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* test-suite/tests/sort.test: Added. Both tests in that file did

Browse source 
fail (one even with a segfault) with CVS guile before the recent
	changes to libguile/sort.c.

	* libguile/sort.c: Replaced hand-made trampline code by the new
	official mechanism from eval.c.  This fixes a segfault in the new
	test file test-suite/tests/sort.test.

	(quicksort, compare_function, scm_restricted_vector_sort_x,
	scm_sorted_p, scm_merge, scm_merge_list_x, scm_merge_x,
	scm_merge_list_step, scm_sort_x, scm_sort, scm_merge_vector_x,
	scm_merge_vector_step, scm_stable_sort_x, scm_stable_sort,
	scm_sort_list_x, scm_sort_list): Use trampoline mechanism from
	eval.c.

	(subr2less, lsubrless, closureless, applyless, scm_cmp_function,
	cmp_fun_t): Removed.

	(compare_function): Added.

	* libguile/sort.c (quicksort, SWAP, stack_node): Replaced pointer
	arithmetics with index arithmetics.  Changed quicksort to work on
	an array of SCM values instead of an array of characters.  Avoid
	bytewise copying of SCM elements.  Avoid allocating memory on the
	stack with alloca.  Fixed some comments.
This commit is contained in:
Dirk Herrmann 2003-04-22 23:32:40 +00:00
parent 2d2f76fc5f
commit d339981a5a
4 changed files with 225 additions and 280 deletions
Download patch file Download diff file Expand all files Collapse all files

24
libguile/ChangeLog
View file

@ -1,3 +1,27 @@
2003-04-23 Dirk Herrmann <D.Herrmann@tu-bs.de>
* sort.c: Replaced hand-made trampline code by the new official
mechanism from eval.c. This fixes a segfault in the new test file
sort.test.
(quicksort, compare_function, scm_restricted_vector_sort_x,
scm_sorted_p, scm_merge, scm_merge_list_x, scm_merge_x,
scm_merge_list_step, scm_sort_x, scm_sort, scm_merge_vector_x,
scm_merge_vector_step, scm_stable_sort_x, scm_stable_sort,
scm_sort_list_x, scm_sort_list): Use trampoline mechanism from
eval.c.
(subr2less, lsubrless, closureless, applyless, scm_cmp_function,
cmp_fun_t): Removed.
(compare_function): Added.
* sort.c (quicksort, SWAP, stack_node): Replaced pointer
arithmetics with index arithmetics. Changed quicksort to work on
an array of SCM values instead of an array of characters. Avoid
bytewise copying of SCM elements. Avoid allocating memory on the
stack with alloca. Fixed some comments.
2003-04-21 Dirk Herrmann <D.Herrmann@tu-bs.de> 2003-04-21 Dirk Herrmann <D.Herrmann@tu-bs.de>
* eval.c (EXTEND_ENV): Eliminated. * eval.c (EXTEND_ENV): Eliminated.

446
libguile/sort.c
View file

@ -32,34 +32,8 @@
* quicksort code. * quicksort code.
*/ */
/* We need this to get the definitions for HAVE_ALLOCA_H, etc. */
#if HAVE_CONFIG_H
# include <config.h>
#endif
/* do we still need this here? */
#include "libguile/scmconfig.h"
/* AIX requires this to be the first thing in the file. The #pragma
directive is indented so pre-ANSI compilers will ignore it, rather
than choke on it. */
#ifndef __GNUC__
# if HAVE_ALLOCA_H
# include <alloca.h>
# else
# ifdef _AIX
#pragma alloca
# else
# ifndef alloca /* predefined by HP cc +Olibcalls */
char *alloca ();
# endif
# endif
# endif
#endif
#include <string.h> #include <string.h>
#include "libguile/_scm.h" #include "libguile/_scm.h"
#include "libguile/eval.h" #include "libguile/eval.h"
#include "libguile/unif.h" #include "libguile/unif.h"
#include "libguile/ramap.h" #include "libguile/ramap.h"
@ -72,6 +46,7 @@ char *alloca ();
#include "libguile/validate.h" #include "libguile/validate.h"
#include "libguile/sort.h" #include "libguile/sort.h"
/* The routine quicksort was extracted from the GNU C Library qsort.c /* The routine quicksort was extracted from the GNU C Library qsort.c
written by Douglas C. Schmidt (schmidt@ics.uci.edu) written by Douglas C. Schmidt (schmidt@ics.uci.edu)
and adapted to guile by adding an extra pointer less and adapted to guile by adding an extra pointer less
@ -85,300 +60,225 @@ char *alloca ();
version but doesn't consume extra memory. version but doesn't consume extra memory.
*/ */
/* Byte-wise swap two items of size SIZE. */ #define SWAP(a, b) do { const SCM _tmp = a; a = b; b = _tmp; } while (0)
#define SWAP(a, b, size) \
do \
{ \
register size_t __size = (size); \
register char *__a = (a), *__b = (b); \
do \
{ \
char __tmp = *__a; \
*__a++ = *__b; \
*__b++ = __tmp; \
} while (--__size > 0); \
} while (0)
/* Discontinue quicksort algorithm when partition gets below this size.
This particular magic number was chosen to work best on a Sun 4/260. */
#define MAX_THRESH 4
/* Stack node declarations used to store unfulfilled partition obligations. */
typedef struct
{
char *lo;
char *hi;
}
stack_node;
/* The next 4 #defines implement a very fast in-line stack abstraction. */
#define STACK_SIZE (8 * sizeof(unsigned long int))
#define PUSH(low, high) ((void) ((top->lo = (low)), (top->hi = (high)), ++top))
#define POP(low, high) ((void) (--top, (low = top->lo), (high = top->hi)))
#define STACK_NOT_EMPTY (stack < top)
/* Order size using quicksort. This implementation incorporates /* Order size using quicksort. This implementation incorporates
four optimizations discussed in Sedgewick: four optimizations discussed in Sedgewick:
1. Non-recursive, using an explicit stack of pointer that store the 1. Non-recursive, using an explicit stack of pointer that store the next
next array partition to sort. To save time, this maximum amount array partition to sort. To save time, this maximum amount of space
of space required to store an array of MAX_INT is allocated on the required to store an array of MAX_SIZE_T is allocated on the stack.
stack. Assuming a 32-bit integer, this needs only 32 * Assuming a bit width of 32 bits for size_t, this needs only
sizeof(stack_node) == 136 bits. Pretty cheap, actually. 32 * sizeof (stack_node) == 128 bytes. Pretty cheap, actually.
2. Chose the pivot element using a median-of-three decision tree. 2. Chose the pivot element using a median-of-three decision tree. This
This reduces the probability of selecting a bad pivot value and reduces the probability of selecting a bad pivot value and eliminates
eliminates certain extraneous comparisons. certain extraneous comparisons.
3. Only quicksorts TOTAL_ELEMS / MAX_THRESH partitions, leaving 3. Only quicksorts NR_ELEMS / MAX_THRESH partitions, leaving insertion sort
insertion sort to order the MAX_THRESH items within each partition. to order the MAX_THRESH items within each partition. This is a big win,
This is a big win, since insertion sort is faster for small, mostly since insertion sort is faster for small, mostly sorted array segments.
sorted array segments.
4. The larger of the two sub-partitions is always pushed onto the 4. The larger of the two sub-partitions is always pushed onto the
stack first, with the algorithm then concentrating on the stack first, with the algorithm then concentrating on the
smaller partition. This *guarantees* no more than log (n) smaller partition. This *guarantees* no more than log (n)
stack size is needed (actually O(1) in this case)! */ stack size is needed (actually O(1) in this case)! */
typedef int (*cmp_fun_t) (SCM less,
const void*,
const void*);
static const char s_buggy_less[] = "buggy less predicate used when sorting"; /* Discontinue quicksort algorithm when partition gets below this size.
* This particular magic number was chosen to work best on a Sun 4/260. */
#define MAX_THRESH 4
/* Inline stack abstraction: The stack size for quicksorting at most as many
* elements as can be given by a value of type size_t is, as described above,
* log (MAX_SIZE_T), which is the number of bits of size_t. More accurately,
* we would only need ceil (log (MAX_SIZE_T / MAX_THRESH)), but this is
* ignored below. */
/* Stack node declarations used to store unfulfilled partition obligations. */
typedef struct {
size_t lo;
size_t hi;
} stack_node;
#define STACK_SIZE (8 * sizeof (size_t)) /* assume 8 bit char */
#define PUSH(low, high) ((void) ((top->lo = (low)), (top->hi = (high)), ++top))
#define POP(low, high) ((void) (--top, (low = top->lo), (high = top->hi)))
#define STACK_NOT_EMPTY (stack < top)
static void static void
quicksort (void *const pbase, quicksort (SCM *const base_ptr, size_t nr_elems, scm_t_trampoline_2 cmp, SCM less)
size_t total_elems,
size_t size,
cmp_fun_t cmp,
SCM less)
{ {
register char *base_ptr = (char *) pbase; static const char s_buggy_less[] = "buggy less predicate used when sorting";
/* Allocating SIZE bytes for a pivot buffer facilitates a better if (nr_elems == 0)
algorithm below since we can do comparisons directly on the pivot. */
char *pivot_buffer = (char *) alloca (size);
const size_t max_thresh = MAX_THRESH * size;
if (total_elems == 0)
/* Avoid lossage with unsigned arithmetic below. */ /* Avoid lossage with unsigned arithmetic below. */
return; return;
if (total_elems > MAX_THRESH) if (nr_elems > MAX_THRESH)
{ {
char *lo = base_ptr; size_t lo = 0;
char *hi = &lo[size * (total_elems - 1)]; size_t hi = nr_elems - 1;
/* Largest size needed for 32-bit int!!! */
stack_node stack[STACK_SIZE]; stack_node stack[STACK_SIZE];
stack_node *top = stack + 1; stack_node *top = stack + 1;
while (STACK_NOT_EMPTY) while (STACK_NOT_EMPTY)
{ {
char *left_ptr; size_t left;
char *right_ptr; size_t right;
char *pivot = pivot_buffer;
/* Select median value from among LO, MID, and HI. Rearrange /* Select median value from among LO, MID, and HI. Rearrange
LO and HI so the three values are sorted. This lowers the LO and HI so the three values are sorted. This lowers the
probability of picking a pathological pivot value and probability of picking a pathological pivot value and
skips a comparison for both the LEFT_PTR and RIGHT_PTR. */ skips a comparison for both the left and right. */
char *mid = lo + size * ((hi - lo) / size >> 1); size_t mid = lo + (hi - lo) / 2;
if ((*cmp) (less, (void *) mid, (void *) lo)) if (!SCM_FALSEP ((*cmp) (less, base_ptr[mid], base_ptr[lo])))
SWAP (mid, lo, size); SWAP (base_ptr[mid], base_ptr[lo]);
if ((*cmp) (less, (void *) hi, (void *) mid)) if (!SCM_FALSEP ((*cmp) (less, base_ptr[hi], base_ptr[mid])))
SWAP (mid, hi, size); SWAP (base_ptr[mid], base_ptr[hi]);
else else
goto jump_over; goto jump_over;
if ((*cmp) (less, (void *) mid, (void *) lo)) if (!SCM_FALSEP ((*cmp) (less, base_ptr[mid], base_ptr[lo])))
SWAP (mid, lo, size); SWAP (base_ptr[mid], base_ptr[lo]);
jump_over:; jump_over:;
memcpy (pivot, mid, size);
pivot = pivot_buffer;
left_ptr = lo + size; left = lo + 1;
right_ptr = hi - size; right = hi - 1;
/* Here's the famous ``collapse the walls'' section of quicksort. /* Here's the famous ``collapse the walls'' section of quicksort.
Gotta like those tight inner loops! They are the main reason Gotta like those tight inner loops! They are the main reason
that this algorithm runs much faster than others. */ that this algorithm runs much faster than others. */
do do
{ {
while ((*cmp) (less, (void *) left_ptr, (void *) pivot)) while (!SCM_FALSEP ((*cmp) (less, base_ptr[left], base_ptr[mid])))
{ {
left_ptr += size; left++;
/* The comparison predicate may be buggy */ /* The comparison predicate may be buggy */
if (left_ptr > hi) if (left > hi)
scm_misc_error (NULL, s_buggy_less, SCM_EOL); scm_misc_error (NULL, s_buggy_less, SCM_EOL);
} }
while ((*cmp) (less, (void *) pivot, (void *) right_ptr)) while (!SCM_FALSEP ((*cmp) (less, base_ptr[mid], base_ptr[right])))
{ {
right_ptr -= size; right--;
/* The comparison predicate may be buggy */ /* The comparison predicate may be buggy */
if (right_ptr < lo) if (right < lo)
scm_misc_error (NULL, s_buggy_less, SCM_EOL); scm_misc_error (NULL, s_buggy_less, SCM_EOL);
} }
if (left_ptr < right_ptr) if (left < right)
{ {
SWAP (left_ptr, right_ptr, size); SWAP (base_ptr[left], base_ptr[right]);
left_ptr += size; left++;
right_ptr -= size; right--;
} }
else if (left_ptr == right_ptr) else if (left == right)
{ {
left_ptr += size; left++;
right_ptr -= size; right--;
break; break;
} }
} }
while (left_ptr <= right_ptr); while (left <= right);
/* Set up pointers for next iteration. First determine whether /* Set up pointers for next iteration. First determine whether
left and right partitions are below the threshold size. If so, left and right partitions are below the threshold size. If so,
ignore one or both. Otherwise, push the larger partition's ignore one or both. Otherwise, push the larger partition's
bounds on the stack and continue sorting the smaller one. */ bounds on the stack and continue sorting the smaller one. */
if ((size_t) (right_ptr - lo) <= max_thresh) if ((size_t) (right - lo) <= MAX_THRESH)
{ {
if ((size_t) (hi - left_ptr) <= max_thresh) if ((size_t) (hi - left) <= MAX_THRESH)
/* Ignore both small partitions. */ /* Ignore both small partitions. */
POP (lo, hi); POP (lo, hi);
else else
/* Ignore small left partition. */ /* Ignore small left partition. */
lo = left_ptr; lo = left;
} }
else if ((size_t) (hi - left_ptr) <= max_thresh) else if ((size_t) (hi - left) <= MAX_THRESH)
/* Ignore small right partition. */ /* Ignore small right partition. */
hi = right_ptr; hi = right;
else if ((right_ptr - lo) > (hi - left_ptr)) else if ((right - lo) > (hi - left))
{ {
/* Push larger left partition indices. */ /* Push larger left partition indices. */
PUSH (lo, right_ptr); PUSH (lo, right);
lo = left_ptr; lo = left;
} }
else else
{ {
/* Push larger right partition indices. */ /* Push larger right partition indices. */
PUSH (left_ptr, hi); PUSH (left, hi);
hi = right_ptr; hi = right;
} }
} }
} }
/* Once the BASE_PTR array is partially sorted by quicksort the rest /* Once the BASE_PTR array is partially sorted by quicksort the rest is
is completely sorted using insertion sort, since this is efficient completely sorted using insertion sort, since this is efficient for
for partitions below MAX_THRESH size. BASE_PTR points to the beginning partitions below MAX_THRESH size. BASE_PTR points to the beginning of the
of the array to sort, and END_PTR points at the very last element in array to sort, and END idexes the very last element in the array (*not*
the array (*not* one beyond it!). */ one beyond it!). */
{ {
char *const end_ptr = &base_ptr[size * (total_elems - 1)]; size_t tmp = 0;
char *tmp_ptr = base_ptr; size_t end = nr_elems - 1;
char *thresh = min (end_ptr, base_ptr + max_thresh); size_t thresh = min (end, MAX_THRESH);
register char *run_ptr; size_t run;
/* Find smallest element in first threshold and place it at the /* Find smallest element in first threshold and place it at the
array's beginning. This is the smallest array element, array's beginning. This is the smallest array element,
and the operation speeds up insertion sort's inner loop. */ and the operation speeds up insertion sort's inner loop. */
for (run_ptr = tmp_ptr + size; run_ptr <= thresh; run_ptr += size) for (run = tmp + 1; run <= thresh; run++)
if ((*cmp) (less, (void *) run_ptr, (void *) tmp_ptr)) if (!SCM_FALSEP ((*cmp) (less, base_ptr[run], base_ptr[tmp])))
tmp_ptr = run_ptr; tmp = run;
if (tmp_ptr != base_ptr) if (tmp != 0)
SWAP (tmp_ptr, base_ptr, size); SWAP (base_ptr[tmp], base_ptr[0]);
/* Insertion sort, running from left-hand-side up to right-hand-side. */ /* Insertion sort, running from left-hand-side up to right-hand-side. */
run_ptr = base_ptr + size; run = 1;
while ((run_ptr += size) <= end_ptr) while (++run <= end)
{ {
tmp_ptr = run_ptr - size; tmp = run - 1;
while ((*cmp) (less, (void *) run_ptr, (void *) tmp_ptr)) while (!SCM_FALSEP ((*cmp) (less, base_ptr[run], base_ptr[tmp])))
{ {
tmp_ptr -= size;
/* The comparison predicate may be buggy */ /* The comparison predicate may be buggy */
if (tmp_ptr < base_ptr) if (tmp == 0)
scm_misc_error (NULL, s_buggy_less, SCM_EOL); scm_misc_error (NULL, s_buggy_less, SCM_EOL);
tmp--;
} }
tmp_ptr += size; tmp++;
if (tmp_ptr != run_ptr) if (tmp != run)
{ {
char *trav; SCM to_insert = base_ptr[run];
size_t hi, lo;
trav = run_ptr + size; for (hi = lo = run; --lo >= tmp; hi = lo)
while (--trav >= run_ptr) base_ptr[hi] = base_ptr[lo];
{ base_ptr[hi] = to_insert;
char c = *trav;
char *hi, *lo;
for (hi = lo = trav; (lo -= size) >= tmp_ptr; hi = lo)
*hi = *lo;
*hi = c;
}
} }
} }
} }
} /* quicksort */ }
/* comparison routines */ static scm_t_trampoline_2
compare_function (SCM less, unsigned int arg_nr, const char* fname)
static int
subr2less (SCM less, const void *a, const void *b)
{ {
return SCM_NFALSEP (SCM_SUBRF (less) (*(SCM *) a, *(SCM *) b)); const scm_t_trampoline_2 cmp = scm_trampoline_2 (less);
} /* subr2less */ SCM_ASSERT_TYPE (cmp != NULL, less, arg_nr, fname, "less predicate");
return cmp;
static int }
lsubrless (SCM less, const void *a, const void *b)
{
return SCM_NFALSEP (SCM_SUBRF (less)
(scm_cons (*(SCM *) a,
scm_cons (*(SCM *) b, SCM_EOL))));
} /* lsubrless */
static int
closureless (SCM code, const void *a, const void *b)
{
SCM env = SCM_EXTEND_ENV (SCM_CLOSURE_FORMALS (code),
scm_cons (*(SCM *) a,
scm_cons (*(SCM *) b, SCM_EOL)),
SCM_ENV (code));
/* Evaluate the closure body */
return !SCM_FALSEP (scm_eval_body (SCM_CLOSURE_BODY (code), env));
} /* closureless */
static int
applyless (SCM less, const void *a, const void *b)
{
return SCM_NFALSEP (scm_call_2 (less, *(SCM *) a, *(SCM *) b));
} /* applyless */
static cmp_fun_t
scm_cmp_function (SCM p)
{
switch (SCM_TYP7 (p))
{
case scm_tc7_subr_2:
case scm_tc7_subr_2o:
case scm_tc7_rpsubr:
case scm_tc7_asubr:
return subr2less;
case scm_tc7_lsubr:
return lsubrless;
case scm_tcs_closures:
return closureless;
default:
return applyless;
}
} /* scm_cmp_function */
/* Question: Is there any need to make this a more general array sort? /* Question: Is there any need to make this a more general array sort?
@ -394,12 +294,11 @@ SCM_DEFINE (scm_restricted_vector_sort_x, "restricted-vector-sort!", 4, 0, 0,
"is not specified.") "is not specified.")
#define FUNC_NAME s_scm_restricted_vector_sort_x #define FUNC_NAME s_scm_restricted_vector_sort_x
{ {
size_t vlen, spos, len, size = sizeof (SCM); const scm_t_trampoline_2 cmp = compare_function (less, 2, FUNC_NAME);
size_t vlen, spos, len;
SCM *vp; SCM *vp;
SCM_VALIDATE_VECTOR (1, vec); SCM_VALIDATE_VECTOR (1, vec);
SCM_VALIDATE_NIM (2, less);
vp = SCM_WRITABLE_VELTS (vec); /* vector pointer */ vp = SCM_WRITABLE_VELTS (vec); /* vector pointer */
vlen = SCM_VECTOR_LENGTH (vec); vlen = SCM_VECTOR_LENGTH (vec);
@ -408,13 +307,14 @@ SCM_DEFINE (scm_restricted_vector_sort_x, "restricted-vector-sort!", 4, 0, 0,
SCM_VALIDATE_INUM_RANGE (4, endpos,0, vlen+1); SCM_VALIDATE_INUM_RANGE (4, endpos,0, vlen+1);
len = SCM_INUM (endpos) - spos; len = SCM_INUM (endpos) - spos;
quicksort (&vp[spos], len, size, scm_cmp_function (less), less); quicksort (&vp[spos], len, cmp, less);
scm_remember_upto_here_1 (vec);
return scm_return_first (SCM_UNSPECIFIED, vec); return SCM_UNSPECIFIED;
/* return vec; */
} }
#undef FUNC_NAME #undef FUNC_NAME
/* (sorted? sequence less?) /* (sorted? sequence less?)
* is true when sequence is a list (x0 x1 ... xm) or a vector #(x0 ... xm) * is true when sequence is a list (x0 x1 ... xm) or a vector #(x0 ... xm)
* such that for all 1 <= i <= m, * such that for all 1 <= i <= m,
@ -426,16 +326,14 @@ SCM_DEFINE (scm_sorted_p, "sorted?", 2, 0, 0,
"applied to all elements i - 1 and i") "applied to all elements i - 1 and i")
#define FUNC_NAME s_scm_sorted_p #define FUNC_NAME s_scm_sorted_p
{ {
const scm_t_trampoline_2 cmp = compare_function (less, 2, FUNC_NAME);
long len, j; /* list/vector length, temp j */ long len, j; /* list/vector length, temp j */
SCM item, rest; /* rest of items loop variable */ SCM item, rest; /* rest of items loop variable */
SCM const *vp; SCM const *vp;
cmp_fun_t cmp = scm_cmp_function (less);
if (SCM_NULL_OR_NIL_P (items)) if (SCM_NULL_OR_NIL_P (items))
return SCM_BOOL_T; return SCM_BOOL_T;
SCM_VALIDATE_NIM (2, less);
if (SCM_CONSP (items)) if (SCM_CONSP (items))
{ {
len = scm_ilength (items); /* also checks that it's a pure list */ len = scm_ilength (items); /* also checks that it's a pure list */
@ -448,7 +346,7 @@ SCM_DEFINE (scm_sorted_p, "sorted?", 2, 0, 0,
j = len - 1; j = len - 1;
while (j > 0) while (j > 0)
{ {
if ((*cmp) (less, SCM_CARLOC(rest), &item)) if (!SCM_FALSEP ((*cmp) (less, SCM_CAR (rest), item)))
return SCM_BOOL_F; return SCM_BOOL_F;
else else
{ {
@ -468,7 +366,7 @@ SCM_DEFINE (scm_sorted_p, "sorted?", 2, 0, 0,
j = len - 1; j = len - 1;
while (j > 0) while (j > 0)
{ {
if ((*cmp) (less, &vp[1], vp)) if (!SCM_FALSEP ((*cmp) (less, vp[1], vp[0])))
return SCM_BOOL_F; return SCM_BOOL_F;
else else
{ {
@ -483,6 +381,7 @@ SCM_DEFINE (scm_sorted_p, "sorted?", 2, 0, 0,
} }
#undef FUNC_NAME #undef FUNC_NAME
/* (merge a b less?) /* (merge a b less?)
takes two lists a and b such that (sorted? a less?) and (sorted? b less?) takes two lists a and b such that (sorted? a less?) and (sorted? b less?)
and returns a new list in which the elements of a and b have been stably and returns a new list in which the elements of a and b have been stably
@ -499,10 +398,7 @@ SCM_DEFINE (scm_merge, "merge", 3, 0, 0,
"Note: this does _not_ accept vectors.") "Note: this does _not_ accept vectors.")
#define FUNC_NAME s_scm_merge #define FUNC_NAME s_scm_merge
{ {
long alen, blen; /* list lengths */ SCM build;
SCM build, last;
cmp_fun_t cmp = scm_cmp_function (less);
SCM_VALIDATE_NIM (3, less);
if (SCM_NULL_OR_NIL_P (alist)) if (SCM_NULL_OR_NIL_P (alist))
return blist; return blist;
@ -510,9 +406,13 @@ SCM_DEFINE (scm_merge, "merge", 3, 0, 0,
return alist; return alist;
else else
{ {
const scm_t_trampoline_2 cmp = compare_function (less, 3, FUNC_NAME);
long alen, blen; /* list lengths */
SCM last;
SCM_VALIDATE_NONEMPTYLIST_COPYLEN (1, alist, alen); SCM_VALIDATE_NONEMPTYLIST_COPYLEN (1, alist, alen);
SCM_VALIDATE_NONEMPTYLIST_COPYLEN (2, blist, blen); SCM_VALIDATE_NONEMPTYLIST_COPYLEN (2, blist, blen);
if ((*cmp) (less, SCM_CARLOC (blist), SCM_CARLOC (alist))) if (!SCM_FALSEP ((*cmp) (less, SCM_CAR (blist), SCM_CAR (alist))))
{ {
build = scm_cons (SCM_CAR (blist), SCM_EOL); build = scm_cons (SCM_CAR (blist), SCM_EOL);
blist = SCM_CDR (blist); blist = SCM_CDR (blist);
@ -527,7 +427,7 @@ SCM_DEFINE (scm_merge, "merge", 3, 0, 0,
last = build; last = build;
while ((alen > 0) && (blen > 0)) while ((alen > 0) && (blen > 0))
{ {
if ((*cmp) (less, SCM_CARLOC (blist), SCM_CARLOC (alist))) if (!SCM_FALSEP ((*cmp) (less, SCM_CAR (blist), SCM_CAR (alist))))
{ {
SCM_SETCDR (last, scm_cons (SCM_CAR (blist), SCM_EOL)); SCM_SETCDR (last, scm_cons (SCM_CAR (blist), SCM_EOL));
blist = SCM_CDR (blist); blist = SCM_CDR (blist);
@ -554,7 +454,7 @@ SCM_DEFINE (scm_merge, "merge", 3, 0, 0,
static SCM static SCM
scm_merge_list_x (SCM alist, SCM blist, scm_merge_list_x (SCM alist, SCM blist,
long alen, long blen, long alen, long blen,
cmp_fun_t cmp, SCM less) scm_t_trampoline_2 cmp, SCM less)
{ {
SCM build, last; SCM build, last;
@ -564,7 +464,7 @@ scm_merge_list_x (SCM alist, SCM blist,
return alist; return alist;
else else
{ {
if ((*cmp) (less, SCM_CARLOC (blist), SCM_CARLOC (alist))) if (!SCM_FALSEP ((*cmp) (less, SCM_CAR (blist), SCM_CAR (alist))))
{ {
build = blist; build = blist;
blist = SCM_CDR (blist); blist = SCM_CDR (blist);
@ -579,7 +479,7 @@ scm_merge_list_x (SCM alist, SCM blist,
last = build; last = build;
while ((alen > 0) && (blen > 0)) while ((alen > 0) && (blen > 0))
{ {
if ((*cmp) (less, SCM_CARLOC (blist), SCM_CARLOC (alist))) if (!SCM_FALSEP ((*cmp) (less, SCM_CAR (blist), SCM_CAR (alist))))
{ {
SCM_SETCDR (last, blist); SCM_SETCDR (last, blist);
blist = SCM_CDR (blist); blist = SCM_CDR (blist);
@ -601,6 +501,7 @@ scm_merge_list_x (SCM alist, SCM blist,
return build; return build;
} /* scm_merge_list_x */ } /* scm_merge_list_x */
SCM_DEFINE (scm_merge_x, "merge!", 3, 0, 0, SCM_DEFINE (scm_merge_x, "merge!", 3, 0, 0,
(SCM alist, SCM blist, SCM less), (SCM alist, SCM blist, SCM less),
"Takes two lists @var{alist} and @var{blist} such that\n" "Takes two lists @var{alist} and @var{blist} such that\n"
@ -612,35 +513,29 @@ SCM_DEFINE (scm_merge_x, "merge!", 3, 0, 0,
"Note: this does _not_ accept vectors.") "Note: this does _not_ accept vectors.")
#define FUNC_NAME s_scm_merge_x #define FUNC_NAME s_scm_merge_x
{ {
long alen, blen; /* list lengths */
SCM_VALIDATE_NIM (3, less);
if (SCM_NULL_OR_NIL_P (alist)) if (SCM_NULL_OR_NIL_P (alist))
return blist; return blist;
else if (SCM_NULL_OR_NIL_P (blist)) else if (SCM_NULL_OR_NIL_P (blist))
return alist; return alist;
else else
{ {
const scm_t_trampoline_2 cmp = compare_function (less, 3, FUNC_NAME);
long alen, blen; /* list lengths */
SCM_VALIDATE_NONEMPTYLIST_COPYLEN (1, alist, alen); SCM_VALIDATE_NONEMPTYLIST_COPYLEN (1, alist, alen);
SCM_VALIDATE_NONEMPTYLIST_COPYLEN (2, blist, blen); SCM_VALIDATE_NONEMPTYLIST_COPYLEN (2, blist, blen);
return scm_merge_list_x (alist, blist, return scm_merge_list_x (alist, blist, alen, blen, cmp, less);
alen, blen,
scm_cmp_function (less),
less);
} }
} }
#undef FUNC_NAME #undef FUNC_NAME
/* This merge sort algorithm is same as slib's by Richard A. O'Keefe. /* This merge sort algorithm is same as slib's by Richard A. O'Keefe.
The algorithm is stable. We also tried to use the algorithm used by The algorithm is stable. We also tried to use the algorithm used by
scsh's merge-sort but that algorithm showed to not be stable, even scsh's merge-sort but that algorithm showed to not be stable, even
though it claimed to be. though it claimed to be.
*/ */
static SCM static SCM
scm_merge_list_step (SCM * seq, scm_merge_list_step (SCM * seq, scm_t_trampoline_2 cmp, SCM less, long n)
cmp_fun_t cmp,
SCM less,
long n)
{ {
SCM a, b; SCM a, b;
@ -659,7 +554,7 @@ scm_merge_list_step (SCM * seq,
SCM y = SCM_CAR (SCM_CDR (*seq)); SCM y = SCM_CAR (SCM_CDR (*seq));
*seq = SCM_CDR (rest); *seq = SCM_CDR (rest);
SCM_SETCDR (rest, SCM_EOL); SCM_SETCDR (rest, SCM_EOL);
if ((*cmp) (less, &y, &x)) if (!SCM_FALSEP ((*cmp) (less, y, x)))
{ {
SCM_SETCAR (p, y); SCM_SETCAR (p, y);
SCM_SETCAR (rest, x); SCM_SETCAR (rest, x);
@ -678,7 +573,6 @@ scm_merge_list_step (SCM * seq,
} /* scm_merge_list_step */ } /* scm_merge_list_step */
/* scm_sort_x manages lists and vectors, not stable sort */
SCM_DEFINE (scm_sort_x, "sort!", 2, 0, 0, SCM_DEFINE (scm_sort_x, "sort!", 2, 0, 0,
(SCM items, SCM less), (SCM items, SCM less),
"Sort the sequence @var{items}, which may be a list or a\n" "Sort the sequence @var{items}, which may be a list or a\n"
@ -692,12 +586,11 @@ SCM_DEFINE (scm_sort_x, "sort!", 2, 0, 0,
if (SCM_NULL_OR_NIL_P (items)) if (SCM_NULL_OR_NIL_P (items))
return items; return items;
SCM_VALIDATE_NIM (2, less);
if (SCM_CONSP (items)) if (SCM_CONSP (items))
{ {
const scm_t_trampoline_2 cmp = compare_function (less, 2, FUNC_NAME);
SCM_VALIDATE_LIST_COPYLEN (1, items, len); SCM_VALIDATE_LIST_COPYLEN (1, items, len);
return scm_merge_list_step (&items, scm_cmp_function (less), less, len); return scm_merge_list_step (&items, cmp, less, len);
} }
else if (SCM_VECTORP (items)) else if (SCM_VECTORP (items))
{ {
@ -713,7 +606,6 @@ SCM_DEFINE (scm_sort_x, "sort!", 2, 0, 0,
} }
#undef FUNC_NAME #undef FUNC_NAME
/* scm_sort manages lists and vectors, not stable sort */
SCM_DEFINE (scm_sort, "sort", 2, 0, 0, SCM_DEFINE (scm_sort, "sort", 2, 0, 0,
(SCM items, SCM less), (SCM items, SCM less),
@ -725,14 +617,14 @@ SCM_DEFINE (scm_sort, "sort", 2, 0, 0,
if (SCM_NULL_OR_NIL_P (items)) if (SCM_NULL_OR_NIL_P (items))
return items; return items;
SCM_VALIDATE_NIM (2, less);
if (SCM_CONSP (items)) if (SCM_CONSP (items))
{ {
const scm_t_trampoline_2 cmp = compare_function (less, 2, FUNC_NAME);
long len; long len;
SCM_VALIDATE_LIST_COPYLEN (1, items, len); SCM_VALIDATE_LIST_COPYLEN (1, items, len);
items = scm_list_copy (items); items = scm_list_copy (items);
return scm_merge_list_step (&items, scm_cmp_function (less), less, len); return scm_merge_list_step (&items, cmp, less, len);
} }
#if SCM_HAVE_ARRAYS #if SCM_HAVE_ARRAYS
/* support ordinary vectors even if arrays not available? */ /* support ordinary vectors even if arrays not available? */
@ -754,10 +646,11 @@ SCM_DEFINE (scm_sort, "sort", 2, 0, 0,
} }
#undef FUNC_NAME #undef FUNC_NAME
static void static void
scm_merge_vector_x (SCM vec, scm_merge_vector_x (SCM vec,
SCM * temp, SCM * temp,
cmp_fun_t cmp, scm_t_trampoline_2 cmp,
SCM less, SCM less,
long low, long low,
long mid, long mid,
@ -778,7 +671,7 @@ scm_merge_vector_x (SCM vec,
*/ */
register SCM *vp = SCM_WRITABLE_VELTS(vec); register SCM *vp = SCM_WRITABLE_VELTS(vec);
if ((*cmp) (less, &vp[i2], &vp[i1])) if (!SCM_FALSEP ((*cmp) (less, vp[i2], vp[i1])))
temp[it] = vp[i2++]; temp[it] = vp[i2++];
else else
temp[it] = vp[i1++]; temp[it] = vp[i1++];
@ -801,10 +694,11 @@ scm_merge_vector_x (SCM vec,
} }
} /* scm_merge_vector_x */ } /* scm_merge_vector_x */
static void static void
scm_merge_vector_step (SCM vp, scm_merge_vector_step (SCM vp,
SCM * temp, SCM * temp,
cmp_fun_t cmp, scm_t_trampoline_2 cmp,
SCM less, SCM less,
long low, long low,
long high) long high)
@ -819,8 +713,6 @@ scm_merge_vector_step (SCM vp,
} /* scm_merge_vector_step */ } /* scm_merge_vector_step */
/* stable-sort! manages lists and vectors */
SCM_DEFINE (scm_stable_sort_x, "stable-sort!", 2, 0, 0, SCM_DEFINE (scm_stable_sort_x, "stable-sort!", 2, 0, 0,
(SCM items, SCM less), (SCM items, SCM less),
"Sort the sequence @var{items}, which may be a list or a\n" "Sort the sequence @var{items}, which may be a list or a\n"
@ -830,16 +722,16 @@ SCM_DEFINE (scm_stable_sort_x, "stable-sort!", 2, 0, 0,
"This is a stable sort.") "This is a stable sort.")
#define FUNC_NAME s_scm_stable_sort_x #define FUNC_NAME s_scm_stable_sort_x
{ {
const scm_t_trampoline_2 cmp = compare_function (less, 2, FUNC_NAME);
long len; /* list/vector length */ long len; /* list/vector length */
if (SCM_NULL_OR_NIL_P (items)) if (SCM_NULL_OR_NIL_P (items))
return items; return items;
SCM_VALIDATE_NIM (2, less);
if (SCM_CONSP (items)) if (SCM_CONSP (items))
{ {
SCM_VALIDATE_LIST_COPYLEN (1, items, len); SCM_VALIDATE_LIST_COPYLEN (1, items, len);
return scm_merge_list_step (&items, scm_cmp_function (less), less, len); return scm_merge_list_step (&items, cmp, less, len);
} }
else if (SCM_VECTORP (items)) else if (SCM_VECTORP (items))
{ {
@ -852,12 +744,7 @@ SCM_DEFINE (scm_stable_sort_x, "stable-sort!", 2, 0, 0,
*/ */
temp = scm_malloc (len * sizeof(SCM)); temp = scm_malloc (len * sizeof(SCM));
scm_merge_vector_step (items, scm_merge_vector_step (items, temp, cmp, less, 0, len - 1);
temp,
scm_cmp_function (less),
less,
0,
len - 1);
free(temp); free(temp);
return items; return items;
} }
@ -866,7 +753,7 @@ SCM_DEFINE (scm_stable_sort_x, "stable-sort!", 2, 0, 0,
} }
#undef FUNC_NAME #undef FUNC_NAME
/* stable_sort manages lists and vectors */
SCM_DEFINE (scm_stable_sort, "stable-sort", 2, 0, 0, SCM_DEFINE (scm_stable_sort, "stable-sort", 2, 0, 0,
(SCM items, SCM less), (SCM items, SCM less),
"Sort the sequence @var{items}, which may be a list or a\n" "Sort the sequence @var{items}, which may be a list or a\n"
@ -874,17 +761,18 @@ SCM_DEFINE (scm_stable_sort, "stable-sort", 2, 0, 0,
"This is a stable sort.") "This is a stable sort.")
#define FUNC_NAME s_scm_stable_sort #define FUNC_NAME s_scm_stable_sort
{ {
const scm_t_trampoline_2 cmp = compare_function (less, 2, FUNC_NAME);
if (SCM_NULL_OR_NIL_P (items)) if (SCM_NULL_OR_NIL_P (items))
return items; return items;
SCM_VALIDATE_NIM (2, less);
if (SCM_CONSP (items)) if (SCM_CONSP (items))
{ {
long len; /* list/vector length */ long len; /* list/vector length */
SCM_VALIDATE_LIST_COPYLEN (1, items, len); SCM_VALIDATE_LIST_COPYLEN (1, items, len);
items = scm_list_copy (items); items = scm_list_copy (items);
return scm_merge_list_step (&items, scm_cmp_function (less), less, len); return scm_merge_list_step (&items, cmp, less, len);
} }
#if SCM_HAVE_ARRAYS #if SCM_HAVE_ARRAYS
/* support ordinary vectors even if arrays not available? */ /* support ordinary vectors even if arrays not available? */
@ -895,12 +783,7 @@ SCM_DEFINE (scm_stable_sort, "stable-sort", 2, 0, 0,
SCM retvec = scm_make_uve (len, scm_array_prototype (items)); SCM retvec = scm_make_uve (len, scm_array_prototype (items));
scm_array_copy_x (items, retvec); scm_array_copy_x (items, retvec);
scm_merge_vector_step (retvec, scm_merge_vector_step (retvec, temp, cmp, less, 0, len - 1);
temp,
scm_cmp_function (less),
less,
0,
len - 1);
free (temp); free (temp);
return retvec; return retvec;
} }
@ -910,7 +793,7 @@ SCM_DEFINE (scm_stable_sort, "stable-sort", 2, 0, 0,
} }
#undef FUNC_NAME #undef FUNC_NAME
/* stable */
SCM_DEFINE (scm_sort_list_x, "sort-list!", 2, 0, 0, SCM_DEFINE (scm_sort_list_x, "sort-list!", 2, 0, 0,
(SCM items, SCM less), (SCM items, SCM less),
"Sort the list @var{items}, using @var{less} for comparing the\n" "Sort the list @var{items}, using @var{less} for comparing the\n"
@ -919,28 +802,31 @@ SCM_DEFINE (scm_sort_list_x, "sort-list!", 2, 0, 0,
"This is a stable sort.") "This is a stable sort.")
#define FUNC_NAME s_scm_sort_list_x #define FUNC_NAME s_scm_sort_list_x
{ {
const scm_t_trampoline_2 cmp = compare_function (less, 2, FUNC_NAME);
long len; long len;
SCM_VALIDATE_LIST_COPYLEN (1, items, len); SCM_VALIDATE_LIST_COPYLEN (1, items, len);
SCM_VALIDATE_NIM (2, less); return scm_merge_list_step (&items, cmp, less, len);
return scm_merge_list_step (&items, scm_cmp_function (less), less, len);
} }
#undef FUNC_NAME #undef FUNC_NAME
/* stable */
SCM_DEFINE (scm_sort_list, "sort-list", 2, 0, 0, SCM_DEFINE (scm_sort_list, "sort-list", 2, 0, 0,
(SCM items, SCM less), (SCM items, SCM less),
"Sort the list @var{items}, using @var{less} for comparing the\n" "Sort the list @var{items}, using @var{less} for comparing the\n"
"list elements. This is a stable sort.") "list elements. This is a stable sort.")
#define FUNC_NAME s_scm_sort_list #define FUNC_NAME s_scm_sort_list
{ {
const scm_t_trampoline_2 cmp = compare_function (less, 2, FUNC_NAME);
long len; long len;
SCM_VALIDATE_LIST_COPYLEN (1, items, len); SCM_VALIDATE_LIST_COPYLEN (1, items, len);
SCM_VALIDATE_NIM (2, less);
items = scm_list_copy (items); items = scm_list_copy (items);
return scm_merge_list_step (&items, scm_cmp_function (less), less, len); return scm_merge_list_step (&items, cmp, less, len);
} }
#undef FUNC_NAME #undef FUNC_NAME
void void
scm_init_sort () scm_init_sort ()
{ {

6
test-suite/ChangeLog
View file

@ -1,3 +1,9 @@
2003-04-21 Dirk Herrmann <D.Herrmann@tu-bs.de>
* tests/sort.test: Added. Both tests in that file did fail (one
even with a segfault) with CVS guile before the recent changes to
sort.c.
2003-04-17 Mikael Djurfeldt <djurfeldt@nada.kth.se> 2003-04-17 Mikael Djurfeldt <djurfeldt@nada.kth.se>
* tests/goops.test: Added tests for correctness of class * tests/goops.test: Added tests for correctness of class

29
test-suite/tests/sort.test Normal file
View file

@ -0,0 +1,29 @@
;;;; sort.test --- tests Guile's sort functions -*- scheme -*-
;;;; Copyright (C) 2003 Free Software Foundation, Inc.
;;;;
;;;; This program is free software; you can redistribute it and/or modify
;;;; it under the terms of the GNU General Public License as published by
;;;; the Free Software Foundation; either version 2, or (at your option)
;;;; any later version.
;;;;
;;;; This program is distributed in the hope that it will be useful,
;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;;; GNU General Public License for more details.
;;;;
;;;; You should have received a copy of the GNU General Public License
;;;; along with this software; see the file COPYING. If not, write to
;;;; the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
;;;; Boston, MA 02111-1307 USA
(use-modules (test-suite lib))
(with-test-prefix "sort"
(pass-if-exception "less function taking less than two arguments"
exception:wrong-type-arg
(sort '(1 2) (lambda (x) #t)))
(pass-if-exception "less function taking more than two arguments"
exception:wrong-type-arg
(sort '(1 2) (lambda (x y z) z))))