Chapter 28a: Modules and Lazy Class Initializationlinear-chapter28a

Co-authored-by: Hsiang-Ying Fu <66062782+fuhsnn@users.noreply.github.com>
Co-authored-by: fuhsnn <66062782+fuhsnn@users.noreply.github.com>
Co-authored-by: Symious <14933944+symious@users.noreply.github.com>
Co-authored-by: Jun Kawasaki <jun784@gmail.com>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

1 files changed, 40 insertions, 0 deletions

diff --git a/src/test/java/com/seaofnodes/simple/BulkMemPhiTest.java b/src/test/java/com/seaofnodes/simple/BulkMemPhiTest.java
new file mode 100644
index 00000000..31c0302b
--- /dev/null
+++ b/src/test/java/com/seaofnodes/simple/BulkMemPhiTest.java
@@ -0,0 +1,40 @@
+package com.seaofnodes.simple;
+
+import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.TypeInteger;
+import com.seaofnodes.simple.type.TypeMem;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class BulkMemPhiTest {
+    // Reduced from Capitalize's Lower-phase failure. A precise MemMerge slot
+    // may still be supplied by bulk memory which covers the requested alias.
+    @Test public void testBulkInPreciseSlot() {
+        CodeGen code=new CodeGen("");
+        code._phase=CodeGen.Phase.Lower;
+        Node m0=code.con(TypeMem.START), m1=code.con(TypeMem.BOT);
+        Node ctrl=new CProjNode(code._start,0,"Ctrl").init();
+        Node iff=new IfNode(ctrl,code.con(TypeInteger.BOOL)).init();
+        RegionNode region=new RegionNode(null,null,
+            new CProjNode(iff,0,"True").init(),
+            new CProjNode(iff,1,"False").init()).init();
+        BulkMemPhiNode bulk=new BulkMemPhiNode("$mem",region,m0,m1).init();
+        // A later init check proves its call arm dead. Its precise Phi can
+        // collapse before the surrounding aggregate gets another peephole.
+        RegionNode done=new RegionNode(null,null,region,code.XCTRL).init();
+        MemPhiNode precise=new MemPhiNode("$4",4,done,bulk,m1).init();
+        MemMergeNode merge=new MemMergeNode(null,m0);
+        merge.alias(4,precise);
+        merge.init();
+        Node folded=precise.peepholeOpt();
+        assertSame(bulk,folded);
+        precise.subsume(folded);
+
+        assertFalse(bulk.isSplit(4));
+        assertSame(bulk,merge.alias(4));
+        // Splitting this still-covered alias must tolerate the direct bulk use.
+        Node mem = bulk.idealize();
+        bulk.subsume(mem);
+    }
+}