Merge pull request #3429 from alyssarosenzweig/cleanup/nzcv-helpers

Cleanup NZCV metadata

FEXCore/Source/Interface/Core/OpcodeDispatcher.cpp

@@ -441,14 +441,7 @@ void OpDispatchBuilder::SecondaryALUOp(OpcodeArgs) {
     break;
     }
     case FEXCore::IR::IROps::OP_ANDWITHFLAGS: {
-      InvalidateDeferredFlags();
-
-      // SF/ZF/CF/OF
-      CachedNZCV = nullptr;
-      PossiblySetNZCVBits = (1u << 31) | (1u << 30);
-      NZCVDirty = false;
-
-      // PF/AF
+      HandleNZ00Write();
       CalculatePF(Result);
       _InvalidateFlags(1 << X86State::RFLAG_AF_RAW_LOC);
     break;
@@ -1298,16 +1291,8 @@ void OpDispatchBuilder::TESTOp(OpcodeArgs) {
       Src = Dest;
   }
 
-  InvalidateDeferredFlags();
-
-  // SF/ZF/CF/OF
-  OrderedNode *ALUOp = _AndWithFlags(IR::SizeToOpSize(Size), Dest, Src);
-  CachedNZCV = nullptr;
-  PossiblySetNZCVBits = (1u << 31) | (1u << 30);
-  NZCVDirty = false;
-
-  // PF/AF
-  CalculatePF(ALUOp);
+  HandleNZ00Write();
+  CalculatePF(_AndWithFlags(IR::SizeToOpSize(Size), Dest, Src));
   _InvalidateFlags(1 << X86State::RFLAG_AF_RAW_LOC);
 }
 
@@ -5278,14 +5263,7 @@ void OpDispatchBuilder::ALUOpImpl(OpcodeArgs, FEXCore::IR::IROps ALUIROp, FEXCor
     break;
     }
     case FEXCore::IR::IROps::OP_ANDWITHFLAGS: {
-      InvalidateDeferredFlags();
-
-      // SF/ZF/CF/OF
-      CachedNZCV = nullptr;
-      PossiblySetNZCVBits = (1u << 31) | (1u << 30);
-      NZCVDirty = false;
-
-      // PF/AF
+      HandleNZ00Write();
       CalculatePF(Result);
       _InvalidateFlags(1 << X86State::RFLAG_AF_RAW_LOC);
     break;

FEXCore/Source/Interface/Core/OpcodeDispatcher.h

@@ -1263,6 +1263,30 @@ private:
     return NZCVMask;
   }
 
+  // Set flag tracking to prepare for an operation that directly writes NZCV. If
+  // some bits are known to be zeroed, the PossiblySetNZCVBits mask can be
+  // passed. Otherwise, it defaults to assuming all bits may be set after
+  // (this is conservative).
+  void HandleNZCVWrite(uint32_t _PossiblySetNZCVBits = ~0) {
+    InvalidateDeferredFlags();
+    CachedNZCV = nullptr;
+    PossiblySetNZCVBits = _PossiblySetNZCVBits;
+    NZCVDirty = false;
+  }
+
+  // Set flag tracking to prepare for a read-modify-write operation on NZCV.
+  void HandleNZCV_RMW(uint32_t _PossiblySetNZCVBits = ~0) {
+    if (NZCVDirty && CachedNZCV)
+      _StoreNZCV(CachedNZCV);
+
+    HandleNZCVWrite(_PossiblySetNZCVBits);
+  }
+
+  // Special case of the above where we are known to zero C/V
+  void HandleNZ00Write() {
+    HandleNZCVWrite((1u << 31) | (1u << 30));
+  }
+
   OrderedNode *GetNZCV() {
     if (!CachedNZCV) {
       CachedNZCV = _LoadNZCV();

FEXCore/Source/Interface/Core/OpcodeDispatcher/Flags.cpp

@@ -495,12 +495,8 @@ void OpDispatchBuilder::CalculateFlags_ADC(uint8_t SrcSize, OrderedNode *Res, Or
   CalculatePF(Res);
 
   if (SrcSize >= 4) {
-    if (NZCVDirty && CachedNZCV)
-      _StoreNZCV(CachedNZCV);
-    CachedNZCV = nullptr;
-
+    HandleNZCV_RMW();
     _AdcNZCV(OpSize, Src1, Src2);
-    PossiblySetNZCVBits = ~0;
   } else {
     // SF/ZF
     SetNZ_ZeroCV(SrcSize, Res);
@@ -531,13 +527,8 @@ void OpDispatchBuilder::CalculateFlags_SBB(uint8_t SrcSize, OrderedNode *Res, Or
     // Rectify input carry
     CarryInvert();
 
-    if (NZCVDirty && CachedNZCV)
-      _StoreNZCV(CachedNZCV);
-    CachedNZCV = nullptr;
-    NZCVDirty = false;
-
+    HandleNZCV_RMW();
     _SbbNZCV(OpSize, Src1, Src2);
-    PossiblySetNZCVBits = ~0;
 
     // Rectify output carry
     CarryInvert();
@@ -568,10 +559,8 @@ void OpDispatchBuilder::CalculateFlags_SUB(uint8_t SrcSize, OrderedNode *Res, Or
   // Stash CF before stomping over it
   auto OldCF = UpdateCF ? nullptr : GetRFLAG(FEXCore::X86State::RFLAG_CF_RAW_LOC);
 
+  HandleNZCVWrite();
   _SubNZCV(IR::SizeToOpSize(SrcSize), Src1, Src2);
-  CachedNZCV = nullptr;
-  NZCVDirty = false;
-  PossiblySetNZCVBits = ~0;
 
   // If we're updating CF, we need to invert it for correctness. If we're not
   // updating CF, we need to restore the CF since we stomped over it.
@@ -590,10 +579,8 @@ void OpDispatchBuilder::CalculateFlags_ADD(uint8_t SrcSize, OrderedNode *Res, Or
   // Stash CF before stomping over it
   auto OldCF = UpdateCF ? nullptr : GetRFLAG(FEXCore::X86State::RFLAG_CF_RAW_LOC);
 
+  HandleNZCVWrite();
   _AddNZCV(IR::SizeToOpSize(SrcSize), Src1, Src2);
-  CachedNZCV = nullptr;
-  NZCVDirty = false;
-  PossiblySetNZCVBits = ~0;
 
   // We stomped over CF while calculation flags, restore it.
   if (!UpdateCF)
@@ -601,6 +588,8 @@ void OpDispatchBuilder::CalculateFlags_ADD(uint8_t SrcSize, OrderedNode *Res, Or
 }
 
 void OpDispatchBuilder::CalculateFlags_MUL(uint8_t SrcSize, OrderedNode *Res, OrderedNode *High) {
+  HandleNZCVWrite();
+
   // PF/AF/ZF/SF
   // Undefined
   {
@@ -619,13 +608,12 @@ void OpDispatchBuilder::CalculateFlags_MUL(uint8_t SrcSize, OrderedNode *Res, Or
     // undefined, this does what we need.
     auto Zero = _Constant(0);
     _CondAddNZCV(OpSize::i64Bit, Zero, Zero, CondClassType{COND_EQ}, 0x3 /* nzCV */);
-    CachedNZCV = nullptr;
-    NZCVDirty = false;
-    PossiblySetNZCVBits = ~0;
   }
 }
 
 void OpDispatchBuilder::CalculateFlags_UMUL(OrderedNode *High) {
+  HandleNZCVWrite();
+
   auto Zero = _Constant(0);
   OpSize Size = IR::SizeToOpSize(GetOpSize(High));
 
@@ -645,9 +633,6 @@ void OpDispatchBuilder::CalculateFlags_UMUL(OrderedNode *High) {
     // If High = 0, then sets to nZcv. Else sets to nzCV. Since SF/ZF undefined,
     // this does what we need.
     _CondAddNZCV(Size, Zero, Zero, CondClassType{COND_EQ}, 0x3 /* nzCV */);
-    CachedNZCV = nullptr;
-    NZCVDirty = false;
-    PossiblySetNZCVBits = ~0;
   }
 }
 

FEXCore/Source/Interface/Core/OpcodeDispatcher/Vector.cpp

@@ -3422,15 +3422,12 @@ void OpDispatchBuilder::VPALIGNROp(OpcodeArgs) {
 
 template<size_t ElementSize>
 void OpDispatchBuilder::UCOMISxOp(OpcodeArgs) {
-  InvalidateDeferredFlags();
-
   const auto SrcSize = Op->Src[0].IsGPR() ? GetGuestVectorLength() : GetSrcSize(Op);
   OrderedNode *Src1 = LoadSource_WithOpSize(FPRClass, Op, Op->Dest, GetGuestVectorLength(), Op->Flags);
   OrderedNode *Src2 = LoadSource_WithOpSize(FPRClass, Op, Op->Src[0], SrcSize, Op->Flags);
 
-  CachedNZCV = nullptr;
+  HandleNZCVWrite();
   _FCmp(ElementSize, Src1, Src2);
-  PossiblySetNZCVBits = ~0;
   ConvertNZCVToSSE();
 
   // Zero AF. Note that the comparison sets the raw PF to 0/1 above, so PF[4] is