*
* sort_template.h
*
* A template for a sort algorithm that supports varying degrees of
* specialization.
*
* Portions Copyright (c) 2020 Huawei Technologies Co.,Ltd.
* Portions Copyright (c) 2021, PostgreSQL Global Development Group
* Portions Copyright (c) 1992-1994, Regents of the University of California
* Portions Copyright (c) 2021, openGauss Contributors
*
* IDENTIFICATION
* src/include/lib/sort_template.h
*
*-------------------------------------------------------------------------
*/
#define ST_MAKE_PREFIX(a) CppConcat(a,_)
#define ST_MAKE_NAME(a,b) ST_MAKE_NAME_(ST_MAKE_PREFIX(a),b)
#define ST_MAKE_NAME_(a,b) CppConcat(a,b)
#ifdef ST_ELEMENT_TYPE_VOID
#define ST_ELEMENT_TYPE void
#define ST_SORT_PROTO_ELEMENT_SIZE , size_t element_size
#define ST_SORT_INVOKE_ELEMENT_SIZE , element_size
#else
#define ST_SORT_PROTO_ELEMENT_SIZE
#define ST_SORT_INVOKE_ELEMENT_SIZE
#endif
#ifdef ST_COMPARE_RUNTIME_POINTER
#ifndef ST_COMPARATOR_TYPE_NAME
#define ST_COMPARATOR_TYPE_NAME ST_MAKE_NAME(ST_SORT, compare_function)
#endif
#define ST_COMPARE compare
#ifndef ST_COMPARE_ARG_TYPE
#define ST_SORT_PROTO_COMPARE , ST_COMPARATOR_TYPE_NAME compare
#define ST_SORT_INVOKE_COMPARE , compare
#else
#define ST_SORT_PROTO_COMPARE , ST_COMPARATOR_TYPE_NAME compare
#define ST_SORT_INVOKE_COMPARE , compare
#endif
#else
#define ST_SORT_PROTO_COMPARE
#define ST_SORT_INVOKE_COMPARE
#endif
#ifdef ST_COMPARE_ARG_TYPE
#define ST_SORT_PROTO_ARG , ST_COMPARE_ARG_TYPE *arg
#define ST_SORT_INVOKE_ARG , arg
#else
#define ST_SORT_PROTO_ARG
#define ST_SORT_INVOKE_ARG
#endif
#ifdef ST_DECLARE
#ifdef ST_COMPARE_RUNTIME_POINTER
typedef int (*ST_COMPARATOR_TYPE_NAME) (const ST_ELEMENT_TYPE *,
const ST_ELEMENT_TYPE *ST_SORT_PROTO_ARG);
#endif
ST_SCOPE void ST_SORT(ST_ELEMENT_TYPE *first, size_t n
ST_SORT_PROTO_ELEMENT_SIZE
ST_SORT_PROTO_COMPARE
ST_SORT_PROTO_ARG);
#endif
#ifdef ST_DEFINE
#define ST_MED3 ST_MAKE_NAME(ST_SORT, med3)
#define ST_SWAP ST_MAKE_NAME(ST_SORT, swap)
#define ST_SWAPN ST_MAKE_NAME(ST_SORT, swapn)
#ifdef ST_CHECK_FOR_INTERRUPTS
#define DO_CHECK_FOR_INTERRUPTS() CHECK_FOR_INTERRUPTS()
#else
#define DO_CHECK_FOR_INTERRUPTS()
#endif
#ifdef ST_COMPARE_RUNTIME_POINTER
#define DO_COMPARE(a_, b_) ST_COMPARE((a_), (b_) ST_SORT_INVOKE_ARG)
#elif defined(ST_COMPARE_ARG_TYPE)
#define DO_COMPARE(a_, b_) ST_COMPARE((a_), (b_), arg)
#else
#define DO_COMPARE(a_, b_) ST_COMPARE((a_), (b_))
#endif
#define DO_MED3(a_, b_, c_) \
(ST_POINTER_TYPE *)ST_MED3((a_), (b_), (c_) \
ST_SORT_INVOKE_COMPARE \
ST_SORT_INVOKE_ARG)
#define DO_SORT(a_, n_) \
ST_SORT((a_), (n_) \
ST_SORT_INVOKE_ELEMENT_SIZE \
ST_SORT_INVOKE_COMPARE \
ST_SORT_INVOKE_ARG)
#ifndef ST_ELEMENT_TYPE_VOID
#define ST_POINTER_TYPE ST_ELEMENT_TYPE
#define ST_POINTER_STEP (unsigned int)1
#define DO_SWAPN(a_, b_, n_) ST_SWAPN((a_), (b_), (n_))
#define DO_SWAP(a_, b_) ST_SWAP((a_), (b_))
#else
#define ST_POINTER_TYPE uint8
#define ST_POINTER_STEP (unsigned int)element_size
#define DO_SWAPN(a_, b_, n_) ST_SWAPN((a_), (b_), (n_))
#define DO_SWAP(a_, b_) DO_SWAPN((a_), (b_), element_size)
#endif
static pg_noinline ST_ELEMENT_TYPE *
ST_MED3(ST_ELEMENT_TYPE *a,
ST_ELEMENT_TYPE *b,
ST_ELEMENT_TYPE *c
ST_SORT_PROTO_COMPARE
ST_SORT_PROTO_ARG)
{
return DO_COMPARE(a, b) < 0 ?
(DO_COMPARE(b, c) < 0 ? b : (DO_COMPARE(a, c) < 0 ? c : a))
: (DO_COMPARE(b, c) > 0 ? b : (DO_COMPARE(a, c) < 0 ? a : c));
}
static inline void
ST_SWAP(ST_POINTER_TYPE *a, ST_POINTER_TYPE *b)
{
ST_POINTER_TYPE tmp = *a;
*a = *b;
*b = tmp;
}
static inline void
ST_SWAPN(ST_POINTER_TYPE *a, ST_POINTER_TYPE *b, size_t n)
{
for (size_t i = 0; i < n; ++i)
ST_SWAP(&a[i], &b[i]);
}
ST_SCOPE void
ST_SORT(ST_ELEMENT_TYPE *data, size_t n
ST_SORT_PROTO_ELEMENT_SIZE
ST_SORT_PROTO_COMPARE
ST_SORT_PROTO_ARG)
{
ST_POINTER_TYPE *a = (ST_POINTER_TYPE *) data,
*pa,
*pb,
*pc,
*pd,
*pl,
*pm,
*pn;
size_t d1,
d2;
int r,
presorted;
loop:
DO_CHECK_FOR_INTERRUPTS();
if (n < 7)
{
for (pm = a + ST_POINTER_STEP; pm < a + n * ST_POINTER_STEP;
pm += ST_POINTER_STEP)
for (pl = pm; pl > a && DO_COMPARE(pl - ST_POINTER_STEP, pl) > 0;
pl -= ST_POINTER_STEP)
DO_SWAP(pl, pl - ST_POINTER_STEP);
return;
}
presorted = 1;
for (pm = a + ST_POINTER_STEP; pm < a + n * ST_POINTER_STEP;
pm += ST_POINTER_STEP)
{
DO_CHECK_FOR_INTERRUPTS();
if (DO_COMPARE(pm - ST_POINTER_STEP, pm) > 0)
{
presorted = 0;
break;
}
}
if (presorted)
return;
pm = a + (n / 2) * ST_POINTER_STEP;
if (n > 7)
{
pl = a;
pn = a + (n - 1) * ST_POINTER_STEP;
if (n > 40)
{
size_t d = (n / 8) * ST_POINTER_STEP;
pl = DO_MED3(pl, pl + d, pl + 2 * d);
pm = DO_MED3(pm - d, pm, pm + d);
pn = DO_MED3(pn - 2 * d, pn - d, pn);
}
pm = DO_MED3(pl, pm, pn);
}
DO_SWAP(a, pm);
pa = pb = a + ST_POINTER_STEP;
pc = pd = a + (n - 1) * ST_POINTER_STEP;
for (;;)
{
while (pb <= pc && (r = DO_COMPARE(pb, a)) <= 0)
{
if (r == 0)
{
DO_SWAP(pa, pb);
pa += ST_POINTER_STEP;
}
pb += ST_POINTER_STEP;
DO_CHECK_FOR_INTERRUPTS();
}
while (pb <= pc && (r = DO_COMPARE(pc, a)) >= 0)
{
if (r == 0)
{
DO_SWAP(pc, pd);
pd -= ST_POINTER_STEP;
}
pc -= ST_POINTER_STEP;
DO_CHECK_FOR_INTERRUPTS();
}
if (pb > pc)
break;
DO_SWAP(pb, pc);
pb += ST_POINTER_STEP;
pc -= ST_POINTER_STEP;
}
pn = a + n * ST_POINTER_STEP;
d1 = Min(pa - a, pb - pa);
DO_SWAPN(a, pb - d1, d1);
d1 = Min(pd - pc, pn - pd - ST_POINTER_STEP);
DO_SWAPN(pb, pn - d1, d1);
d1 = pb - pa;
d2 = pd - pc;
if (d1 <= d2)
{
if (d1 > ST_POINTER_STEP)
DO_SORT(a, d1 / ST_POINTER_STEP);
if (d2 > ST_POINTER_STEP)
{
a = pn - d2;
n = d2 / ST_POINTER_STEP;
goto loop;
}
}
else
{
if (d2 > ST_POINTER_STEP)
DO_SORT(pn - d2, d2 / ST_POINTER_STEP);
if (d1 > ST_POINTER_STEP)
{
n = d1 / ST_POINTER_STEP;
goto loop;
}
}
}
#endif
#undef DO_CHECK_FOR_INTERRUPTS
#undef DO_COMPARE
#undef DO_MED3
#undef DO_SORT
#undef DO_SWAP
#undef DO_SWAPN
#undef ST_COMPARATOR_TYPE_NAME
#undef ST_COMPARE
#undef ST_COMPARE_ARG_TYPE
#undef ST_COMPARE_RUNTIME_POINTER
#undef ST_ELEMENT_TYPE
#undef ST_ELEMENT_TYPE_VOID
#undef ST_MAKE_NAME
#undef ST_MAKE_NAME_
#undef ST_MAKE_PREFIX
#undef ST_MED3
#undef ST_POINTER_STEP
#undef ST_POINTER_TYPE
#undef ST_SCOPE
#undef ST_SORT
#undef ST_SORT_INVOKE_ARG
#undef ST_SORT_INVOKE_COMPARE
#undef ST_SORT_INVOKE_ELEMENT_SIZE
#undef ST_SORT_PROTO_ARG
#undef ST_SORT_PROTO_COMPARE
#undef ST_SORT_PROTO_ELEMENT_SIZE
#undef ST_SWAP
#undef ST_SWAPN