Implement enable_cycle_counting

src/dynarmic/backend/x64/a32_emit_x64.cpp

@@ -149,7 +149,9 @@ A32EmitX64::BlockDescriptor A32EmitX64::Emit(IR::Block& block) {
 
     reg_alloc.AssertNoMoreUses();
 
-    EmitAddCycles(block.CycleCount());
+    if (conf.enable_cycle_counting) {
+        EmitAddCycles(block.CycleCount());
+    }
     EmitX64::EmitTerminal(block.GetTerminal(), ctx.Location().SetSingleStepping(false), ctx.IsSingleStep());
     code.int3();
 
@@ -184,7 +186,9 @@ void A32EmitX64::EmitCondPrelude(const A32EmitContext& ctx) {
     ASSERT(ctx.block.HasConditionFailedLocation());
 
     Xbyak::Label pass = EmitCond(ctx.block.GetCondition());
-    EmitAddCycles(ctx.block.ConditionFailedCycleCount());
+    if (conf.enable_cycle_counting) {
+        EmitAddCycles(ctx.block.ConditionFailedCycleCount());
+    }
     EmitTerminal(IR::Term::LinkBlock{ctx.block.ConditionFailedLocation()}, ctx.Location().SetSingleStepping(false), ctx.IsSingleStep());
     code.L(pass);
 }
@@ -715,31 +719,37 @@ void A32EmitX64::EmitA32UpdateUpperLocationDescriptor(A32EmitContext& ctx, IR::I
 }
 
 void A32EmitX64::EmitA32CallSupervisor(A32EmitContext& ctx, IR::Inst* inst) {
-    ctx.reg_alloc.HostCall(nullptr);
-
     code.SwitchMxcsrOnExit();
-    code.mov(code.ABI_PARAM2, qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_to_run)]);
+
-    code.sub(code.ABI_PARAM2, qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)]);
+    if (conf.enable_cycle_counting) {
-    Devirtualize<&A32::UserCallbacks::AddTicks>(conf.callbacks).EmitCall(code);
+        ctx.reg_alloc.HostCall(nullptr);
-    ctx.reg_alloc.EndOfAllocScope();
+        code.mov(code.ABI_PARAM2, qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_to_run)]);
+        code.sub(code.ABI_PARAM2, qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)]);
+        Devirtualize<&A32::UserCallbacks::AddTicks>(conf.callbacks).EmitCall(code);
+        ctx.reg_alloc.EndOfAllocScope();
+    }
 
     auto args = ctx.reg_alloc.GetArgumentInfo(inst);
     ctx.reg_alloc.HostCall(nullptr, {}, args[0]);
     Devirtualize<&A32::UserCallbacks::CallSVC>(conf.callbacks).EmitCall(code);
 
-    Devirtualize<&A32::UserCallbacks::GetTicksRemaining>(conf.callbacks).EmitCall(code);
+    if (conf.enable_cycle_counting) {
-    code.mov(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_to_run)], code.ABI_RETURN);
+        Devirtualize<&A32::UserCallbacks::GetTicksRemaining>(conf.callbacks).EmitCall(code);
-    code.mov(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)], code.ABI_RETURN);
+        code.mov(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_to_run)], code.ABI_RETURN);
-    code.SwitchMxcsrOnEntry();
+        code.mov(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)], code.ABI_RETURN);
+        code.SwitchMxcsrOnEntry();
+    }
 }
 
 void A32EmitX64::EmitA32ExceptionRaised(A32EmitContext& ctx, IR::Inst* inst) {
-    ctx.reg_alloc.HostCall(nullptr);
-
     code.SwitchMxcsrOnExit();
-    code.mov(code.ABI_PARAM2, qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_to_run)]);
+
-    code.sub(code.ABI_PARAM2, qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)]);
+    ctx.reg_alloc.HostCall(nullptr);
-    Devirtualize<&A32::UserCallbacks::AddTicks>(conf.callbacks).EmitCall(code);
+    if (conf.enable_cycle_counting) {
+        code.mov(code.ABI_PARAM2, qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_to_run)]);
+        code.sub(code.ABI_PARAM2, qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)]);
+        Devirtualize<&A32::UserCallbacks::AddTicks>(conf.callbacks).EmitCall(code);
+    }
     ctx.reg_alloc.EndOfAllocScope();
 
     auto args = ctx.reg_alloc.GetArgumentInfo(inst);
@@ -751,10 +761,12 @@ void A32EmitX64::EmitA32ExceptionRaised(A32EmitContext& ctx, IR::Inst* inst) {
         code.mov(param[1], exception);
     });
 
-    Devirtualize<&A32::UserCallbacks::GetTicksRemaining>(conf.callbacks).EmitCall(code);
+    if (conf.enable_cycle_counting) {
-    code.mov(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_to_run)], code.ABI_RETURN);
+        Devirtualize<&A32::UserCallbacks::GetTicksRemaining>(conf.callbacks).EmitCall(code);
-    code.mov(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)], code.ABI_RETURN);
+        code.mov(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_to_run)], code.ABI_RETURN);
-    code.SwitchMxcsrOnEntry();
+        code.mov(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)], code.ABI_RETURN);
+        code.SwitchMxcsrOnEntry();
+    }
 }
 
 static u32 GetFpscrImpl(A32JitState* jit_state) {
@@ -1134,14 +1146,26 @@ void A32EmitX64::EmitTerminalImpl(IR::Term::LinkBlock terminal, IR::LocationDesc
         return;
     }
 
-    code.cmp(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)], 0);
+    if (conf.enable_cycle_counting) {
+        code.cmp(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)], 0);
 
-    patch_information[terminal.next].jg.emplace_back(code.getCurr());
+        patch_information[terminal.next].jg.emplace_back(code.getCurr());
-    if (const auto next_bb = GetBasicBlock(terminal.next)) {
+        if (const auto next_bb = GetBasicBlock(terminal.next)) {
-        EmitPatchJg(terminal.next, next_bb->entrypoint);
+            EmitPatchJg(terminal.next, next_bb->entrypoint);
+        } else {
+            EmitPatchJg(terminal.next);
+        }
     } else {
-        EmitPatchJg(terminal.next);
+        code.cmp(dword[r15 + offsetof(A32JitState, halt_reason)], 0);
+
+        patch_information[terminal.next].jz.emplace_back(code.getCurr());
+        if (const auto next_bb = GetBasicBlock(terminal.next)) {
+            EmitPatchJz(terminal.next, next_bb->entrypoint);
+        } else {
+            EmitPatchJz(terminal.next);
+        }
     }
+
     Xbyak::Label dest;
     code.jmp(dest, Xbyak::CodeGenerator::T_NEAR);
 
@@ -1222,6 +1246,17 @@ void A32EmitX64::EmitPatchJg(const IR::LocationDescriptor& target_desc, CodePtr
     code.EnsurePatchLocationSize(patch_location, 14);
 }
 
+void A32EmitX64::EmitPatchJz(const IR::LocationDescriptor& target_desc, CodePtr target_code_ptr) {
+    const CodePtr patch_location = code.getCurr();
+    if (target_code_ptr) {
+        code.jz(target_code_ptr);
+    } else {
+        code.mov(MJitStateReg(A32::Reg::PC), A32::LocationDescriptor{target_desc}.PC());
+        code.jz(code.GetReturnFromRunCodeAddress());
+    }
+    code.EnsurePatchLocationSize(patch_location, 14);
+}
+
 void A32EmitX64::EmitPatchJmp(const IR::LocationDescriptor& target_desc, CodePtr target_code_ptr) {
     const CodePtr patch_location = code.getCurr();
     if (target_code_ptr) {

src/dynarmic/backend/x64/a32_emit_x64.h

@@ -138,6 +138,7 @@ protected:
     // Patching
     void Unpatch(const IR::LocationDescriptor& target_desc) override;
     void EmitPatchJg(const IR::LocationDescriptor& target_desc, CodePtr target_code_ptr = nullptr) override;
+    void EmitPatchJz(const IR::LocationDescriptor& target_desc, CodePtr target_code_ptr = nullptr) override;
     void EmitPatchJmp(const IR::LocationDescriptor& target_desc, CodePtr target_code_ptr = nullptr) override;
     void EmitPatchMovRcx(CodePtr target_code_ptr = nullptr) override;
 };

src/dynarmic/backend/x64/a32_interface.cpp

@@ -32,11 +32,12 @@ namespace Dynarmic::A32 {
 
 using namespace Backend::X64;
 
-static RunCodeCallbacks GenRunCodeCallbacks(A32::UserCallbacks* cb, CodePtr (*LookupBlock)(void* lookup_block_arg), void* arg) {
+static RunCodeCallbacks GenRunCodeCallbacks(A32::UserCallbacks* cb, CodePtr (*LookupBlock)(void* lookup_block_arg), void* arg, const A32::UserConfig& conf) {
     return RunCodeCallbacks{
         std::make_unique<ArgCallback>(LookupBlock, reinterpret_cast<u64>(arg)),
         std::make_unique<ArgCallback>(Devirtualize<&A32::UserCallbacks::AddTicks>(cb)),
         std::make_unique<ArgCallback>(Devirtualize<&A32::UserCallbacks::GetTicksRemaining>(cb)),
+        conf.enable_cycle_counting,
     };
 }
 
@@ -59,7 +60,7 @@ static Optimization::PolyfillOptions GenPolyfillOptions(const BlockOfCode& code)
 
 struct Jit::Impl {
     Impl(Jit* jit, A32::UserConfig conf)
-            : block_of_code(GenRunCodeCallbacks(conf.callbacks, &GetCurrentBlockThunk, this), JitStateInfo{jit_state}, conf.code_cache_size, conf.far_code_offset, GenRCP(conf))
+            : block_of_code(GenRunCodeCallbacks(conf.callbacks, &GetCurrentBlockThunk, this, conf), JitStateInfo{jit_state}, conf.code_cache_size, conf.far_code_offset, GenRCP(conf))
             , emitter(block_of_code, conf, jit)
             , polyfill_options(GenPolyfillOptions(block_of_code))
             , conf(std::move(conf))

src/dynarmic/backend/x64/a64_emit_x64.cpp

@@ -121,7 +121,9 @@ A64EmitX64::BlockDescriptor A64EmitX64::Emit(IR::Block& block) {
 
     reg_alloc.AssertNoMoreUses();
 
-    EmitAddCycles(block.CycleCount());
+    if (conf.enable_cycle_counting) {
+        EmitAddCycles(block.CycleCount());
+    }
     EmitX64::EmitTerminal(block.GetTerminal(), ctx.Location().SetSingleStepping(false), ctx.IsSingleStep());
     code.int3();
 
@@ -619,14 +621,26 @@ void A64EmitX64::EmitTerminalImpl(IR::Term::LinkBlock terminal, IR::LocationDesc
         return;
     }
 
-    code.cmp(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)], 0);
+    if (conf.enable_cycle_counting) {
+        code.cmp(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)], 0);
 
-    patch_information[terminal.next].jg.emplace_back(code.getCurr());
+        patch_information[terminal.next].jg.emplace_back(code.getCurr());
-    if (auto next_bb = GetBasicBlock(terminal.next)) {
+        if (const auto next_bb = GetBasicBlock(terminal.next)) {
-        EmitPatchJg(terminal.next, next_bb->entrypoint);
+            EmitPatchJg(terminal.next, next_bb->entrypoint);
+        } else {
+            EmitPatchJg(terminal.next);
+        }
     } else {
-        EmitPatchJg(terminal.next);
+        code.cmp(dword[r15 + offsetof(A64JitState, halt_reason)], 0);
+
+        patch_information[terminal.next].jz.emplace_back(code.getCurr());
+        if (const auto next_bb = GetBasicBlock(terminal.next)) {
+            EmitPatchJz(terminal.next, next_bb->entrypoint);
+        } else {
+            EmitPatchJz(terminal.next);
+        }
     }
+
     code.mov(rax, A64::LocationDescriptor{terminal.next}.PC());
     code.mov(qword[r15 + offsetof(A64JitState, pc)], rax);
     code.ForceReturnFromRunCode();
@@ -708,6 +722,18 @@ void A64EmitX64::EmitPatchJg(const IR::LocationDescriptor& target_desc, CodePtr
     code.EnsurePatchLocationSize(patch_location, 23);
 }
 
+void A64EmitX64::EmitPatchJz(const IR::LocationDescriptor& target_desc, CodePtr target_code_ptr) {
+    const CodePtr patch_location = code.getCurr();
+    if (target_code_ptr) {
+        code.jz(target_code_ptr);
+    } else {
+        code.mov(rax, A64::LocationDescriptor{target_desc}.PC());
+        code.mov(qword[r15 + offsetof(A64JitState, pc)], rax);
+        code.jz(code.GetReturnFromRunCodeAddress());
+    }
+    code.EnsurePatchLocationSize(patch_location, 23);
+}
+
 void A64EmitX64::EmitPatchJmp(const IR::LocationDescriptor& target_desc, CodePtr target_code_ptr) {
     const CodePtr patch_location = code.getCurr();
     if (target_code_ptr) {

src/dynarmic/backend/x64/a64_emit_x64.h

@@ -135,6 +135,7 @@ protected:
     // Patching
     void Unpatch(const IR::LocationDescriptor& target_desc) override;
     void EmitPatchJg(const IR::LocationDescriptor& target_desc, CodePtr target_code_ptr = nullptr) override;
+    void EmitPatchJz(const IR::LocationDescriptor& target_desc, CodePtr target_code_ptr = nullptr) override;
     void EmitPatchJmp(const IR::LocationDescriptor& target_desc, CodePtr target_code_ptr = nullptr) override;
     void EmitPatchMovRcx(CodePtr target_code_ptr = nullptr) override;
 };

src/dynarmic/backend/x64/a64_interface.cpp

@@ -27,11 +27,12 @@ namespace Dynarmic::A64 {
 
 using namespace Backend::X64;
 
-static RunCodeCallbacks GenRunCodeCallbacks(A64::UserCallbacks* cb, CodePtr (*LookupBlock)(void* lookup_block_arg), void* arg) {
+static RunCodeCallbacks GenRunCodeCallbacks(A64::UserCallbacks* cb, CodePtr (*LookupBlock)(void* lookup_block_arg), void* arg, const A64::UserConfig& conf) {
     return RunCodeCallbacks{
         std::make_unique<ArgCallback>(LookupBlock, reinterpret_cast<u64>(arg)),
         std::make_unique<ArgCallback>(Devirtualize<&A64::UserCallbacks::AddTicks>(cb)),
         std::make_unique<ArgCallback>(Devirtualize<&A64::UserCallbacks::GetTicksRemaining>(cb)),
+        conf.enable_cycle_counting,
     };
 }
 
@@ -56,7 +57,7 @@ struct Jit::Impl final {
 public:
     Impl(Jit* jit, UserConfig conf)
             : conf(conf)
-            , block_of_code(GenRunCodeCallbacks(conf.callbacks, &GetCurrentBlockThunk, this), JitStateInfo{jit_state}, conf.code_cache_size, conf.far_code_offset, GenRCP(conf))
+            , block_of_code(GenRunCodeCallbacks(conf.callbacks, &GetCurrentBlockThunk, this, conf), JitStateInfo{jit_state}, conf.code_cache_size, conf.far_code_offset, GenRCP(conf))
             , emitter(block_of_code, conf, jit)
             , polyfill_options(GenPolyfillOptions(block_of_code)) {
         ASSERT(conf.page_table_address_space_bits >= 12 && conf.page_table_address_space_bits <= 64);

src/dynarmic/backend/x64/block_of_code.cpp

@@ -238,9 +238,11 @@ void BlockOfCode::GenRunCode(std::function<void(BlockOfCode&)> rcp) {
     mov(r15, ABI_PARAM1);
     mov(rbx, ABI_PARAM2);  // save temporarily in non-volatile register
 
-    cb.GetTicksRemaining->EmitCall(*this);
+    if (cb.enable_cycle_counting) {
-    mov(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_to_run)], ABI_RETURN);
+        cb.GetTicksRemaining->EmitCall(*this);
-    mov(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)], ABI_RETURN);
+        mov(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_to_run)], ABI_RETURN);
+        mov(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)], ABI_RETURN);
+    }
 
     rcp(*this);
 
@@ -257,8 +259,10 @@ void BlockOfCode::GenRunCode(std::function<void(BlockOfCode&)> rcp) {
 
     mov(r15, ABI_PARAM1);
 
-    mov(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_to_run)], 1);
+    if (cb.enable_cycle_counting) {
-    mov(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)], 1);
+        mov(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_to_run)], 1);
+        mov(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)], 1);
+    }
 
     rcp(*this);
 
@@ -277,8 +281,10 @@ void BlockOfCode::GenRunCode(std::function<void(BlockOfCode&)> rcp) {
 
     cmp(dword[r15 + jsi.offsetof_halt_reason], 0);
     jne(return_to_caller);
-    cmp(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)], 0);
+    if (cb.enable_cycle_counting) {
-    jng(return_to_caller);
+        cmp(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)], 0);
+        jng(return_to_caller);
+    }
     cb.LookupBlock->EmitCall(*this);
     jmp(ABI_RETURN);
 
@@ -287,8 +293,10 @@ void BlockOfCode::GenRunCode(std::function<void(BlockOfCode&)> rcp) {
 
     cmp(dword[r15 + jsi.offsetof_halt_reason], 0);
     jne(return_to_caller_mxcsr_already_exited);
-    cmp(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)], 0);
+    if (cb.enable_cycle_counting) {
-    jng(return_to_caller_mxcsr_already_exited);
+        cmp(qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)], 0);
+        jng(return_to_caller_mxcsr_already_exited);
+    }
     SwitchMxcsrOnEntry();
     cb.LookupBlock->EmitCall(*this);
     jmp(ABI_RETURN);
@@ -303,10 +311,12 @@ void BlockOfCode::GenRunCode(std::function<void(BlockOfCode&)> rcp) {
     return_from_run_code[MXCSR_ALREADY_EXITED | FORCE_RETURN] = getCurr<const void*>();
     L(return_to_caller_mxcsr_already_exited);
 
-    cb.AddTicks->EmitCall(*this, [this](RegList param) {
+    if (cb.enable_cycle_counting) {
-        mov(param[0], qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_to_run)]);
+        cb.AddTicks->EmitCall(*this, [this](RegList param) {
-        sub(param[0], qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)]);
+            mov(param[0], qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_to_run)]);
-    });
+            sub(param[0], qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)]);
+        });
+    }
 
     xor_(eax, eax);
     lock();
@@ -339,6 +349,10 @@ void BlockOfCode::LeaveStandardASIMD() {
 }
 
 void BlockOfCode::UpdateTicks() {
+    if (!cb.enable_cycle_counting) {
+        return;
+    }
+
     cb.AddTicks->EmitCall(*this, [this](RegList param) {
         mov(param[0], qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_to_run)]);
         sub(param[0], qword[rsp + ABI_SHADOW_SPACE + offsetof(StackLayout, cycles_remaining)]);

src/dynarmic/backend/x64/block_of_code.h

@@ -30,6 +30,7 @@ struct RunCodeCallbacks {
     std::unique_ptr<Callback> LookupBlock;
     std::unique_ptr<Callback> AddTicks;
     std::unique_ptr<Callback> GetTicksRemaining;
+    bool enable_cycle_counting;
 };
 
 class BlockOfCode final : public Xbyak::CodeGenerator {

src/dynarmic/backend/x64/emit_x64.cpp

@@ -306,6 +306,11 @@ void EmitX64::Patch(const IR::LocationDescriptor& target_desc, CodePtr target_co
         EmitPatchJg(target_desc, target_code_ptr);
     }
 
+    for (CodePtr location : patch_info.jz) {
+        code.SetCodePtr(location);
+        EmitPatchJz(target_desc, target_code_ptr);
+    }
+
     for (CodePtr location : patch_info.jmp) {
         code.SetCodePtr(location);
         EmitPatchJmp(target_desc, target_code_ptr);

src/dynarmic/backend/x64/emit_x64.h

@@ -111,12 +111,14 @@ protected:
     // Patching
     struct PatchInformation {
         std::vector<CodePtr> jg;
+        std::vector<CodePtr> jz;
         std::vector<CodePtr> jmp;
         std::vector<CodePtr> mov_rcx;
     };
     void Patch(const IR::LocationDescriptor& target_desc, CodePtr target_code_ptr);
     virtual void Unpatch(const IR::LocationDescriptor& target_desc);
     virtual void EmitPatchJg(const IR::LocationDescriptor& target_desc, CodePtr target_code_ptr = nullptr) = 0;
+    virtual void EmitPatchJz(const IR::LocationDescriptor& target_desc, CodePtr target_code_ptr = nullptr) = 0;
     virtual void EmitPatchJmp(const IR::LocationDescriptor& target_desc, CodePtr target_code_ptr = nullptr) = 0;
     virtual void EmitPatchMovRcx(CodePtr target_code_ptr = nullptr) = 0;
 

src/dynarmic/interface/A32/config.h

@@ -208,6 +208,10 @@ struct UserConfig {
     /// to avoid writting certain unnecessary code only needed for cycle timers.
     bool wall_clock_cntpct = false;
 
+    /// This option allows you to disable cycle counting. If this is set to false,
+    /// AddTicks and GetTicksRemaining are never called, and no cycle counting is done.
+    bool enable_cycle_counting = true;
+
     /// This option relates to the CPSR.E flag. Enabling this option disables modification
     /// of CPSR.E by the emulated program, forcing it to 0.
     /// NOTE: Calling Jit::SetCpsr with CPSR.E=1 while this option is enabled may result

src/dynarmic/interface/A64/config.h

@@ -273,9 +273,9 @@ struct UserConfig {
     /// to avoid writting certain unnecessary code only needed for cycle timers.
     bool wall_clock_cntpct = false;
 
-    // Determines whether AddTicks and GetTicksRemaining are called.
+    /// This option allows you to disable cycle counting. If this is set to false,
-    // If false, execution will continue until soon after Jit::HaltExecution is called.
+    /// AddTicks and GetTicksRemaining are never called, and no cycle counting is done.
-    // bool enable_ticks = true; // TODO
+    bool enable_cycle_counting = true;
 
     // Minimum size is about 8MiB. Maximum size is about 2GiB. Maximum size is limited by
     // the maximum length of a x64 jump.