system: Raise exception for YIELD, WFE, WFI, SEV, SEVL

include/dynarmic/A64/config.h

@@ -28,6 +28,16 @@ enum class Exception {
     /// This behaviour is up to the user of this library to define.
     /// Note: Constraints on unpredictable behaviour are specified in the ARMv8 ARM.
     UnpredictableInstruction,
+    /// A WFI instruction was executed. You may now enter a low-power state.
+    WaitForInterrupt,
+    /// A WFE instruction was executed. You may now enter a low-power state if the event register is clear.
+    WaitForEvent,
+    /// A SEV instruction was executed. The event register of all PEs should be set.
+    SendEvent,
+    /// A SEV instruction was executed. The event register of the current PE should be set.
+    SendEventLocal,
+    /// A YIELD instruction was executed.
+    Yield,
 };
 
 enum class DataCacheOperation {

src/frontend/A64/translate/impl/impl.cpp

@@ -16,9 +16,7 @@ bool TranslatorVisitor::InterpretThisInstruction() {
 }
 
 bool TranslatorVisitor::UnpredictableInstruction() {
-    ir.ExceptionRaised(Exception::UnpredictableInstruction);
-    ir.SetTerm(IR::Term::CheckHalt{IR::Term::ReturnToDispatch{}});
-    return false;
+    return RaiseException(Exception::UnpredictableInstruction);
 }
 
 bool TranslatorVisitor::DecodeError() {
@@ -27,13 +25,15 @@ bool TranslatorVisitor::DecodeError() {
 }
 
 bool TranslatorVisitor::ReservedValue() {
-    ir.ExceptionRaised(Exception::ReservedValue);
-    ir.SetTerm(IR::Term::CheckHalt{IR::Term::ReturnToDispatch{}});
-    return false;
+    return RaiseException(Exception::ReservedValue);
 }
 
 bool TranslatorVisitor::UnallocatedEncoding() {
-    ir.ExceptionRaised(Exception::UnallocatedEncoding);
+    return RaiseException(Exception::UnallocatedEncoding);
+}
+
+bool TranslatorVisitor::RaiseException(Exception exception) {
+    ir.ExceptionRaised(exception);
     ir.SetTerm(IR::Term::CheckHalt{IR::Term::ReturnToDispatch{}});
     return false;
 }

src/frontend/A64/translate/impl/impl.h

@@ -35,6 +35,7 @@ struct TranslatorVisitor final {
     bool DecodeError();
     bool ReservedValue();
     bool UnallocatedEncoding();
+    bool RaiseException(Exception exception);
 
     struct BitMasks {
         u64 wmask, tmask;

src/frontend/A64/translate/impl/system.cpp

@@ -17,23 +17,23 @@ bool TranslatorVisitor::NOP() {
 }
 
 bool TranslatorVisitor::YIELD() {
-    return true;
+    return RaiseException(Exception::Yield);
 }
 
 bool TranslatorVisitor::WFE() {
-    return true;
+    return RaiseException(Exception::WaitForEvent);
 }
 
 bool TranslatorVisitor::WFI() {
-    return true;
+    return RaiseException(Exception::WaitForInterrupt);
 }
 
 bool TranslatorVisitor::SEV() {
-    return true;
+    return RaiseException(Exception::SendEvent);
 }
 
 bool TranslatorVisitor::SEVL() {
-    return true;
+    return RaiseException(Exception::SendEventLocal);
 }
 
 bool TranslatorVisitor::CLREX(Imm<4> /*CRm*/) {