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Update and use internal qsort everywhere

This commit is contained in:
Ebrahim Byagowi 2019-06-07 12:58:09 +04:30 committed by Behdad Esfahbod
parent 5074d665a8
commit eff579f743
3 changed files with 158 additions and 60 deletions
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204
src/hb-algs.hh
View File

@ -653,115 +653,213 @@ hb_bsearch (const void *key, const void *base,
/* From https://github.com/noporpoise/sort_r
* With following modifications:
*
* 10 November 2018:
* https://github.com/noporpoise/sort_r/issues/7
*/
Feb 5, 2019 (c8c65c1e)
Modified to support optional argument using templates */
/* Isaac Turner 29 April 2014 Public Domain */
/*
hb_sort_r function to be exported.
hb_qsort function to be exported.
Parameters:
base is the array to be sorted
nel is the number of elements in the array
width is the size in bytes of each element of the array
compar is the comparison function
arg is a pointer to be passed to the comparison function
arg (optional) is a pointer to be passed to the comparison function
void hb_sort_r(void *base, size_t nel, size_t width,
int (*compar)(const void *_a, const void *_b, void *_arg),
void *arg);
void hb_sort(void *base, size_t nel, size_t width,
int (*compar)(const void *_a, const void *_b, [void *_arg]),
[void *arg]);
*/
#define SORT_R_SWAP(a,b,tmp) ((tmp) = (a), (a) = (b), (b) = (tmp))
/* swap a, b iff a>b */
/* __restrict is same as restrict but better support on old machines */
static int sort_r_cmpswap(char *__restrict a, char *__restrict b, size_t w,
int (*compar)(const void *_a, const void *_b,
void *_arg),
void *arg)
/* swap a and b */
/* a and b must not be equal! */
static inline void sort_r_swap(char *__restrict a, char *__restrict b,
size_t w)
{
char tmp, *end = a+w;
if(compar(a, b, arg) > 0) {
for(; a < end; a++, b++) { tmp = *a; *a = *b; *b = tmp; }
for(; a < end; a++, b++) { SORT_R_SWAP(*a, *b, tmp); }
}
/* swap a, b iff a>b */
/* a and b must not be equal! */
/* __restrict is same as restrict but better support on old machines */
template <typename ...Ts>
static inline int sort_r_cmpswap(char *__restrict a,
char *__restrict b, size_t w,
int (*compar)(const void *_a,
const void *_b,
Ts... _ds),
Ts... ds)
{
if(compar(a, b, ds...) > 0) {
sort_r_swap(a, b, w);
return 1;
}
return 0;
}
/*
Swap consecutive blocks of bytes of size na and nb starting at memory addr ptr,
with the smallest swap so that the blocks are in the opposite order. Blocks may
be internally re-ordered e.g.
12345ab -> ab34512
123abc -> abc123
12abcde -> deabc12
*/
static inline void sort_r_swap_blocks(char *ptr, size_t na, size_t nb)
{
if(na > 0 && nb > 0) {
if(na > nb) { sort_r_swap(ptr, ptr+na, nb); }
else { sort_r_swap(ptr, ptr+nb, na); }
}
}
/* Implement recursive quicksort ourselves */
/* Note: quicksort is not stable, equivalent values may be swapped */
template <typename ...Ts>
static inline void sort_r_simple(void *base, size_t nel, size_t w,
int (*compar)(const void *_a, const void *_b,
void *_arg),
void *arg)
int (*compar)(const void *_a,
const void *_b,
Ts... _ds),
Ts... ds)
{
char *b = (char *)base, *end = b + nel*w;
if(nel < 7) {
/* for(size_t i=0; i<nel; i++) {printf("%4i", *(int*)(b + i*sizeof(int)));}
printf("\n"); */
if(nel < 10) {
/* Insertion sort for arbitrarily small inputs */
char *pi, *pj;
for(pi = b+w; pi < end; pi += w) {
for(pj = pi; pj > b && sort_r_cmpswap(pj-w,pj,w,compar,arg); pj -= w) {}
for(pj = pi; pj > b && sort_r_cmpswap(pj-w,pj,w,compar,ds...); pj -= w) {}
}
}
else
{
/* nel > 6; Quicksort */
/* nel > 9; Quicksort */
/* Use median of first, middle and last items as pivot */
char *x, *y, *xend, ch;
char *pl, *pm, *pr;
int cmp;
char *pl, *ple, *pr, *pre, *pivot;
char *last = b+w*(nel-1), *tmp;
/*
Use median of second, middle and second-last items as pivot.
First and last may have been swapped with pivot and therefore be extreme
*/
char *l[3];
l[0] = b;
l[0] = b + w;
l[1] = b+w*(nel/2);
l[2] = last;
l[2] = last - w;
if(compar(l[0],l[1],arg) > 0) { tmp=l[0]; l[0]=l[1]; l[1]=tmp; }
if(compar(l[1],l[2],arg) > 0) {
tmp=l[1]; l[1]=l[2]; l[2]=tmp; /* swap(l[1],l[2]) */
if(compar(l[0],l[1],arg) > 0) { tmp=l[0]; l[0]=l[1]; l[1]=tmp; }
/* printf("pivots: %i, %i, %i\n", *(int*)l[0], *(int*)l[1], *(int*)l[2]); */
if(compar(l[0],l[1],ds...) > 0) { SORT_R_SWAP(l[0], l[1], tmp); }
if(compar(l[1],l[2],ds...) > 0) {
SORT_R_SWAP(l[1], l[2], tmp);
if(compar(l[0],l[1],ds...) > 0) { SORT_R_SWAP(l[0], l[1], tmp); }
}
/* swap l[id], l[2] to put pivot as last element */
for(x = l[1], y = last, xend = x+w; x<xend; x++, y++) {
ch = *x; *x = *y; *y = ch;
}
/* swap mid value (l[1]), and last element to put pivot as last element */
if(l[1] != last) { sort_r_swap(l[1], last, w); }
pl = b;
pr = last;
/*
pl is the next item on the left to be compared to the pivot
pr is the last item on the right that was compared to the pivot
ple is the left position to put the next item that equals the pivot
ple is the last right position where we put an item that equals the pivot
v- end (beyond the array)
EEEEEELLLLLLLLuuuuuuuuGGGGGGGEEEEEEEE.
^- b ^- ple ^- pl ^- pr ^- pre ^- last (where the pivot is)
Pivot comparison key:
E = equal, L = less than, u = unknown, G = greater than, E = equal
*/
pivot = last;
ple = pl = b;
pre = pr = last;
/*
Strategy:
Loop into the list from the left and right at the same time to find:
- an item on the left that is greater than the pivot
- an item on the right that is less than the pivot
Once found, they are swapped and the loop continues.
Meanwhile items that are equal to the pivot are moved to the edges of the
array.
*/
while(pl < pr) {
pm = pl+((pr-pl+1)>>1);
for(; pl < pm; pl += w) {
if(sort_r_cmpswap(pl, pr, w, compar, arg)) {
pr -= w; /* pivot now at pl */
break;
/* Move left hand items which are equal to the pivot to the far left.
break when we find an item that is greater than the pivot */
for(; pl < pr; pl += w) {
cmp = compar(pl, pivot, ds...);
if(cmp > 0) { break; }
else if(cmp == 0) {
if(ple < pl) { sort_r_swap(ple, pl, w); }
ple += w;
}
}
pm = pl+((pr-pl)>>1);
for(; pm < pr; pr -= w) {
if(sort_r_cmpswap(pl, pr, w, compar, arg)) {
pl += w; /* pivot now at pr */
/* break if last batch of left hand items were equal to pivot */
if(pl >= pr) { break; }
/* Move right hand items which are equal to the pivot to the far right.
break when we find an item that is less than the pivot */
for(; pl < pr; ) {
pr -= w; /* Move right pointer onto an unprocessed item */
cmp = compar(pr, pivot, ds...);
if(cmp == 0) {
pre -= w;
if(pr < pre) { sort_r_swap(pr, pre, w); }
}
else if(cmp < 0) {
if(pl < pr) { sort_r_swap(pl, pr, w); }
pl += w;
break;
}
}
}
sort_r_simple(b, (pl-b)/w, w, compar, arg);
sort_r_simple(pl+w, (end-(pl+w))/w, w, compar, arg);
pl = pr; /* pr may have gone below pl */
/*
Now we need to go from: EEELLLGGGGEEEE
to: LLLEEEEEEEGGGG
Pivot comparison key:
E = equal, L = less than, u = unknown, G = greater than, E = equal
*/
sort_r_swap_blocks(b, ple-b, pl-ple);
sort_r_swap_blocks(pr, pre-pr, end-pre);
/*for(size_t i=0; i<nel; i++) {printf("%4i", *(int*)(b + i*sizeof(int)));}
printf("\n");*/
sort_r_simple(b, (pl-ple)/w, w, compar, ds...);
sort_r_simple(end-(pre-pr), (pre-pr)/w, w, compar, ds...);
}
}
static inline void
hb_sort_r (void *base, size_t nel, size_t width,
hb_qsort (void *base, size_t nel, size_t width,
int (*compar)(const void *_a, const void *_b))
{
#ifdef __OPTIMIZE_SIZE__
qsort (base, nel, width, compar);
#else
sort_r_simple (base, nel, width, compar);
#endif
}
static inline void
hb_qsort (void *base, size_t nel, size_t width,
int (*compar)(const void *_a, const void *_b, void *_arg),
void *arg)
{
#ifdef HAVE_GNU_QSORT_R
qsort_r (base, nel, width, compar, arg);
#else
sort_r_simple (base, nel, width, compar, arg);
#endif
}

6
src/hb-array.hh
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@ -141,13 +141,13 @@ struct hb_array_t : hb_iter_with_fallback_t<hb_array_t<Type>, Type&>
hb_sorted_array_t<Type> qsort (int (*cmp_)(const void*, const void*))
{
if (likely (length))
::qsort (arrayZ, length, this->item_size, cmp_);
hb_qsort (arrayZ, length, this->item_size, cmp_);
return hb_sorted_array_t<Type> (*this);
}
hb_sorted_array_t<Type> qsort ()
{
if (likely (length))
::qsort (arrayZ, length, this->item_size, Type::cmp);
hb_qsort (arrayZ, length, this->item_size, Type::cmp);
return hb_sorted_array_t<Type> (*this);
}
void qsort (unsigned int start, unsigned int end)
@ -155,7 +155,7 @@ struct hb_array_t : hb_iter_with_fallback_t<hb_array_t<Type>, Type&>
end = hb_min (end, length);
assert (start <= end);
if (likely (start < end))
::qsort (arrayZ + start, end - start, this->item_size, Type::cmp);
hb_qsort (arrayZ + start, end - start, this->item_size, Type::cmp);
}
/*

2
src/hb-ot-post-table.hh
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@ -157,7 +157,7 @@ struct post
for (unsigned int i = 0; i < count; i++)
gids[i] = i;
hb_sort_r (gids, count, sizeof (gids[0]), cmp_gids, (void *) this);
hb_qsort (gids, count, sizeof (gids[0]), cmp_gids, (void *) this);
if (unlikely (!gids_sorted_by_name.cmpexch (nullptr, gids)))
{