diff --git a/src/alloy/backend/ivm/ivm_assembler.cc b/src/alloy/backend/ivm/ivm_assembler.cc
index 6bdb846b8..c01eeb209 100644
--- a/src/alloy/backend/ivm/ivm_assembler.cc
+++ b/src/alloy/backend/ivm/ivm_assembler.cc
@@ -83,7 +83,7 @@ int IVMAssembler::Assemble(FunctionInfo* symbol_info, HIRBuilder* builder,
     stack_offset += type_size;
   }
   // Ensure 16b alignment.
-  stack_offset = poly::align(stack_offset, 16ull);
+  stack_offset = poly::align(stack_offset, static_cast<size_t>(16));
   ctx.stack_size = stack_offset;
 
   auto block = builder->first_block();
diff --git a/src/alloy/backend/ivm/ivm_intcode.cc b/src/alloy/backend/ivm/ivm_intcode.cc
index 96043200d..03a7e1690 100644
--- a/src/alloy/backend/ivm/ivm_intcode.cc
+++ b/src/alloy/backend/ivm/ivm_intcode.cc
@@ -102,7 +102,8 @@ uint32_t AllocConstant(TranslationContext& ctx, Value* value) {
 uint32_t AllocLabel(TranslationContext& ctx, Label* label) {
   // If it's a back-branch to an already tagged label avoid setting up
   // a reference.
-  uint32_t value = reinterpret_cast<uint32_t>(label->tag);
+  uint32_t value =
+      static_cast<uint32_t>(reinterpret_cast<uintptr_t>(label->tag));
   if (value & 0x80000000) {
     // Already set.
     return AllocConstant(ctx, value & ~0x80000000);
@@ -125,7 +126,7 @@ uint32_t AllocLabel(TranslationContext& ctx, Label* label) {
 
 uint32_t AllocDynamicRegister(TranslationContext& ctx, Value* value) {
   if (value->flags & VALUE_IS_ALLOCATED) {
-    return reinterpret_cast<uint32_t>(value->tag);
+    return static_cast<uint32_t>(reinterpret_cast<uintptr_t>(value->tag));
   } else {
     value->flags |= VALUE_IS_ALLOCATED;
     auto reg = ctx.register_count++;
@@ -2334,13 +2335,13 @@ int Translate_DID_SATURATE(TranslationContext& ctx, Instr* i) {
   }                                                                          \
   return IA_NEXT;
 
-uint32_t IntCode_VECTOR_COMPARE_EQ_I8(IntCodeState& ics, const IntCode* i){
+uint32_t IntCode_VECTOR_COMPARE_EQ_I8(IntCodeState& ics, const IntCode* i) {
     VECTOR_COMPARER(uint8_t, b16, b16, 16, == )};
-uint32_t IntCode_VECTOR_COMPARE_EQ_I16(IntCodeState& ics, const IntCode* i){
+uint32_t IntCode_VECTOR_COMPARE_EQ_I16(IntCodeState& ics, const IntCode* i) {
     VECTOR_COMPARER(uint16_t, s8, s8, 8, == )};
-uint32_t IntCode_VECTOR_COMPARE_EQ_I32(IntCodeState& ics, const IntCode* i){
+uint32_t IntCode_VECTOR_COMPARE_EQ_I32(IntCodeState& ics, const IntCode* i) {
     VECTOR_COMPARER(uint32_t, i4, i4, 4, == )};
-uint32_t IntCode_VECTOR_COMPARE_EQ_F32(IntCodeState& ics, const IntCode* i){
+uint32_t IntCode_VECTOR_COMPARE_EQ_F32(IntCodeState& ics, const IntCode* i) {
     VECTOR_COMPARER(float, f4, i4, 4, == )};
 int Translate_VECTOR_COMPARE_EQ(TranslationContext& ctx, Instr* i) {
   static IntCodeFn fns[] = {
@@ -2352,13 +2353,13 @@ int Translate_VECTOR_COMPARE_EQ(TranslationContext& ctx, Instr* i) {
   return DispatchToC(ctx, i, fns[i->flags]);
 }
 
-uint32_t IntCode_VECTOR_COMPARE_SGT_I8(IntCodeState& ics, const IntCode* i){
+uint32_t IntCode_VECTOR_COMPARE_SGT_I8(IntCodeState& ics, const IntCode* i) {
     VECTOR_COMPARER(int8_t, b16, b16, 16, > )};
-uint32_t IntCode_VECTOR_COMPARE_SGT_I16(IntCodeState& ics, const IntCode* i){
+uint32_t IntCode_VECTOR_COMPARE_SGT_I16(IntCodeState& ics, const IntCode* i) {
     VECTOR_COMPARER(int16_t, s8, s8, 8, > )};
-uint32_t IntCode_VECTOR_COMPARE_SGT_I32(IntCodeState& ics, const IntCode* i){
+uint32_t IntCode_VECTOR_COMPARE_SGT_I32(IntCodeState& ics, const IntCode* i) {
     VECTOR_COMPARER(int32_t, i4, i4, 4, > )};
-uint32_t IntCode_VECTOR_COMPARE_SGT_F32(IntCodeState& ics, const IntCode* i){
+uint32_t IntCode_VECTOR_COMPARE_SGT_F32(IntCodeState& ics, const IntCode* i) {
     VECTOR_COMPARER(float, f4, i4, 4, > )};
 int Translate_VECTOR_COMPARE_SGT(TranslationContext& ctx, Instr* i) {
   static IntCodeFn fns[] = {
diff --git a/src/alloy/backend/x64/x64_code_cache_posix.cc b/src/alloy/backend/x64/x64_code_cache_posix.cc
index 7570e119d..63a44e709 100644
--- a/src/alloy/backend/x64/x64_code_cache_posix.cc
+++ b/src/alloy/backend/x64/x64_code_cache_posix.cc
@@ -9,10 +9,11 @@
 
 #include <alloy/backend/x64/x64_code_cache.h>
 
-#include <poly/assert.h>
-
 #include <sys/mman.h>
 
+#include <poly/assert.h>
+#include <poly/math.h>
+
 namespace alloy {
 namespace backend {
 namespace x64 {
@@ -51,7 +52,7 @@ void* X64CodeCache::PlaceCode(void* machine_code, size_t code_size,
 
   // Always move the code to land on 16b alignment. We do this by rounding up
   // to 16b so that all offsets are aligned.
-  code_size = XEROUNDUP(code_size, 16);
+  code_size = poly::round_up(code_size, 16);
 
   lock_.lock();
 
diff --git a/src/alloy/backend/x64/x64_emitter.cc b/src/alloy/backend/x64/x64_emitter.cc
index 00c84936e..7d387600e 100644
--- a/src/alloy/backend/x64/x64_emitter.cc
+++ b/src/alloy/backend/x64/x64_emitter.cc
@@ -127,7 +127,7 @@ int X64Emitter::Emit(HIRBuilder* builder, size_t& out_stack_size) {
   }
   // Ensure 16b alignment.
   stack_offset -= StackLayout::GUEST_STACK_SIZE;
-  stack_offset = poly::align(stack_offset, 16ull);
+  stack_offset = poly::align(stack_offset, static_cast<size_t>(16));
 
   // Function prolog.
   // Must be 16b aligned.
@@ -242,7 +242,7 @@ void X64Emitter::EmitTraceSource(const Instr* instr) {
   uint8_t dest_reg_1 = instr->flags >> 8;
 
   xdb::protocol::EventType event_type;
-  size_t event_size;
+  size_t event_size = 0;
   if (dest_reg_0 == 100) {
     event_type = xdb::protocol::EventType::INSTR;
     event_size = sizeof(xdb::protocol::InstrEvent);
@@ -269,6 +269,7 @@ void X64Emitter::EmitTraceSource(const Instr* instr) {
       event_size = sizeof(xdb::protocol::InstrEventR8R8);
     }
   }
+  assert_not_zero(event_size);
 
   mov(rax, trace_base);
   mov(r8d, static_cast<uint32_t>(event_size));
@@ -289,6 +290,7 @@ void X64Emitter::EmitTraceSource(const Instr* instr) {
   mov(word[r8 + 2], ax);
 
   switch (event_type) {
+    default:
     case xdb::protocol::EventType::INSTR:
       break;
     case xdb::protocol::EventType::INSTR_R8:
@@ -330,8 +332,7 @@ void X64Emitter::EmitTraceSourceAppendValue(const Value* value,
 
 void X64Emitter::EmitGetCurrentThreadId() {
   // rcx must point to context. We could fetch from the stack if needed.
-  mov(ax,
-      word[rcx + runtime_->frontend()->context_info()->thread_id_offset()]);
+  mov(ax, word[rcx + runtime_->frontend()->context_info()->thread_id_offset()]);
 }
 
 void X64Emitter::EmitTraceUserCallReturn() {
@@ -345,7 +346,7 @@ void X64Emitter::EmitTraceUserCallReturn() {
   lock();
   xadd(qword[rax], r8);
   mov(rax, static_cast<uint64_t>(xdb::protocol::EventType::USER_CALL_RETURN) |
-                (static_cast<uint64_t>(0) << 8) | (0ull << 32));
+               (static_cast<uint64_t>(0) << 8) | (0ull << 32));
   mov(qword[r8], rax);
   EmitGetCurrentThreadId();
   mov(word[r8 + 2], ax);
@@ -645,8 +646,6 @@ void X64Emitter::CallExtern(const hir::Instr* instr,
         static_cast<uint32_t>(sizeof(xdb::protocol::KernelCallReturnEvent)));
     lock();
     xadd(qword[rax], r8);
-    uint32_t module_id = 0;
-    uint32_t ordinal = 0;
     mov(rax,
         static_cast<uint64_t>(xdb::protocol::EventType::KERNEL_CALL_RETURN) |
             (static_cast<uint64_t>(0) << 8) | (0));
diff --git a/src/alloy/backend/x64/x64_sequences.cc b/src/alloy/backend/x64/x64_sequences.cc
index fed77e3a4..0de164066 100644
--- a/src/alloy/backend/x64/x64_sequences.cc
+++ b/src/alloy/backend/x64/x64_sequences.cc
@@ -4491,26 +4491,24 @@ EMITTER_OPCODE_TABLE(
 // TODO(benvanik): AVX512 has a native variable rotate (rolv).
 EMITTER(VECTOR_ROTATE_LEFT_V128, MATCH(I<OPCODE_VECTOR_ROTATE_LEFT, V128<>, V128<>, V128<>>)) {
   static __m128i EmulateVectorRotateLeftI8(__m128i src1, __m128i src2) {
-    alignas(16) __m128i value;
-    alignas(16) __m128i shamt;
-    _mm_store_si128(&value, src1);
-    _mm_store_si128(&shamt, src2);
+    alignas(16) uint8_t value[16];
+    alignas(16) uint8_t shamt[16];
+    _mm_store_si128(reinterpret_cast<__m128i*>(&value), src1);
+    _mm_store_si128(reinterpret_cast<__m128i*>(&shamt), src2);
     for (size_t i = 0; i < 16; ++i) {
-      value.m128i_u8[i] = poly::rotate_left<uint8_t>(
-          value.m128i_u8[i], shamt.m128i_u8[i] & 0x3);
+      value[i] = poly::rotate_left<uint8_t>(value[i], shamt[i] & 0x3);
     }
-    return _mm_load_si128(&value);
+    return _mm_load_si128(reinterpret_cast<__m128i*>(&value));
   }
   static __m128i EmulateVectorRotateLeftI16(__m128i src1, __m128i src2) {
-    alignas(16) __m128i value;
-    alignas(16) __m128i shamt;
-    _mm_store_si128(&value, src1);
-    _mm_store_si128(&shamt, src2);
+    alignas(16) uint16_t value[8];
+    alignas(16) uint16_t shamt[8];
+    _mm_store_si128(reinterpret_cast<__m128i*>(&value), src1);
+    _mm_store_si128(reinterpret_cast<__m128i*>(&shamt), src2);
     for (size_t i = 0; i < 8; ++i) {
-      value.m128i_u16[i] = poly::rotate_left<uint16_t>(
-          value.m128i_u16[i], shamt.m128i_u16[i] & 0xF);
+      value[i] = poly::rotate_left<uint16_t>(value[i], shamt[i] & 0xF);
     }
-    return _mm_load_si128(&value);
+    return _mm_load_si128(reinterpret_cast<__m128i*>(&value));
   }
   static void Emit(X64Emitter& e, const EmitArgType& i) {
     switch (i.instr->flags) {
diff --git a/src/alloy/compiler/passes/context_promotion_pass.h b/src/alloy/compiler/passes/context_promotion_pass.h
index 0f4758af1..db6480da7 100644
--- a/src/alloy/compiler/passes/context_promotion_pass.h
+++ b/src/alloy/compiler/passes/context_promotion_pass.h
@@ -19,6 +19,7 @@
 #include <llvm/ADT/BitVector.h>
 #pragma warning(pop)
 #else
+#include <cmath>
 #include <llvm/ADT/BitVector.h>
 #endif  // XE_COMPILER_MSVC
 
diff --git a/src/alloy/frontend/ppc/ppc_context.cc b/src/alloy/frontend/ppc/ppc_context.cc
index c7a070696..6bb9fea2b 100644
--- a/src/alloy/frontend/ppc/ppc_context.cc
+++ b/src/alloy/frontend/ppc/ppc_context.cc
@@ -9,6 +9,8 @@
 
 #include <alloy/frontend/ppc/ppc_context.h>
 
+#include <cstdlib>
+
 namespace alloy {
 namespace frontend {
 namespace ppc {
diff --git a/src/alloy/string_buffer.cc b/src/alloy/string_buffer.cc
index aa9a0897e..b53601aa3 100644
--- a/src/alloy/string_buffer.cc
+++ b/src/alloy/string_buffer.cc
@@ -14,7 +14,7 @@
 namespace alloy {
 
 StringBuffer::StringBuffer(size_t initial_capacity) {
-  buffer_.reserve(std::max(initial_capacity, 1024ull));
+  buffer_.reserve(std::max(initial_capacity, static_cast<size_t>(1024)));
 }
 
 StringBuffer::~StringBuffer() = default;
diff --git a/src/poly/assert.h b/src/poly/assert.h
index 80d1898c4..596dc2363 100644
--- a/src/poly/assert.h
+++ b/src/poly/assert.h
@@ -19,7 +19,7 @@ namespace poly {
 
 #define static_assert_size(type, size) \
   static_assert(sizeof(type) == size,  \
-                "bad definition for "## #type##": must be "## #size##" bytes")
+                "bad definition for " #type ": must be " #size " bytes")
 
 // We rely on assert being compiled out in NDEBUG.
 #define poly_assert assert
diff --git a/src/poly/atomic.h b/src/poly/atomic.h
index 4d8473e23..6c11a4172 100644
--- a/src/poly/atomic.h
+++ b/src/poly/atomic.h
@@ -40,10 +40,12 @@ inline int64_t atomic_exchange(int64_t new_value, volatile int64_t* value) {
   return OSAtomicCompareAndSwap64Barrier(*value, new_value, value);
 }
 
-//inline int32_t atomic_exchange_add(int32_t amount, volatile int32_t* value) {
-//}
-//inline int64_t atomic_exchange_add(int64_t amount, volatile int64_t* value) {
-//}
+inline int32_t atomic_exchange_add(int32_t amount, volatile int32_t* value) {
+  return OSAtomicAdd32Barrier(amount, value) - amount;
+}
+inline int64_t atomic_exchange_add(int64_t amount, volatile int64_t* value) {
+  return OSAtomicAdd64Barrier(amount, value) - amount;
+}
 
 inline bool atomic_cas(int32_t old_value, int32_t new_value,
                        volatile int32_t* value) {
@@ -51,7 +53,7 @@ inline bool atomic_cas(int32_t old_value, int32_t new_value,
       old_value, new_value, reinterpret_cast<volatile int32_t*>(value));
 }
 inline bool atomic_cas(int64_t old_value, int64_t new_value,
-                       volatile int32_t* value) {
+                       volatile int64_t* value) {
   return OSAtomicCompareAndSwap64Barrier(
       old_value, new_value, reinterpret_cast<volatile int64_t*>(value));
 }
@@ -110,10 +112,12 @@ inline int64_t atomic_exchange(int64_t new_value, volatile int64_t* value) {
   return __sync_val_compare_and_swap(*value, value, new_value);
 }
 
-//inline int32_t atomic_exchange_add(int32_t amount, volatile int32_t* value) {
-//}
-//inline int64_t atomic_exchange_add(int64_t amount, volatile int64_t* value) {
-//}
+inline int32_t atomic_exchange_add(int32_t amount, volatile int32_t* value) {
+  return __sync_fetch_and_add(amount, value);
+}
+inline int64_t atomic_exchange_add(int64_t amount, volatile int64_t* value) {
+  return __sync_fetch_and_add(amount, value);
+}
 
 inline bool atomic_cas(int32_t old_value, int32_t new_value,
                        volatile int32_t* value) {
diff --git a/src/poly/cxx_compat.h b/src/poly/cxx_compat.h
index fd0f26d81..632be698e 100644
--- a/src/poly/cxx_compat.h
+++ b/src/poly/cxx_compat.h
@@ -36,12 +36,14 @@
 // C++1y make_unique.
 // http://herbsutter.com/2013/05/29/gotw-89-solution-smart-pointers/
 // This is present in clang with -std=c++1y, but not otherwise.
+#if __clang_major__ < 3 || (__clang_major__ == 3 && __clang_minor__ < 4)
 namespace std {
 template <typename T, typename... Args>
 unique_ptr<T> make_unique(Args&&... args) {
   return unique_ptr<T>(new T(forward<Args>(args)...));
 }
 }  // namespace std
+#endif  // clang < 3.4
 #endif  // !XE_COMPILER_MSVC
 
 namespace poly {}  // namespace poly
diff --git a/src/poly/main_posix.cc b/src/poly/main_posix.cc
index 5af8b2437..353a0d2be 100644
--- a/src/poly/main_posix.cc
+++ b/src/poly/main_posix.cc
@@ -9,22 +9,20 @@
 
 #include <poly/main.h>
 
+#include <gflags/gflags.h>
 #include <poly/string.h>
 
 namespace poly {
 
-bool has_console_attached() {
-  return true;
-}
+bool has_console_attached() { return true; }
 
 }  // namespace poly
 
-
 extern "C" int main(int argc, char** argv) {
   auto entry_info = poly::GetEntryInfo();
 
   google::SetUsageMessage(std::string("usage: ") +
-      poly::to_string(entry_info.usage));
+                          poly::to_string(entry_info.usage));
   google::SetVersionString("1.0");
   google::ParseCommandLineFlags(&argc, &argv, true);
 
diff --git a/src/poly/mapped_memory_posix.cc b/src/poly/mapped_memory_posix.cc
index 825361983..c5358d582 100644
--- a/src/poly/mapped_memory_posix.cc
+++ b/src/poly/mapped_memory_posix.cc
@@ -36,22 +36,22 @@ class PosixMappedMemory : public MappedMemory {
 std::unique_ptr<MappedMemory> MappedMemory::Open(const std::wstring& path,
                                                  Mode mode, size_t offset,
                                                  size_t length) {
-  const char* mode;
+  const char* mode_str;
   int prot;
   switch (mode) {
     case Mode::READ:
-      mode = "rb";
+      mode_str = "rb";
       prot = PROT_READ;
       break;
     case Mode::READ_WRITE:
-      mode = "r+b";
+      mode_str = "r+b";
       prot = PROT_READ | PROT_WRITE;
       break;
   }
 
   auto mm = std::make_unique<PosixMappedMemory>(path, mode);
 
-  mm->file_handle = fopen(poly::to_string(path).c_str(), mode);
+  mm->file_handle = fopen(poly::to_string(path).c_str(), mode_str);
   if (!mm->file_handle) {
     return nullptr;
   }
diff --git a/src/poly/math.h b/src/poly/math.h
index 1b059c53d..b8ab8c6de 100644
--- a/src/poly/math.h
+++ b/src/poly/math.h
@@ -14,6 +14,7 @@
 
 #include <cstdint>
 #include <cstring>
+#include <type_traits>
 
 #include <poly/config.h>
 #include <poly/platform.h>
diff --git a/src/poly/string.cc b/src/poly/string.cc
index 8c877ec0d..f2a822ce0 100644
--- a/src/poly/string.cc
+++ b/src/poly/string.cc
@@ -10,6 +10,7 @@
 #include <poly/string.h>
 
 #include <codecvt>
+#include <locale>
 
 namespace poly {
 
diff --git a/xenia.gyp b/xenia.gyp
index e98acf017..ebbd30f68 100644
--- a/xenia.gyp
+++ b/xenia.gyp
@@ -110,7 +110,7 @@
           'SYMROOT': '<(DEPTH)/build/xenia/',
           'ALWAYS_SEARCH_USER_PATHS': 'NO',
           'ARCHS': ['x86_64'],
-          'CLANG_CXX_LANGUAGE_STANDARD': 'c++11',
+          'CLANG_CXX_LANGUAGE_STANDARD': 'c++1y',
           'COMBINE_HIDPI_IMAGES': 'YES',
           'GCC_C_LANGUAGE_STANDARD': 'gnu99',
           'GCC_SYMBOLS_PRIVATE_EXTERN': 'YES',