SDL  2.0
SDL_qsort.c File Reference
#include "../SDL_internal.h"
#include "SDL_stdinc.h"
#include "SDL_assert.h"
+ Include dependency graph for SDL_qsort.c:

Go to the source code of this file.

Data Structures

struct  stack_entry
 

Macros

#define assert   SDL_assert
 
#define malloc   SDL_malloc
 
#define free   SDL_free
 
#define memcpy   SDL_memcpy
 
#define memmove   SDL_memmove
 
#define qsortG   SDL_qsort
 
#define WORD_BYTES   sizeof(int)
 
#define STACK_SIZE   (8*sizeof(size_t))
 
#define TRUNC_nonaligned   12
 
#define TRUNC_aligned   12
 
#define TRUNC_words   12*WORD_BYTES /* nb different meaning */
 
#define PIVOT_THRESHOLD   40
 
#define pushLeft   {stack[stacktop].first=ffirst;stack[stacktop++].last=last;}
 
#define pushRight   {stack[stacktop].first=first;stack[stacktop++].last=llast;}
 
#define doLeft   {first=ffirst;llast=last;continue;}
 
#define doRight   {ffirst=first;last=llast;continue;}
 
#define pop
 
#define Recurse(Trunc)
 
#define Pivot(swapper, sz)
 
#define Partition(swapper, sz)
 
#define PreInsertion(swapper, limit, sz)
 
#define Insertion(swapper)
 
#define SWAP_nonaligned(a, b)
 
#define SWAP_aligned(a, b)
 
#define SWAP_words(a, b)
 

Functions

static char * pivot_big (char *first, char *mid, char *last, size_t size, int compare(const void *, const void *))
 
static void qsort_nonaligned (void *base, size_t nmemb, size_t size, int(*compare)(const void *, const void *))
 
static void qsort_aligned (void *base, size_t nmemb, size_t size, int(*compare)(const void *, const void *))
 
static void qsort_words (void *base, size_t nmemb, int(*compare)(const void *, const void *))
 
void qsortG (void *base, size_t nmemb, size_t size, int(*compare)(const void *, const void *))
 

Macro Definition Documentation

◆ assert

#define assert   SDL_assert

Definition at line 43 of file SDL_qsort.c.

◆ doLeft

#define doLeft   {first=ffirst;llast=last;continue;}

Definition at line 190 of file SDL_qsort.c.

◆ doRight

#define doRight   {ffirst=first;last=llast;continue;}

Definition at line 191 of file SDL_qsort.c.

◆ free

#define free   SDL_free

Definition at line 51 of file SDL_qsort.c.

◆ Insertion

#define Insertion (   swapper)
Value:
last=((char*)base)+nmemb*size; \
for (first=((char*)base)+size;first!=last;first+=size) { \
char *test; \
/* Find the right place for |first|. \
* My apologies for var reuse. */ \
for (test=first-size;compare(test,first)>0;test-=size) ; \
test+=size; \
if (test!=first) { \
/* Shift everything in [test,first) \
* up by one, and place |first| \
* where |test| is. */ \
memcpy(pivot,first,size); \
memmove(test+size,test,first-test); \
memcpy(test,pivot,size); \
} \
}

Definition at line 330 of file SDL_qsort.c.

◆ malloc

#define malloc   SDL_malloc

Definition at line 47 of file SDL_qsort.c.

◆ memcpy

#define memcpy   SDL_memcpy

Definition at line 55 of file SDL_qsort.c.

◆ memmove

#define memmove   SDL_memmove

Definition at line 59 of file SDL_qsort.c.

◆ Partition

#define Partition (   swapper,
  sz 
)
Value:
{ \
do { \
while (compare(first,pivot)<0) first+=sz; \
while (compare(pivot,last)<0) last-=sz; \
if (first<last) { \
swapper(first,last); \
first+=sz; last-=sz; } \
else if (first==last) { first+=sz; last-=sz; break; }\
} while (first<=last); \
}

Definition at line 301 of file SDL_qsort.c.

◆ Pivot

#define Pivot (   swapper,
  sz 
)
Value:
if ((size_t)(last-first)>PIVOT_THRESHOLD*sz) mid=pivot_big(first,mid,last,sz,compare);\
else { \
if (compare(first,mid)<0) { \
if (compare(mid,last)>0) { \
swapper(mid,last); \
if (compare(first,mid)>0) swapper(first,mid);\
} \
} \
else { \
if (compare(mid,last)>0) swapper(first,last)\
else { \
swapper(first,mid); \
if (compare(mid,last)>0) swapper(mid,last);\
} \
} \
first+=sz; last-=sz; \
}

Definition at line 277 of file SDL_qsort.c.

◆ PIVOT_THRESHOLD

#define PIVOT_THRESHOLD   40

Definition at line 185 of file SDL_qsort.c.

◆ pop

#define pop
Value:
{if (--stacktop<0) break;\
first=ffirst=stack[stacktop].first;\
last=llast=stack[stacktop].last;\
continue;}

Definition at line 192 of file SDL_qsort.c.

◆ PreInsertion

#define PreInsertion (   swapper,
  limit,
  sz 
)
Value:
first=base; \
last=first + ((nmemb>limit ? limit : nmemb)-1)*sz;\
while (last!=base) { \
if (compare(first,last)>0) first=last; \
last-=sz; } \
if (first!=base) swapper(first,(char*)base);

Definition at line 321 of file SDL_qsort.c.

◆ pushLeft

#define pushLeft   {stack[stacktop].first=ffirst;stack[stacktop++].last=last;}

Definition at line 188 of file SDL_qsort.c.

◆ pushRight

#define pushRight   {stack[stacktop].first=first;stack[stacktop++].last=llast;}

Definition at line 189 of file SDL_qsort.c.

◆ qsortG

#define qsortG   SDL_qsort

Definition at line 63 of file SDL_qsort.c.

◆ Recurse

#define Recurse (   Trunc)
Value:
{ size_t l=last-ffirst,r=llast-first; \
if (l<Trunc) { \
if (r>=Trunc) doRight \
else pop \
} \
else if (l<=r) { pushLeft; doRight } \
else if (r>=Trunc) { pushRight; doLeft }\
else doLeft \
}

Definition at line 265 of file SDL_qsort.c.

◆ STACK_SIZE

#define STACK_SIZE   (8*sizeof(size_t))

Definition at line 168 of file SDL_qsort.c.

◆ SWAP_aligned

#define SWAP_aligned (   a,
  b 
)
Value:
{ \
register int *aa=(int*)(a),*bb=(int*)(b); \
register size_t sz=size; \
do { register int t=*aa;*aa++=*bb; *bb++=t; } while (sz-=WORD_BYTES); }

Definition at line 350 of file SDL_qsort.c.

◆ SWAP_nonaligned

#define SWAP_nonaligned (   a,
  b 
)
Value:
{ \
register char *aa=(a),*bb=(b); \
register size_t sz=size; \
do { register char t=*aa; *aa++=*bb; *bb++=t; } while (--sz); }

Definition at line 345 of file SDL_qsort.c.

◆ SWAP_words

#define SWAP_words (   a,
  b 
)
Value:
{ \
register int t=*((int*)a); *((int*)a)=*((int*)b); *((int*)b)=t; }

Definition at line 355 of file SDL_qsort.c.

◆ TRUNC_aligned

#define TRUNC_aligned   12

Definition at line 178 of file SDL_qsort.c.

◆ TRUNC_nonaligned

#define TRUNC_nonaligned   12

Definition at line 177 of file SDL_qsort.c.

◆ TRUNC_words

#define TRUNC_words   12*WORD_BYTES /* nb different meaning */

Definition at line 179 of file SDL_qsort.c.

◆ WORD_BYTES

#define WORD_BYTES   sizeof(int)

Definition at line 163 of file SDL_qsort.c.

Function Documentation

◆ pivot_big()

static char* pivot_big ( char *  first,
char *  mid,
char *  last,
size_t  size,
int   compareconst void *, const void * 
)
static

Definition at line 360 of file SDL_qsort.c.

364  {
365  size_t d=(((last-first)/size)>>3)*size;
366 #ifdef DEBUG_QSORT
367 fprintf(stderr, "pivot_big: first=%p last=%p size=%lu n=%lu\n", first, (unsigned long)last, size, (unsigned long)((last-first+1)/size));
368 #endif
369  char *m1,*m2,*m3;
370  { char *a=first, *b=first+d, *c=first+2*d;
371 #ifdef DEBUG_QSORT
372 fprintf(stderr,"< %d %d %d @ %p %p %p\n",*(int*)a,*(int*)b,*(int*)c, a,b,c);
373 #endif
374  m1 = compare(a,b)<0 ?
375  (compare(b,c)<0 ? b : (compare(a,c)<0 ? c : a))
376  : (compare(a,c)<0 ? a : (compare(b,c)<0 ? c : b));
377  }
378  { char *a=mid-d, *b=mid, *c=mid+d;
379 #ifdef DEBUG_QSORT
380 fprintf(stderr,". %d %d %d @ %p %p %p\n",*(int*)a,*(int*)b,*(int*)c, a,b,c);
381 #endif
382  m2 = compare(a,b)<0 ?
383  (compare(b,c)<0 ? b : (compare(a,c)<0 ? c : a))
384  : (compare(a,c)<0 ? a : (compare(b,c)<0 ? c : b));
385  }
386  { char *a=last-2*d, *b=last-d, *c=last;
387 #ifdef DEBUG_QSORT
388 fprintf(stderr,"> %d %d %d @ %p %p %p\n",*(int*)a,*(int*)b,*(int*)c, a,b,c);
389 #endif
390  m3 = compare(a,b)<0 ?
391  (compare(b,c)<0 ? b : (compare(a,c)<0 ? c : a))
392  : (compare(a,c)<0 ? a : (compare(b,c)<0 ? c : b));
393  }
394 #ifdef DEBUG_QSORT
395 fprintf(stderr,"-> %d %d %d @ %p %p %p\n",*(int*)m1,*(int*)m2,*(int*)m3, m1,m2,m3);
396 #endif
397  return compare(m1,m2)<0 ?

References d.

◆ qsort_aligned()

static void qsort_aligned ( void base,
size_t  nmemb,
size_t  size,
int(*)(const void *, const void *)  compare 
)
static

Definition at line 432 of file SDL_qsort.c.

436  {
437 
438  stack_entry stack[STACK_SIZE];
439  int stacktop=0;
440  char *first,*last;
441  char *pivot=malloc(size);
442  size_t trunc=TRUNC_aligned*size;
443  assert(pivot!=0);
444 
445  first=(char*)base; last=first+(nmemb-1)*size;
446 
447  if ((size_t)(last-first)>=trunc) {
448  char *ffirst=first,*llast=last;
449  while (1) {
450  /* Select pivot */
451  { char * mid=first+size*((last-first)/size >> 1);
453  memcpy(pivot,mid,size);
454  }
455  /* Partition. */
457  /* Prepare to recurse/iterate. */
458  Recurse(trunc)
459  }
460  }

Referenced by qsortG().

◆ qsort_nonaligned()

static void qsort_nonaligned ( void base,
size_t  nmemb,
size_t  size,
int(*)(const void *, const void *)  compare 
)
static

Definition at line 401 of file SDL_qsort.c.

405  {
406 
407  stack_entry stack[STACK_SIZE];
408  int stacktop=0;
409  char *first,*last;
410  char *pivot=malloc(size);
411  size_t trunc=TRUNC_nonaligned*size;
412  assert(pivot!=0);
413 
414  first=(char*)base; last=first+(nmemb-1)*size;
415 
416  if ((size_t)(last-first)>=trunc) {
417  char *ffirst=first, *llast=last;
418  while (1) {
419  /* Select pivot */
420  { char * mid=first+size*((last-first)/size >> 1);
422  memcpy(pivot,mid,size);
423  }
424  /* Partition. */
426  /* Prepare to recurse/iterate. */
427  Recurse(trunc)
428  }
429  }

References assert, Insertion, malloc, memcpy, Partition, Pivot, PreInsertion, Recurse, STACK_SIZE, SWAP_nonaligned, and TRUNC_nonaligned.

Referenced by qsortG().

◆ qsort_words()

static void qsort_words ( void base,
size_t  nmemb,
int(*)(const void *, const void *)  compare 
)
static

Definition at line 463 of file SDL_qsort.c.

467  {
468 
469  stack_entry stack[STACK_SIZE];
470  int stacktop=0;
471  char *first,*last;
472  char *pivot=malloc(WORD_BYTES);
473  assert(pivot!=0);
474 
475  first=(char*)base; last=first+(nmemb-1)*WORD_BYTES;
476 
477  if (last-first>=TRUNC_words) {
478  char *ffirst=first, *llast=last;
479  while (1) {
480 #ifdef DEBUG_QSORT
481 fprintf(stderr,"Doing %d:%d: ",
482  (first-(char*)base)/WORD_BYTES,
483  (last-(char*)base)/WORD_BYTES);
484 #endif
485  /* Select pivot */
486  { char * mid=first+WORD_BYTES*((last-first) / (2*WORD_BYTES));
488  *(int*)pivot=*(int*)mid;
489 #ifdef DEBUG_QSORT
490 fprintf(stderr,"pivot = %p = #%lu = %d\n", mid, (unsigned long)(((int*)mid)-((int*)base)), *(int*)mid);
491 #endif
492  }
493  /* Partition. */
495 #ifdef DEBUG_QSORT
496 fprintf(stderr, "after partitioning first=#%lu last=#%lu\n", (first-(char*)base)/4lu, (last-(char*)base)/4lu);
497 #endif
498  /* Prepare to recurse/iterate. */
500  }
501  }
503  /* Now do insertion sort. */
504  last=((char*)base)+nmemb*WORD_BYTES;
505  for (first=((char*)base)+WORD_BYTES;first!=last;first+=WORD_BYTES) {
506  /* Find the right place for |first|. My apologies for var reuse */
507  int *pl=(int*)(first-WORD_BYTES),*pr=(int*)first;
508  *(int*)pivot=*(int*)first;
509  for (;compare(pl,pivot)>0;pr=pl,--pl) {
510  *pr=*pl; }
511  if (pr!=(int*)first) *pr=*(int*)pivot;

Referenced by qsortG().

◆ qsortG()

void qsortG ( void base,
size_t  nmemb,
size_t  size,
int(*)(const void *, const void *)  compare 
)

Definition at line 515 of file SDL_qsort.c.

519  {
520 
521  if (nmemb<=1) return;
522  if (((size_t)base|size)&(WORD_BYTES-1))
523  qsort_nonaligned(base,nmemb,size,compare);
524  else if (size!=WORD_BYTES)
525  qsort_aligned(base,nmemb,size,compare);

References qsort_aligned(), qsort_nonaligned(), qsort_words(), and WORD_BYTES.

malloc
#define malloc
Definition: SDL_qsort.c:47
SWAP_aligned
#define SWAP_aligned(a, b)
Definition: SDL_qsort.c:350
qsort_aligned
static void qsort_aligned(void *base, size_t nmemb, size_t size, int(*compare)(const void *, const void *))
Definition: SDL_qsort.c:432
c
const GLubyte * c
Definition: SDL_opengl_glext.h:11093
WORD_BYTES
#define WORD_BYTES
Definition: SDL_qsort.c:163
PreInsertion
#define PreInsertion(swapper, limit, sz)
Definition: SDL_qsort.c:321
memcpy
#define memcpy
Definition: SDL_qsort.c:55
limit
GLint limit
Definition: SDL_opengl_glext.h:8766
pushRight
#define pushRight
Definition: SDL_qsort.c:189
b
GLboolean GLboolean GLboolean b
Definition: SDL_opengl_glext.h:1109
TRUNC_aligned
#define TRUNC_aligned
Definition: SDL_qsort.c:178
r
GLdouble GLdouble GLdouble r
Definition: SDL_opengl.h:2079
Pivot
#define Pivot(swapper, sz)
Definition: SDL_qsort.c:277
a
GLboolean GLboolean GLboolean GLboolean a
Definition: SDL_opengl_glext.h:1109
STACK_SIZE
#define STACK_SIZE
Definition: SDL_qsort.c:168
pivot_big
static char * pivot_big(char *first, char *mid, char *last, size_t size, int compare(const void *, const void *))
Definition: SDL_qsort.c:360
stack_entry
Definition: SDL_qsort.c:187
SWAP_words
#define SWAP_words(a, b)
Definition: SDL_qsort.c:355
qsort_nonaligned
static void qsort_nonaligned(void *base, size_t nmemb, size_t size, int(*compare)(const void *, const void *))
Definition: SDL_qsort.c:401
TRUNC_nonaligned
#define TRUNC_nonaligned
Definition: SDL_qsort.c:177
t
GLdouble GLdouble t
Definition: SDL_opengl.h:2071
doRight
#define doRight
Definition: SDL_qsort.c:191
Recurse
#define Recurse(Trunc)
Definition: SDL_qsort.c:265
pop
#define pop
Definition: SDL_qsort.c:192
SWAP_nonaligned
#define SWAP_nonaligned(a, b)
Definition: SDL_qsort.c:345
size
GLsizeiptr size
Definition: SDL_opengl_glext.h:537
first
const GLint * first
Definition: SDL_opengl_glext.h:368
doLeft
#define doLeft
Definition: SDL_qsort.c:190
TRUNC_words
#define TRUNC_words
Definition: SDL_qsort.c:179
PIVOT_THRESHOLD
#define PIVOT_THRESHOLD
Definition: SDL_qsort.c:185
pushLeft
#define pushLeft
Definition: SDL_qsort.c:188
Partition
#define Partition(swapper, sz)
Definition: SDL_qsort.c:301
assert
#define assert
Definition: SDL_qsort.c:43
d
const SDL_PRINTF_FORMAT_STRING char int const SDL_PRINTF_FORMAT_STRING char int const SDL_PRINTF_FORMAT_STRING char int const SDL_PRINTF_FORMAT_STRING char const char const SDL_SCANF_FORMAT_STRING char return SDL_ThreadFunction const char void return Uint32 return Uint32 SDL_AssertionHandler void SDL_SpinLock SDL_atomic_t int int return SDL_atomic_t return void void void return void return int return SDL_AudioSpec SDL_AudioSpec return int int return return int SDL_RWops int SDL_AudioSpec Uint8 ** d
Definition: SDL_dynapi_procs.h:117