Changeset 97290 in vbox

Timestamp:

Oct 25, 2022 7:57:28 AM (2 years ago)

Author:

vboxsync

Message:

VMM/IEM: Treat zero as a Normal in fptan, bugref:9898

File:

• trunk/src/VBox/VMM/VMMAll/IEMAllAImplC.cpp (modified) (2 diffs)

trunk/src/VBox/VMM/VMMAll/IEMAllAImplC.cpp

@@ -6200 +6200 @@
     uint16_t fFsw       = (pFpuState->FSW & (X86_FSW_C0 | /*X86_FSW_C2 |*/ X86_FSW_C3)) | (6 << X86_FSW_TOP_SHIFT);
 
-    if (RTFLOAT80U_IS_NORMAL(pr80Val))
+    if (RTFLOAT80U_IS_ZERO(pr80Val))
+    {
+        pFpuResTwo->r80Result1 = *pr80Val;
+        pFpuResTwo->r80Result2 = g_ar80One[0];
+    }
+    else if (RTFLOAT80U_IS_NORMAL(pr80Val))
     {
         if (pr80Val->s.uExponent >= RTFLOAT80U_EXP_BIAS + 63)
@@ -6229 +6234 @@
         fFsw |= X86_FSW_IE;
         if (!(fFcw & X86_FCW_IM))
-            fFsw |= X86_FSW_ES | X86_FSW_B;
+            fFsw |= X86_FSW_ES | X86_FSW_B | (7 << X86_FSW_TOP_SHIFT);
     }