diff -r 1262b3ddd7e4 -r a333fdeb8de0 make/autoconf/toolchain.m4
--- a/make/autoconf/toolchain.m4	Sat Aug 31 09:18:40 2019 -0700
+++ b/make/autoconf/toolchain.m4	Fri Aug 30 09:37:41 2019 +0200
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2018, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2019, 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
@@ -286,7 +286,8 @@
     $ECHO "$XLCLANG_VERSION_OUTPUT" | $GREP "IBM XL C/C++ for AIX" > /dev/null
     if test $? -eq 0; then
       AC_MSG_NOTICE([xlclang++ output: $XLCLANG_VERSION_OUTPUT])
-      XLC_USES_CLANG=true
+    else
+      AC_MSG_ERROR([xlclang++ version output check failed, output: $XLCLANG_VERSION_OUTPUT])
     fi
   fi
 
@@ -294,21 +295,13 @@
   TOOLCHAIN_CC_BINARY_gcc="gcc"
   TOOLCHAIN_CC_BINARY_microsoft="cl$EXE_SUFFIX"
   TOOLCHAIN_CC_BINARY_solstudio="cc"
-  TOOLCHAIN_CC_BINARY_xlc="xlc_r"
+  TOOLCHAIN_CC_BINARY_xlc="xlclang"
 
   TOOLCHAIN_CXX_BINARY_clang="clang++"
   TOOLCHAIN_CXX_BINARY_gcc="g++"
   TOOLCHAIN_CXX_BINARY_microsoft="cl$EXE_SUFFIX"
   TOOLCHAIN_CXX_BINARY_solstudio="CC"
-  TOOLCHAIN_CXX_BINARY_xlc="xlC_r"
-
-  if test "x$OPENJDK_TARGET_OS" = xaix; then
-    if test "x$XLC_USES_CLANG" = xtrue; then
-      AC_MSG_NOTICE([xlclang++ detected, using it])
-      TOOLCHAIN_CC_BINARY_xlc="xlclang"
-      TOOLCHAIN_CXX_BINARY_xlc="xlclang++"
-    fi
-  fi
+  TOOLCHAIN_CXX_BINARY_xlc="xlclang++"
 
   # Use indirect variable referencing
   toolchain_var_name=TOOLCHAIN_DESCRIPTION_$TOOLCHAIN_TYPE