Simplify intermediate 16-bit register usage

EightBit/BigEndianProcessor.cs

@@ -34,12 +34,12 @@ namespace EightBit
             into.Low = this.MemoryRead();
         }
 
-        protected override Register16 GetWordPaged()
+        protected override void GetPagedInto(Register16 into)
         {
-            this.Intermediate.High = this.MemoryRead();
+            ArgumentNullException.ThrowIfNull(into);
+            into.High = this.MemoryRead();
             ++this.Bus.Address.Low;
-            this.Intermediate.Low = this.MemoryRead();
-            return this.Intermediate;
+            into.Low = this.MemoryRead();
         }
 
         protected override void PopInto(Register16 into)
@@ -64,7 +64,7 @@ namespace EightBit
             this.MemoryWrite(value.Low);
         }
 
-        protected override void SetWordPaged(Register16 value)
+        protected override void SetPaged(Register16 value)
         {
             ArgumentNullException.ThrowIfNull(value);
             this.MemoryWrite(value.High);

EightBit/IntelProcessor.cs

@@ -155,11 +155,10 @@ namespace EightBit
             return this.Bus.Data;
         }
 
-        protected sealed override Register16 GetWord()
+        protected sealed override void GetWord()
         {
-            _ = base.GetWord();
+            base.GetWord();
             this.MEMPTR.Assign(this.Bus.Address);
-            return this.Intermediate;
         }
 
         protected sealed override void SetWord(Register16 value)

EightBit/LittleEndianProcessor.cs

@@ -35,12 +35,12 @@ namespace EightBit
             into.High = this.MemoryRead();
         }
 
-        protected override Register16 GetWordPaged()
+        protected override void GetPagedInto(Register16 into)
         {
-            this.Intermediate.Low = this.MemoryRead();
+            ArgumentNullException.ThrowIfNull(into);
+            into.Low = this.MemoryRead();
             ++this.Bus.Address.Low;
-            this.Intermediate.High = this.MemoryRead();
-            return this.Intermediate;
+            into.High = this.MemoryRead();
         }
 
         protected override void PopInto(Register16 into)
@@ -65,7 +65,7 @@ namespace EightBit
             this.MemoryWrite(value.High);
         }
 
-        protected override void SetWordPaged(Register16 value)
+        protected override void SetPaged(Register16 value)
         {
             ArgumentNullException.ThrowIfNull(value);
             this.MemoryWrite(value.Low);

EightBit/Processor.cs

@@ -219,45 +219,59 @@ namespace EightBit
 
         protected abstract void GetInto(Register16 into);
 
-        protected virtual Register16 GetWord()
+        protected virtual void GetWord()
         {
             this.GetInto(this.Intermediate);
-            return this.Intermediate;
         }
 
         protected abstract void SetWord(Register16 value);
 
-        protected abstract Register16 GetWordPaged();
+        protected abstract void GetPagedInto(Register16 into);
 
-        protected Register16 GetWordPaged(byte page, byte offset)
+        protected virtual void GetWordPaged()
         {
-            this.Bus.Address.Assign(offset, page);
-            return this.GetWordPaged();
+            this.GetPagedInto(this.Intermediate);
         }
 
-        protected abstract void SetWordPaged(Register16 value);
+        protected void GetWordPaged(byte page, byte offset)
+        {
+            this.Bus.Address.Assign(offset, page);
+            this.GetWordPaged();
+        }
 
-        protected void SetWordPaged(Register16 address, Register16 value)
+        protected void GetPagedInto(byte page, byte offset, Register16 into)
+        {
+            ArgumentNullException.ThrowIfNull(into);
+            this.Bus.Address.Assign(offset, page);
+            this.GetPagedInto(into);
+        }
+
+        protected abstract void SetPaged(Register16 value);
+
+        protected void SetPaged(Register16 address, Register16 value)
         {
             this.Bus.Address.Assign(address);
-            this.SetWordPaged(value);
+            this.SetPaged(value);
         }
 
-        protected void SetWordPaged(byte page, byte offset, Register16 value)
+        protected void SetPaged(byte page, byte offset, Register16 value)
         {
             this.Bus.Address.Assign(offset, page);
-            this.SetWordPaged(value);
+            this.SetPaged(value);
         }
 
         protected abstract void FetchInto(Register16 into);
 
-        protected Register16 FetchWord()
+        protected void FetchWord()
         {
             this.FetchInto(this.Intermediate);
-            return this.Intermediate;
         }
 
-        protected void FetchWordAddress() => this.Bus.Address.Assign(this.FetchWord());
+        protected void FetchWordAddress()
+        {
+            this.FetchWord();
+            this.Bus.Address.Assign(this.Intermediate);
+        }
 
         protected abstract void Push(byte value);
 
@@ -267,10 +281,10 @@ namespace EightBit
 
         protected abstract void PopInto(Register16 into);
 
-        protected Register16 GetWord(Register16 address)
+        protected void GetWord(Register16 address)
         {
             this.Bus.Address.Assign(address);
-            return this.GetWord();
+            this.GetWord();
         }
 
         protected void SetWord(Register16 address, Register16 value)

Intel8080/Intel8080.cs

@@ -787,9 +787,8 @@ namespace Intel8080
 
         private void XHTL(Register16 exchange)
         {
-            this.MEMPTR.Low = this.MemoryRead(this.SP);
-            this.Bus.Address.Increment();
-            this.MEMPTR.High = this.MemoryRead();
+            this.Bus.Address.Assign(this.SP);
+            this.GetInto(this.MEMPTR);
             this.Bus.Data = exchange.High;
             exchange.High = this.MEMPTR.High;
             this.MemoryUpdate(2);

LR35902/LR35902.cs

@@ -533,7 +533,8 @@ namespace LR35902
                                 case 0: // NOP
                                     break;
                                 case 1: // GB: LD (nn),SP
-                                    this.Bus.Address.Assign(this.FetchWord());
+                                    this.FetchWord();
+                                    this.Bus.Address.Assign(this.Intermediate);
                                     this.SetWord(this.SP);
                                     break;
                                 case 2: // GB: STOP

LR35902/SM83.HarteTest/SM83.HarteTest.csproj

@@ -9,6 +9,14 @@
 	<AnalysisLevel>latest-all</AnalysisLevel>
   </PropertyGroup>
 
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
+    <WarningLevel>9999</WarningLevel>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
+    <WarningLevel>9999</WarningLevel>
+  </PropertyGroup>
+
 	<ItemGroup>
 		<ProjectReference Include="..\..\EightBit\EightBit.csproj" />
 		<ProjectReference Include="..\LR35902.csproj" />

M6502/Core.cs

@@ -215,7 +215,8 @@ namespace M6502
                 this.Push((byte)(this.P | (source == InterruptSource.hardware ? 0 : (byte)StatusBits.BF)));
             }
             this.SetFlag(StatusBits.IF);   // Disable IRQ
-            this.Jump(this.GetWordPaged(0xff, vector));
+            this.GetWordPaged(0xff, vector);
+            this.Jump(this.Intermediate);
         }
 
         #region Interrupt etc. handlers
@@ -659,7 +660,7 @@ namespace M6502
 
         protected void GetAddressPaged()
         {
-            _ = this.GetWordPaged();
+            this.GetWordPaged();
             this.Bus.Address.Assign(this.Intermediate);
         }
 

MC6809/MC6809.cs

@@ -495,7 +495,8 @@ namespace MC6809
             this.DP = 0;
             this.CC = SetBit(this.CC, StatusBits.IF);  // Disable IRQ
             this.CC = SetBit(this.CC, StatusBits.FF);  // Disable FIRQ
-            this.Jump(this.GetWordPaged(0xff, RESET_vector));
+            this.GetWordPaged(0xff, RESET_vector);
+            this.Jump(this.Intermediate);
             this.Tick(10);
         }
 
@@ -506,7 +507,8 @@ namespace MC6809
             this.RaiseBS();
             this.SaveEntireRegisterState();
             this.CC = SetBit(this.CC, StatusBits.IF);  // Disable IRQ
-            this.Jump(this.GetWordPaged(0xff, IRQ_vector));
+            this.GetWordPaged(0xff, IRQ_vector);
+            this.Jump(this.Intermediate);
             this.Tick(12);
         }
 
@@ -524,7 +526,8 @@ namespace MC6809
             this.SaveEntireRegisterState();
             this.CC = SetBit(this.CC, StatusBits.IF);  // Disable IRQ
             this.CC = SetBit(this.CC, StatusBits.FF);  // Disable FIRQ
-            this.Jump(this.GetWordPaged(0xff, NMI_vector));
+            this.GetWordPaged(0xff, NMI_vector);
+            this.Jump(this.Intermediate);
             this.Tick(12);
         }
 
@@ -536,7 +539,8 @@ namespace MC6809
             this.SavePartialRegisterState();
             this.CC = SetBit(this.CC, StatusBits.IF);  // Disable IRQ
             this.CC = SetBit(this.CC, StatusBits.FF);  // Disable FIRQ
-            this.Jump(this.GetWordPaged(0xff, FIRQ_vector));
+            this.GetWordPaged(0xff, FIRQ_vector);
+            this.Jump(this.Intermediate);
             this.Tick(12);
         }
 
@@ -610,7 +614,8 @@ namespace MC6809
 
         private Register16 Address_relative_word()
         {
-            var offset = (short)this.FetchWord().Word;
+            this.FetchWord();
+            var offset = (short)this.Intermediate.Word;
             this.Intermediate.Word = (ushort)(this.PC.Word + offset);
             return this.Intermediate;
         }
@@ -622,7 +627,11 @@ namespace MC6809
             return this.Intermediate;
         }
 
-        private Register16 Address_extended() => this.FetchWord();
+        private Register16 Address_extended()
+        {
+            this.FetchWord();
+            return this.Intermediate;
+        }
 
         private Register16 RR(int which)
         {
@@ -682,7 +691,8 @@ namespace MC6809
                         break;
                     case 0b1001: // n,R (sixteen-bit)
                         this.Tick(4);
-                        this.Intermediate.Word = (ushort)(r.Word + (short)this.FetchWord().Word);
+                        this.FetchWord();
+                        this.Intermediate.Word += r.Word;
                         break;
                     case 0b1011: // D,R
                         this.Tick(4);
@@ -708,7 +718,8 @@ namespace MC6809
                 if (indirect != 0)
                 {
                     this.Tick(3);
-                    this.Intermediate.Word = this.GetWord(this.Intermediate).Word;
+                    var address = this.Intermediate;
+                    this.GetWord(address);
                 }
             }
             else
@@ -745,13 +756,29 @@ namespace MC6809
             return this.Bus.Data;
         }
 
-        private Register16 AM_immediate_word() => this.FetchWord();
+        private Register16 AM_immediate_word()
+        {
+            this.FetchWord();
+            return this.Intermediate;
+        }
 
-        private Register16 AM_direct_word() => this.GetWord(this.Address_direct());
+        private Register16 AM_direct_word()
+        {
+            this.GetWord(this.Address_direct());
+            return this.Intermediate;
+        }
 
-        private Register16 AM_indexed_word() => this.GetWord(this.Address_indexed());
+        private Register16 AM_indexed_word()
+        {
+            this.GetWord(this.Address_indexed());
+            return this.Intermediate;
+        }
 
-        private Register16 AM_extended_word() => this.GetWord(this.Address_extended());
+        private Register16 AM_extended_word()
+        {
+            this.GetWord(this.Address_extended());
+            return this.Intermediate;
+        }
 
         #endregion
 
@@ -1746,19 +1773,22 @@ namespace MC6809
             this.SaveEntireRegisterState();
             this.CC = SetBit(this.CC, StatusBits.IF);  // Disable IRQ
             this.CC = SetBit(this.CC, StatusBits.FF);  // Disable FIRQ
-            this.Jump(this.GetWordPaged(0xff, SWI_vector));
+            this.GetWordPaged(0xff, SWI_vector);
+            this.Jump(this.Intermediate);
         }
 
         private void SWI2()
         {
             this.SaveEntireRegisterState();
-            this.Jump(this.GetWordPaged(0xff, SWI2_vector));
+            this.GetWordPaged(0xff, SWI2_vector);
+            this.Jump(this.Intermediate);
         }
 
         private void SWI3()
         {
             this.SaveEntireRegisterState();
-            this.Jump(this.GetWordPaged(0xff, SWI3_vector));
+            this.GetWordPaged(0xff, SWI3_vector);
+            this.Jump(this.Intermediate);
         }
 
         private void TST(byte data) => this.CMP(data, 0);

Z80/Z80.cs

@@ -580,8 +580,8 @@ namespace Z80
                     break;
                 case 2:
                     this.Tick();
-                    this.MEMPTR.Assign(this.GetWordPaged(data, this.IV));
-                    this.Call(this.MEMPTR);
+                    this.GetPagedInto(data, this.IV, this.MEMPTR);
+                    base.Call();
                     Debug.Assert(this.Cycles == 19);
                     break;
                 default:
@@ -963,7 +963,8 @@ namespace Z80
                                     this.SetWord(this.RP(p));
                                     break;
                                 case 1: // LD rp[p], (nn)
-                                    this.RP(p).Assign(this.GetWord());
+                                    this.GetWord();
+                                    this.RP(p).Assign(this.Intermediate);
                                     break;
                                 default:
                                     throw new NotSupportedException("Invalid operation mode");
@@ -1215,7 +1216,8 @@ namespace Z80
                                             break;
                                         case 2: // LD HL,(nn)
                                             this.FetchWordAddress();
-                                            this.HL2().Assign(this.GetWord());
+                                            this.GetWord();
+                                            this.HL2().Assign(this.Intermediate);
                                             break;
                                         case 3: // LD A,(nn)
                                             this.FetchInto(this.MEMPTR);
@@ -1940,9 +1942,8 @@ namespace Z80
 
         private void XHTL(Register16 exchange)
         {
-            this.MEMPTR.Low = this.MemoryRead(this.SP);
-            this.Bus.Address.Increment();
-            this.MEMPTR.High = this.MemoryRead();
+            this.Bus.Address.Assign(this.SP);
+            this.GetInto(this.MEMPTR);
             this.Bus.Data = exchange.High;
             exchange.High = this.MEMPTR.High;
             this.MemoryUpdate(2);