3.63

Solution

long switch_prob(long x, long n)
    x in %rdi, n in %rsi
1   0000000000400590 <switch_prob>:
2   400590: 48 83 ee 3c sub $0x3c,%rsi  # n - 60
3   400594: 48 83 fe 05 cmp $0x5,%rsi   # compare n-60:5
4   400598: 77 29   ja  4005c3 <switch_prob+0x33>   # if n-60 > 5, goto line 17
5   40059a: ff 24 f5 f8 06 40 00    jmpq    *0x4006f8(,%rsi,8)  # use lookup table to go to case code
6   4005a1: 48 8d 04 fd 00 00 00    lea 0x0(,%rdi,8),%rax   result = 8*x
7   4005a8: 00                          # noop
8   4005a9: c3  retq
9   4005aa: 4889f8  mov %rdi,%rax       # result = x
10  4005ad: 48 c1 f8 03 sar $0x3,%rax   # result >>= 3
11  4005b1: c3  retq
12  4005b2: 4889f8  mov %rdi,%rax       # result = x
13  4005b5: 48 c1 e0 04 shl $0x4,%rax   # result <<= 4
14  4005b9: 4829f8  sub %rdi,%rax       # result -= x
15  4005bc: 4889c7  mov %rax,%rdi       # x = result
16  4005bf: 48 0f af ff imul    %rdi,%rdi   # x = x* x
17  4005c3: 48 8d 47 4b lea 0x4b(%rdi),%rax # x + 75
18  4005c7: c3  retq

Solution code:

    long switch_prob(long x, long n) {
        long result = x;
        switch(n) {
        case 60:
        case 62:
            result = 8 * x;
            break;
        case 63:
            result = x >> 3;            
            break;
        case 64:
            x = (x << 4) - x;
        case 65:
            x = x * x;
        default:
            result = x + 75
        }
        return result;
    }