--- a/hotspot/src/cpu/s390/vm/s390.ad	Wed Jul 05 22:55:08 2017 +0200
+++ b/hotspot/src/cpu/s390/vm/s390.ad	Fri Feb 24 12:41:26 2017 -0500
@@ -6768,6 +6768,7 @@
   format %{ "SLL     $dst,$src,$nbits\t# use RISC-like SLLG also for int" %}
   ins_encode %{
     int Nbit = $nbits$$constant;
+    assert((Nbit & (BitsPerJavaInteger - 1)) == Nbit, "Check shift mask in ideal graph");
     __ z_sllg($dst$$Register, $src$$Register, Nbit & (BitsPerJavaInteger - 1), Z_R0);
   %}
   ins_pipe(pipe_class_dummy);
@@ -6841,6 +6842,7 @@
   format %{ "SRA     $dst,$src" %}
   ins_encode %{
     int Nbit = $src$$constant;
+    assert((Nbit & (BitsPerJavaInteger - 1)) == Nbit, "Check shift mask in ideal graph");
     __ z_sra($dst$$Register, Nbit & (BitsPerJavaInteger - 1), Z_R0);
   %}
   ins_pipe(pipe_class_dummy);
@@ -6893,6 +6895,7 @@
   format %{ "SRL     $dst,$src" %}
   ins_encode %{
     int Nbit = $src$$constant;
+    assert((Nbit & (BitsPerJavaInteger - 1)) == Nbit, "Check shift mask in ideal graph");
     __ z_srl($dst$$Register, Nbit & (BitsPerJavaInteger - 1), Z_R0);
   %}
   ins_pipe(pipe_class_dummy);