diff -urN jdk9u-jdk-9.0.4+12.orig/common/autoconf/flags.m4 jdk9u-jdk-9.0.4+12/common/autoconf/flags.m4
--- jdk9u-jdk-9.0.4+12.orig/common/autoconf/flags.m4	2017-12-20 00:25:20.000000000 +0100
+++ jdk9u-jdk-9.0.4+12/common/autoconf/flags.m4	2020-08-29 23:58:39.603994302 +0200
@@ -215,7 +215,10 @@
     COMPILER_COMMAND_FILE_FLAG="-f"
     COMPILER_BINDCMD_FILE_FLAG="-bloadmap:"
   else
-    COMPILER_TARGET_BITS_FLAG="-m"
+    case $CC in
+      *x32-*) COMPILER_TARGET_BITS_FLAG="-mx";;
+      *) COMPILER_TARGET_BITS_FLAG="-m"
+    esac
     COMPILER_COMMAND_FILE_FLAG="@"
     COMPILER_BINDCMD_FILE_FLAG=""
 
diff -urN jdk9u-jdk-9.0.4+12.orig/common/autoconf/platform.m4 jdk9u-jdk-9.0.4+12/common/autoconf/platform.m4
--- jdk9u-jdk-9.0.4+12.orig/common/autoconf/platform.m4	2017-12-20 00:25:20.000000000 +0100
+++ jdk9u-jdk-9.0.4+12/common/autoconf/platform.m4	2020-08-29 23:54:36.322300132 +0200
@@ -31,10 +31,20 @@
   # First argument is the cpu name from the trip/quad
   case "$1" in
     x86_64)
-      VAR_CPU=x86_64
-      VAR_CPU_ARCH=x86
-      VAR_CPU_BITS=64
-      VAR_CPU_ENDIAN=little
+      case "$target_os" in
+        *x32)
+          VAR_CPU=x32
+          VAR_CPU_ARCH=x86
+          VAR_CPU_BITS=32
+          VAR_CPU_ENDIAN=little
+          ;;
+        *)
+          VAR_CPU=x86_64
+          VAR_CPU_ARCH=x86
+          VAR_CPU_BITS=64
+          VAR_CPU_ENDIAN=little
+          ;;
+      esac
       ;;
     i?86)
       VAR_CPU=x86
@@ -408,6 +418,14 @@
     HOTSPOT_$1_CPU_DEFINE=IA32
   elif test "x$OPENJDK_$1_CPU" = xx86_64; then
     HOTSPOT_$1_CPU_DEFINE=AMD64
+      case "$target_os" in
+        *x32)
+          HOTSPOT_$1_CPU_DEFINE=X32
+          ;;
+        *)
+          HOTSPOT_$1_CPU_DEFINE=AMD64
+          ;;
+      esac
   elif test "x$OPENJDK_$1_CPU" = xsparcv9; then
     HOTSPOT_$1_CPU_DEFINE=SPARC
   elif test "x$OPENJDK_$1_CPU" = xaarch64; then
diff -urN jdk9u-jdk-9.0.4+12.orig/hotspot/src/os/linux/vm/os_linux.cpp jdk9u-jdk-9.0.4+12/hotspot/src/os/linux/vm/os_linux.cpp
--- jdk9u-jdk-9.0.4+12.orig/hotspot/src/os/linux/vm/os_linux.cpp	2020-08-29 23:50:35.510694441 +0200
+++ jdk9u-jdk-9.0.4+12/hotspot/src/os/linux/vm/os_linux.cpp	2020-08-29 23:55:07.785416515 +0200
@@ -1770,7 +1770,7 @@
 
 #if  (defined IA32)
   static  Elf32_Half running_arch_code=EM_386;
-#elif   (defined AMD64)
+#elif   (defined AMD64) || (defined X32)
   static  Elf32_Half running_arch_code=EM_X86_64;
 #elif  (defined IA64)
   static  Elf32_Half running_arch_code=EM_IA_64;
diff -urN jdk9u-jdk-9.0.4+12.orig/jdk/make/gensrc/GensrcX11Wrappers.gmk jdk9u-jdk-9.0.4+12/jdk/make/gensrc/GensrcX11Wrappers.gmk
--- jdk9u-jdk-9.0.4+12.orig/jdk/make/gensrc/GensrcX11Wrappers.gmk	2018-01-13 03:07:38.000000000 +0100
+++ jdk9u-jdk-9.0.4+12/jdk/make/gensrc/GensrcX11Wrappers.gmk	2020-08-29 23:55:48.198473585 +0200
@@ -87,9 +87,11 @@
 	$(TOOL_WRAPPERGENERATOR) $(@D) $(GENSRC_SIZER_DIR)/xlibtypes.txt "sizer" $*
 
   # use -m32/-m64 only if the compiler supports it
+  ifneq ($(OPENJDK_TARGET_CPU),x32)
   ifeq ($(COMPILER_SUPPORTS_TARGET_BITS_FLAG), true)
     MEMORY_MODEL_FLAG="$(COMPILER_TARGET_BITS_FLAG)$*"
   endif
+  endif
 
   SIZER_CFLAGS := \
       -I$(JDK_TOPDIR)/src/java.base/share/native/include \
diff -urN jdk9u-jdk-9.0.4+12.orig/jdk/src/jdk.pack/share/native/common-unpack/unpack.cpp jdk9u-jdk-9.0.4+12/jdk/src/jdk.pack/share/native/common-unpack/unpack.cpp
--- jdk9u-jdk-9.0.4+12.orig/jdk/src/jdk.pack/share/native/common-unpack/unpack.cpp	2018-01-13 03:07:38.000000000 +0100
+++ jdk9u-jdk-9.0.4+12/jdk/src/jdk.pack/share/native/common-unpack/unpack.cpp	2020-08-29 23:59:35.900292250 +0200
@@ -37,7 +37,7 @@
  * Solaris compilers will define __sparcv9 or __x86_64 on 64bit compilations.
  */
 #if !defined (_MSC_VER) && \
-    (defined(_LP64) || defined(__sparcv9) || defined(__x86_64))
+    (defined(_LP64) || defined(__sparcv9) || defined(__x86_64) && !defined(__ILP32__))
   #define LONG_LONG_FORMAT "%ld"
   #define LONG_LONG_HEX_FORMAT "%lx"
 #else