Shark: fix ldc(Class)

[Andrew Haley]

I've been trying to track down a mysterious bug in Shark for a couple
of weeks, and I finally got it.  It turns out that there's no code
generated for ldc(Class).  What fun!

Oh well, I learned a lot...  :-)

Andrew.


2009-01-12  Andrew Haley  <aph at redhat.com>

        * ports/hotspot/src/share/vm/shark/sharkBlock.cpp (SharkBlock::do_ldc):
        Add logic for ldc(Class).

diff -r 79f28ead8d7b ports/hotspot/src/share/vm/shark/sharkBlock.cpp
--- a/ports/hotspot/src/share/vm/shark/sharkBlock.cpp   Mon Jan 05 11:42:35 2009 +0000
+++ b/ports/hotspot/src/share/vm/shark/sharkBlock.cpp   Mon Jan 12 17:25:51 2009 +0000
@@ -1236,10 +1236,11 @@
     SharkConstantPool constants(this);

     BasicBlock *resolved   = function()->CreateBlock("resolved");
+    BasicBlock *resolved_class = function()->CreateBlock("resolved_class");
     BasicBlock *unresolved = function()->CreateBlock("unresolved");
     BasicBlock *unknown    = function()->CreateBlock("unknown");
     BasicBlock *done       = function()->CreateBlock("done");
-
+
     SwitchInst *switchinst = builder()->CreateSwitch(
       constants.tag_at(iter()->get_constant_index()),
       unknown, 5);
@@ -1247,7 +1248,7 @@
     switchinst->addCase(
       LLVMValue::jbyte_constant(JVM_CONSTANT_String), resolved);
     switchinst->addCase(
-      LLVMValue::jbyte_constant(JVM_CONSTANT_Class), resolved);
+      LLVMValue::jbyte_constant(JVM_CONSTANT_Class), resolved_class);
     switchinst->addCase(
       LLVMValue::jbyte_constant(JVM_CONSTANT_UnresolvedString), unresolved);
     switchinst->addCase(
@@ -1258,6 +1259,26 @@

     builder()->SetInsertPoint(resolved);
     Value *resolved_value = constants.object_at(iter()->get_constant_index());
+    builder()->CreateBr(done);
+
+    builder()->SetInsertPoint(resolved_class);
+    Value *resolved_class_value
+      = constants.object_at(iter()->get_constant_index());
+    resolved_class_value
+      = builder()->CreatePtrToInt(resolved_class_value,
+                                  SharkType::intptr_type());
+    resolved_class_value
+      = (builder()->CreateAdd
+         (resolved_class_value,
+          (LLVMValue::intptr_constant
+           (klassOopDesc::klass_part_offset_in_bytes()
+            + Klass::java_mirror_offset_in_bytes()))));
+    resolved_class_value
+      // FIXME: We need a memory barrier before this load.
+      = (builder()->CreateLoad
+         (builder()->CreateIntToPtr
+          (resolved_class_value,
+           PointerType::getUnqual(SharkType::jobject_type()))));
     builder()->CreateBr(done);

     builder()->SetInsertPoint(unresolved);
@@ -1272,6 +1293,7 @@
     builder()->SetInsertPoint(done);
     PHINode *phi = builder()->CreatePHI(SharkType::jobject_type(), "constant");
     phi->addIncoming(resolved_value, resolved);
+    phi->addIncoming(resolved_class_value, resolved_class);
     phi->addIncoming(unresolved_value, unresolved);
     value = SharkValue::create_jobject(phi);
   }