SizeOf/fi

program sizeOfDemo(input, output, stderr);

{$typedAddress on}

uses
    heaptrc;

type
    s = record
        c: char;
        i: longint;
    end;

var
    x: ^s;

begin
    returnNilIfGrowHeapFails := true;
    
    getMem(x, sizeOf(x));
    
    if not assigned(x) then
    begin
        writeLn(stderr, 'malloc for x failed');
        halt(1);
    end;
    
    x^.c := 'r';
    x^.i := -42;
    
    freeMem(x, sizeOf(x));
end.

program sizeOfDemo(input, output, stderr);

type
    integerArray = array of integer;

function sum(const f: integerArray): int64;
{$ifdef CPUx86_64}
assembler;
{$asmMode intel}
asm// ensure f is in a particular register// rsi := f  (pointer to an array)// check for nil pointer (i.e. empty array)// rsi = 0 ?// if rsi = nil then goto abort// load last index of array [theoretically there is highF]// rcx := (rsi - sizeOf(sizeInt))^// load first element, since loop condition won't reach it{$if sizeOf(integer) = 4}// eax := rsi^{$elseif sizeOf(integer) = 2}// ax := rsi^{$else}{$error unexpected integer size}{$endif}// we're done, if f doesn't contain any more elements// rcx = 0 ?// if high(f) = 0 then goto done{$if sizeOf(integer) = 4}// edx := (rsi + 4 * rcx)^{$elseif sizeOf(integer) = 2}// dx := (rsi + 2 * rcx)^{$else}{$error unexpected scale factor}{$endif}// rax := rax + rdx// if OF then goto abort// dec(rcx)// if rcx <> 0 then goto iterate// goto done// load neutral element for addition// rax := 0
    // ensure f is in a particular register
    mov rsi, f                       // rsi := f  (pointer to an array)
    
    // check for nil pointer (i.e. empty array)
    test rsi, rsi                    // rsi = 0 ?
    jz @sum_abort                    // if rsi = nil then goto abort
    
    // load last index of array [theoretically there is highF]
    mov rcx, [rsi] - sizeOf(sizeInt) // rcx := (rsi - sizeOf(sizeInt))^
    
    // load first element, since loop condition won't reach it
    {$if sizeOf(integer) = 4}
    mov eax, [rsi]                   // eax := rsi^
    {$elseif sizeOf(integer) = 2}
    mov ax, [rsi]                    // ax := rsi^
    {$else} {$error unexpected integer size} {$endif}
    
    // we're done, if f doesn't contain any more elements
    test rcx, rcx                    // rcx = 0 ?
    jz @sum_done                     // if high(f) = 0 then goto done
    
@sum_iterate:
    {$if sizeOf(integer) = 4}
    mov edx, [rsi + rcx * 4]         // edx := (rsi + 4 * rcx)^
    {$elseif sizeOf(integer) = 2}
    mov dx, [rsi + rcx * 2]          // dx := (rsi + 2 * rcx)^
    {$else} {$error unexpected scale factor} {$endif}
    
    add rax, rdx                     // rax := rax + rdx
    
    jo @sum_abort                    // if OF then goto abort
    
    loop @sum_iterate                // dec(rcx)
                                     // if rcx <> 0 then goto iterate
    
    jmp @sum_done                    // goto done
    
@sum_abort:
    // load neutral element for addition
    xor rax, rax                     // rax := 0
    
@sum_done:
END;
{$else}
unimplemented;
begin
    sum := 0;
end;
{$endif}

begin
    writeLn(sum(integerArray.create(2, 5, 11, 17, 23)));
end.

program dynamicArraySizeDemo(input, output, stderr);

uses
    sysUtils;

resourcestring
    enteredN = 'You''ve entered %0:d integers';
    totalData = 'occupying a total of %0:d Bytes.';

var
    f: array of longint;

begin
    setLength(f, 0);
    
    while not eof() do
    begin
        setLength(f, length(f) + 1);
        readLn(f[length(f)]);
    end;
    
    writeLn(format(enteredN, [length(f)]));
    writeLn(format(totalData, [length(f) * sizeOf(f[0])]));
end.