Ternary operator is twice as slow as an if-else block?

Question

I read everywhere that ternary operator is supposed to be faster than, or at least the same as, its equivalent if-else block.

However, I di

Answer 1

The assembler code generated will tell the story:

a = (b > c) ? 1 : 0;

Generates:

mov  edx, DWORD PTR a[rip]
mov  eax, DWORD PTR b[rip]
cmp  edx, eax
setg al

Whereas:

if (a > b) printf("a");
else printf("b");

Generates:

mov edx, DWORD PTR a[rip]
mov eax, DWORD PTR b[rip]
cmp edx, eax
jle .L4
    ;printf a
jmp .L5
.L4:
    ;printf b
.L5:

So the ternary can be shorter and faster simply due to using fewer instructions and no jumps if you are looking for true/false. If you use values other than 1 and 0, you will get the same code as an if/else, for example:

a = (b > c) ? 2 : 3;

Generates:

mov edx, DWORD PTR b[rip]
mov eax, DWORD PTR c[rip]
cmp edx, eax
jle .L6
    mov eax, 2
jmp .L7
.L6:
    mov eax, 3
.L7:

Which is the same as the if/else.