src/bdd/cudd/cuddCache.c File Reference

#include "util_hack.h"
#include "cuddInt.h"

Include dependency graph for cuddCache.c:

Go to the source code of this file.

Functions
int	cuddInitCache (DdManager *unique, unsigned int cacheSize, unsigned int maxCacheSize)
void	cuddCacheInsert (DdManager *table, ptruint op, DdNode *f, DdNode *g, DdNode *h, DdNode *data)
void	cuddCacheInsert2 (DdManager *table, DdNode *(*op)(DdManager *, DdNode *, DdNode *), DdNode *f, DdNode *g, DdNode *data)
void	cuddCacheInsert1 (DdManager *table, DdNode *(*op)(DdManager *, DdNode *), DdNode *f, DdNode *data)
DdNode *	cuddCacheLookup (DdManager *table, ptruint op, DdNode *f, DdNode *g, DdNode *h)
DdNode *	cuddCacheLookupZdd (DdManager *table, ptruint op, DdNode *f, DdNode *g, DdNode *h)
DdNode *	cuddCacheLookup2 (DdManager *table, DdNode *(*op)(DdManager *, DdNode *, DdNode *), DdNode *f, DdNode *g)
DdNode *	cuddCacheLookup1 (DdManager *table, DdNode *(*op)(DdManager *, DdNode *), DdNode *f)
DdNode *	cuddCacheLookup2Zdd (DdManager *table, DdNode *(*op)(DdManager *, DdNode *, DdNode *), DdNode *f, DdNode *g)
DdNode *	cuddCacheLookup1Zdd (DdManager *table, DdNode *(*op)(DdManager *, DdNode *), DdNode *f)
DdNode *	cuddConstantLookup (DdManager *table, ptruint op, DdNode *f, DdNode *g, DdNode *h)
int	cuddCacheProfile (DdManager *table, FILE *fp)
void	cuddCacheResize (DdManager *table)
void	cuddCacheFlush (DdManager *table)
int	cuddComputeFloorLog2 (unsigned int value)
Variables
static char rcsid[]	DD_UNUSED = "$Id: cuddCache.c,v 1.1.1.1 2003/02/24 22:23:51 wjiang Exp $"

---

Function Documentation

void cuddCacheFlush

(

DdManager *

table

)

Function********************************************************************

Synopsis [Flushes the cache.]

Description []

SideEffects [None]

SeeAlso []

Definition at line 974 of file cuddCache.c.

{
    int i, slots;
    DdCache *cache;

    slots = table->cacheSlots;
    cache = table->cache;
    for (i = 0; i < slots; i++) {
        table->cachedeletions += cache[i].data != NULL;
        cache[i].data = NULL;
    }
    table->cacheLastInserts = table->cacheinserts;

    return;

} /* end of cuddCacheFlush */

void cuddCacheInsert	(	DdManager *	table,
		ptruint	op,
		DdNode *	f,
		DdNode *	g,
		DdNode *	h,
		DdNode *	data
	)

Function********************************************************************

Synopsis [Inserts a result in the cache.]

Description []

SideEffects [None]

SeeAlso [cuddCacheInsert2 cuddCacheInsert1]

Definition at line 187 of file cuddCache.c.

{
    int posn;
    register DdCache *entry;
    ptruint uf, ug, uh;

    uf = (ptruint) f | (op & 0xe);
    ug = (ptruint) g | (op >> 4);
    uh = (ptruint) h;

    posn = ddCHash2(uh,uf,ug,table->cacheShift);
    entry = &table->cache[posn];

    table->cachecollisions += entry->data != NULL;
    table->cacheinserts++;

    entry->f    = (DdNode *) uf;
    entry->g    = (DdNode *) ug;
    entry->h    = uh;
    entry->data = data;
#ifdef DD_CACHE_PROFILE
    entry->count++;
#endif

} /* end of cuddCacheInsert */

void cuddCacheInsert1	(	DdManager *	table,
		DdNode *(*)(DdManager *, DdNode *)	op,
		DdNode *	f,
		DdNode *	data
	)

Function********************************************************************

Synopsis [Inserts a result in the cache for a function with two operands.]

Description []

SideEffects [None]

SeeAlso [cuddCacheInsert cuddCacheInsert2]

Definition at line 275 of file cuddCache.c.

{
    int posn;
    register DdCache *entry;

    posn = ddCHash2(op,f,f,table->cacheShift);
    entry = &table->cache[posn];

    if (entry->data != NULL) {
        table->cachecollisions++;
    }
    table->cacheinserts++;

    entry->f = f;
    entry->g = f;
    entry->h = (ptruint) op;
    entry->data = data;
#ifdef DD_CACHE_PROFILE
    entry->count++;
#endif

} /* end of cuddCacheInsert1 */

void cuddCacheInsert2	(	DdManager *	table,
		DdNode *(*)(DdManager *, DdNode *, DdNode *)	op,
		DdNode *	f,
		DdNode *	g,
		DdNode *	data
	)

Function********************************************************************

Synopsis [Inserts a result in the cache for a function with two operands.]

Description []

SideEffects [None]

SeeAlso [cuddCacheInsert cuddCacheInsert1]

Definition at line 233 of file cuddCache.c.

{
    int posn;
    register DdCache *entry;

    posn = ddCHash2(op,f,g,table->cacheShift);
    entry = &table->cache[posn];

    if (entry->data != NULL) {
        table->cachecollisions++;
    }
    table->cacheinserts++;

    entry->f = f;
    entry->g = g;
    entry->h = (ptruint) op;
    entry->data = data;
#ifdef DD_CACHE_PROFILE
    entry->count++;
#endif

} /* end of cuddCacheInsert2 */

DdNode* cuddCacheLookup	(	DdManager *	table,
		ptruint	op,
		DdNode *	f,
		DdNode *	g,
		DdNode *	h
	)

Function********************************************************************

Synopsis [Looks up in the cache for the result of op applied to f, g, and h.]

Description [Returns the result if found; it returns NULL if no result is found.]

SideEffects [None]

SeeAlso [cuddCacheLookup2 cuddCacheLookup1]

Definition at line 317 of file cuddCache.c.

{
    int posn;
    DdCache *en,*cache;
    DdNode *data;
    ptruint uf, ug, uh;

    uf = (ptruint) f | (op & 0xe);
    ug = (ptruint) g | (op >> 4);
    uh = (ptruint) h;

    cache = table->cache;
#ifdef DD_DEBUG
    if (cache == NULL) {
        return(NULL);
    }
#endif

    posn = ddCHash2(uh,uf,ug,table->cacheShift);
    en = &cache[posn];
    if (en->data != NULL && en->f==(DdNodePtr)uf && en->g==(DdNodePtr)ug &&
        en->h==uh) {
        data = Cudd_Regular(en->data);
        table->cacheHits++;
        if (data->ref == 0) {
            cuddReclaim(table,data);
        }
        return(en->data);
    }

    /* Cache miss: decide whether to resize. */
    table->cacheMisses++;

    if (table->cacheSlack >= 0 &&
        table->cacheHits > table->cacheMisses * table->minHit) {
        cuddCacheResize(table);
    }

    return(NULL);

} /* end of cuddCacheLookup */

DdNode* cuddCacheLookup1	(	DdManager *	table,
		DdNode *(*)(DdManager *, DdNode *)	op,
		DdNode *	f
	)

Function********************************************************************

Synopsis [Looks up in the cache for the result of op applied to f.]

Description [Returns the result if found; it returns NULL if no result is found.]

SideEffects [None]

SeeAlso [cuddCacheLookup cuddCacheLookup2]

Definition at line 495 of file cuddCache.c.

{
    int posn;
    DdCache *en,*cache;
    DdNode *data;

    cache = table->cache;
#ifdef DD_DEBUG
    if (cache == NULL) {
        return(NULL);
    }
#endif

    posn = ddCHash2(op,f,f,table->cacheShift);
    en = &cache[posn];
    if (en->data != NULL && en->f==f && en->h==(ptruint)op) {
        data = Cudd_Regular(en->data);
        table->cacheHits++;
        if (data->ref == 0) {
            cuddReclaim(table,data);
        }
        return(en->data);
    }

    /* Cache miss: decide whether to resize. */
    table->cacheMisses++;

    if (table->cacheSlack >= 0 &&
        table->cacheHits > table->cacheMisses * table->minHit) {
        cuddCacheResize(table);
    }

    return(NULL);

} /* end of cuddCacheLookup1 */

DdNode* cuddCacheLookup1Zdd	(	DdManager *	table,
		DdNode *(*)(DdManager *, DdNode *)	op,
		DdNode *	f
	)

Function********************************************************************

Synopsis [Looks up in the cache for the result of op applied to f.]

Description [Returns the result if found; it returns NULL if no result is found.]

SideEffects [None]

SeeAlso [cuddCacheLookupZdd cuddCacheLookup2Zdd]

Definition at line 603 of file cuddCache.c.

{
    int posn;
    DdCache *en,*cache;
    DdNode *data;

    cache = table->cache;
#ifdef DD_DEBUG
    if (cache == NULL) {
        return(NULL);
    }
#endif

    posn = ddCHash2(op,f,f,table->cacheShift);
    en = &cache[posn];
    if (en->data != NULL && en->f==f && en->h==(ptruint)op) {
        data = Cudd_Regular(en->data);
        table->cacheHits++;
        if (data->ref == 0) {
            cuddReclaimZdd(table,data);
        }
        return(en->data);
    }

    /* Cache miss: decide whether to resize. */
    table->cacheMisses++;

    if (table->cacheSlack >= 0  &&
        table->cacheHits > table->cacheMisses * table->minHit) {
        cuddCacheResize(table);
    }

    return(NULL);

} /* end of cuddCacheLookup1Zdd */

DdNode* cuddCacheLookup2	(	DdManager *	table,
		DdNode *(*)(DdManager *, DdNode *, DdNode *)	op,
		DdNode *	f,
		DdNode *	g
	)

Function********************************************************************

Synopsis [Looks up in the cache for the result of op applied to f and g.]

Description [Returns the result if found; it returns NULL if no result is found.]

SideEffects [None]

SeeAlso [cuddCacheLookup cuddCacheLookup1]

Definition at line 441 of file cuddCache.c.

{
    int posn;
    DdCache *en,*cache;
    DdNode *data;

    cache = table->cache;
#ifdef DD_DEBUG
    if (cache == NULL) {
        return(NULL);
    }
#endif

    posn = ddCHash2(op,f,g,table->cacheShift);
    en = &cache[posn];
    if (en->data != NULL && en->f==f && en->g==g && en->h==(ptruint)op) {
        data = Cudd_Regular(en->data);
        table->cacheHits++;
        if (data->ref == 0) {
            cuddReclaim(table,data);
        }
        return(en->data);
    }

    /* Cache miss: decide whether to resize. */
    table->cacheMisses++;

    if (table->cacheSlack >= 0 &&
        table->cacheHits > table->cacheMisses * table->minHit) {
        cuddCacheResize(table);
    }

    return(NULL);

} /* end of cuddCacheLookup2 */

DdNode* cuddCacheLookup2Zdd	(	DdManager *	table,
		DdNode *(*)(DdManager *, DdNode *, DdNode *)	op,
		DdNode *	f,
		DdNode *	g
	)

Function********************************************************************

Synopsis [Looks up in the cache for the result of op applied to f and g.]

Description [Returns the result if found; it returns NULL if no result is found.]

SideEffects [None]

SeeAlso [cuddCacheLookupZdd cuddCacheLookup1Zdd]

Definition at line 549 of file cuddCache.c.

{
    int posn;
    DdCache *en,*cache;
    DdNode *data;

    cache = table->cache;
#ifdef DD_DEBUG
    if (cache == NULL) {
        return(NULL);
    }
#endif

    posn = ddCHash2(op,f,g,table->cacheShift);
    en = &cache[posn];
    if (en->data != NULL && en->f==f && en->g==g && en->h==(ptruint)op) {
        data = Cudd_Regular(en->data);
        table->cacheHits++;
        if (data->ref == 0) {
            cuddReclaimZdd(table,data);
        }
        return(en->data);
    }

    /* Cache miss: decide whether to resize. */
    table->cacheMisses++;

    if (table->cacheSlack >= 0 &&
        table->cacheHits > table->cacheMisses * table->minHit) {
        cuddCacheResize(table);
    }

    return(NULL);

} /* end of cuddCacheLookup2Zdd */

DdNode* cuddCacheLookupZdd	(	DdManager *	table,
		ptruint	op,
		DdNode *	f,
		DdNode *	g,
		DdNode *	h
	)

Function********************************************************************

Synopsis [Looks up in the cache for the result of op applied to f, g, and h.]

Description [Returns the result if found; it returns NULL if no result is found.]

SideEffects [None]

SeeAlso [cuddCacheLookup2Zdd cuddCacheLookup1Zdd]

Definition at line 379 of file cuddCache.c.

{
    int posn;
    DdCache *en,*cache;
    DdNode *data;
    ptruint uf, ug, uh;

    uf = (ptruint) f | (op & 0xe);
    ug = (ptruint) g | (op >> 4);
    uh = (ptruint) h;

    cache = table->cache;
#ifdef DD_DEBUG
    if (cache == NULL) {
        return(NULL);
    }
#endif

    posn = ddCHash2(uh,uf,ug,table->cacheShift);
    en = &cache[posn];
    if (en->data != NULL && en->f==(DdNodePtr)uf && en->g==(DdNodePtr)ug &&
        en->h==uh) {
        data = Cudd_Regular(en->data);
        table->cacheHits++;
        if (data->ref == 0) {
            cuddReclaimZdd(table,data);
        }
        return(en->data);
    }

    /* Cache miss: decide whether to resize. */
    table->cacheMisses++;

    if (table->cacheSlack >= 0 &&
        table->cacheHits > table->cacheMisses * table->minHit) {
        cuddCacheResize(table);
    }

    return(NULL);

} /* end of cuddCacheLookupZdd */

int cuddCacheProfile	(	DdManager *	table,
		FILE *	fp
	)

Function********************************************************************

Synopsis [Computes and prints a profile of the cache usage.]

Description [Computes and prints a profile of the cache usage. Returns 1 if successful; 0 otherwise.]

SideEffects [None]

SeeAlso []

Definition at line 719 of file cuddCache.c.

{
    DdCache *cache = table->cache;
    int slots = table->cacheSlots;
    int nzeroes = 0;
    int i, retval;
    double exUsed;

#ifdef DD_CACHE_PROFILE
    double count, mean, meansq, stddev, expected;
    long max, min;
    int imax, imin;
    double *hystogramQ, *hystogramR; /* histograms by quotient and remainder */
    int nbins = DD_HYSTO_BINS;
    int bin;
    long thiscount;
    double totalcount, exStddev;

    meansq = mean = expected = 0.0;
    max = min = (long) cache[0].count;
    imax = imin = 0;
    totalcount = 0.0;

    hystogramQ = ALLOC(double, nbins);
    if (hystogramQ == NULL) {
        table->errorCode = CUDD_MEMORY_OUT;
        return(0);
    }
    hystogramR = ALLOC(double, nbins);
    if (hystogramR == NULL) {
        FREE(hystogramQ);
        table->errorCode = CUDD_MEMORY_OUT;
        return(0);
    }
    for (i = 0; i < nbins; i++) {
        hystogramQ[i] = 0;
        hystogramR[i] = 0;
    }

    for (i = 0; i < slots; i++) {
        thiscount = (long) cache[i].count;
        if (thiscount > max) {
            max = thiscount;
            imax = i;
        }
        if (thiscount < min) {
            min = thiscount;
            imin = i;
        }
        if (thiscount == 0) {
            nzeroes++;
        }
        count = (double) thiscount;
        mean += count;
        meansq += count * count;
        totalcount += count;
        expected += count * (double) i;
        bin = (i * nbins) / slots;
        hystogramQ[bin] += (double) thiscount;
        bin = i % nbins;
        hystogramR[bin] += (double) thiscount;
    }
    mean /= (double) slots;
    meansq /= (double) slots;
    
    /* Compute the standard deviation from both the data and the
    ** theoretical model for a random distribution. */
    stddev = sqrt(meansq - mean*mean);
    exStddev = sqrt((1 - 1/(double) slots) * totalcount / (double) slots);

    retval = fprintf(fp,"Cache average accesses = %g\n",  mean);
    if (retval == EOF) return(0);
    retval = fprintf(fp,"Cache access standard deviation = %g ", stddev);
    if (retval == EOF) return(0);
    retval = fprintf(fp,"(expected = %g)\n", exStddev);
    if (retval == EOF) return(0);
    retval = fprintf(fp,"Cache max accesses = %ld for slot %d\n", max, imax);
    if (retval == EOF) return(0);
    retval = fprintf(fp,"Cache min accesses = %ld for slot %d\n", min, imin);
    if (retval == EOF) return(0);
    exUsed = 100.0 * (1.0 - exp(-totalcount / (double) slots));
    retval = fprintf(fp,"Cache used slots = %.2f%% (expected %.2f%%)\n",
                     100.0 - (double) nzeroes * 100.0 / (double) slots,
                     exUsed);
    if (retval == EOF) return(0);

    if (totalcount > 0) {
        expected /= totalcount;
        retval = fprintf(fp,"Cache access hystogram for %d bins", nbins);
        if (retval == EOF) return(0);
        retval = fprintf(fp," (expected bin value = %g)\nBy quotient:",
                         expected);
        if (retval == EOF) return(0);
        for (i = nbins - 1; i>=0; i--) {
            retval = fprintf(fp," %.0f", hystogramQ[i]);
            if (retval == EOF) return(0);
        }
        retval = fprintf(fp,"\nBy residue: ");
        if (retval == EOF) return(0);
        for (i = nbins - 1; i>=0; i--) {
            retval = fprintf(fp," %.0f", hystogramR[i]);
            if (retval == EOF) return(0);
        }
        retval = fprintf(fp,"\n");
        if (retval == EOF) return(0);
    }

    FREE(hystogramQ);
    FREE(hystogramR);
#else
    for (i = 0; i < slots; i++) {
        nzeroes += cache[i].h == 0;
    }
    exUsed = 100.0 *
        (1.0 - exp(-(table->cacheinserts - table->cacheLastInserts) /
                   (double) slots));
    retval = fprintf(fp,"Cache used slots = %.2f%% (expected %.2f%%)\n",
                     100.0 - (double) nzeroes * 100.0 / (double) slots,
                     exUsed);
    if (retval == EOF) return(0);
#endif
    return(1);

} /* end of cuddCacheProfile */

void cuddCacheResize

(

DdManager *

table

)

Function********************************************************************

Synopsis [Resizes the cache.]

Description []

SideEffects [None]

SeeAlso []

Definition at line 859 of file cuddCache.c.

{
    DdCache *cache, *oldcache, *oldacache, *entry, *old;
    int i;
    int posn, shift;
    unsigned int slots, oldslots;
    double offset;
    int moved = 0;
    extern void (*MMoutOfMemory)(long);
    void (*saveHandler)(long);
#ifndef DD_CACHE_PROFILE
    ptruint misalignment;
    DdNodePtr *mem;
#endif

    oldcache = table->cache;
    oldacache = table->acache;
    oldslots = table->cacheSlots;
    slots = table->cacheSlots = oldslots << 1;

#ifdef DD_VERBOSE
    (void) fprintf(table->err,"Resizing the cache from %d to %d entries\n",
                   oldslots, slots);
    (void) fprintf(table->err,
                   "\thits = %g\tmisses = %g\thit ratio = %5.3f\n",
                   table->cacheHits, table->cacheMisses,
                   table->cacheHits / (table->cacheHits + table->cacheMisses));
#endif

    saveHandler = MMoutOfMemory;
    MMoutOfMemory = Cudd_OutOfMem;
    table->acache = cache = ALLOC(DdCache,slots+1);
    MMoutOfMemory = saveHandler;
    /* If we fail to allocate the new table we just give up. */
    if (cache == NULL) {
#ifdef DD_VERBOSE
        (void) fprintf(table->err,"Resizing failed. Giving up.\n");
#endif
        table->cacheSlots = oldslots;
        table->acache = oldacache;
        /* Do not try to resize again. */
        table->maxCacheHard = oldslots - 1;
        table->cacheSlack = - (oldslots + 1);
        return;
    }
    /* If the size of the cache entry is a power of 2, we want to
    ** enforce alignment to that power of two. This happens when
    ** DD_CACHE_PROFILE is not defined. */
#ifdef DD_CACHE_PROFILE
    table->cache = cache;
#else
    mem = (DdNodePtr *) cache;
    misalignment = (ptruint) mem & (sizeof(DdCache) - 1);
    mem += (sizeof(DdCache) - misalignment) / sizeof(DdNodePtr);
    table->cache = cache = (DdCache *) mem;
    assert(((ptruint) table->cache & (sizeof(DdCache) - 1)) == 0);
#endif
    shift = --(table->cacheShift);
    table->memused += (slots - oldslots) * sizeof(DdCache);
    table->cacheSlack -= slots; /* need these many slots to double again */

    /* Clear new cache. */
    for (i = 0; (unsigned) i < slots; i++) {
        cache[i].data = NULL;
        cache[i].h = 0;
#ifdef DD_CACHE_PROFILE
        cache[i].count = 0;
#endif
    }

    /* Copy from old cache to new one. */
    for (i = 0; (unsigned) i < oldslots; i++) {
        old = &oldcache[i];
        if (old->data != NULL) {
            posn = ddCHash2(old->h,old->f,old->g,shift);
            entry = &cache[posn];
            entry->f = old->f;
            entry->g = old->g;
            entry->h = old->h;
            entry->data = old->data;    
#ifdef DD_CACHE_PROFILE
            entry->count = 1;
#endif
            moved++;
        }
    }

    FREE(oldacache);

    /* Reinitialize measurements so as to avoid division by 0 and
    ** immediate resizing.
    */
    offset = (double) (int) (slots * table->minHit + 1);
    table->totCacheMisses += table->cacheMisses - offset;
    table->cacheMisses = offset;
    table->totCachehits += table->cacheHits;
    table->cacheHits = 0;
    table->cacheLastInserts = table->cacheinserts - (double) moved;

} /* end of cuddCacheResize */

int cuddComputeFloorLog2

(

unsigned int

value

)

Function********************************************************************

Synopsis [Returns the floor of the logarithm to the base 2.]

Description [Returns the floor of the logarithm to the base 2. The input value is assumed to be greater than 0.]

SideEffects [None]

SeeAlso []

Definition at line 1006 of file cuddCache.c.

{
    int floorLog = 0;
#ifdef DD_DEBUG
    assert(value > 0);
#endif
    while (value > 1) {
        floorLog++;
        value >>= 1;
    }
    return(floorLog);

} /* end of cuddComputeFloorLog2 */

DdNode* cuddConstantLookup	(	DdManager *	table,
		ptruint	op,
		DdNode *	f,
		DdNode *	g,
		DdNode *	h
	)

Function********************************************************************

Synopsis [Looks up in the cache for the result of op applied to f, g, and h.]

Description [Looks up in the cache for the result of op applied to f, g, and h. Assumes that the calling procedure (e.g., Cudd_bddIteConstant) is only interested in whether the result is constant or not. Returns the result if found (possibly DD_NON_CONSTANT); otherwise it returns NULL.]

SideEffects [None]

SeeAlso [cuddCacheLookup]

Definition at line 660 of file cuddCache.c.

{
    int posn;
    DdCache *en,*cache;
    ptruint uf, ug, uh;

    uf = (ptruint) f | (op & 0xe);
    ug = (ptruint) g | (op >> 4);
    uh = (ptruint) h;

    cache = table->cache;
#ifdef DD_DEBUG
    if (cache == NULL) {
        return(NULL);
    }
#endif
    posn = ddCHash2(uh,uf,ug,table->cacheShift);
    en = &cache[posn];

    /* We do not reclaim here because the result should not be
     * referenced, but only tested for being a constant.
     */
    if (en->data != NULL &&
        en->f == (DdNodePtr)uf && en->g == (DdNodePtr)ug && en->h == uh) {
        table->cacheHits++;
        return(en->data);
    }

    /* Cache miss: decide whether to resize. */
    table->cacheMisses++;

    if (table->cacheSlack >= 0 &&
        table->cacheHits > table->cacheMisses * table->minHit) {
        cuddCacheResize(table);
    }

    return(NULL);

} /* end of cuddConstantLookup */

int cuddInitCache	(	DdManager *	unique,
		unsigned int	cacheSize,
		unsigned int	maxCacheSize
	)

AutomaticStart AutomaticEnd Function********************************************************************

Synopsis [Initializes the computed table.]

Description [Initializes the computed table. It is called by Cudd_Init. Returns 1 in case of success; 0 otherwise.]

SideEffects [None]

SeeAlso [Cudd_Init]

Definition at line 105 of file cuddCache.c.

{
    int i;
    unsigned int logSize;
#ifndef DD_CACHE_PROFILE
    DdNodePtr *mem;
    ptruint offset;
#endif

    /* Round cacheSize to largest power of 2 not greater than the requested
    ** initial cache size. */
    logSize = cuddComputeFloorLog2(ddMax(cacheSize,unique->slots/2));
    cacheSize = 1 << logSize;
    unique->acache = ALLOC(DdCache,cacheSize+1);
    if (unique->acache == NULL) {
        unique->errorCode = CUDD_MEMORY_OUT;
        return(0);
    }
    /* If the size of the cache entry is a power of 2, we want to
    ** enforce alignment to that power of two. This happens when
    ** DD_CACHE_PROFILE is not defined. */
#ifdef DD_CACHE_PROFILE
    unique->cache = unique->acache;
    unique->memused += (cacheSize) * sizeof(DdCache);
#else
    mem = (DdNodePtr *) unique->acache;
    offset = (ptruint) mem & (sizeof(DdCache) - 1);
    mem += (sizeof(DdCache) - offset) / sizeof(DdNodePtr);
    unique->cache = (DdCache *) mem;
    assert(((ptruint) unique->cache & (sizeof(DdCache) - 1)) == 0);
    unique->memused += (cacheSize+1) * sizeof(DdCache);
#endif
    unique->cacheSlots = cacheSize;
    unique->cacheShift = sizeof(int) * 8 - logSize;
    unique->maxCacheHard = maxCacheSize;
    /* If cacheSlack is non-negative, we can resize. */
    unique->cacheSlack = (int) ddMin(maxCacheSize,
        DD_MAX_CACHE_TO_SLOTS_RATIO*unique->slots) -
        2 * (int) cacheSize;
    Cudd_SetMinHit(unique,DD_MIN_HIT);
    /* Initialize to avoid division by 0 and immediate resizing. */
    unique->cacheMisses = (double) (int) (cacheSize * unique->minHit + 1);
    unique->cacheHits = 0;
    unique->totCachehits = 0;
    /* The sum of cacheMisses and totCacheMisses is always correct,
    ** even though cacheMisses is larger than it should for the reasons
    ** explained above. */
    unique->totCacheMisses = -unique->cacheMisses;
    unique->cachecollisions = 0;
    unique->cacheinserts = 0;
    unique->cacheLastInserts = 0;
    unique->cachedeletions = 0;

    /* Initialize the cache */
    for (i = 0; (unsigned) i < cacheSize; i++) {
        unique->cache[i].h = 0; /* unused slots */
        unique->cache[i].data = NULL; /* invalid entry */
#ifdef DD_CACHE_PROFILE
        unique->cache[i].count = 0;
#endif
    }

    return(1);

} /* end of cuddInitCache */

---

Variable Documentation

char rcsid [] DD_UNUSED = "$Id: cuddCache.c,v 1.1.1.1 2003/02/24 22:23:51 wjiang Exp $" [static]

CFile***********************************************************************

FileName [cuddCache.c]

PackageName [cudd]

Synopsis [Functions for cache insertion and lookup.]

Description [Internal procedures included in this module:

• cuddInitCache()
• cuddCacheInsert()
• cuddCacheInsert2()
• cuddCacheLookup()
• cuddCacheLookupZdd()
• cuddCacheLookup2()
• cuddCacheLookup2Zdd()
• cuddConstantLookup()
• cuddCacheProfile()
• cuddCacheResize()
• cuddCacheFlush()
• cuddComputeFloorLog2()

Static procedures included in this module:

SeeAlso []

Author [Fabio Somenzi]

Copyright [ This file was created at the University of Colorado at Boulder. The University of Colorado at Boulder makes no warranty about the suitability of this software for any purpose. It is presented on an AS IS basis.]

Definition at line 65 of file cuddCache.c.