8329726: Use non-short forward jumps in lightweight locking

Reviewed-by: shade, kvn, aboldtch

Author: rkennke

src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp

@@ -1022,15 +1022,18 @@ void C2_MacroAssembler::fast_lock_lightweight(Register obj, Register box, Regist
 #ifdef ASSERT
   // Check that locked label is reached with ZF set.
   Label zf_correct;
-  jccb(Assembler::zero, zf_correct);
-  stop("Fast Lock ZF != 1");
+  Label zf_bad_zero;
+  jcc(Assembler::zero, zf_correct);
+  jmp(zf_bad_zero);
 #endif
 
   bind(slow_path);
 #ifdef ASSERT
   // Check that slow_path label is reached with ZF not set.
-  jccb(Assembler::notZero, zf_correct);
+  jcc(Assembler::notZero, zf_correct);
   stop("Fast Lock ZF != 0");
+  bind(zf_bad_zero);
+  stop("Fast Lock ZF != 1");
   bind(zf_correct);
 #endif
   // C2 uses the value of ZF to determine the continuation.
@@ -1161,7 +1164,7 @@ void C2_MacroAssembler::fast_unlock_lightweight(Register obj, Register reg_rax,
 #ifdef ASSERT
   // Check that unlocked label is reached with ZF set.
   Label zf_correct;
-  jccb(Assembler::zero, zf_correct);
+  jcc(Assembler::zero, zf_correct);
   stop("Fast Unlock ZF != 1");
 #endif
 

test/hotspot/jtreg/compiler/c2/TestLWLockingCodeGen.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @summary Tests correct code generation of lightweight locking when using -XX:+ShowMessageBoxOnError; times-out on failure
+ * @bug 8329726
+ * @run main/othervm -XX:+ShowMessageBoxOnError -Xcomp -XX:-TieredCompilation -XX:CompileOnly=TestLWLockingCodeGen::sync TestLWLockingCodeGen
+ */
+public class TestLWLockingCodeGen {
+    private static int val = 0;
+    public static void main(String[] args) {
+        sync();
+    }
+    private static synchronized void sync() {
+        val = val + (int)(Math.random() * 42);
+    }
+}