Backport e1d0a9c832ef3e92faaed7f290ff56c0ed8a9d94

Author: duke

make/autoconf/flags-cflags.m4

@@ -743,7 +743,7 @@ AC_DEFUN([FLAGS_SETUP_CFLAGS_CPU_DEP],
       elif test "x$FLAGS_CPU" = xppc64le; then
         # Little endian machine uses ELFv2 ABI.
         # Use Power8, this is the first CPU to support PPC64 LE with ELFv2 ABI.
-        $1_CFLAGS_CPU_JVM="${$1_CFLAGS_CPU_JVM} -DABI_ELFv2 -mcpu=power8 -mtune=power8"
+        $1_CFLAGS_CPU_JVM="${$1_CFLAGS_CPU_JVM} -DABI_ELFv2 -mcpu=power8 -mtune=power10"
       fi
     elif test "x$FLAGS_CPU" = xs390x; then
       $1_CFLAGS_CPU="-mbackchain -march=z10"
@@ -764,7 +764,7 @@ AC_DEFUN([FLAGS_SETUP_CFLAGS_CPU_DEP],
       if test "x$FLAGS_CPU" = xppc64le; then
         # Little endian machine uses ELFv2 ABI.
         # Use Power8, this is the first CPU to support PPC64 LE with ELFv2 ABI.
-        $1_CFLAGS_CPU_JVM="${$1_CFLAGS_CPU_JVM} -DABI_ELFv2 -mcpu=power8 -mtune=power8"
+        $1_CFLAGS_CPU_JVM="${$1_CFLAGS_CPU_JVM} -DABI_ELFv2 -mcpu=power8 -mtune=power10"
       fi
     fi
     if test "x$OPENJDK_TARGET_OS" = xaix; then