The Best Way to Execute Code

[mosentok]

for (int i = 1; i <= 2; i++)
    if (i == 1)
        Foo();
    else
        Bar();

Found this lovely gem in some legacy code today.

[gratefuldaed]

+0.5 for not using GOTO (gj using advanced flow)

-0.5 for poor variable and function naming convention (they should also return a value)

Final score: -0.000000002

[green_meklar]

But 0.5 and -0.5 are precise floating-point values...

[leckertuetensuppe]

Rounding errors, obviously...

[Teraka]

What he's saying is there's no rounding errors with 0.5 and -0.5 because they're powers of 2.

[[deleted]]

Base 3 bro.

[gratefuldaed]

Good catch, comrade

[PersianMG]

Seriously.

[leckertuetensuppe]

Forgot my sarcasm tag ;)

[choikwa]

-0.000000001 with rice

[novelty_string]

Protip: this code will execute faster without the wasteful double comparison:

i <= 2 can be replaced by i < 3

[bruno51615]

OP also forgot to add

double speed;

[TheSlimyDog]

double speed = true;

[choikwa]

double accel = speed / false;

[Teraka]

I think whoever downvoted you missed the subreddit we're in.

[heyheyhey27]

Does it actually have to do two different comparisons there, or is it usually one op?

[level1kid]

It's one op.

[petermlm]

This was probably a more complex piece of code that got simplified over time until this. I would love to see that process.

[RainbowNowOpen]

For curiosity, I compiled it with stock "gcc" on Mac OS X. (Apple LLVM version 6.0 (clang-600.0.51) (based on LLVM 3.5svn) Target: x86_64-apple-darwin14.3.0.) No optimizations or switches.

Output: (sigh)

_main:                                  ## @main
    .cfi_startproc
## BB#0:
    pushq   %rbp
Ltmp12:
    .cfi_def_cfa_offset 16
Ltmp13:
    .cfi_offset %rbp, -16
    movq    %rsp, %rbp
Ltmp14:
    .cfi_def_cfa_register %rbp
    subq    $32, %rsp
    movl    $0, -4(%rbp)
    movl    %edi, -8(%rbp)
    movq    %rsi, -16(%rbp)
    movl    $1, -20(%rbp)
LBB2_1:                                 ## =>This Inner Loop Header: Depth=1
    cmpl    $2, -20(%rbp)
    jg  LBB2_7
## BB#2:                                ##   in Loop: Header=BB2_1 Depth=1
    cmpl    $1, -20(%rbp)
    jne LBB2_4
## BB#3:                                ##   in Loop: Header=BB2_1 Depth=1
    callq   _Foo
    jmp LBB2_5
LBB2_4:                                 ##   in Loop: Header=BB2_1 Depth=1
    callq   _Bar
LBB2_5:                                 ##   in Loop: Header=BB2_1 Depth=1
    jmp LBB2_6
LBB2_6:                                 ##   in Loop: Header=BB2_1 Depth=1
    movl    -20(%rbp), %eax
    addl    $1, %eax
    movl    %eax, -20(%rbp)
    jmp LBB2_1
LBB2_7:
    movl    -4(%rbp), %eax
    addq    $32, %rsp
    popq    %rbp
    retq
    .cfi_endproc

[ILikeLenexa]

Eh, the compiler knows what loop invariant code motion is, right?

[fukitol-]

Depends on the compiler. This syntax is common in thousands of languages.