# HG changeset patch
# User Christos Kotselidis <christos.kotselidis@oracle.com>
# Date 1371576622 -7200
# Node ID 72eafe3a1c34b2f0fa8a5dcf4f0fd153c544c6e1
# Parent  665e95c28965b7b8b987cafef83f5d0f328db411
Add comments in Compressed Oops

diff -r 665e95c28965 -r 72eafe3a1c34 graal/com.oracle.graal.lir.amd64/src/com/oracle/graal/lir/amd64/AMD64Move.java
--- a/graal/com.oracle.graal.lir.amd64/src/com/oracle/graal/lir/amd64/AMD64Move.java	Tue Jun 18 16:39:17 2013 +0200
+++ b/graal/com.oracle.graal.lir.amd64/src/com/oracle/graal/lir/amd64/AMD64Move.java	Tue Jun 18 19:30:22 2013 +0200
@@ -669,6 +669,8 @@
             // Otherwise the narrow heap base, which resides always in register 12, is subtracted
             // followed by right shift.
             masm.testq(scratchRegister, scratchRegister);
+            // If the stored reference is null, move the heap to scratch
+            // register and then calculate the compressed oop value.
             masm.cmovq(ConditionFlag.Equal, scratchRegister, AMD64.r12);
             masm.subq(scratchRegister, AMD64.r12);
             masm.shrq(scratchRegister, logMinObjAlignment);