[aarch64-port-dev ] jdk1 Fix for hotspot/test/gc/g1/TestJNIWeakG1/TestJNIWeakG1.java

[Stuart Monteith]

Hello,
  Bug number pending - Ningsheng/Felix/Yang - could you open a bug please?

There was a bug introduced by "8176100 G1 Need prebarrier on deference
of weak JNI handles" where a rscratch1 is being passed to
g1_write_barrier_pre where it is already using rscratch1. This causes
the TestJNIWeakG1 testcase to SIGSEGV as the temporary register is
being used fro two conflicting purposes.

There don't appear to be any other problems of this type with 8176100.

Regards,
   Stuart

# HG changeset patch
# User smonteith
# Date 1502900365 -3600
#      Wed Aug 16 17:19:25 2017 +0100
# Node ID a3ec37c8743c9ce18cdbc0da204d07baf37e640f
# Parent  525e9457b66a62b50c7ae7350da0c8031f671b92
Aarch64: Fix hotspot/test/gc/g1/TestJNIWeakG1/TestJNIWeakG1.java

diff -r 525e9457b66a -r a3ec37c8743c
src/cpu/aarch64/vm/sharedRuntime_aarch64.cpp
--- a/src/cpu/aarch64/vm/sharedRuntime_aarch64.cpp      Tue Aug 15
15:02:40 2017 +0300
+++ b/src/cpu/aarch64/vm/sharedRuntime_aarch64.cpp      Wed Aug 16
17:19:25 2017 +0100
@@ -2067,7 +2067,7 @@
       __ g1_write_barrier_pre(noreg /* obj */,
                               r0 /* pre_val */,
                               rthread /* thread */,
-                              rscratch1 /* tmp */,
+                              rscratch2 /* tmp */,
                               true /* tosca_live */,
                               true /* expand_call */);
     }