Interpreter: Optimize FEX calculation

The next commit will make the interpreter run this after every float instruction, so I think a little optimization here is justified.
dolphin-emu · Oct 13, 2021 · 89a464d · 89a464d
1 parent 83c6df1
commit 89a464d
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Showing 2 changed files with 7 additions and 2 deletions.
diff --git a/Source/Core/Core/PowerPC/Gekko.h b/Source/Core/Core/PowerPC/Gekko.h
@@ -419,11 +419,17 @@ enum FPSCRExceptionFlag : u32
   FPSCR_VXSQRT = 1U << (31 - 22),
   FPSCR_VXCVI = 1U << (31 - 23),
   FPSCR_VE = 1U << (31 - 24),
+  FPSCR_OE = 1U << (31 - 25),
+  FPSCR_UE = 1U << (31 - 26),
+  FPSCR_ZE = 1U << (31 - 27),
+  FPSCR_XE = 1U << (31 - 28),
 
   FPSCR_VX_ANY = FPSCR_VXSNAN | FPSCR_VXISI | FPSCR_VXIDI | FPSCR_VXZDZ | FPSCR_VXIMZ | FPSCR_VXVC |
                  FPSCR_VXSOFT | FPSCR_VXSQRT | FPSCR_VXCVI,
 
   FPSCR_ANY_X = FPSCR_OX | FPSCR_UX | FPSCR_ZX | FPSCR_XX | FPSCR_VX_ANY,
+
+  FPSCR_ANY_E = FPSCR_VE | FPSCR_OE | FPSCR_UE | FPSCR_ZE | FPSCR_XE,
 };
 
 // Floating Point Status and Control Register

diff --git a/Source/Core/Core/PowerPC/Interpreter/Interpreter_SystemRegisters.cpp b/Source/Core/Core/PowerPC/Interpreter/Interpreter_SystemRegisters.cpp
@@ -40,8 +40,7 @@ static void FPSCRUpdated(UReg_FPSCR fp)
 static void UpdateFPSCR(UReg_FPSCR* fpscr)
 {
   fpscr->VX = (fpscr->Hex & FPSCR_VX_ANY) != 0;
-  fpscr->FEX = (fpscr->VX & fpscr->VE) | (fpscr->OX & fpscr->OE) | (fpscr->UX & fpscr->UE) |
-               (fpscr->ZX & fpscr->ZE) | (fpscr->XX & fpscr->XE);
+  fpscr->FEX = ((fpscr->Hex >> 22) & (fpscr->Hex & FPSCR_ANY_E)) != 0;
 }
 
 void Interpreter::mtfsb0x(UGeckoInstruction inst)