diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -3395,7 +3395,7 @@
      return SemaBuiltinConstantArgRange(TheCall, 3, 0, 7);
   case PPC::BI__builtin_ppc_tw:
   case PPC::BI__builtin_ppc_tdw:
-    return SemaBuiltinConstantArgRange(TheCall, 2, 0, 31);
+    return SemaBuiltinConstantArgRange(TheCall, 2, 1, 31);
   case PPC::BI__builtin_ppc_cmpeqb:
   case PPC::BI__builtin_ppc_setb:
   case PPC::BI__builtin_ppc_maddhd:
diff --git a/clang/test/CodeGen/builtins-ppc-xlcompat-error.c b/clang/test/CodeGen/builtins-ppc-xlcompat-error.c
--- a/clang/test/CodeGen/builtins-ppc-xlcompat-error.c
+++ b/clang/test/CodeGen/builtins-ppc-xlcompat-error.c
@@ -17,9 +17,11 @@
 
 void test_trap(void) {
 #ifdef __PPC64__
-  __tdw(lla, llb, 50); //expected-error {{argument value 50 is outside the valid range [0, 31]}}
+  __tdw(lla, llb, 50); //expected-error {{argument value 50 is outside the valid range [1, 31]}}
+  __tdw(lla, llb, 0); //expected-error {{argument value 0 is outside the valid range [1, 31]}}
 #endif
-  __tw(ia, ib, 50); //expected-error {{argument value 50 is outside the valid range [0, 31]}}
+  __tw(ia, ib, 50); //expected-error {{argument value 50 is outside the valid range [1, 31]}}
+  __tw(ia, ib, 0); //expected-error {{argument value 0 is outside the valid range [1, 31]}}
 }
 
 void test_builtin_ppc_rldimi() {