8307513: C2: intrinsify Math.max(long,long) and Math.min(long,long)

src/hotspot/share/opto/library_call.cpp

@@ -1943,9 +1943,9 @@ bool LibraryCallKit::inline_notify(vmIntrinsics::ID id) {
 
 //----------------------------inline_min_max-----------------------------------
 bool LibraryCallKit::inline_min_max(vmIntrinsics::ID id) {
-  Node *a = nullptr;
-  Node *b = nullptr;
-  Node *n = nullptr;
+  Node* a = nullptr;
+  Node* b = nullptr;
+  Node* n = nullptr;
   switch (id) {
     case vmIntrinsics::_min:
     case vmIntrinsics::_max:

test/hotspot/jtreg/compiler/c2/irTests/TestMinMaxIdentities.java

@@ -112,9 +112,11 @@ public int intMaxMax(int a, int b) {
 
     // Longs
 
-    // As Math.min/max(LL) is not intrinsified, it first needs to be transformed into CMoveL and then MinL/MaxL before
+    // As Math.min/max(LL) is not intrinsified in the backend, it first needs to be transformed into CMoveL and then MinL/MaxL before
     // the identity can be matched. However, the outer min/max is not transformed into CMove because of the CMove cost model.
-    // As JDK-8307513 adds intrinsics for the methods, the tests will be updated then.
+    // JDK-8307513 adds intrinsics for the methods such that MinL/MaxL replace the ternary operations,
+    // and this enables identities to be matched.
+    // Note that before JDK-8307513 MinL/MaxL nodes were already present before macro expansion.
 
     @Test
     @IR(applyIfPlatform = { "riscv64", "false" }, phase = { CompilePhase.BEFORE_MACRO_EXPANSION }, counts = { IRNode.MIN_L, "1" })
@@ -123,13 +125,13 @@ public long longMinMin(long a, long b) {
     }
 
     @Test
-    @IR(applyIfPlatform = { "riscv64", "false" }, phase = { CompilePhase.BEFORE_MACRO_EXPANSION }, counts = { IRNode.MIN_L, "1" })
+    @IR(failOn = { IRNode.MIN_L, IRNode.MAX_L })
     public long longMinMax(long a, long b) {
         return Math.min(a, Math.max(a, b));
     }
 
     @Test
-    @IR(applyIfPlatform = { "riscv64", "false" }, phase = { CompilePhase.BEFORE_MACRO_EXPANSION }, counts = { IRNode.MAX_L, "1" })
+    @IR(failOn = { IRNode.MIN_L, IRNode.MAX_L })
     public long longMaxMin(long a, long b) {
         return Math.max(a, Math.min(a, b));
     }

test/hotspot/jtreg/compiler/intrinsics/math/TestMinMaxInlining.java

@@ -73,6 +73,10 @@ public static void checkTestIntMax(int result) {
         }
     }
 
+    // JDK-8307513 does not changes the way MinL/MaxL nodes intrinsified in backend.
+    // So they are still transformed into CmpL + CMoveL nodes after macro expansion.
+    // This is the reason for the different before/after macro expansion assertions below.
+
     @Test
     @Arguments(values = { Argument.NUMBER_MINUS_42, Argument.NUMBER_42 })
     @IR(phase = { CompilePhase.BEFORE_MACRO_EXPANSION }, counts = { IRNode.MIN_L, "1" })

test/hotspot/jtreg/compiler/loopopts/superword/MinMaxRed_Long.java

@@ -0,0 +1,155 @@
+/*
+ * Copyright (c) 2023, 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 8307513
+ * @summary [SuperWord] MaxReduction and MinReduction should vectorize for long
+ * @library /test/lib /
+ * @run driver compiler.loopopts.superword.MinMaxRed_Long
+ */
+
+package compiler.loopopts.superword;
+
+import compiler.lib.ir_framework.*;
+import jdk.test.lib.Utils;
+
+import java.util.Arrays;
+import java.util.Random;
+import java.util.stream.LongStream;
+
+public class MinMaxRed_Long {
+
+    private static final Random random = Utils.getRandomInstance();
+
+    public static void main(String[] args) throws Exception {
+        TestFramework framework = new TestFramework();
+        framework.addFlags("-XX:+IgnoreUnrecognizedVMOptions",
+                           "-XX:LoopUnrollLimit=250",
+                           "-XX:CompileThresholdScaling=0.1");
+        framework.start();
+    }
+
+    @Run(test = {"maxReductionImplement"},
+         mode = RunMode.STANDALONE)
+    public void runMaxTest() {
+        runMaxTest(50);
+        runMaxTest(80);
+        runMaxTest(100);
+    }
+
+    private static void runMaxTest(int probability) {
+        long[] longs = new long[1024];
+        ReductionInit(longs, probability);
+        long res = 0;
+        for (int j = 0; j < 2000; j++) {
+            res = maxReductionImplement(longs, res);
+        }
+        if (res == 11 * Arrays.stream(longs).max().getAsLong()) {
+            System.out.println("Success");
+        } else {
+            throw new AssertionError("Failed");
+        }
+    }
+
+    @Run(test = {"minReductionImplement"},
+         mode = RunMode.STANDALONE)
+    public void runMinTest() {
+        runMinTest(50);
+        runMinTest(80);
+        runMinTest(100);
+    }
+
+    private static void runMinTest(int probability) {
+        long[] longs = new long[1024];
+        ReductionInit(longs, probability);
+        // Negating the values generated for controlling max branching
+        // allows same logic to be used for min tests.
+        longs = negate(longs);
+        long res = 0;
+        for (int j = 0; j < 2000; j++) {
+            res = minReductionImplement(longs, res);
+        }
+        if (res == 11 * Arrays.stream(longs).min().getAsLong()) {
+            System.out.println("Success");
+        } else {
+            throw new AssertionError("Failed");
+        }
+    }
+
+    static long[] negate(long[] nums) {
+        return LongStream.of(nums).map(l -> -l).toArray();
+    }
+
+    public static void ReductionInit(long[] longs, int probability) {
+        int aboveCount, abovePercent;
+
+        // Iterate until you find a set that matches the requirement probability
+        do {
+            long max = random.nextLong(10);
+            longs[0] = max;
+
+            aboveCount = 0;
+            for (int i = 1; i < longs.length; i++) {
+                long value;
+                if (random.nextLong(101) <= probability) {
+                    long increment = random.nextLong(10);
+                    value = max + increment;
+                    aboveCount++;
+                } else {
+                    // Decrement by at least 1
+                    long decrement = random.nextLong(10) + 1;
+                    value = max - decrement;
+                }
+                longs[i] = value;
+                max = Math.max(max, value);
+            }
+
+            abovePercent = ((aboveCount + 1) * 100) / longs.length;
+        } while (abovePercent != probability);
+    }
+
+    @Test
+    @IR(applyIf = {"SuperWordReductions", "true"},
+        applyIfCPUFeatureOr = { "avx512", "true" },
+        counts = {IRNode.MIN_REDUCTION_V, " > 0"})
+    public static long minReductionImplement(long[] a, long res) {
+        for (int i = 0; i < a.length; i++) {
+            final long v = 11 * a[i];
+            res = Math.min(res, v);
+        }
+        return res;
+    }
+
+    @Test
+    @IR(applyIf = {"SuperWordReductions", "true"},
+        applyIfCPUFeatureOr = { "avx512", "true" },
+        counts = {IRNode.MAX_REDUCTION_V, " > 0"})
+    public static long maxReductionImplement(long[] a, long res) {
+        for (int i = 0; i < a.length; i++) {
+            final long v = 11 * a[i];
+            res = Math.max(res, v);
+        }
+        return res;
+    }
+}

test/micro/org/openjdk/bench/java/lang/MinMaxVector.java

@@ -67,6 +67,7 @@ public void setup() {
             resultIntArray = new int[size];
             resultLongArray = new long[size];
         }
+
         static long[] negate(long[] nums) {
             return LongStream.of(nums).map(l -> -l).toArray();
         }