ADDITIONAL SYSTEM INFORMATION :
>>>>>>>>>>>>>>> System properties BEGIN <<<<<<<<<<<<<<<<<<<<<<<
java.specification.version = 23
sun.jnu.encoding = ANSI_X3.4-1968
java.class.path = /home/debian/mp-jnhw/de.ibapl.jnhw.libloader/target/test-classes:/home/debian/.m2/repository/org/junit/jupiter/junit-jupiter-api/5.11.4/junit-jupiter-api-5.11.4.jar:/home/debian/.m2/repository/org/opentest4j/opentest4j/1.3.0/opentest4j-1.3.0.jar:/home/debian/.m2/repository/org/junit/platform/junit-platform-commons/1.11.4/junit-platform-commons-1.11.4.jar:/home/debian/.m2/repository/org/apiguardian/apiguardian-api/1.1.2/apiguardian-api-1.1.2.jar:/home/debian/.m2/repository/org/junit/jupiter/junit-jupiter-engine/5.11.4/junit-jupiter-engine-5.11.4.jar:/home/debian/.m2/repository/org/junit/platform/junit-platform-engine/1.11.4/junit-platform-engine-1.11.4.jar:
java.vm.vendor = Debian
sun.arch.data.model = 32
java.vendor.url = https://tracker.debian.org/openjdk-23
java.vm.specification.version = 23
os.name = Linux
sun.java.launcher = SUN_STANDARD
user.country = US
sun.boot.library.path = /usr/lib/jvm/java-23-openjdk-powerpc/lib
sun.java.command = org.apache.maven.surefire.booter.ForkedBooter /home/debian/mp-jnhw/de.ibapl.jnhw.libloader/target/surefire 2025-03-20T08-37-56_397-jvmRun1 surefire-20250320083801812_1tmp surefire_0-20250320083801812_2tmp
jdk.debug = release
surefire.test.class.path = /home/debian/mp-jnhw/de.ibapl.jnhw.libloader/target/test-classes:/home/debian/.m2/repository/org/junit/jupiter/junit-jupiter-api/5.11.4/junit-jupiter-api-5.11.4.jar:/home/debian/.m2/repository/org/opentest4j/opentest4j/1.3.0/opentest4j-1.3.0.jar:/home/debian/.m2/repository/org/junit/platform/junit-platform-commons/1.11.4/junit-platform-commons-1.11.4.jar:/home/debian/.m2/repository/org/apiguardian/apiguardian-api/1.1.2/apiguardian-api-1.1.2.jar:/home/debian/.m2/repository/org/junit/jupiter/junit-jupiter-engine/5.11.4/junit-jupiter-engine-5.11.4.jar:/home/debian/.m2/repository/org/junit/platform/junit-platform-engine/1.11.4/junit-platform-engine-1.11.4.jar:
sun.cpu.endian = big
user.home = /home/debian
user.language = en
java.specification.vendor = Oracle Corporation
jdk.module.path = /home/debian/mp-jnhw/de.ibapl.jnhw.libloader/target/classes
java.version.date = 2025-01-21
java.home = /usr/lib/jvm/java-23-openjdk-powerpc
file.separator = /
basedir = /home/debian/mp-jnhw/de.ibapl.jnhw.libloader
line.separator =

java.vm.specification.vendor = Oracle Corporation
java.specification.name = Java Platform API Specification
surefire.real.class.path = /home/debian/.m2/repository/org/apache/maven/surefire/surefire-booter/3.5.2/surefire-booter-3.5.2.jar:/home/debian/.m2/repository/org/apache/maven/surefire/surefire-api/3.5.2/surefire-api-3.5.2.jar:/home/debian/.m2/repository/org/apache/maven/surefire/surefire-extensions-spi/3.5.2/surefire-extensions-spi-3.5.2.jar:/home/debian/.m2/repository/org/apache/maven/surefire/surefire-shared-utils/3.5.2/surefire-shared-utils-3.5.2.jar:/home/debian/.m2/repository/org/apache/maven/surefire/surefire-logger-api/3.5.2/surefire-logger-api-3.5.2.jar:/home/debian/mp-jnhw/de.ibapl.jnhw.libloader/target/test-classes:/home/debian/.m2/repository/org/junit/jupiter/junit-jupiter-api/5.11.4/junit-jupiter-api-5.11.4.jar:/home/debian/.m2/repository/org/opentest4j/opentest4j/1.3.0/opentest4j-1.3.0.jar:/home/debian/.m2/repository/org/junit/platform/junit-platform-commons/1.11.4/junit-platform-commons-1.11.4.jar:/home/debian/.m2/repository/org/apiguardian/apiguardian-api/1.1.2/apiguardian-api-1.1.2.jar:/home/debian/.m2/repository/org/junit/jupiter/junit-jupiter-engine/5.11.4/junit-jupiter-engine-5.11.4.jar:/home/debian/.m2/repository/org/junit/platform/junit-platform-engine/1.11.4/junit-platform-engine-1.11.4.jar:/home/debian/.m2/repository/org/apache/maven/surefire/surefire-junit-platform/3.5.2/surefire-junit-platform-3.5.2.jar:/home/debian/.m2/repository/org/apache/maven/surefire/common-java5/3.5.2/common-java5-3.5.2.jar:/home/debian/.m2/repository/org/junit/platform/junit-platform-launcher/1.11.4/junit-platform-launcher-1.11.4.jar
java.runtime.version = 23.0.2+7-Debian-1
user.name = debian
stdout.encoding = ANSI_X3.4-1968
path.separator = :
os.version = 6.12.15-powerpc-smp
java.runtime.name = OpenJDK Runtime Environment
file.encoding = UTF-8
java.vm.name = OpenJDK Zero VM
localRepository = /home/debian/.m2/repository
java.vendor.url.bug = https://bugs.debian.org/openjdk-23
java.io.tmpdir = /tmp
java.version = 23.0.2
user.dir = /home/debian/mp-jnhw/de.ibapl.jnhw.libloader
os.arch = ppc
java.vm.specification.name = Java Virtual Machine Specification
native.encoding = ANSI_X3.4-1968
java.library.path = /usr/java/packages/lib:/usr/lib/powerpc-linux-gnu/jni:/lib/powerpc-linux-gnu:/usr/lib/powerpc-linux-gnu:/usr/lib/jni:/lib:/usr/lib
java.vm.info = interpreted mode
stderr.encoding = ANSI_X3.4-1968
java.vendor = Debian
java.vm.version = 23.0.2+7-Debian-1
sun.io.unicode.encoding = UnicodeBig
java.class.version = 67.0

>>>>>>>>>>>>>>> System properties END <<<<<<<<<<<<<<<<<<<<<<<


A DESCRIPTION OF THE PROBLEM :
returning int8_t or int16_t returns garbage whereas int32_t and int64_t returns the expected value.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
compile native part extracted from testcase comment in a native lib and run testcases with correct native lib name on powerpc 32bit Big Endian

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
all tests pass
ACTUAL -
int8_t and int16_t tests fail int32_t test passes

---------- BEGIN SOURCE ----------
import java.lang.foreign.Arena;
import java.lang.foreign.FunctionDescriptor;
import java.lang.foreign.Linker;
import java.lang.foreign.MemorySegment;
import java.lang.foreign.SymbolLookup;
import java.lang.foreign.ValueLayout;
import java.lang.invoke.MethodHandle;
import static org.junit.jupiter.api.Assertions.assertEquals;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.ValueSource;

/*create and compile into a lib a c file with the following content:
#include <stdint.h>

#define JNHW_Integer_Test( datatype ) \
datatype jnhw_ ## datatype ## _mem; \
void jnhw_ ## datatype ## _set( datatype value ) { jnhw_ ## datatype ## _mem = value; } \
datatype jnhw_ ## datatype ## _get() { return jnhw_ ## datatype ## _mem; }

JNHW_Integer_Test( uint8_t )
JNHW_Integer_Test( int8_t )
JNHW_Integer_Test( uint16_t )
JNHW_Integer_Test( int16_t )
JNHW_Integer_Test( uint32_t )
JNHW_Integer_Test( int32_t )
JNHW_Integer_Test( uint64_t )
JNHW_Integer_Test( int64_t )
 */
/**
 *
 * @author aploese
 */
public class Test_PPC {

    //Change this path to the correct value
    private String NATIVE_TEST_LIB_PATH = "/home/debian/mp-jnhw/de.ibapl.jnhw.common/src/test/resources/lib/powerpc-linux-gnu/libjnhw-common-test.so.4";

    @ParameterizedTest
    @ValueSource(bytes = {
        (byte) 0x01,
        (byte) 0x8f,
        (byte) 0x00,
        (byte) 0xf0,
        (byte) 0xff})
    public void testInt8_t(final byte value) throws Throwable {

        final Linker linker = Linker.nativeLinker();
        try (Arena arena = Arena.ofConfined()) {
            final SymbolLookup sb = SymbolLookup.libraryLookup(NATIVE_TEST_LIB_PATH, arena);
            MemorySegment msSet = sb.findOrThrow("jnhw_int8_t_set");
            MethodHandle mhSet = linker.downcallHandle(msSet, FunctionDescriptor.ofVoid(ValueLayout.JAVA_BYTE));

            mhSet.invokeExact(value);

            MemorySegment msMem = sb.findOrThrow("jnhw_int8_t_mem").reinterpret(ValueLayout.JAVA_BYTE.byteSize(), arena, null);

            assertEquals(value, msMem.get(ValueLayout.JAVA_BYTE, 0));

            MemorySegment msGet = sb.findOrThrow("jnhw_int8_t_get");
            MethodHandle mhGet = linker.downcallHandle(msGet, FunctionDescriptor.of(ValueLayout.JAVA_BYTE));

            assertEquals(value, (byte) mhGet.invokeExact());
        }
    }

    @ParameterizedTest
    @ValueSource(shorts = {
        (short) 0x0001,
        (short) 0x8fff,
        (short) 0x0000,
        (short) 0xf000,
        (short) 0xffff})
    public void testInt16_t(final short value) throws Throwable {

        final Linker linker = Linker.nativeLinker();
        try (Arena arena = Arena.ofConfined()) {
            final SymbolLookup sb = SymbolLookup.libraryLookup(NATIVE_TEST_LIB_PATH, arena);
            MemorySegment msSet = sb.findOrThrow("jnhw_int16_t_set");
            MethodHandle mhSet = linker.downcallHandle(msSet, FunctionDescriptor.ofVoid(ValueLayout.JAVA_SHORT));

            mhSet.invokeExact(value);

            MemorySegment msMem = sb.findOrThrow("jnhw_int16_t_mem").reinterpret(ValueLayout.JAVA_SHORT.byteSize(), arena, null);

            assertEquals(value, msMem.get(ValueLayout.JAVA_SHORT, 0));

            MemorySegment msGet = sb.findOrThrow("jnhw_int16_t_get");
            MethodHandle mhGet = linker.downcallHandle(msGet, FunctionDescriptor.of(ValueLayout.JAVA_SHORT));

            assertEquals(value, (short) mhGet.invokeExact());
        }
    }

    @ParameterizedTest
    @ValueSource(ints = {
        0x00000001,
        0x8fffffff,
        0x00000000,
        0xf0000000,
        0xffffffff})
    public void testInt32_t(final int value) throws Throwable {

        final Linker linker = Linker.nativeLinker();
        try (Arena arena = Arena.ofConfined()) {
            final SymbolLookup sb = SymbolLookup.libraryLookup(NATIVE_TEST_LIB_PATH, arena);
            MemorySegment msSet = sb.findOrThrow("jnhw_int32_t_set");
            MethodHandle mhSet = linker.downcallHandle(msSet, FunctionDescriptor.ofVoid(ValueLayout.JAVA_INT));

            mhSet.invokeExact(value);

            MemorySegment msMem = sb.findOrThrow("jnhw_int32_t_mem").reinterpret(ValueLayout.JAVA_INT.byteSize(), arena, null);

            assertEquals(value, msMem.get(ValueLayout.JAVA_INT, 0));

            MemorySegment msGet = sb.findOrThrow("jnhw_int32_t_get");
            MethodHandle mhGet = linker.downcallHandle(msGet, FunctionDescriptor.of(ValueLayout.JAVA_INT));

            assertEquals(value, (int) mhGet.invokeExact());
        }
    }

}

---------- END SOURCE ----------