SDL_qsort.c: sync comments with version 1.15 from mainstream

This commit is contained in:
Ozkan Sezer 2019-10-31 17:10:02 +03:00
parent 88ba6798e9
commit fea3c8bdef

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@ -64,7 +64,7 @@ SDL_qsort(void *base, size_t nmemb, size_t size, int (*compare) (const void *, c
/*
This code came from Gareth McCaughan, under the zlib license.
Specifically this: https://www.mccaughan.org.uk/software/qsort.c-1.14
Specifically this: https://www.mccaughan.org.uk/software/qsort.c-1.15
Everything below this comment until the HAVE_QSORT #endif was from Gareth
(any minor changes will be noted inline).
@ -143,6 +143,10 @@ benefit!
* 2016-02-21 v1.14 Replace licence with 2-clause BSD,
* and clarify a couple of things in
* comments. No code changes.
* 2016-03-10 v1.15 Fix bug kindly reported by Ryan Gordon
* (pre-insertion-sort messed up).
* Disable DEBUG_QSORT by default.
* Tweak comments very slightly.
*/
/* BEGIN SDL CHANGE ... commented this out with an #if 0 block. --ryan. */
@ -151,9 +155,9 @@ benefit!
#include <stdlib.h>
#include <string.h>
#define DEBUG_QSORT
#undef DEBUG_QSORT
static char _ID[]="<qsort.c gjm 1.14 2016-02-21>";
static char _ID[]="<qsort.c gjm 1.15 2016-03-10>";
#endif
/* END SDL CHANGE ... commented this out with an #if 0 block. --ryan. */
@ -316,7 +320,9 @@ typedef struct { char * first; char * last; } stack_entry;
* We find the smallest element from the first |nmemb|,
* or the first |limit|, whichever is smaller;
* therefore we must have ensured that the globally smallest
* element is in the first |limit|.
* element is in the first |limit| (because our
* quicksort recursion bottoms out only once we
* reach subarrays smaller than |limit|).
*/
#define PreInsertion(swapper,limit,sz) \
first=base; \
@ -499,7 +505,7 @@ fprintf(stderr, "after partitioning first=#%lu last=#%lu\n", (first-(char*)base)
Recurse(TRUNC_words)
}
}
PreInsertion(SWAP_words,(TRUNC_words/WORD_BYTES),WORD_BYTES);
PreInsertion(SWAP_words,TRUNC_words/WORD_BYTES,WORD_BYTES);
/* Now do insertion sort. */
last=((char*)base)+nmemb*WORD_BYTES;
for (first=((char*)base)+WORD_BYTES;first!=last;first+=WORD_BYTES) {
@ -527,7 +533,6 @@ extern void qsortG(void *base, size_t nmemb, size_t size,
qsort_words(base,nmemb,compare);
}
#endif /* HAVE_QSORT */
/* vi: set ts=4 sw=4 expandtab: */