[common] Fix RDTSC nanosecond conversion (#4422)

Split the RDTSC ticks-per-nanosecond ratio into integer and Q0.64 fractional components. This avoids overflowing GetFixedPoint64Factor for TSC frequencies above 1 GHz while preserving the multiply-only conversion path.

Use the invariant clock only above 1 GHz because the reverse nanoseconds-per-tick factor cannot represent an exact ratio of one.

- [x] I have read and followed the [Contribution Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/CONTRIBUTING.md#code-contributions).
- [x] I have read and followed the [AI Policy](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/AI.md)
- [x] I have read and followed the [Coding Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/Coding.md) to the best of my ability.

-------------------

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4422
Reviewed-by: lizzie <lizzie@eden-emu.dev>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>

.patch/ffmpeg/0001-steamdeck.patch

@@ -1,34 +0,0 @@
-diff --git a/libavutil/hwcontext_vulkan.c b/libavutil/hwcontext_vulkan.c
-index 2859ee1..766961f 100644
---- a/libavutil/hwcontext_vulkan.c
-+++ b/libavutil/hwcontext_vulkan.c
-@@ -1688,10 +1688,12 @@ static int setup_queue_families(AVHWDeviceContext *ctx, VkDeviceCreateInfo *cd)
- 
-     hwctx->nb_qf = 0;
-     hwctx->queue_flags = 0;
-+/* SD gamemode vkroots crash
- #ifdef VK_KHR_internally_synchronized_queues
-     if (p->vkctx.extensions & FF_VK_EXT_INTERNAL_QUEUE_SYNC)
-         hwctx->queue_flags |= VK_DEVICE_QUEUE_CREATE_INTERNALLY_SYNCHRONIZED_BIT_KHR;
- #endif
-+*/
- 
-     /* Pick each queue family to use. */
- #define PICK_QF(type, vid_op)                                            \
-diff --git a/libavutil/vulkan.c b/libavutil/vulkan.c
-index b2e575c..5b3c9cf 100644
---- a/libavutil/vulkan.c
-+++ b/libavutil/vulkan.c
-@@ -574,10 +574,12 @@ int ff_vk_exec_pool_init(FFVulkanContext *s, AVVulkanDeviceQueueFamily *qf,
-         e->qf = qf->idx;
-         VkDeviceQueueInfo2 qinfo = {
-             .sType            = VK_STRUCTURE_TYPE_DEVICE_QUEUE_INFO_2,
-+/* SD gamemode vkroots crash
- #ifdef VK_KHR_internally_synchronized_queues
-             .flags            = internal_queue_sync ?
-                                 VK_DEVICE_QUEUE_CREATE_INTERNALLY_SYNCHRONIZED_BIT_KHR : 0,
- #endif
-+*/
-             .queueFamilyIndex = qf->idx,
-             .queueIndex       = e->qi,
-         };

cpmfile.json

@@ -70,9 +70,9 @@
         "version": "v1.3.18"
     },
     "ffmpeg": {
-        "hash": "68f46abf0d5dc47ab95083d59e273131a8df7948b82e62db00f00fa416e1d0bd24b799671b5a60752209bb2ac0f75295055ed0085c89a98113323cde23b69710",
+        "hash": "ed177621176b3961bdcaa339187d3a7688c1c8b060b79c4bb0257cbc67ad7021ae5d5adca5303b45625abbbe3d9aafdd87ce777b8690ac295290d744c875489a",
         "repo": "FFmpeg/FFmpeg",
-        "version": "6efe500d2e"
+        "version": "c7b5f1537d"
     },
     "ffmpeg-ci": {
         "ci": true,

src/common/cpu_features.cpp

@@ -244,7 +244,8 @@ 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}
+    , rdtsc_ns_integer{invariant_ ? rdtsc_frequency_ / NsRatio::den : 1}
+    , rdtsc_ns_factor{invariant_ ? GetFixedPoint64Factor(rdtsc_frequency_ % NsRatio::den, NsRatio::den) : 0}
     , cntpct_rdtsc_factor{invariant_ ? GetFixedPoint64Factor(CNTFRQ, rdtsc_frequency_) : 0}
     , gputick_rdtsc_factor{invariant_ ? GetFixedPoint64Factor(GPUTickFreq, rdtsc_frequency_) : 0}
     , invariant{invariant_}
@@ -291,7 +292,7 @@ bool WallClock::IsNative() const {
 }
 
 u64 WallClock::NsToTicks(std::chrono::nanoseconds ns) const {
-    return invariant ? MultiplyHigh(ns.count(), rdtsc_ns_factor) : ns.count();
+    return ns.count() * rdtsc_ns_integer + MultiplyHigh(ns.count(), rdtsc_ns_factor);
 }
 #elif defined(HAS_NCE)
 namespace {
@@ -416,7 +417,7 @@ u64 WallClock::NsToTicks(std::chrono::nanoseconds ns) const {
 const WallClock g_wall_clock = [] {
 #if defined(ARCHITECTURE_x86_64)
     auto const& caps = Common::g_cpu_caps;
-    return WallClock(caps.invariant_tsc && caps.tsc_frequency >= std::nano::den, caps.tsc_frequency);
+    return WallClock(caps.invariant_tsc && caps.tsc_frequency > std::nano::den, caps.tsc_frequency);
 #elif defined(HAS_NCE)
     return WallClock(false, 1);
 #else

src/common/cpu_features.h

@@ -96,6 +96,7 @@ public:
     u64 ns_rdtsc_factor;
     u64 us_rdtsc_factor;
     u64 ms_rdtsc_factor;
+    u64 rdtsc_ns_integer;
     u64 rdtsc_ns_factor;
     u64 cntpct_rdtsc_factor;
     u64 gputick_rdtsc_factor;