Add atomicops for AIX/POWER + IBM xlC compiler.

src/google/protobuf/stubs/atomicops.h

@@ -62,6 +62,15 @@ namespace google {
 namespace protobuf {
 namespace internal {
 
+#if defined(GOOGLE_PROTOBUF_ARCH_POWER)
+#if defined(_LP64) || defined(__LP64__)
+typedef int32 Atomic32;
+typedef intptr_t Atomic64;
+#else
+typedef intptr_t Atomic32;
+typedef int64 Atomic64;
+#endif
+#else
 typedef int32 Atomic32;
 #ifdef GOOGLE_PROTOBUF_ARCH_64_BIT
 // We need to be able to go between Atomic64 and AtomicWord implicitly.  This
@@ -75,6 +84,7 @@ typedef int64 Atomic64;
 typedef intptr_t Atomic64;
 #endif
 #endif
+#endif
 
 // Use AtomicWord for a machine-sized pointer.  It will use the Atomic32 or
 // Atomic64 routines below, depending on your architecture.
@@ -179,6 +189,10 @@ GOOGLE_PROTOBUF_ATOMICOPS_ERROR
 #elif defined(GOOGLE_PROTOBUF_OS_SOLARIS)
 #include <google/protobuf/stubs/atomicops_internals_solaris.h>
 
+// AIX
+#elif defined(GOOGLE_PROTOBUF_OS_AIX)
+#include <google/protobuf/stubs/atomicops_internals_aix.h>
+
 // Apple.
 #elif defined(GOOGLE_PROTOBUF_OS_APPLE)
 #include <google/protobuf/stubs/atomicops_internals_macosx.h>

src/google/protobuf/stubs/platform_macros.h

@@ -72,6 +72,9 @@
 #else
 #define GOOGLE_PROTOBUF_ARCH_32_BIT 1
 #endif
+#elif defined(_POWER)
+#define GOOGLE_PROTOBUF_ARCH_POWER 1
+#define GOOGLE_PROTOBUF_ARCH_64_BIT 1
 #elif defined(__GNUC__)
 # if (((__GNUC__ == 4) && (__GNUC_MINOR__ >= 7)) || (__GNUC__ > 4))
 // We fallback to the generic Clang/GCC >= 4.7 implementation in atomicops.h
@@ -96,6 +99,8 @@ GOOGLE_PROTOBUF_PLATFORM_ERROR
 #define GOOGLE_PROTOBUF_OS_NACL
 #elif defined(sun)
 #define GOOGLE_PROTOBUF_OS_SOLARIS
+#elif defined(_AIX)
+#define GOOGLE_PROTOBUF_OS_AIX
 #endif
 
 #undef GOOGLE_PROTOBUF_PLATFORM_ERROR