Find out max & min from two numbers without using If else?

Question

I can find out the logic: Here

r = y ^ ((x ^ y) & -(x < y)); // min(x, y)
r = x ^ ((x ^ y) & -(x < y)); // max(x, y)

He says faster than doing

r = (x < y) ? x : y

Can someone explain a little more about this in order to figure this out with an example. How can it be faster?

Answer 1

Discussing optimization without using specific equipment makes no sense. You really cannot say which one is faster without going into the details of a particular system. Feel free to make the expression that the first alternative is the fastest without any specific equipment, this is only a preliminary optimization.

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Answer 2

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Answer 4

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; r = y ^ ((x ^ y) & -(x < y))
xor    edx,edx
cmp    ebx,eax
mov    ecx,eax
setl   dl
xor    ecx,ebx
neg    edx
and    edx,ecx  
xor    eax,edx  

; r = (x < y) ? x : y
cmp    ebx,eax  
cmovl  eax,ebx  

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Answer 5

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void func(int a,int b){
    int c = a - b;
    int k = (c >> 31) & 0x1;
    int max = a - k * c;
    int min = b + k * c;
    printf("max = %d\nmin = %d",max,min);
    }