Use 64-bit integers inside Stopwatch to enable longer timings.

1 files changed, 13 insertions, 11 deletions

diff --git a/Kernel/i386.h b/Kernel/i386.h
index 4dc56620d4..9b2b3447d4 100644
--- a/Kernel/i386.h
+++ b/Kernel/i386.h
@@ -269,27 +269,29 @@ inline void read_tsc(dword& lsw, dword& msw)
 }
 
 struct Stopwatch {
+    union SplitQword {
+        struct {
+            uint32_t lsw;
+            uint32_t msw;
+        };
+        uint64_t qw { 0 };
+    };
 public:
     Stopwatch(const char* name)
         : m_name(name)
     {
-        read_tsc(m_start_lsw, m_start_msw);
+        read_tsc(m_start.lsw, m_start.msw);
     }
 
     ~Stopwatch()
     {
-        dword end_lsw;
-        dword end_msw;
-        read_tsc(end_lsw, end_msw);
-        if (m_start_msw != end_msw) {
-            dbgprintf("stopwatch: differing msw, no result for %s\n", m_name);
-        }
-        dword diff = end_lsw - m_start_lsw;
-        dbgprintf("Stopwatch(%s): %u ticks\n", m_name, diff);
+        SplitQword end;
+        read_tsc(end.lsw, end.msw);
+        uint64_t diff = end.qw - m_start.qw;
+        dbgprintf("Stopwatch(%s): %q ticks\n", m_name, diff);
     }
 
 private:
     const char* m_name { nullptr };
-    dword m_start_lsw { 0 };
-    dword m_start_msw { 0 };
+    SplitQword m_start;
 };