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[buddy] Reduce the size of bddNode to improve cache efficiency.

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The unicity table was mixed with the bddNode table for now
apparent reason.  After the hash of some node is computed,
bddnodes[hash] did only contain some random node (not the one
looked for) whose .hash member would point to the actual node with
this hash.  So that's a two step lookup.  With this patch, we sill
have a two step lookup, but the .hash member have been moved to a
separate array.  A consequence is that bddNode is now 16-byte long
(instead of 20) so it will never span across two cache lines.

* src/kernel.h (bddNode): Remove the hash member, and move it...
(bddhash): ... as this new separate table.
* src/kernel.c, src/reorder.c: Adjust all code.
This commit is contained in:
Alexandre Duret-Lutz 2012-06-08 11:28:48 +02:00
parent 96c436e0e2
commit e7a46e10e2
4 changed files with 75 additions and 43 deletions
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56
buddy/src/reorder.c
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@ -902,14 +902,11 @@ static int mark_roots(void)
addDependencies(dep);
}
/* Make sure the hash field is empty. This saves a loop in the
initial GBC */
node->hash = 0;
}
bddnodes[0].hash = 0;
bddnodes[1].hash = 0;
/* Make sure the hash is empty. This saves a loop in the initial
GBC */
memset(bddhash, 0, bddnodesize*sizeof(*bddhash));
free(dep);
return 0;
@ -938,8 +935,8 @@ static void reorder_gbc(void)
register unsigned int hash;
hash = NODEHASH(VARp(node), LOWp(node), HIGHp(node));
node->next = bddnodes[hash].hash;
bddnodes[hash].hash = n;
node->next = bddhash[hash];
bddhash[hash] = n;
}
else
@ -987,8 +984,7 @@ static void reorder_rehashAll(void)
reorder_setLevellookup();
bddfreepos = 0;
for (n=bddnodesize-1 ; n>=0 ; n--)
bddnodes[n].hash = 0;
memset(bddhash, 0, sizeof(*bddhash)*bddnodesize);
for (n=bddnodesize-1 ; n>=2 ; n--)
{
@ -999,8 +995,8 @@ static void reorder_rehashAll(void)
register unsigned int hash;
hash = NODEHASH(VARp(node), LOWp(node), HIGHp(node));
node->next = bddnodes[hash].hash;
bddnodes[hash].hash = n;
node->next = bddhash[hash];
bddhash[hash] = n;
}
else
{
@ -1038,7 +1034,7 @@ static int reorder_makenode(int var, int low, int high)
/* Try to find an existing node of this kind */
hash = NODEHASH(var, low, high);
res = bddnodes[hash].hash;
res = bddhash[hash];
while(res != 0)
{
@ -1097,8 +1093,8 @@ static int reorder_makenode(int var, int low, int high)
HIGHp(node) = high;
/* Insert node in hash chain */
node->next = bddnodes[hash].hash;
bddnodes[hash].hash = res;
node->next = bddhash[hash];
bddhash[hash] = res;
/* Make sure it is reference counted */
node->refcou = 1;
@ -1128,8 +1124,8 @@ static int reorder_downSimple(int var0)
{
int r;
r = bddnodes[n + vl0].hash;
bddnodes[n + vl0].hash = 0;
r = bddhash[n + vl0];
bddhash[n + vl0] = 0;
while (r != 0)
{
@ -1139,8 +1135,8 @@ static int reorder_downSimple(int var0)
if (VAR(LOWp(node)) != var1 && VAR(HIGHp(node)) != var1)
{
/* Node does not depend on next var, let it stay in the chain */
node->next = bddnodes[n+vl0].hash;
bddnodes[n+vl0].hash = r;
node->next = bddhash[n+vl0];
bddhash[n+vl0] = r;
levels[var0].nodenum++;
}
else
@ -1219,8 +1215,8 @@ static void reorder_swap(int toBeProcessed, int var0)
/* Rehash the node since it got new childs */
hash = NODEHASH(VARp(node), LOWp(node), HIGHp(node));
node->next = bddnodes[hash].hash;
bddnodes[hash].hash = toBeProcessed;
node->next = bddhash[hash];
bddhash[hash] = toBeProcessed;
toBeProcessed = next;
}
@ -1241,8 +1237,8 @@ static void reorder_localGbc(int var0)
for (n=0 ; n<size1 ; n++)
{
int hash = n+vl1;
int r = bddnodes[hash].hash;
bddnodes[hash].hash = 0;
int r = bddhash[hash];
bddhash[hash] = 0;
while (r)
{
@ -1251,8 +1247,8 @@ static void reorder_localGbc(int var0)
if (node->refcou > 0)
{
node->next = bddnodes[hash].hash;
bddnodes[hash].hash = r;
node->next = bddhash[hash];
bddhash[hash] = r;
}
else
{
@ -1343,8 +1339,8 @@ static void reorder_localGbcResize(int toBeProcessed, int var0)
for (n=0 ; n<size1 ; n++)
{
int hash = n+vl1;
int r = bddnodes[hash].hash;
bddnodes[hash].hash = 0;
int r = bddhash[hash];
bddhash[hash] = 0;
while (r)
{
@ -1388,8 +1384,8 @@ static void reorder_localGbcResize(int toBeProcessed, int var0)
int next = node->next;
int hash = NODEHASH(VARp(node), LOWp(node), HIGHp(node));
node->next = bddnodes[hash].hash;
bddnodes[hash].hash = toBeProcessed;
node->next = bddhash[hash];
bddhash[hash] = toBeProcessed;
toBeProcessed = next;
}
@ -1420,7 +1416,7 @@ static void sanitycheck(void)
for (n=0 ; n<levels[v].size ; n++)
{
r = bddnodes[n+levels[v].start].hash;
r = bddhash[n+levels[v].start];
while (r)
{