Changeset 185 for branches/virtualcpu4/UInstructionWriter.pas

Timestamp:

May 1, 2019, 9:48:46 PM (6 years ago)

Author:

chronos

Message:

• Added: Assembler labels reference address calculation.
• Fixed: Displaying address/data hex numbers in opcode and instruction.

File:

• branches/virtualcpu4/UInstructionWriter.pas (modified) (7 diffs)

branches/virtualcpu4/UInstructionWriter.pas

@@ -25 +25 @@
     Prefix: Boolean;
     procedure Init;
+    function GetRelativeAddr(BitWidth: TBitWidth; BaseIP, TargetAddr: QWord): Int64;
     procedure Write8(Value: Byte);
     procedure Write16(Value: Word);
@@ -132 +133 @@
 end;
 
+function TInstructionWriter.GetRelativeAddr(BitWidth: TBitWidth; BaseIP, TargetAddr: QWord): Int64;
+begin
+  Result := Int64(TargetAddr) - (BaseIP + 1 + BitWidthBytes[BitWidth]);
+end;
+
 procedure TInstructionWriter.JumpRel(Addr: QWord);
 var
-  NextIP: QWord;
-begin
-  PrefixBegin;
-  NextIP := IP + 1 + BitWidthBytes[Cpu.AddrSize];
+  RelAddr: Int64;
+begin
+  PrefixBegin;
+  RelAddr := GetRelativeAddr(AddrSize, IP, Addr);
   Write8(Byte(opJumpRel));
-  WriteAddressSigned(Int64(Addr) - Int64(NextIP));
+  WriteAddressSigned(RelAddr);
   PrefixEnd;
 end;
@@ -145 +151 @@
 procedure TInstructionWriter.JumpRelNotZero(Addr: QWord);
 var
-  NextIP: QWord;
-begin
-  PrefixBegin;
-  NextIP := IP + 1 + BitWidthBytes[Cpu.AddrSize];
+  RelAddr: Int64;
+begin
+  PrefixBegin;
+  RelAddr := GetRelativeAddr(AddrSize, IP, Addr);
   Write8(Byte(opJumpRelNotZero));
-  WriteAddressSigned(Int64(Addr) - Int64(NextIP));
+  WriteAddressSigned(RelAddr);
   PrefixEnd;
 end;
@@ -156 +162 @@
 procedure TInstructionWriter.JumpRelZero(Addr: QWord);
 var
-  NextIP: QWord;
-begin
-  PrefixBegin;
-  NextIP := IP + 1 + BitWidthBytes[Cpu.AddrSize];
+  RelAddr: Int64;
+begin
+  PrefixBegin;
+  RelAddr := GetRelativeAddr(AddrSize, IP, Addr);
   Write8(Byte(opJumpRelZero));
-  WriteAddressSigned(Int64(Addr) - Int64(NextIP));
+  WriteAddressSigned(RelAddr);
   PrefixEnd;
 end;
@@ -360 +366 @@
 begin
   case AddrSize of
-    bw8: Write8(Value);
-    bw16: Write16(Value);
-    bw32: Write32(Value);
+    bw8: Write8(Value and $ff);
+    bw16: Write16(Value and $ffff);
+    bw32: Write32(Value and $ffffffff);
     bw64: Write64(Value);
   end;
@@ -370 +376 @@
 begin
   case AddrSize of
-    bw8: Write8(Byte(Value));
-    bw16: Write16(Word(Value));
-    bw32: Write32(DWord(Value));
+    bw8: Write8(Byte(Value and $ff));
+    bw16: Write16(Word(Value and $ffff));
+    bw32: Write32(DWord(Value and $ffffffff));
     bw64: Write64(QWord(Value));
   end;
@@ -380 +386 @@
 begin
   case DataSize of
-    bw8: Write8(Value);
-    bw16: Write16(Value);
-    bw32: Write32(Value);
+    bw8: Write8(Value and $ff);
+    bw16: Write16(Value and $ffff);
+    bw32: Write32(Value and $ffffffff);
     bw64: Write64(Value);
   end;