test/hotspot/jtreg/compiler/floatingpoint/TestSubNodeFloatDoubleNegation.java

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/**
 * @test
 * @bug 8351515
 * @summary The compiler must not fold `0-(0-x)` for x: float | double
 * @library /test/lib /
 * @modules jdk.incubator.vector
 * @run driver compiler.floatingpoint.TestSubNodeFloatDoubleNegation
 */
package compiler.floatingpoint;

import compiler.lib.ir_framework.*;
import jdk.incubator.vector.Float16;
import jdk.test.lib.Asserts;

public class TestSubNodeFloatDoubleNegation {

    public static void main(String[] args) {
        TestFramework.runWithFlags("--add-modules=jdk.incubator.vector", "-XX:CompileCommand=inline,jdk.incubator.vector.Float16::*");
    }

    @Run(test = { "testHalfFloat", "testFloat", "testDouble" })
    public static void assertResults() {
        short halfFloatRes = Float16.float16ToShortBits(testHalfFloat(Float16.valueOf(-0.0f)));
        int floatRes = Float.floatToIntBits(testFloat(-0.0f));
        long doubleRes = Double.doubleToLongBits(testDouble(-0.0));

        Asserts.assertEQ((short) 0, halfFloatRes);
        Asserts.assertEQ((int) 0, floatRes);
        Asserts.assertEQ((long) 0, doubleRes);
    }

    @Test
    @IR(counts = { IRNode.SUB, "2" }, applyIfPlatform = {"x64", "true"}, applyIfCPUFeature = {"avx512_fp16", "false"})
    @IR(counts = { IRNode.SUB_HF, "2" }, applyIfPlatform = {"x64", "true"}, applyIfCPUFeature = {"avx512_fp16", "true"})
    @IR(counts = { IRNode.SUB, "2" }, applyIfPlatform = {"aarch64", "true"}, applyIfCPUFeatureAnd = {"fphp", "false", "asimdhp", "false"})
    @IR(counts = { IRNode.SUB_HF, "2" }, applyIfPlatform = {"aarch64", "true"}, applyIfCPUFeatureAnd = {"fphp", "true", "asimdhp", "true"})
    @IR(counts = { IRNode.SUB, "2" }, applyIfPlatform = {"riscv64", "true"}, applyIfCPUFeature = {"zfh", "false"})
    @IR(counts = { IRNode.SUB_HF, "2" }, applyIfPlatform = {"riscv64", "true"}, applyIfCPUFeature = {"zfh", "true"})
    @IR(counts = { IRNode.SUB, "2" }, applyIfPlatformAnd = {"x64", "false", "aarch64", "false", "riscv64", "false"})
    // Checks that the subtractions in 0 - (0 - hf) do not get eliminiated
    public static Float16 testHalfFloat(Float16 hf) {
        return Float16.subtract(
                Float16.shortBitsToFloat16((short) 0),
                Float16.subtract(Float16.shortBitsToFloat16((short) 0), hf));
    }

    @Test
    @IR(counts = { IRNode.SUB_F, "2" })
    // Checks that the subtractions in 0 - (0 - f) do not get eliminated
    public static float testFloat(float f) {
        return 0 - (0 - f);
    }

    @Test
    @IR(counts = { IRNode.SUB_D, "2" })
    // Checks that the subtractions in 0 - (0 - d) do not get eliminated
    public static double testDouble(double d) {
        return 0 - (0 - d);
    }

}