Python script to validate haproxy optimisation

test_haproxy.py

# Based on https://github.com/haproxy/haproxy/blob/50d8c187423d6b7e9b1083e05370885f6d12e844/src/h1.c#L578
test_nums = list(range(0x20, 0x27)) + list(range(0x7b, 0x81))

def test1(a, b, c, d):
   # What I expected the code to skip given the comment
   return all([0x24 <= a <= 0x7e, 0x24 <= b <= 0x7e,0x24 <= c <= 0x7e,0x24 <= d <= 0x7e])

def test3(a, b, c, d):
   # What it actually does skip
   return all([0x24 <= a, 0x24 <= b, 0x24 <= c, 0x24 <= d]) and any([a <= 0x7e, b <= 0x7e, c <= 0x7e, d <= 0x7e])

def test2(a, b, c, d):
    # Shortcut in haproxy code
    n = (a << 24) + (b << 16) + (c << 8) + d
    
    n1 = n = (n - 0x24242424) & 0xFFFFFFFF
    
    if n & 0x80808080:
        return False, n1, 0
        
    n2 = n = (n - 0x5b5b5b5b) & 0xFFFFFFFF
    
    if not (n & 0x80808080):
        return False, n1, n2
        
    return True, n1, n2
    

def test4(a, b, c, d):
    # Corrected shortcut in haproxy code
    n = (a << 24) + (b << 16) + (c << 8) + d
    
    n1 = (n - 0x24242424) & 0xFFFFFFFF
    
    if n1 & 0x80808080:
        return False, n1, 0
        
    n2 = (~n - ~0x7e7e7e7e) & 0xFFFFFFFF
    
    if (n2 & 0x80808080):
        return False, n1, n2
        
    return True, n1, n2
    

for a in test_nums:
    for b in test_nums:
        for c in test_nums:
            for d in test_nums:
                r1 = test1(a, b, c, d)
                r2, n1, n2 = test2(a, b, c, d)
                r3 = test3(a, b, c, d)
                r4, n3, n4 = test4(a, b, c, d)

                if r2 != r3:
                    # Never hit
                    print("XXX")                
                if r1 != r4:
                    # Never hit
                    print("XXX")                
                print("%X%X%X%X  %5s %5s %5s%s %5s%s %08X %08X %08X" % (
                      a, b, c, d, 
                      r1, r2, 
                      r3, ("*" if r2 != r3 else " "), 
                      r4, ("*" if r1 != r4 else " "),
                      n1, n2, n4))