From 33f6f5bba3f1be0f8cc3b00a9defd3c35bd48b37 Mon Sep 17 00:00:00 2001
From: lizzie <lizzie@eden-emu.dev>
Date: Sun, 24 May 2026 01:48:00 +0000
Subject: [PATCH] fuckery squared

---
 src/common/cpu_features.cpp | 16 +++++++++++++---
 src/common/cpu_features.h   | 11 +++++------
 src/common/thread.cpp       |  2 +-
 3 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/src/common/cpu_features.cpp b/src/common/cpu_features.cpp
index 2bfcf9baec..bb1c7c8577 100644
--- a/src/common/cpu_features.cpp
+++ b/src/common/cpu_features.cpp
@@ -238,9 +238,6 @@ const CPUCaps g_cpu_caps = [] {
         } else {
             caps.tsc_frequency = X64::EstimateRDTSCFrequency();
         }
-        caps.tsc_to_ns_ratio = GetFixedPoint64Factor(NsRatio::den, caps.tsc_frequency);
-    } else {
-        caps.tsc_to_ns_ratio = 1;
     }
 
     if (max_std_fn >= 0x16) {
@@ -262,6 +259,7 @@ WallClock::WallClock(bool invariant_, u64 rdtsc_frequency_) noexcept
     , ns_rdtsc_factor{invariant_ ? GetFixedPoint64Factor(NsRatio::den, rdtsc_frequency_) : 0}
     , us_rdtsc_factor{invariant_ ? GetFixedPoint64Factor(UsRatio::den, rdtsc_frequency_) : 0}
     , ms_rdtsc_factor{invariant_ ? GetFixedPoint64Factor(MsRatio::den, rdtsc_frequency_) : 0}
+    , rdtsc_ns_factor{invariant_ ? GetFixedPoint64Factor(rdtsc_frequency_, NsRatio::den) : 1}
     , cntpct_rdtsc_factor{invariant_ ? GetFixedPoint64Factor(CNTFRQ, rdtsc_frequency_) : 0}
     , gputick_rdtsc_factor{invariant_ ? GetFixedPoint64Factor(GPUTickFreq, rdtsc_frequency_) : 0}
     , invariant{invariant_}
@@ -306,6 +304,10 @@ s64 WallClock::GetUptime() const {
 bool WallClock::IsNative() const {
     return invariant;
 }
+
+u64 WallClock::NsToTicks(std::chrono::nanoseconds ns) const {
+    return invariant ? MultiplyHigh(ns.count(), rdtsc_ns_factor) : ns.count();
+}
 #elif defined(HAS_NCE)
 namespace {
 
@@ -387,6 +389,10 @@ s64 WallClock::GetUptime() const {
 bool WallClock::IsNative() const {
     return true;
 }
+
+u64 WallClock::NsToTicks(std::chrono::nanoseconds ns) const {
+    return ns;
+}
 #else
 WallClock::WallClock(bool invariant_, u64 rdtsc_frequency_) noexcept {}
 
@@ -417,6 +423,10 @@ s64 WallClock::GetUptime() const {
 bool WallClock::IsNative() const {
     return false;
 }
+
+u64 WallClock::NsToTicks(std::chrono::nanoseconds ns) const {
+    return ns;
+}
 #endif
 
 // Wall clock MUST be initialized AFTER g_cpu_caps
diff --git a/src/common/cpu_features.h b/src/common/cpu_features.h
index b332dbde85..9655af3ee6 100644
--- a/src/common/cpu_features.h
+++ b/src/common/cpu_features.h
@@ -46,6 +46,9 @@ public:
     /// @returns Whether the clock directly uses the host's hardware clock.
     bool IsNative() const;
 
+    // @returns Nanoseconds to native ticks
+    u64 NsToTicks(std::chrono::nanoseconds ns) const;
+
     static inline u64 NSToCNTPCT(u64 ns) {
         return ns * NsToCNTPCTRatio::num / NsToCNTPCTRatio::den;
     }
@@ -72,7 +75,6 @@ public:
         return cpu_tick * CPUTickToGPUTickRatio::num / CPUTickToGPUTickRatio::den;
     }
 
-protected:
     using NsRatio = std::nano;
     using UsRatio = std::micro;
     using MsRatio = std::milli;
@@ -94,17 +96,15 @@ protected:
     u64 ns_rdtsc_factor;
     u64 us_rdtsc_factor;
     u64 ms_rdtsc_factor;
+    u64 rdtsc_ns_factor;
     u64 cntpct_rdtsc_factor;
     u64 gputick_rdtsc_factor;
     bool invariant;
 #elif defined(HAS_NCE)
-public:
     using FactorType = unsigned __int128;
-
-    FactorType GetGuestCNTFRQFactor() const {
+    [[nodiscard]] inline FactorType GetGuestCNTFRQFactor() const {
         return guest_cntfrq_factor;
     }
-protected:
     FactorType ns_cntfrq_factor;
     FactorType us_cntfrq_factor;
     FactorType ms_cntfrq_factor;
@@ -138,7 +138,6 @@ struct CPUCaps {
     u32 tsc_crystal_ratio_numerator;
     u32 crystal_frequency;
     u64 tsc_frequency; // Derived from the above three values
-    u64 tsc_to_ns_ratio; // Derived
 
     bool sse3 : 1;
     bool ssse3 : 1;
diff --git a/src/common/thread.cpp b/src/common/thread.cpp
index 1a02adc4eb..d53ba59131 100644
--- a/src/common/thread.cpp
+++ b/src/common/thread.cpp
@@ -174,7 +174,7 @@ __attribute__((target("waitpkg,mwaitx")))
 bool Event::WaitFor(const std::chrono::nanoseconds time) {
     auto const start = Common::X64::FencedRDTSC();
     auto const& caps = Common::g_cpu_caps;
-    [[maybe_unused]] auto const end = start + time.count() * caps.tsc_to_ns_ratio;
+    [[maybe_unused]] auto const end = start + Common::g_wall_clock.NsToTicks(time);
     if (caps.monitorx) {
         while (true) {
             // Armed monitor, as per manual, MWAITX must be conditional if the condition isn't satisfied