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Use memcmp() rather than strncmp() when shorter string length is known.

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It appears that this will be faster for all but the shortest strings;
at least one some platforms, memcmp() can use word-at-a-time comparisons.

Noah Misch, somewhat pared down.
This commit is contained in:
Robert Haas
2010-12-21 22:11:40 -05:00
parent c5160b7eec
commit 32ba2b5160
7 changed files with 33 additions and 33 deletions
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6
src/backend/utils/adt/varchar.c
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@ -690,7 +690,7 @@ bpchareq(PG_FUNCTION_ARGS)
if (len1 != len2)
result = false;
else
result = (strncmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), len1) == 0);
result = (memcmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), len1) == 0);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
@ -717,7 +717,7 @@ bpcharne(PG_FUNCTION_ARGS)
if (len1 != len2)
result = true;
else
result = (strncmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), len1) != 0);
result = (memcmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), len1) != 0);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
@ -905,7 +905,7 @@ internal_bpchar_pattern_compare(BpChar *arg1, BpChar *arg2)
len1 = bcTruelen(arg1);
len2 = bcTruelen(arg2);
result = strncmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), Min(len1, len2));
result = memcmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), Min(len1, len2));
if (result != 0)
return result;
else if (len1 < len2)