Fix altivec defines, reduce dependencies (#66)

diff --git a/highwayhash/hh_vsx.h b/highwayhash/hh_vsx.h
index 1e32cfe..578caa7 100644
--- a/highwayhash/hh_vsx.h
+++ b/highwayhash/hh_vsx.h

@@ -30,13 +30,15 @@
 #ifndef HH_DISABLE_TARGET_SPECIFIC
 
 #include <altivec.h>
-#include <string>
+#undef vector
+#undef pixel
+#undef bool
 
 namespace highwayhash {
 
-typedef vector unsigned long long PPC_VEC_U64;  // NOLINT
-typedef vector unsigned int PPC_VEC_U32;
-typedef vector unsigned char PPC_VEC_U8;
+typedef __vector unsigned long long PPC_VEC_U64;  // NOLINT
+typedef __vector unsigned int PPC_VEC_U32;
+typedef __vector unsigned char PPC_VEC_U8;
 
 // See vector128.h for why this namespace is necessary;
 namespace HH_TARGET_NAME {
@@ -186,7 +188,9 @@
   }
 
   static HH_INLINE void ZeroInitialize(char* HH_RESTRICT buffer_bytes) {
-    memset(buffer_bytes, 0, sizeof(HHPacket));
+    for (size_t i = 0; i < sizeof(HHPacket); ++i) {
+      buffer_bytes[i] = 0;
+    }
   }
 
   static HH_INLINE void CopyPartial(const char* HH_RESTRICT from,

diff --git a/highwayhash/highwayhash_test.cc b/highwayhash/highwayhash_test.cc
index 4687b5e..aed9a9e 100644
--- a/highwayhash/highwayhash_test.cc
+++ b/highwayhash/highwayhash_test.cc

@@ -21,7 +21,6 @@
 #include <atomic>
 #include <cstdio>
 #include <cstdlib>
-#include <vector>
 
 #ifdef HH_GOOGLETEST
 #include "testing/base/public/gunit.h"
@@ -113,11 +112,10 @@
                      0x0F0E0D0C0B0A0908ULL, 0x0706050403020100ULL};
 
   const size_t kMaxSize = 3 * 35;
-  std::vector<char> flat;
-  flat.reserve(kMaxSize);
+  char flat[kMaxSize];
   srand(129);
   for (size_t size = 0; size < kMaxSize; ++size) {
-    flat.push_back(static_cast<char>(rand() & 0xFF));
+    flat[size] = static_cast<char>(rand() & 0xFF);
   }
 
   std::atomic<TargetBits> targets{~0U};
@@ -125,7 +123,7 @@
   pool->Run(0, kMaxSize, [&key, &flat, &targets](const uint32_t i) {
     Result dummy;
     targets.fetch_and(InstructionSets::RunAll<HighwayHashCatTest>(
-        key, flat.data(), i, &dummy, &OnCatFailure));
+        key, flat, i, &dummy, &OnCatFailure));
   });
   return targets.load();
 }

diff --git a/highwayhash/scalar.h b/highwayhash/scalar.h
index 3c56247..21181e7 100644
--- a/highwayhash/scalar.h
+++ b/highwayhash/scalar.h

@@ -114,7 +114,7 @@
   HH_INLINE Scalar& operator<<=(const int count) {
     // In C, int64_t << 64 is undefined, but we want to match the sensible
     // behavior of SSE2 (zeroing).
-    if (count >= sizeof(T) * 8) {
+    if (count >= static_cast<int>(sizeof(T)) * 8) {
       v_ = 0;
     } else {
       v_ <<= count;

diff --git a/highwayhash/vector_test.cc b/highwayhash/vector_test.cc
index 94e4532..8ecd89f 100644
--- a/highwayhash/vector_test.cc
+++ b/highwayhash/vector_test.cc

@@ -25,6 +25,10 @@
 namespace highwayhash {
 namespace {
 
+#ifdef HH_DISABLE_TARGET_SPECIFIC
+void RunTests() {}
+#else
+
 void NotifyFailure(const char* target, const size_t size) {
   const size_t lane_bits = (size & 0xFF) * 8;
   const size_t lane_index = (size >> 8) & 0xFF;
@@ -39,14 +43,14 @@
 }
 
 void RunTests() {
-#ifndef HH_DISABLE_TARGET_SPECIFIC
   const TargetBits tested = InstructionSets::RunAll<VectorTest>(&NotifyFailure);
   HH_TARGET_NAME::ForeachTarget(tested, [](const TargetBits target) {
     printf("%10s: done\n", TargetName(target));
   });
-#endif
 }
 
+#endif  // HH_DISABLE_TARGET_SPECIFIC
+
 #ifdef HH_GOOGLETEST
 TEST(VectorTest, Run) { RunTests(); }
 #endif