function SameText(const S1, S2: string): Boolean; assembler;
asm
        CMP     EAX,EDX
        JZ      @1
        OR      EAX,EAX
        JZ      @2
        OR      EDX,EDX
        JZ      @3
        MOV     ECX,[EAX-4]
        CMP     ECX,[EDX-4]
        JNE     @3
        CALL    CompareText
        TEST    EAX,EAX
        JNZ     @3
@1:     MOV     AL,1
@2:     RET
@3:     XOR     EAX,EAX
end;　

var
  str1,str2: string;
  b: Boolean;
begin
  str1 := 'Delphi';
  str2 := 'delphi';

  b:= SameText(str1, str2);  //True   不区分大小写
  ShowMessage(BoolToStr(b,false) );
end;