom.idom();
+                    while( idom != null && idom.nIns() > 0 && idom.in(0) != iff ) idom = idom.idom();
                     if( idom instanceof CProjNode proj && proj._idx==1 )
                         return val;
                 }
-- 
cgit v1.2.3