And - in case you're looking for an implementation of the 32-bit mumurhash
in PL/I, here's the code I came up with.
Note, mumurash is endian-dependent (you get different values on big-endian
vs. little-endian machines). Also, the 128-bit version does not generate the
same values as the 32-bit version.
But - I slapped this together from the C source, and verified it got the same
results with the small example found here:
test: proc options(main);
mumur3_32: proc(data, nbytes) returns(fixed unsigned bin(32));
dcl data pointer;
dcl nbytes fixed bin(31);
if (data = SYSNULL() | nbytes = 0) then
return (0);
dcl c1 unsigned fixed bin(32) init('cc9e2d51'XU);
dcl c2 unsigned fixed bin(32) init('1b873593'XU);
dcl nblocks fixed bin(31) init(ISRL(nbytes,2)); /* nbytes/4 */
dcl blocks(0:(nblocks-1)) unsigned fixed bin(32) based(data);
dcl tail(0:2) unsigned fixed bin(8) based(tailp);
dcl tailp pointer;
tailp = pointeradd(data, nbytes * 4);
dcl h unsigned fixed bin(32) init(0);
dcl i fixed bin(31);
dcl k unsigned fixed bin(32);
do i=0 to nblocks-1;
k = blocks(i);
k = k * c1;
k = ior(isll(k,15), isrl(k, 32-15));
k = k * c2;
h = ieor(h,k);
h = ior(isll(h,13), isrl(h, 32-13));
h = (h * 5) + 'e6546b64'xu;
end;
k = 0;
select( iand(nbytes, 3) );
when(3) do;
k = ieor(k, isll(tail(2), 16));
goto case_2;
end;
when(2) do;
case_2: ;
k = ieor(k, isll(tail(1), 8));
goto case_1;
end;
when(1) do;
case_1: ;
k = ieor(k, tail(0));
k = k * c1;
k = ieor( isll(k,15), isrl(k,32-15));
k = k * c2;
h = ieor(h, k);
end;
otherwise; /* do nothing */
end;
h = ieor(h, nbytes);
h = ieor(h, isrl(h,16));
h = h * '85ebca6b'xu;
h = ieor(h, isrl(h,13));
h = h * 'c2b2ae35'xu;
h = ieor(h, isrl(h,16));
return(h);
end;
dcl data char(28) init('Some string data to test out');
dcl val fixed bin(32) unsigned;
val = mumur3_32(addr(data), length(data));
put skip list('val is ', val);
end;
- Dave R. -
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