[INTERPRETER] Improve x87 comparison (backported from Box64)

ptitSeb · Dec 4, 2024 · 512f0a6 · 512f0a6
1 parent 1c280bd
commit 512f0a6
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/src/emu/x87emu_private.h b/src/emu/x87emu_private.h
@@ -84,6 +84,10 @@ static inline void fpu_fcom(x86emu_t* emu, double b)
         emu->sw.f.F87_C0 = 1;
         emu->sw.f.F87_C2 = 1;
         emu->sw.f.F87_C3 = 1;
+    } else if ((b==-INFINITY) || (ST0.d==INFINITY)) {
+        emu->sw.f.F87_C0 = 0;
+        emu->sw.f.F87_C2 = 0;
+        emu->sw.f.F87_C3 = 0;
     } else if (isgreater(ST0.d, b)) {
         emu->sw.f.F87_C0 = 0;
         emu->sw.f.F87_C2 = 0;
@@ -111,6 +115,10 @@ static inline void fpu_fcomi(x86emu_t* emu, double b)
         SET_FLAG(F_CF);
         SET_FLAG(F_PF);
         SET_FLAG(F_ZF);
+    } else if ((b==-INFINITY) || (ST0.d==INFINITY)) {
+        CLEAR_FLAG(F_CF);
+        CLEAR_FLAG(F_PF);
+        CLEAR_FLAG(F_ZF);
     } else if (isgreater(ST0.d, b)) {
         CLEAR_FLAG(F_CF);
         CLEAR_FLAG(F_PF);