https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68398
Bug ID: 68398
Summary: coremark regression due to r229685
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: spop at gcc dot gnu.org
Target Milestone: ---
We have seen a performance regression due to r229685.
We see fewer FSM jump threads on the reduced testcase.
CC=2015-11-02-23-23-28-d3063db-trunk/bin/gcc
$CC -O3 m.c -fdump-tree-dom1-details=a -o a.out
CC=2015-11-02-23-25-06-f497d67-trunk/bin/gcc
$CC -O3 m.c -fdump-tree-dom1-details=b -o b.out
$ grep FSM a | wc -l
17
$ grep FSM b | wc -l
15
on x86_64 valgrind indicates that with the patch we have 2.5% more instructions
executed:
+ valgrind --dsymutil=yes --tool=callgrind --callgrind-out-file=a.call ./a.out
==27524== Callgrind, a call-graph generating cache profiler
==27524== Copyright (C) 2002-2013, and GNU GPL'd, by Josef Weidendorfer et al.
==27524== Using Valgrind-3.10.0.SVN and LibVEX; rerun with -h for copyright
info
==27524== Command: ./a.out
==27524==
==27524== For interactive control, run 'callgrind_control -h'.
==27524==
==27524== Events : Ir
==27524== Collected : 209839882
==27524==
==27524== I refs: 209,839,882
+ valgrind --dsymutil=yes --tool=callgrind --callgrind-out-file=b.call ./b.out
==27585== Callgrind, a call-graph generating cache profiler
==27585== Copyright (C) 2002-2013, and GNU GPL'd, by Josef Weidendorfer et al.
==27585== Using Valgrind-3.10.0.SVN and LibVEX; rerun with -h for copyright
info
==27585== Command: ./b.out
==27585==
==27585== For interactive control, run 'callgrind_control -h'.
==27585==
==27585== Events : Ir
==27585== Collected : 213154557
==27585==
==27585== I refs: 213,154,557
+ callgrind_annotate a.call
--------------------------------------------------------------------------------
Profile data file 'a.call' (creator: callgrind-3.10.0.SVN)
--------------------------------------------------------------------------------
I1 cache:
D1 cache:
LL cache:
Timerange: Basic block 0 - 46055772
Trigger: Program termination
Profiled target: ./a.out (PID 27524, part 1)
Events recorded: Ir
Events shown: Ir
Event sort order: Ir
Thresholds: 99
Include dirs:
User annotated:
Auto-annotation: off
--------------------------------------------------------------------------------
Ir
--------------------------------------------------------------------------------
209,839,882 PROGRAM TOTALS
--------------------------------------------------------------------------------
Ir file:function
--------------------------------------------------------------------------------
138,250,035 ???:core_bench_list [a.out]
69,160,889 ???:core_list_mergesort.constprop.2 [a.out]
2,309,860 ???:core_list_init [a.out]
+ callgrind_annotate b.call
--------------------------------------------------------------------------------
Profile data file 'b.call' (creator: callgrind-3.10.0.SVN)
--------------------------------------------------------------------------------
I1 cache:
D1 cache:
LL cache:
Timerange: Basic block 0 - 48409229
Trigger: Program termination
Profiled target: ./b.out (PID 27585, part 1)
Events recorded: Ir
Events shown: Ir
Event sort order: Ir
Thresholds: 99
Include dirs:
User annotated:
Auto-annotation: off
--------------------------------------------------------------------------------
Ir
--------------------------------------------------------------------------------
213,154,557 PROGRAM TOTALS
--------------------------------------------------------------------------------
Ir file:function
--------------------------------------------------------------------------------
138,845,638 ???:core_bench_list [b.out]
71,879,961 ???:core_list_mergesort.constprop.2 [b.out]
2,309,860 ???:core_list_init [b.out]
$ cat m.c
typedef struct list_data_s {
short data16;
short idx;
} list_data;
typedef struct list_head_s {
struct list_head_s *next;
struct list_data_s *info;
} list_head;
list_head *core_list_find(list_head *list,list_data *info);
list_head *core_list_reverse(list_head *list);
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_insert_new(list_head *insert_point
, list_data *info, list_head **memblock,
list_data **datablock
, list_head *memblock_end, list_data
*datablock_end);
typedef int(*list_cmp)(list_data *a, list_data *b);
list_head *core_list_mergesort(list_head *list, list_cmp cmp);
short state_scores[4] = {-29126, 24894, -24736, -272};
short matrix_scores[4] = {8151, -30381, -32453, 11169};
unsigned state_idx = 0, matrix_idx = 0;
short calc_func(short *pdata) {
short data=*pdata;
short retval;
unsigned char optype=(data>>7) & 1;
if (optype)
return (data & 0x007f);
else {
short flag=data & 0x7;
short dtype=((data>>3) & 0xf);
dtype |= dtype << 4;
switch (flag) {
case 0:
if (dtype<0x22)
dtype=0x22;
retval=state_scores[state_idx++];
break;
case 1:
retval=matrix_scores[matrix_idx++];
break;
default:
retval=data;
break;
}
retval &= 0x007f;
*pdata = (data & 0xff00) | 0x0080 | retval;
return retval;
}
}
int cmp_complex(list_data *a, list_data *b) {
short val1=calc_func(&(a->data16));
short val2=calc_func(&(b->data16));
return val1 - val2;
}
int cmp_idx(list_data *a, list_data *b) {
a->data16 = (a->data16 & 0xff00) | (0x00ff & (a->data16>>8));
b->data16 = (b->data16 & 0xff00) | (0x00ff & (b->data16>>8));
return a->idx - b->idx;
}
void copy_info(list_data *to,list_data *from) {
to->data16=from->data16;
to->idx=from->idx;
}
unsigned short core_bench_list(list_head *list, short find_num, short
finder_idx) {
unsigned short retval=0;
unsigned short found=0,missed=0;
list_head *this_find;
list_head *finder, *remover;
list_data info;
short i;
info.idx=finder_idx;
for (i=0; i<find_num; i++) {
info.data16= (i & 0xff) ;
this_find=core_list_find(list,&info);
list=core_list_reverse(list);
if (this_find==0) {
missed++;
retval+=(list->next->info->data16 >> 8) & 1;
}
else {
found++;
if (this_find->info->data16 & 0x1)
retval+=(this_find->info->data16 >> 9) & 1;
if (this_find->next != 0) {
finder = this_find->next;
this_find->next = finder->next;
finder->next=list->next;
list->next=finder;
}
}
if (info.idx>=0)
info.idx++;
}
retval+=found*4-missed;
if (finder_idx>0)
list=core_list_mergesort(list,cmp_complex);
remover=core_list_remove(list->next);
finder=core_list_find(list,&info);
if (!finder)
finder=list->next;
while (finder) {
finder=finder->next;
}
remover=core_list_undo_remove(remover,list->next);
list=core_list_mergesort(list,cmp_idx);
finder=list->next;
while (finder) {
finder=finder->next;
}
return retval;
}
list_head *core_list_init(unsigned blksize, list_head *memblock, short seed) {
unsigned per_item=16+sizeof(struct list_data_s);
unsigned size=(blksize/per_item)-2;
list_head *memblock_end=memblock+size;
list_data *datablock=(list_data *)(memblock_end);
list_data *datablock_end=datablock+size;
unsigned i;
list_head *finder,*list=memblock;
list_data info;
list->next=0;
list->info=datablock;
list->info->idx=0x0000;
list->info->data16=(short)0x8080;
memblock++;
datablock++;
info.idx=0x7fff;
info.data16=(short)0xffff;
core_list_insert_new(list,&info,&memblock,&datablock,memblock_end,datablock_end);
for (i=0; i<size; i++) {
unsigned short datpat=((unsigned short)(seed^i) & 0xf);
unsigned short dat=(datpat<<3) | (i&0x7);
info.data16=(dat<<8) | dat;
core_list_insert_new(list,&info,&memblock,&datablock,memblock_end,datablock_end);
}
finder=list->next;
i=1;
while (finder->next!=0) {
if (i<size/5)
finder->info->idx=i++;
else {
unsigned short pat=(unsigned short)(i++ ^ seed);
finder->info->idx=0x3fff & (((i & 0x07) << 8) | pat);
}
finder=finder->next;
}
list = core_list_mergesort(list,cmp_idx);
return list;
}
list_head *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;
if ((*memblock+1) >= memblock_end)
return 0;
if ((*datablock+1) >= datablock_end)
return 0;
newitem=*memblock;
(*memblock)++;
newitem->next=insert_point->next;
insert_point->next=newitem;
newitem->info=*datablock;
(*datablock)++;
copy_info(newitem->info,info);
return newitem;
}
list_head *core_list_remove(list_head *item) {
list_data *tmp;
list_head *ret=item->next;
tmp=item->info;
item->info=ret->info;
ret->info=tmp;
item->next=item->next->next;
ret->next=0;
return ret;
}
list_head *core_list_undo_remove(list_head *item_removed, list_head
*item_modified) {
list_data *tmp;
tmp=item_removed->info;
item_removed->info=item_modified->info;
item_modified->info=tmp;
item_removed->next=item_modified->next;
item_modified->next=item_removed;
return item_removed;
}
list_head *core_list_find(list_head *list,list_data *info) {
if (info->idx>=0) {
while (list && (list->info->idx != info->idx))
list=list->next;
return list;
} else {
while (list && ((list->info->data16 & 0xff) != info->data16))
list=list->next;
return list;
}
}
list_head *core_list_reverse(list_head *list) {
list_head *next=0, *tmp;
while (list) {
tmp=list->next;
list->next=next;
next=list;
list=tmp;
}
return next;
}
list_head *core_list_mergesort(list_head *list, list_cmp cmp) {
list_head *p, *q, *e, *tail;
int insize, nmerges, psize, qsize, i;
insize = 1;
while (1) {
p = list;
list = 0;
tail = 0;
nmerges = 0;
while (p) {
nmerges++;
q = p;
psize = 0;
for (i = 0; i < insize; i++) {
psize++;
q = q->next;
if (!q) break;
}
qsize = insize;
while (psize > 0 || (qsize > 0 && q)) {
if (psize == 0) {
e = q; q = q->next; qsize--;
} else if (qsize == 0 || !q) {
e = p; p = p->next; psize--;
} else if (cmp(p->info,q->info) <= 0) {
e = p; p = p->next; psize--;
} else {
e = q; q = q->next; qsize--;
}
if (tail) {
tail->next = e;
} else {
list = e;
}
tail = e;
}
p = q;
}
tail->next = 0;
if (nmerges <= 1)
return list;
insize *= 2;
}
return list;
}
#define N 1000000
unsigned char pp[N];
int main (int argc, char *argv[]) {
list_head *head = core_list_init(N, (list_head *)pp, 0);
core_bench_list(head, 102, 1);
core_bench_list(head, 102, -1);
return 0;
}
