8341834: C2 compilation fails with "bad AD file" due to Replicate

Reviewed-by: kvn, epeter

Author: rwestrel

src/hotspot/share/opto/superwordVTransformBuilder.cpp

@@ -228,7 +228,13 @@ VTransformNode* SuperWordVTransformBuilder::get_or_make_vtnode_vector_input_at_i
       return shift_count;
     } else {
       // Replicate the scalar same_input to every vector element.
-      BasicType element_type = _vloop_analyzer.types().velt_basic_type(p0);
+      // In some rare case, p0 is Convert node such as a ConvL2I: all
+      // ConvL2I nodes in the pack only differ in their types.
+      // velt_basic_type(p0) is the output type of the pack. In the
+      // case of a ConvL2I, it can be int or some narrower type such
+      // as short etc. But given we replicate the input of the Convert
+      // node, we have to use the input type instead.
+      BasicType element_type = p0->is_Convert() ? p0->in(1)->bottom_type()->basic_type() : _vloop_analyzer.types().velt_basic_type(p0);
       if (index == 2 && VectorNode::is_scalar_rotate(p0) && element_type == T_LONG) {
         // Scalar rotate has int rotation value, but the scalar rotate expects longs.
         assert(same_input->bottom_type()->isa_int(), "scalar rotate expects int rotation");

test/hotspot/jtreg/compiler/vectorization/TestReplicateAtConv.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2024, Red Hat, Inc. 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 8341834
+ * @summary C2 compilation fails with "bad AD file" due to Replicate
+ * @run main/othervm -XX:CompileCommand=compileonly,TestReplicateAtConv::test -Xcomp TestReplicateAtConv
+ */
+
+public class TestReplicateAtConv {
+    public static long val = 0;
+
+    public static void test() {
+        int array[] = new int[500];
+
+        for (int i = 0; i < 100; i++) {
+            for (long l = 100; l > i; l--) {
+                val = 42 + (l + i);
+                array[(int)l] = (int)l - (int)val;
+            }
+        }
+    }
+
+    public static void main(String[] args) {
+        test();
+    }
+}