diff --git a/clang/lib/Basic/Targets/X86.cpp b/clang/lib/Basic/Targets/X86.cpp
--- a/clang/lib/Basic/Targets/X86.cpp
+++ b/clang/lib/Basic/Targets/X86.cpp
@@ -1551,8 +1551,8 @@
     return std::string("{si}");
   case 'D':
     return std::string("{di}");
-  case 'p': // Keep 'p' constraint (address).
-    return std::string("p");
+  case 'p': // immediate integer or address.
+    return std::string("ip");
   case 't': // top of floating point stack.
     return std::string("{st}");
   case 'u':                        // second from top of floating point stack.