Changeset 86 for trunk/Target/UTargetC.pas

Timestamp:

Aug 29, 2017, 5:12:18 PM (7 years ago)

Author:

chronos

Message:

• Added: New optimization using relative indexes to eliminate lots of pointer inc/dec operations.
• Added: New command "multiply" extended command to replace while loops used for cell multiplication. Also added related optimization.

File:

• trunk/Target/UTargetC.pas (modified) (3 diffs)

trunk/Target/UTargetC.pas

@@ -15 +15 @@
   TTargetC = class(TBFTarget)
   private
+    function GetMemoryCell: string;
   public
     constructor Create; override;
@@ -46 +47 @@
 end;
 
+function TTargetC.GetMemoryCell: string;
+begin
+  Result := 'Memory[Pos';
+  if FProgram[FProgramIndex].RelIndex > 0 then
+    Result := Result + ' + ' + IntToStr(FProgram[FProgramIndex].RelIndex)
+  else if FProgram[FProgramIndex].RelIndex < 0 then
+    Result := Result + ' - ' + IntToStr(Abs(FProgram[FProgramIndex].RelIndex));
+  Result := Result + ']';
+end;
+
 procedure TTargetC.Compile;
 begin
@@ -67 +78 @@
       cmPointerInc: AddLine('Pos = Pos + ' + IntToStr(FProgram[FProgramIndex].Parameter) + ';');
       cmPointerDec: AddLine('Pos = Pos - ' + IntToStr(FProgram[FProgramIndex].Parameter) + ';');
-      cmInc: AddLine('Memory[Pos] = Memory[Pos] + ' + IntToStr(FProgram[FProgramIndex].Parameter) + ';');
-      cmDec: AddLine('Memory[Pos] = Memory[Pos] - ' + IntToStr(FProgram[FProgramIndex].Parameter) + ';');
-      cmOutput: AddLine('putchar(Memory[Pos]);');
-      cmInput: AddLine('Memory[Pos] = getchar();');
-      cmSet: AddLine('Memory[Pos] = ' + IntToStr(FProgram[FProgramIndex].Parameter) + ';');
+      cmInc: AddLine(GetMemoryCell + ' = ' + GetMemoryCell + ' + ' + IntToStr(FProgram[FProgramIndex].Parameter) + ';');
+      cmDec: AddLine(GetMemoryCell + ' = ' + GetMemoryCell + ' - ' + IntToStr(FProgram[FProgramIndex].Parameter) + ';');
+      cmOutput: AddLine('putchar(' + GetMemoryCell + ');');
+      cmInput: AddLine(GetMemoryCell + ' = getchar();');
+      cmSet: AddLine(GetMemoryCell + ' = ' + IntToStr(FProgram[FProgramIndex].Parameter) + ';');
+      cmMultipy: AddLine(GetMemoryCell + ' = ' + GetMemoryCell + ' + Memory[Pos] * ' + IntToStr(FProgram[FProgramIndex].Parameter) + ';');
       cmLoopStart: begin
-        AddLine('while(Memory[Pos] != 0)');
+        AddLine('while(' + GetMemoryCell + ' != 0)');
         AddLine('{');
         Inc(Indent);