How can I use inline ASM in Delphi

In Delphi, you can use inline assembly code in your programs using the asm keyword. Inline assembly allows you to include low-level machine code instructions in your Delphi code, which can be useful for optimizing certain operations or for accessing hardware resources that are not directly exposed by the Delphi language.

Here is an example of how to use inline assembly in Delphi:

function Add(A, B: Integer): Integer;
asm
  mov eax, [A]
  add eax, [B]
end;

begin
  WriteLn(Add(10, 20)); // outputs 30
end.

function Add(A, B: Integer): Integer;

asm

mov eax, [A]

add eax, [B]

end;

begin

WriteLn(Add(10, 20)); // outputs 30

end.

In this example, the Add function uses inline assembly to add two integers and return the result. The asm keyword is used to mark the beginning of the assembly code block, and the end keyword is used to mark the end of the block.

Inside the assembly block, you can use machine code instructions and labels in the same way you would in a standalone assembly program. In this example, the mov instruction is used to move the value of the A parameter into the eax register, and the add instruction is used to add the value of the B parameter to the eax register. The result is then returned in the eax register when the function exits.

You can also use Delphi variables and constants in your inline assembly code by enclosing them in square brackets ([ ]). In the example above, the A and B parameters are accessed using this notation.

Here is another example that demonstrates how to use inline assembly to optimize a loop:

function Sum(const Values: array of Integer): Integer;
var
  I: Integer;
begin
  Result := 0;
  asm
    mov edx, Values
    mov ecx, Length(Values)
    mov eax, 0
  @Loop:
    add eax, [edx]
    add edx, 4
    dec ecx
    jnz @Loop
  end;
  Result := eax;
end;

begin
  WriteLn(Sum([1, 2, 3, 4, 5])); // outputs 15
end.

function Sum(const Values: array of Integer): Integer;

var

I: Integer;

begin

Result := 0;

asm

mov edx, Values

mov ecx, Length(Values)

mov eax, 0

@Loop:

add eax, [edx]

add edx, 4

dec ecx

jnz @Loop

end;

Result := eax;

end;

begin

WriteLn(Sum([1, 2, 3, 4, 5])); // outputs 15

end.

In this example, the Sum function uses inline assembly to sum the elements of an integer array. The assembly code uses three registers (edx, ecx, and eax) to perform the loop and sum the values. The edx register is used to store a pointer to the array, the ecx register is used to store the length of the array, and the eax register is used to store the running total. The @Loop label is used to mark the beginning of the loop, and the jnz instruction is used to jump back to the @Loop label if the ecx register is not zero.

How can I use inline ASM in Delphi

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