# HG changeset patch
# User Doug Simon <doug.simon@oracle.com>
# Date 1382976239 -3600
# Node ID 7f55cdeec6af6998adccd9933b72f79c2cd2f38f
# Parent  a9f750305a38bf3bbd36716a193370699825f3d8
improved documentation of HotSpotBackend.updateStub()

diff -r a9f750305a38 -r 7f55cdeec6af graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/HotSpotBackend.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/HotSpotBackend.java	Mon Oct 28 16:04:58 2013 +0100
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/HotSpotBackend.java	Mon Oct 28 17:03:59 2013 +0100
@@ -127,6 +127,12 @@
 
     /**
      * Updates a given stub with respect to the registers it destroys.
+     * <p>
+     * Any entry in {@code calleeSaveInfo} that {@linkplain SaveRegistersOp#supportsRemove()
+     * supports} pruning will have {@code destroyedRegisters}
+     * {@linkplain SaveRegistersOp#remove(Set) removed} as these registers are declared as
+     * temporaries in the stub's {@linkplain ForeignCallLinkage linkage} (and thus will be saved by
+     * the stub's caller).
      * 
      * @param stub the stub to update
      * @param destroyedRegisters the registers destroyed by the stub
@@ -141,10 +147,6 @@
         for (Map.Entry<LIRFrameState, SaveRegistersOp> e : calleeSaveInfo.entrySet()) {
             SaveRegistersOp save = e.getValue();
             if (save.supportsRemove()) {
-                // Since the registers destroyed by the stub are declared as temporaries in the
-                // linkage (see ForeignCallLinkage.getTemporaries()) for the stub, the caller
-                // will already save these registers and so there's no need for the stub to
-                // save them again.
                 save.remove(destroyedRegisters);
             }
             DebugInfo info = e.getKey() == null ? null : e.getKey().debugInfo();