| Line 24... |
Line 24... |
Linked list is a common data structure used in many applications.
|
Linked list is a common data structure used in many applications.
|
|
|
For our purposes, this will excercise the memory units of the processor.
|
For our purposes, this will excercise the memory units of the processor.
|
In particular, usage of the list pointers to find and alter data.
|
In particular, usage of the list pointers to find and alter data.
|
|
|
We are not using Malloc since some platforms do not support this library.
|
We are not using Malloc since some platforms do not support this
|
|
library.
|
|
|
Instead, the memory block being passed in is used to create a list,
|
Instead, the memory block being passed in is used to create a list,
|
and the benchmark takes care not to add more items then can be
|
and the benchmark takes care not to add more items then can be
|
accomodated by the memory block. The porting layer will make sure
|
accomodated by the memory block. The porting layer will make sure
|
that we have a valid memory block.
|
that we have a valid memory block.
|
| Line 37... |
Line 38... |
|
|
The list itself contains list pointers and pointers to data items.
|
The list itself contains list pointers and pointers to data items.
|
Data items contain the following:
|
Data items contain the following:
|
|
|
idx - An index that captures the initial order of the list.
|
idx - An index that captures the initial order of the list.
|
data - Variable data initialized based on the input parameters. The 16b are divided as follows:
|
data - Variable data initialized based on the input parameters. The 16b
|
o Upper 8b are backup of original data.
|
are divided as follows: o Upper 8b are backup of original data. o Bit 7
|
o Bit 7 indicates if the lower 7 bits are to be used as is or calculated.
|
indicates if the lower 7 bits are to be used as is or calculated. o Bits 0-2
|
o Bits 0-2 indicate type of operation to perform to get a 7b value.
|
indicate type of operation to perform to get a 7b value. o Bits 3-6 provide
|
o Bits 3-6 provide input for the operation.
|
input for the operation.
|
|
|
*/
|
*/
|
|
|
/* local functions */
|
/* local functions */
|
|
|
list_head *core_list_find(list_head *list,list_data *info);
|
list_head *core_list_find(list_head *list,list_data *info);
|
list_head *core_list_reverse(list_head *list);
|
list_head *core_list_reverse(list_head *list);
|
list_head *core_list_remove(list_head *item);
|
list_head *core_list_remove(list_head *item);
|
list_head *core_list_undo_remove(list_head *item_removed, list_head *item_modified);
|
list_head *core_list_undo_remove(list_head *item_removed,
|
list_head *core_list_insert_new(list_head *insert_point
|
list_head *item_modified);
|
, list_data *info, list_head **memblock, list_data **datablock
|
list_head *core_list_insert_new(list_head * insert_point,
|
, list_head *memblock_end, list_data *datablock_end);
|
list_data * info,
|
|
list_head **memblock,
|
|
list_data **datablock,
|
|
list_head * memblock_end,
|
|
list_data * datablock_end);
|
typedef ee_s32(*list_cmp)(list_data *a, list_data *b, core_results *res);
|
typedef ee_s32(*list_cmp)(list_data *a, list_data *b, core_results *res);
|
list_head *core_list_mergesort(list_head *list, list_cmp cmp, core_results *res);
|
list_head *core_list_mergesort(list_head * list,
|
|
list_cmp cmp,
|
ee_s16 calc_func(ee_s16 *pdata, core_results *res) {
|
core_results *res);
|
ee_s16 data=*pdata;
|
|
|
ee_s16
|
|
calc_func(ee_s16 *pdata, core_results *res)
|
|
{
|
|
ee_s16 data = *pdata;
|
ee_s16 retval;
|
ee_s16 retval;
|
ee_u8 optype=(data>>7) & 1; /* bit 7 indicates if the function result has been cached */
|
ee_u8 optype
|
|
= (data >> 7)
|
|
& 1; /* bit 7 indicates if the function result has been cached */
|
if (optype) /* if cached, use cache */
|
if (optype) /* if cached, use cache */
|
return (data & 0x007f);
|
return (data & 0x007f);
|
else { /* otherwise calculate and cache the result */
|
else
|
|
{ /* otherwise calculate and cache the result */
|
ee_s16 flag=data & 0x7; /* bits 0-2 is type of function to perform */
|
ee_s16 flag=data & 0x7; /* bits 0-2 is type of function to perform */
|
ee_s16 dtype=((data>>3) & 0xf); /* bits 3-6 is specific data for the operation */
|
ee_s16 dtype
|
|
= ((data >> 3)
|
|
& 0xf); /* bits 3-6 is specific data for the operation */
|
dtype |= dtype << 4; /* replicate the lower 4 bits to get an 8b value */
|
dtype |= dtype << 4; /* replicate the lower 4 bits to get an 8b value */
|
switch (flag) {
|
switch (flag)
|
|
{
|
case 0:
|
case 0:
|
if (dtype<0x22) /* set min period for bit corruption */
|
if (dtype<0x22) /* set min period for bit corruption */
|
dtype=0x22;
|
dtype=0x22;
|
retval=core_bench_state(res->size,res->memblock[3],res->seed1,res->seed2,dtype,res->crc);
|
retval = core_bench_state(res->size,
|
|
res->memblock[3],
|
|
res->seed1,
|
|
res->seed2,
|
|
dtype,
|
|
res->crc);
|
if (res->crcstate==0)
|
if (res->crcstate==0)
|
res->crcstate=retval;
|
res->crcstate=retval;
|
break;
|
break;
|
case 1:
|
case 1:
|
retval=core_bench_matrix(&(res->mat),dtype,res->crc);
|
retval=core_bench_matrix(&(res->mat),dtype,res->crc);
|
| Line 95... |
Line 115... |
/* Function: cmp_complex
|
/* Function: cmp_complex
|
Compare the data item in a list cell.
|
Compare the data item in a list cell.
|
|
|
Can be used by mergesort.
|
Can be used by mergesort.
|
*/
|
*/
|
ee_s32 cmp_complex(list_data *a, list_data *b, core_results *res) {
|
ee_s32
|
|
cmp_complex(list_data *a, list_data *b, core_results *res)
|
|
{
|
ee_s16 val1=calc_func(&(a->data16),res);
|
ee_s16 val1=calc_func(&(a->data16),res);
|
ee_s16 val2=calc_func(&(b->data16),res);
|
ee_s16 val2=calc_func(&(b->data16),res);
|
return val1 - val2;
|
return val1 - val2;
|
}
|
}
|
|
|
/* Function: cmp_idx
|
/* Function: cmp_idx
|
Compare the idx item in a list cell, and regen the data.
|
Compare the idx item in a list cell, and regen the data.
|
|
|
Can be used by mergesort.
|
Can be used by mergesort.
|
*/
|
*/
|
ee_s32 cmp_idx(list_data *a, list_data *b, core_results *res) {
|
ee_s32
|
if (res==NULL) {
|
cmp_idx(list_data *a, list_data *b, core_results *res)
|
|
{
|
|
if (res == NULL)
|
|
{
|
a->data16 = (a->data16 & 0xff00) | (0x00ff & (a->data16>>8));
|
a->data16 = (a->data16 & 0xff00) | (0x00ff & (a->data16>>8));
|
b->data16 = (b->data16 & 0xff00) | (0x00ff & (b->data16>>8));
|
b->data16 = (b->data16 & 0xff00) | (0x00ff & (b->data16>>8));
|
}
|
}
|
return a->idx - b->idx;
|
return a->idx - b->idx;
|
}
|
}
|
|
|
void copy_info(list_data *to,list_data *from) {
|
void
|
|
copy_info(list_data *to, list_data *from)
|
|
{
|
to->data16=from->data16;
|
to->data16=from->data16;
|
to->idx=from->idx;
|
to->idx=from->idx;
|
}
|
}
|
|
|
/* Benchmark for linked list:
|
/* Benchmark for linked list:
|
| Line 126... |
Line 153... |
- List sort
|
- List sort
|
- Operate on data from list (crc)
|
- Operate on data from list (crc)
|
- Single remove/reinsert
|
- Single remove/reinsert
|
* At the end of this function, the list is back to original state
|
* At the end of this function, the list is back to original state
|
*/
|
*/
|
ee_u16 core_bench_list(core_results *res, ee_s16 finder_idx) {
|
ee_u16
|
|
core_bench_list(core_results *res, ee_s16 finder_idx)
|
|
{
|
ee_u16 retval=0;
|
ee_u16 retval=0;
|
ee_u16 found=0,missed=0;
|
ee_u16 found=0,missed=0;
|
list_head *list=res->list;
|
list_head *list=res->list;
|
ee_s16 find_num=res->seed3;
|
ee_s16 find_num=res->seed3;
|
list_head *this_find;
|
list_head *this_find;
|
list_head *finder, *remover;
|
list_head *finder, *remover;
|
list_data info;
|
list_data info;
|
ee_s16 i;
|
ee_s16 i;
|
|
|
info.idx=finder_idx;
|
info.idx=finder_idx;
|
/* find <find_num> values in the list, and change the list each time (reverse and cache if value found) */
|
/* find <find_num> values in the list, and change the list each time
|
for (i=0; i<find_num; i++) {
|
* (reverse and cache if value found) */
|
|
for (i = 0; i < find_num; i++)
|
|
{
|
info.data16= (i & 0xff) ;
|
info.data16= (i & 0xff) ;
|
this_find=core_list_find(list,&info);
|
this_find = core_list_find(list, &info);
|
list=core_list_reverse(list);
|
list=core_list_reverse(list);
|
if (this_find==NULL) {
|
if (this_find == NULL)
|
|
{
|
missed++;
|
missed++;
|
retval+=(list->next->info->data16 >> 8) & 1;
|
retval+=(list->next->info->data16 >> 8) & 1;
|
}
|
}
|
else {
|
else
|
|
{
|
found++;
|
found++;
|
if (this_find->info->data16 & 0x1) /* use found value */
|
if (this_find->info->data16 & 0x1) /* use found value */
|
retval+=(this_find->info->data16 >> 9) & 1;
|
retval+=(this_find->info->data16 >> 9) & 1;
|
/* and cache next item at the head of the list (if any) */
|
/* and cache next item at the head of the list (if any) */
|
if (this_find->next != NULL) {
|
if (this_find->next != NULL)
|
|
{
|
finder = this_find->next;
|
finder = this_find->next;
|
this_find->next = finder->next;
|
this_find->next = finder->next;
|
finder->next=list->next;
|
finder->next=list->next;
|
list->next=finder;
|
list->next=finder;
|
}
|
}
|
| Line 169... |
Line 203... |
retval+=found*4-missed;
|
retval+=found*4-missed;
|
/* sort the list by data content and remove one item*/
|
/* sort the list by data content and remove one item*/
|
if (finder_idx>0)
|
if (finder_idx>0)
|
list=core_list_mergesort(list,cmp_complex,res);
|
list=core_list_mergesort(list,cmp_complex,res);
|
remover=core_list_remove(list->next);
|
remover=core_list_remove(list->next);
|
/* CRC data content of list from location of index N forward, and then undo remove */
|
/* CRC data content of list from location of index N forward, and then undo
|
finder=core_list_find(list,&info);
|
* remove */
|
|
finder = core_list_find(list, &info);
|
if (!finder)
|
if (!finder)
|
finder=list->next;
|
finder=list->next;
|
while (finder) {
|
while (finder)
|
|
{
|
retval=crc16(list->info->data16,retval);
|
retval=crc16(list->info->data16,retval);
|
finder=finder->next;
|
finder=finder->next;
|
}
|
}
|
#if CORE_DEBUG
|
#if CORE_DEBUG
|
ee_printf("List sort 1: %04x\n",retval);
|
ee_printf("List sort 1: %04x\n",retval);
|
| Line 185... |
Line 221... |
remover=core_list_undo_remove(remover,list->next);
|
remover=core_list_undo_remove(remover,list->next);
|
/* sort the list by index, in effect returning the list to original state */
|
/* sort the list by index, in effect returning the list to original state */
|
list=core_list_mergesort(list,cmp_idx,NULL);
|
list=core_list_mergesort(list,cmp_idx,NULL);
|
/* CRC data content of list */
|
/* CRC data content of list */
|
finder=list->next;
|
finder=list->next;
|
while (finder) {
|
while (finder)
|
|
{
|
retval=crc16(list->info->data16,retval);
|
retval=crc16(list->info->data16,retval);
|
finder=finder->next;
|
finder=finder->next;
|
}
|
}
|
#if CORE_DEBUG
|
#if CORE_DEBUG
|
ee_printf("List sort 2: %04x\n",retval);
|
ee_printf("List sort 2: %04x\n",retval);
|
| Line 201... |
Line 238... |
|
|
Parameters:
|
Parameters:
|
blksize - Size of memory to be initialized.
|
blksize - Size of memory to be initialized.
|
memblock - Pointer to memory block.
|
memblock - Pointer to memory block.
|
seed - Actual values chosen depend on the seed parameter.
|
seed - Actual values chosen depend on the seed parameter.
|
The seed parameter MUST be supplied from a source that cannot be determined at compile time
|
The seed parameter MUST be supplied from a source that cannot be
|
|
determined at compile time
|
|
|
Returns:
|
Returns:
|
Pointer to the head of the list.
|
Pointer to the head of the list.
|
|
|
*/
|
*/
|
list_head *core_list_init(ee_u32 blksize, list_head *memblock, ee_s16 seed) {
|
list_head *
|
|
core_list_init(ee_u32 blksize, list_head *memblock, ee_s16 seed)
|
|
{
|
/* calculated pointers for the list */
|
/* calculated pointers for the list */
|
ee_u32 per_item=16+sizeof(struct list_data_s);
|
ee_u32 per_item=16+sizeof(struct list_data_s);
|
ee_u32 size=(blksize/per_item)-2; /* to accomodate systems with 64b pointers, and make sure same code is executed, set max list elements */
|
ee_u32 size = (blksize / per_item)
|
|
- 2; /* to accomodate systems with 64b pointers, and make sure
|
|
same code is executed, set max list elements */
|
list_head *memblock_end=memblock+size;
|
list_head *memblock_end=memblock+size;
|
list_data *datablock=(list_data *)(memblock_end);
|
list_data *datablock=(list_data *)(memblock_end);
|
list_data *datablock_end=datablock+size;
|
list_data *datablock_end=datablock+size;
|
/* some useful variables */
|
/* some useful variables */
|
ee_u32 i;
|
ee_u32 i;
|
list_head *finder,*list=memblock;
|
list_head *finder, *list = memblock;
|
list_data info;
|
list_data info;
|
|
|
/* create a fake items for the list head and tail */
|
/* create a fake items for the list head and tail */
|
list->next=NULL;
|
list->next=NULL;
|
list->info=datablock;
|
list->info=datablock;
|
| Line 228... |
Line 270... |
list->info->data16=(ee_s16)0x8080;
|
list->info->data16=(ee_s16)0x8080;
|
memblock++;
|
memblock++;
|
datablock++;
|
datablock++;
|
info.idx=0x7fff;
|
info.idx=0x7fff;
|
info.data16=(ee_s16)0xffff;
|
info.data16=(ee_s16)0xffff;
|
core_list_insert_new(list,&info,&memblock,&datablock,memblock_end,datablock_end);
|
core_list_insert_new(
|
|
list, &info, &memblock, &datablock, memblock_end, datablock_end);
|
|
|
/* then insert size items */
|
/* then insert size items */
|
for (i=0; i<size; i++) {
|
for (i = 0; i < size; i++)
|
|
{
|
ee_u16 datpat=((ee_u16)(seed^i) & 0xf);
|
ee_u16 datpat=((ee_u16)(seed^i) & 0xf);
|
ee_u16 dat=(datpat<<3) | (i&0x7); /* alternate between algorithms */
|
ee_u16 dat
|
info.data16=(dat<<8) | dat; /* fill the data with actual data and upper bits with rebuild value */
|
= (datpat << 3) | (i & 0x7); /* alternate between algorithms */
|
core_list_insert_new(list,&info,&memblock,&datablock,memblock_end,datablock_end);
|
info.data16 = (dat << 8) | dat; /* fill the data with actual data and
|
|
upper bits with rebuild value */
|
|
core_list_insert_new(
|
|
list, &info, &memblock, &datablock, memblock_end, datablock_end);
|
}
|
}
|
/* and now index the list so we know initial seed order of the list */
|
/* and now index the list so we know initial seed order of the list */
|
finder=list->next;
|
finder=list->next;
|
i=1;
|
i=1;
|
while (finder->next!=NULL) {
|
while (finder->next != NULL)
|
|
{
|
if (i<size/5) /* first 20% of the list in order */
|
if (i<size/5) /* first 20% of the list in order */
|
finder->info->idx=i++;
|
finder->info->idx=i++;
|
else {
|
else
|
|
{
|
ee_u16 pat=(ee_u16)(i++ ^ seed); /* get a pseudo random number */
|
ee_u16 pat=(ee_u16)(i++ ^ seed); /* get a pseudo random number */
|
finder->info->idx=0x3fff & (((i & 0x07) << 8) | pat); /* make sure the mixed items end up after the ones in sequence */
|
finder->info->idx = 0x3fff
|
|
& (((i & 0x07) << 8)
|
|
| pat); /* make sure the mixed items end up
|
|
after the ones in sequence */
|
}
|
}
|
finder=finder->next;
|
finder=finder->next;
|
}
|
}
|
list = core_list_mergesort(list,cmp_idx,NULL);
|
list = core_list_mergesort(list,cmp_idx,NULL);
|
#if CORE_DEBUG
|
#if CORE_DEBUG
|
ee_printf("Initialized list:\n");
|
ee_printf("Initialized list:\n");
|
finder=list;
|
finder=list;
|
while (finder) {
|
while (finder)
|
ee_printf("[%04x,%04x]",finder->info->idx,(ee_u16)finder->info->data16);
|
{
|
|
ee_printf(
|
|
"[%04x,%04x]", finder->info->idx, (ee_u16)finder->info->data16);
|
finder=finder->next;
|
finder=finder->next;
|
}
|
}
|
ee_printf("\n");
|
ee_printf("\n");
|
#endif
|
#endif
|
return list;
|
return list;
|
| Line 276... |
Line 330... |
datablock_end - end of region for list data
|
datablock_end - end of region for list data
|
|
|
Returns:
|
Returns:
|
Pointer to new item.
|
Pointer to new item.
|
*/
|
*/
|
list_head *core_list_insert_new(list_head *insert_point, list_data *info, list_head **memblock, list_data **datablock
|
list_head *
|
, list_head *memblock_end, list_data *datablock_end) {
|
core_list_insert_new(list_head * insert_point,
|
|
list_data * info,
|
|
list_head **memblock,
|
|
list_data **datablock,
|
|
list_head * memblock_end,
|
|
list_data * datablock_end)
|
|
{
|
list_head *newitem;
|
list_head *newitem;
|
|
|
if ((*memblock+1) >= memblock_end)
|
if ((*memblock+1) >= memblock_end)
|
return NULL;
|
return NULL;
|
if ((*datablock+1) >= datablock_end)
|
if ((*datablock+1) >= datablock_end)
|
return NULL;
|
return NULL;
|
|
|
newitem=*memblock;
|
newitem = *memblock;
|
(*memblock)++;
|
(*memblock)++;
|
newitem->next=insert_point->next;
|
newitem->next=insert_point->next;
|
insert_point->next=newitem;
|
insert_point->next=newitem;
|
|
|
newitem->info=*datablock;
|
newitem->info = *datablock;
|
(*datablock)++;
|
(*datablock)++;
|
copy_info(newitem->info,info);
|
copy_info(newitem->info,info);
|
|
|
return newitem;
|
return newitem;
|
}
|
}
|
| Line 305... |
Line 365... |
Operation:
|
Operation:
|
For a singly linked list, remove by copying the data from the next item
|
For a singly linked list, remove by copying the data from the next item
|
over to the current cell, and unlinking the next item.
|
over to the current cell, and unlinking the next item.
|
|
|
Note:
|
Note:
|
since there is always a fake item at the end of the list, no need to check for NULL.
|
since there is always a fake item at the end of the list, no need to
|
|
check for NULL.
|
|
|
Returns:
|
Returns:
|
Removed item.
|
Removed item.
|
*/
|
*/
|
list_head *core_list_remove(list_head *item) {
|
list_head *
|
|
core_list_remove(list_head *item)
|
|
{
|
list_data *tmp;
|
list_data *tmp;
|
list_head *ret=item->next;
|
list_head *ret=item->next;
|
/* swap data pointers */
|
/* swap data pointers */
|
tmp=item->info;
|
tmp=item->info;
|
item->info=ret->info;
|
item->info=ret->info;
|
| Line 339... |
Line 402... |
|
|
Returns:
|
Returns:
|
The item that was linked back to the list.
|
The item that was linked back to the list.
|
|
|
*/
|
*/
|
list_head *core_list_undo_remove(list_head *item_removed, list_head *item_modified) {
|
list_head *
|
|
core_list_undo_remove(list_head *item_removed, list_head *item_modified)
|
|
{
|
list_data *tmp;
|
list_data *tmp;
|
/* swap data pointers */
|
/* swap data pointers */
|
tmp=item_removed->info;
|
tmp=item_removed->info;
|
item_removed->info=item_modified->info;
|
item_removed->info=item_modified->info;
|
item_modified->info=tmp;
|
item_modified->info=tmp;
|
| Line 364... |
Line 429... |
info - idx or data to find
|
info - idx or data to find
|
|
|
Returns:
|
Returns:
|
Found item, or NULL if not found.
|
Found item, or NULL if not found.
|
*/
|
*/
|
list_head *core_list_find(list_head *list,list_data *info) {
|
list_head *
|
if (info->idx>=0) {
|
core_list_find(list_head *list, list_data *info)
|
|
{
|
|
if (info->idx >= 0)
|
|
{
|
while (list && (list->info->idx != info->idx))
|
while (list && (list->info->idx != info->idx))
|
list=list->next;
|
list=list->next;
|
return list;
|
return list;
|
} else {
|
}
|
|
else
|
|
{
|
while (list && ((list->info->data16 & 0xff) != info->data16))
|
while (list && ((list->info->data16 & 0xff) != info->data16))
|
list=list->next;
|
list=list->next;
|
return list;
|
return list;
|
}
|
}
|
}
|
}
|
| Line 389... |
Line 459... |
|
|
Returns:
|
Returns:
|
Found item, or NULL if not found.
|
Found item, or NULL if not found.
|
*/
|
*/
|
|
|
list_head *core_list_reverse(list_head *list) {
|
list_head *
|
|
core_list_reverse(list_head *list)
|
|
{
|
list_head *next=NULL, *tmp;
|
list_head *next=NULL, *tmp;
|
while (list) {
|
while (list)
|
|
{
|
tmp=list->next;
|
tmp=list->next;
|
list->next=next;
|
list->next=next;
|
next=list;
|
next=list;
|
list=tmp;
|
list=tmp;
|
}
|
}
|
| Line 404... |
Line 477... |
/* Function: core_list_mergesort
|
/* Function: core_list_mergesort
|
Sort the list in place without recursion.
|
Sort the list in place without recursion.
|
|
|
Description:
|
Description:
|
Use mergesort, as for linked list this is a realistic solution.
|
Use mergesort, as for linked list this is a realistic solution.
|
Also, since this is aimed at embedded, care was taken to use iterative rather then recursive algorithm.
|
Also, since this is aimed at embedded, care was taken to use iterative
|
The sort can either return the list to original order (by idx) ,
|
rather then recursive algorithm. The sort can either return the list to
|
or use the data item to invoke other other algorithms and change the order of the list.
|
original order (by idx) , or use the data item to invoke other other
|
|
algorithms and change the order of the list.
|
|
|
Parameters:
|
Parameters:
|
list - list to be sorted.
|
list - list to be sorted.
|
cmp - cmp function to use
|
cmp - cmp function to use
|
|
|
| Line 420... |
Line 494... |
Note:
|
Note:
|
We have a special header for the list that will always be first,
|
We have a special header for the list that will always be first,
|
but the algorithm could theoretically modify where the list starts.
|
but the algorithm could theoretically modify where the list starts.
|
|
|
*/
|
*/
|
list_head *core_list_mergesort(list_head *list, list_cmp cmp, core_results *res) {
|
list_head *
|
|
core_list_mergesort(list_head *list, list_cmp cmp, core_results *res)
|
|
{
|
list_head *p, *q, *e, *tail;
|
list_head *p, *q, *e, *tail;
|
ee_s32 insize, nmerges, psize, qsize, i;
|
ee_s32 insize, nmerges, psize, qsize, i;
|
|
|
insize = 1;
|
insize = 1;
|
|
|
while (1) {
|
while (1)
|
|
{
|
p = list;
|
p = list;
|
list = NULL;
|
list = NULL;
|
tail = NULL;
|
tail = NULL;
|
|
|
nmerges = 0; /* count number of merges we do in this pass */
|
nmerges = 0; /* count number of merges we do in this pass */
|
|
|
while (p) {
|
while (p)
|
|
{
|
nmerges++; /* there exists a merge to be done */
|
nmerges++; /* there exists a merge to be done */
|
/* step `insize' places along from p */
|
/* step `insize' places along from p */
|
q = p;
|
q = p;
|
psize = 0;
|
psize = 0;
|
for (i = 0; i < insize; i++) {
|
for (i = 0; i < insize; i++)
|
|
{
|
psize++;
|
psize++;
|
q = q->next;
|
q = q->next;
|
if (!q) break;
|
if (!q)
|
|
break;
|
}
|
}
|
|
|
/* if q hasn't fallen off end, we have two lists to merge */
|
/* if q hasn't fallen off end, we have two lists to merge */
|
qsize = insize;
|
qsize = insize;
|
|
|
/* now we have two lists; merge them */
|
/* now we have two lists; merge them */
|
while (psize > 0 || (qsize > 0 && q)) {
|
while (psize > 0 || (qsize > 0 && q))
|
|
{
|
|
|
/* decide whether next element of merge comes from p or q */
|
/* decide whether next element of merge comes from p or q */
|
if (psize == 0) {
|
if (psize == 0)
|
|
{
|
/* p is empty; e must come from q. */
|
/* p is empty; e must come from q. */
|
e = q; q = q->next; qsize--;
|
e = q;
|
} else if (qsize == 0 || !q) {
|
q = q->next;
|
|
qsize--;
|
|
}
|
|
else if (qsize == 0 || !q)
|
|
{
|
/* q is empty; e must come from p. */
|
/* q is empty; e must come from p. */
|
e = p; p = p->next; psize--;
|
e = p;
|
} else if (cmp(p->info,q->info,res) <= 0) {
|
p = p->next;
|
/* First element of p is lower (or same); e must come from p. */
|
psize--;
|
e = p; p = p->next; psize--;
|
}
|
} else {
|
else if (cmp(p->info, q->info, res) <= 0)
|
|
{
|
|
/* First element of p is lower (or same); e must come from
|
|
* p. */
|
|
e = p;
|
|
p = p->next;
|
|
psize--;
|
|
}
|
|
else
|
|
{
|
/* First element of q is lower; e must come from q. */
|
/* First element of q is lower; e must come from q. */
|
e = q; q = q->next; qsize--;
|
e = q;
|
|
q = q->next;
|
|
qsize--;
|
}
|
}
|
|
|
/* add the next element to the merged list */
|
/* add the next element to the merged list */
|
if (tail) {
|
if (tail)
|
|
{
|
tail->next = e;
|
tail->next = e;
|
} else {
|
}
|
|
else
|
|
{
|
list = e;
|
list = e;
|
}
|
}
|
tail = e;
|
tail = e;
|
}
|
}
|
|
|
