8000 ENH: optimize STRING_compare by using memcmp by juliantaylor · Pull Request #4572 · numpy/numpy · GitHub
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ENH: optimize STRING_compare by using memcmp #4572

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Sep 2, 2014
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ENH: optimize STRING_compare by using memcmp #4572

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ENH: optimize STRING_compare by using memcmp
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@juliantaylor
juliantaylor committed May 22, 2014
commit 2f6da63938e516bb653b95f1de7b59b33c05a2fc
13 changes: 8 additions & 5 deletions numpy/core/src/multiarray/arraytypes.c.src
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Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,7 @@
#include "arrayobject.h"

#include "numpyos.h"
#include <string.h>


/*
Expand Down Expand Up @@ -2598,12 +2599,14 @@ STRING_compare(char *ip1, char *ip2, PyArrayObject *ap)
const unsigned char *c1 = (unsigned char *)ip1;
const unsigned char *c2 = (unsigned char *)ip2;
const size_t len = PyArray_DESCR(ap)->elsize;
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Looks good to me, I think it is correct that we compare all bytes, since only trailing 0-bytes are stripped (as\x00d\x00\x00 is 'as\x00d). Probably doesn't matter, butelsize` actually is int I think

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Oh, heh, in my mind I combined the old and new usage of i, so nvm.

size_t i;
int i;

for(i = 0; i < len; ++i) {
if (c1[i] != c2[i]) {
return (c1[i] > c2[i]) ? 1 : -1;
}
i = memcmp(c1, c2, len);
if (i > 0) {
return 1;
}
else if (i < 0) {
return -1;
}
return 0;
}
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0