commit d3b0a4bf6b2e38e6e9e80e203ca753e941084103
author buzbee <buzbee@google.com> Mon Sep 27 11:30:22 2010 -0700
committer buzbee <buzbee@google.com> Tue Sep 28 09:37:22 2010 -0700
tree f84054e500c8ea1a230b20bf0ba763ce7fcbb611
parent 5d00c7f8109b99859347003a21791e9486815b42

Change GC card making to use object head, bug fix for volatile sput obj

This CL changes the way we mark GC card to consistently use the object
head (previously, we marked somewhere in the object - often the head, but
not always).  Also, previously a coding error caused us to skip the card
mark for OP_APUT_OBJECT_VOLATILES.  Fixed here.

Change-Id: I53eb333b9bd0b770201af0dc617d9a8f38afa699

vm/compiler/codegen/arm/CodegenDriver.c

diff --git a/vm/compiler/codegen/arm/CodegenDriver.c b/vm/compiler/codegen/arm/CodegenDriver.c
index f6f2ad9..44f47b7 100644
--- a/vm/compiler/codegen/arm/CodegenDriver.c
+++ b/vm/compiler/codegen/arm/CodegenDriver.c
@@ -1522,7 +1522,9 @@
         case OP_SPUT: {
             int valOffset = offsetof(StaticField, value);
             int tReg = dvmCompilerAllocTemp(cUnit);
+            int objHead;
             bool isVolatile;
+            bool isSputObject;
             const Method *method = (mir->OptimizationFlags & MIR_CALLEE) ?
                 mir->meta.calleeMethod : cUnit->method;
             void *fieldPtr = (void*)
@@ -1532,6 +1534,9 @@
                          (mir->dalvikInsn.opCode == OP_SPUT_OBJECT_VOLATILE) ||
                          dvmIsVolatileField(fieldPtr);
 
+            isSputObject = (mir->dalvikInsn.opCode == OP_SPUT_OBJECT) ||
+                           (mir->dalvikInsn.opCode == OP_SPUT_OBJECT_VOLATILE);
+
             if (fieldPtr == NULL) {
                 LOGE("Unexpected null static field");
                 dvmAbort();
@@ -1540,18 +1545,22 @@
             rlSrc = dvmCompilerGetSrc(cUnit, mir, 0);
             rlSrc = loadValue(cUnit, rlSrc, kAnyReg);
             loadConstant(cUnit, tReg,  (int) fieldPtr + valOffset);
-
+            if (isSputObject) {
+                objHead = dvmCompilerAllocTemp(cUnit);
+                loadConstant(cUnit, objHead, (intptr_t)method->clazz);
+            }
             HEAP_ACCESS_SHADOW(true);
             storeWordDisp(cUnit, tReg, 0 ,rlSrc.lowReg);
+            dvmCompilerFreeTemp(cUnit, tReg);
             HEAP_ACCESS_SHADOW(false);
             if (isVolatile) {
                 dvmCompilerGenMemBarrier(cUnit);
             }
-            if (mir->dalvikInsn.opCode == OP_SPUT_OBJECT) {
-                /* NOTE: marking card based on field address */
-                markCard(cUnit, rlSrc.lowReg, tReg);
+            if (isSputObject) {
+                /* NOTE: marking card based object head */
+                markCard(cUnit, rlSrc.lowReg, objHead);
+                dvmCompilerFreeTemp(cUnit, objHead);
             }
-            dvmCompilerFreeTemp(cUnit, tReg);
 
             break;
         }