A64: Implement system register CNTPCT_EL0

include/dynarmic/A64/config.h

@@ -92,6 +92,8 @@ struct UserCallbacks {
     virtual void AddTicks(std::uint64_t ticks) = 0;
     // How many more ticks am I allowed to execute?
     virtual std::uint64_t GetTicksRemaining() = 0;
+    // Get value in the emulated counter-timer physical count register.
+    virtual std::uint64_t GetCNTPCT() = 0;
 };
 
 struct UserConfig {

src/backend_x64/a64_emit_x64.cpp

@@ -472,6 +472,11 @@ void A64EmitX64::EmitA64DataMemoryBarrier(A64EmitContext&, IR::Inst*) {
     code.lfence();
 }
 
+void A64EmitX64::EmitA64GetCNTPCT(A64EmitContext& ctx, IR::Inst* inst) {
+    ctx.reg_alloc.HostCall(inst);
+    DEVIRT(conf.callbacks, &A64::UserCallbacks::GetCNTPCT).EmitCall(code);
+}
+
 void A64EmitX64::EmitA64GetCTR(A64EmitContext& ctx, IR::Inst* inst) {
     Xbyak::Reg32 result = ctx.reg_alloc.ScratchGpr().cvt32();
     code.mov(result, conf.ctr_el0);

src/frontend/A64/ir_emitter.cpp

@@ -53,6 +53,10 @@ void IREmitter::DataMemoryBarrier() {
     Inst(Opcode::A64DataMemoryBarrier);
 }
 
+IR::U64 IREmitter::GetCNTPCT() {
+    return Inst<IR::U64>(Opcode::A64GetCNTPCT);
+}
+
 IR::U32 IREmitter::GetCTR() {
     return Inst<IR::U32>(Opcode::A64GetCTR);
 }

src/frontend/A64/ir_emitter.h

@@ -44,6 +44,7 @@ public:
     void DataCacheOperationRaised(DataCacheOperation op, const IR::U64& value);
     void DataSynchronizationBarrier();
     void DataMemoryBarrier();
+    IR::U64 GetCNTPCT(); // TODO: Ensure sub-basic-block cycle counts are updated before this.
     IR::U32 GetCTR();
     IR::U32 GetDCZID();
     IR::U64 GetTPIDRRO();

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

@@ -63,6 +63,9 @@ bool TranslatorVisitor::MRS(Imm<1> o0, Imm<3> op1, Imm<4> CRn, Imm<4> CRm, Imm<3
     case 0b11'011'0000'0000'001: // CTR_EL0
         X(32, Rt, ir.GetCTR());
         return true;
+    case 0b11'011'1110'0000'001: // CNTPCT_EL0
+        X(64, Rt, ir.GetCNTPCT());
+        return true;
     }
     return InterpretThisInstruction();
 }

src/frontend/ir/opcodes.inc

@@ -61,6 +61,7 @@ A64OPC(ExceptionRaised,             T::Void,        T::U64,         T::U64
 A64OPC(DataCacheOperationRaised,    T::Void,        T::U64,         T::U64                          )
 A64OPC(DataSynchronizationBarrier,  T::Void,                                                        )
 A64OPC(DataMemoryBarrier,           T::Void,                                                        )
+A64OPC(GetCNTPCT,                   T::U64,                                                         )
 A64OPC(GetCTR,                      T::U32,                                                         )
 A64OPC(GetDCZID,                    T::U32,                                                         )
 A64OPC(GetTPIDRRO,                  T::U64,                                                         )

tests/A64/fuzz_with_unicorn.cpp

@@ -45,9 +45,17 @@ static bool ShouldTestInst(u32 instruction, u64 pc, bool is_last_inst) {
         return false;
     if (auto terminal = block.GetTerminal(); boost::get<IR::Term::Interpret>(&terminal))
         return false;
-    for (const auto& ir_inst : block)
-        if (ir_inst.GetOpcode() == IR::Opcode::A64ExceptionRaised || ir_inst.GetOpcode() == IR::Opcode::A64CallSupervisor || ir_inst.GetOpcode() == IR::Opcode::A64DataCacheOperationRaised)
+    for (const auto& ir_inst : block) {
+        switch (ir_inst.GetOpcode()) {
+        case IR::Opcode::A64ExceptionRaised:
+        case IR::Opcode::A64CallSupervisor:
+        case IR::Opcode::A64DataCacheOperationRaised:
+        case IR::Opcode::A64GetCNTPCT:
             return false;
+        default:
+            continue;
+        }
+    }
     return true;
 }
 

tests/A64/testenv.h

@@ -92,4 +92,7 @@ public:
     std::uint64_t GetTicksRemaining() override {
         return ticks_left;
     }
+    std::uint64_t GetCNTPCT() override {
+        ASSERT_MSG(false, "GetCNTPCT()");
+    }
 };