8358889: C2 hits assert in backend due to malformed uncommon trap

src/hotspot/share/opto/callnode.cpp

@@ -1261,12 +1261,13 @@ bool CallStaticJavaNode::is_uncommon_trap() const {
 int CallStaticJavaNode::uncommon_trap_request() const {
   return is_uncommon_trap() ? extract_uncommon_trap_request(this) : 0;
 }
+
 int CallStaticJavaNode::extract_uncommon_trap_request(const Node* call) {
 #ifndef PRODUCT
   if (!(call->req() > TypeFunc::Parms &&
         call->in(TypeFunc::Parms) != nullptr &&
-        call->in(TypeFunc::Parms)->is_Con() &&
-        call->in(TypeFunc::Parms)->bottom_type()->isa_int())) {
+        call->in(TypeFunc::Parms)->bottom_type()->isa_int() &&
+        call->in(TypeFunc::Parms)->bottom_type()->is_int()->is_con())) {
     assert(in_dump() != 0, "OK if dumping");
     tty->print("[bad uncommon trap]");
     return 0;

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

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2026, 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 8358889
+ * @summary Test that a spilled uncommon trap request is handled properly.
+ * @requires vm.compiler2.enabled
+ * @library /test/lib
+ * @run main ${test.main.class}
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:-TieredCompilation -Xcomp
+ *                   -XX:StressSeed=403 -XX:+StressGCM
+ *                   -XX:CompileCommand=compileonly,${test.main.class}::test
+ *                   -XX:CompileCommand=dontinline,${test.main.class}::dontInline
+ *                   ${test.main.class}
+ */
+
+import jdk.test.lib.Asserts;
+
+public class TestSpilledUncommonTrapRequest {
+    static long sum;
+    static final int[] array = new int[64];
+
+    static int max(int first, int second) {
+        return first > second ? first : second;
+    }
+
+    static int dontInline() {
+        return 42;
+    }
+
+    static void test(double[][] doubles) {
+        // Vectorize a loop such that Compile::current()->max_vector_size() > 0 holds
+        for (int i = 0; i < 64; i++) {
+            array[i] = i;
+        }
+
+        // C2 adds an uncommon trap with 'Reason_null_check == 1' and 'Action_maybe_recompile == 1' for the
+        // null-check of the inner array doubles[0] here. This is encoded as
+        // ~((reason << 3) + action) = ~((1 << 3) + 1) = ~9 = -10
+        // which is then shared with the explicit constant -10 passed as argument here.
+        doubles[0][0] = max(dontInline(), -10);
+
+        // Keep the shared -10 live in a loop phi and create enough register pressure for RA to spill it.
+        int product = -10;
+        for (int i = 0; i < 64; i++) {
+            product *= 79;
+            sum++;
+            array[i] = 0;
+        }
+        sum += product;
+    }
+
+    public static void main(String[] args) {
+        test(new double[1][1]);
+        Asserts.assertEQ(sum, 1573390390L);
+    }
+}
+