Is there any quality difference between MurmurHash32 and static_cast(MurmurHash128)?

Asked Aug 21 '19 at 11:38

Active Aug 21 '19 at 11:38

Viewed 79 times

Given a message, MurmurHash3 can produce a 32-bit hash result or a 128-bit one.

Message msg;
char output_v32_a[4];
char output_v32_b[4];
char output_v128[16];

MurmurHash32(msg, output_v32_a); 
MurmurHash128(msg, output_v128); 
memcpy(output_v32_b, output_v128, 4);

In the pseudocode above, is there any quality difference between output_v32_a and output_v32_b?

asked Aug 21 '19 at 11:38

xmllmx

39,765
26
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What do you mean by "quality"? What are you using the hash for? – President James K. Polk Aug 21 '19 at 13:39
1

Grabbing the first (or last, or middle) 32 bits of Mumur128 will not give you a better hash code (distribution, etc.) than Murmur32. It will *probably* give you approximately the same quality. – Jim Mischel Aug 21 '19 at 17:32

Is there any quality difference between MurmurHash32 and static_cast(MurmurHash128)?

0 Answers0