-Wmaybe-uninitialized

CMakeLists.txt

@@ -72,7 +72,7 @@ set(CMAKE_MACOSX_RPATH 1)
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
 # Create variable to enable additional compiler warnings for SimEng targets only
-set(SIMENG_COMPILE_OPTIONS -Wall -pedantic -Werror) #-Wextra
+set(SIMENG_COMPILE_OPTIONS -Wall -pedantic -Werror -fno-strict-aliasing) #-Wextra
 
 # Disable RTTI for all targets
 add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-fno-rtti>)

src/include/simeng/RegisterValue.hh

@@ -28,13 +28,13 @@ class RegisterValue {
             typename std::enable_if_t<!std::is_pointer_v<T>, T>* = nullptr>
   RegisterValue(T value, uint16_t bytes = sizeof(T)) : bytes(bytes) {
     if (isLocal()) {
-      T* view = reinterpret_cast<T*>(this->value);
+      T* view = reinterpret_cast<T*>(this->localValue);
       view[0] = value;
 
       if (bytes > sizeof(T)) {
         // Zero the remaining bytes not set by the provided value
-        std::fill<char*, uint16_t>(this->value + sizeof(T), this->value + bytes,
-                                   0);
+        std::fill<char*, uint16_t>(this->localValue + sizeof(T),
+                                   this->localValue + bytes, 0);
       }
     } else {
       void* data = pool.allocate(bytes);
@@ -57,7 +57,7 @@ class RegisterValue {
     assert(capacity >= bytes && "Capacity is less than requested bytes");
     char* dest;
     if (isLocal()) {
-      dest = this->value;
+      dest = this->localValue;
     } else {
       dest = static_cast<char*>(pool.allocate(capacity));
       std::memset(dest, 0, capacity);
@@ -96,7 +96,7 @@ class RegisterValue {
            "Attempted to access a RegisterValue as a datatype larger than the "
            "data held");
     if (isLocal()) {
-      return reinterpret_cast<const T*>(value);
+      return reinterpret_cast<const T*>(localValue);
     } else {
       return reinterpret_cast<const T*>(ptr.get());
     }
@@ -128,7 +128,7 @@ class RegisterValue {
 
   /** The underlying local member value. Aligned to 8 bytes to prevent
    * potential alignment issue when casting. */
-  alignas(8) char value[MAX_LOCAL_BYTES];
+  alignas(8) char localValue[MAX_LOCAL_BYTES] = {};
 };
 
 inline bool operator==(const RegisterValue& lhs, const RegisterValue& rhs) {

src/include/simeng/arch/aarch64/helpers/neon.hh

@@ -785,14 +785,21 @@ RegisterValue vecSumElems_2ops(srcValContainer& sourceValues) {
 template <typename D, typename N, int I>
 RegisterValue vecXtn(srcValContainer& sourceValues, bool isXtn2) {
   const D* d;
-  if (isXtn2) d = sourceValues[0].getAsVector<D>();
-  const N* n = sourceValues[isXtn2 ? 1 : 0].getAsVector<N>();
+  const N* n;
+  if (isXtn2) {
+    d = sourceValues[0].getAsVector<D>();
+    n = sourceValues[1].getAsVector<N>();
+  } else {
+    d = {};
+    n = sourceValues[0].getAsVector<N>();
+  }
 
   D out[16 / sizeof(D)] = {0};
   int index = 0;
 
   for (int i = 0; i < I; i++) {
     if (isXtn2 & (i < (I / 2))) {
+      assert(isXtn2 && "isXtn2 is false so d is not initialised");
       out[i] = d[i];
     } else {
       out[i] = static_cast<D>(n[index]);

src/lib/RegisterValue.cc

@@ -19,8 +19,8 @@ RegisterValue RegisterValue::zeroExtend(uint16_t fromBytes,
   auto extended = RegisterValue(0, toBytes);
 
   // Get the appropriate source/destination pointers and copy the data
-  const char* src = (isLocal() ? value : ptr.get());
-  char* dest = (extended.isLocal() ? extended.value : extended.ptr.get());
+  const char* src = (isLocal() ? localValue : ptr.get());
+  char* dest = (extended.isLocal() ? extended.localValue : extended.ptr.get());
 
   std::memcpy(dest, src, fromBytes);
 

src/lib/arch/aarch64/ExceptionHandler.cc

@@ -329,7 +329,7 @@ bool ExceptionHandler::init() {
         return readStringThen(filename, filenamePtr,
                               kernel::Linux::LINUX_PATH_MAX, [=](auto length) {
                                 // Invoke the kernel
-                                kernel::stat statOut;
+                                kernel::stat statOut = {};
                                 uint64_t retval = linux_.newfstatat(
                                     dfd, filename, statOut, flag);
                                 ProcessStateChange stateChange = {

src/lib/arch/riscv/ExceptionHandler.cc

@@ -327,7 +327,7 @@ bool ExceptionHandler::init() {
         return readStringThen(filename, filenamePtr,
                               kernel::Linux::LINUX_PATH_MAX, [=](auto length) {
                                 // Invoke the kernel
-                                kernel::stat statOut;
+                                kernel::stat statOut = {};
                                 uint64_t retval = linux_.newfstatat(
                                     dfd, filename, statOut, flag);
                                 ProcessStateChange stateChange = {

test/unit/RegisterValueTest.cc

@@ -40,7 +40,7 @@ TEST(RegisterValueTest, Reinterpret) {
 TEST(RegisterValueTest, Vector) {
   uint64_t value = 0x0000000200000001;
   auto registerValue = simeng::RegisterValue(value, 8);
-  auto vector = registerValue.getAsVector<uint32_t>();
+  const uint32_t* vector = registerValue.getAsVector<uint32_t>();
   EXPECT_EQ(vector[0], 1);
   EXPECT_EQ(vector[1], 2);
 }