8358592: Assert in Assembler::ptest due to missing SSE42 support

src/hotspot/cpu/x86/vm_version_x86.cpp

@@ -1491,6 +1491,8 @@ void VM_Version::get_processor_features() {
         }
         FLAG_SET_DEFAULT(UseSSE42Intrinsics, false);
       }
+    }else{
+      FLAG_SET_DEFAULT(UseSSE42Intrinsics, false);
     }
 
     if (FLAG_IS_DEFAULT(AllocatePrefetchInstr) && supports_3dnow_prefetch()) {
@@ -1643,6 +1645,8 @@ void VM_Version::get_processor_features() {
         }
         FLAG_SET_DEFAULT(UseSSE42Intrinsics, false);
       }
+    }else{
+      FLAG_SET_DEFAULT(UseSSE42Intrinsics, false);
     }
     if (is_atom_family() || is_knights_family()) {
 #ifdef COMPILER2

test/hotspot/jtreg/compiler/intrinsics/Test8358592.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2025, Oracle and/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
+ * @bug 8358592
+ * @summary Regression test for -XX:+UseSSE42Intrinsics -XX:UseSSE=1 crash
+ * @requires vm.debug
+ * @requires os.arch == "x86_64"
+ * @library /test/lib
+ * @run main/othervm Test8358592
+ */
+
+import jdk.test.lib.process.OutputAnalyzer;
+import jdk.test.lib.process.ProcessTools;
+
+public class Test8358592 {
+    public static void main(String[] args) throws Exception {
+        ProcessBuilder pb = ProcessTools.createTestJavaProcessBuilder(
+            "-XX:+UseSSE42Intrinsics",
+            "-XX:UseSSE=1",
+            "-version"
+        );
+        OutputAnalyzer output = new OutputAnalyzer(pb.start());
+        output.shouldHaveExitValue(0);
+    }
+}