[Ffmpeg-devel] [PATCH] optimize ff_eval
Oded Shimon
ods15
Thu Oct 26 20:45:02 CEST 2006
I took the liberty of optimizing ff_eval for multiple runs by seperating
the parsing/compiling and runtime steps.
before:
97730 dezicycles in ff_eval, 1023 runs, 1 skips
after:
13643 dezicycles in ff_parse, 1023 runs, 1 skips
What should I do with this? Deperecate or keep old ff_eval? update current
calls for ff_eval to this new thing?
Patch is very obviously not cleaned up (there isn't even a free function
yet), just shows what I did...
- ods15
-------------- next part --------------
Index: libavcodec/eval.c
===================================================================
--- libavcodec/eval.c (revision 6797)
+++ libavcodec/eval.c (working copy)
@@ -57,8 +57,6 @@
char **error;
} Parser;
-static double evalExpression(Parser *p);
-
static int8_t si_prefixes['z' - 'E' + 1]={
['y'-'E']= -24,
['z'-'E']= -21,
@@ -126,23 +124,64 @@
return 1;
}
-static double evalPrimary(Parser *p){
- double d, d2=NAN;
+typedef struct expr_s expr_t;
+struct expr_s {
+ int type;
+ double value; // is sign in other types
+ int const_index;
+ double (*func0)(double);
+ double (*func1)(void *, double);
+ double (*func2)(void *, double, double);
+ expr_t * param[2];
+};
+
+static double evalsquish( double d ) { return 1/(1+exp(4*d)); }
+static double evalgauss ( double d ) { return exp(-d*d/2)/sqrt(2*M_PI); }
+static double evalmod (void * a, double d, double d2) { return d - floor(d/d2)*d2; }
+static double evalmax (void * a, double d, double d2) { return d > d2 ? d : d2; }
+static double evalmin (void * a, double d, double d2) { return d < d2 ? d : d2; }
+static double evalgt (void * a, double d, double d2) { return d > d2 ? 1.0 : 0.0; }
+static double evalgte (void * a, double d, double d2) { return d >= d2 ? 1.0 : 0.0; }
+static double evaleq (void * a, double d, double d2) { return d == d2 ? 1.0 : 0.0; }
+static double evalpow (void * a, double d, double d2) { return pow(d, d2); }
+static double evalmul (void * a, double d, double d2) { return d * d2; }
+static double evaldiv (void * a, double d, double d2) { return d / d2; }
+static double evaladd (void * a, double d, double d2) { return d + d2; }
+
+static double eval_expr(Parser * p, expr_t * e) {
+ if (e->type == 0) return e->value;
+ else switch(e->type) {
+ case 1: return e->value * p->const_value[e->const_index];
+ case 2: return e->value * e->func0(eval_expr(p, e->param[0]));
+ case 3: return e->value * e->func1(p->opaque, eval_expr(p, e->param[0]));
+ case 4: return e->value * e->func2(p->opaque, eval_expr(p, e->param[0]), eval_expr(p, e->param[1]));
+ default: assert(0); return 0;
+ }
+}
+
+static expr_t * parse_expr(Parser *p);
+
+static expr_t * parse_primary(Parser *p) {
+ expr_t * d = calloc(1, sizeof(expr_t));
char *next= p->s;
int i;
/* number */
- d= av_strtod(p->s, &next);
+ d->value = av_strtod(p->s, &next);
if(next != p->s){
+ d->type = 0;
p->s= next;
return d;
}
+ d->value = 1;
/* named constants */
for(i=0; p->const_name && p->const_name[i]; i++){
if(strmatch(p->s, p->const_name[i])){
p->s+= strlen(p->const_name[i]);
- return p->const_value[i];
+ d->type = 1;
+ d->const_index = i;
+ return d;
}
}
@@ -150,141 +189,169 @@
if(p->s==NULL){
*p->error = "missing (";
p->s= next;
- return NAN;
+ return NULL;
}
p->s++; // "("
- d= evalExpression(p);
+ if (*next == '(') { // special case do-nothing
+#undef free
+ free(d);
+ d = parse_expr(p);
+ if(p->s[0] != ')'){
+ *p->error = "missing )";
+ return NULL;
+ }
+ p->s++; // ")"
+ return d;
+ }
+ d->param[0] = parse_expr(p);
if(p->s[0]== ','){
p->s++; // ","
- d2= evalExpression(p);
+ d->param[1] = parse_expr(p);
}
if(p->s[0] != ')'){
*p->error = "missing )";
- return NAN;
+ return NULL;
}
p->s++; // ")"
- if( strmatch(next, "sinh" ) ) d= sinh(d);
- else if( strmatch(next, "cosh" ) ) d= cosh(d);
- else if( strmatch(next, "tanh" ) ) d= tanh(d);
- else if( strmatch(next, "sin" ) ) d= sin(d);
- else if( strmatch(next, "cos" ) ) d= cos(d);
- else if( strmatch(next, "tan" ) ) d= tan(d);
- else if( strmatch(next, "atan" ) ) d= atan(d);
- else if( strmatch(next, "asin" ) ) d= asin(d);
- else if( strmatch(next, "acos" ) ) d= acos(d);
- else if( strmatch(next, "exp" ) ) d= exp(d);
- else if( strmatch(next, "log" ) ) d= log(d);
- else if( strmatch(next, "squish") ) d= 1/(1+exp(4*d));
- else if( strmatch(next, "gauss" ) ) d= exp(-d*d/2)/sqrt(2*M_PI);
- else if( strmatch(next, "abs" ) ) d= fabs(d);
- else if( strmatch(next, "mod" ) ) d-= floor(d/d2)*d2;
- else if( strmatch(next, "max" ) ) d= d > d2 ? d : d2;
- else if( strmatch(next, "min" ) ) d= d < d2 ? d : d2;
- else if( strmatch(next, "gt" ) ) d= d > d2 ? 1.0 : 0.0;
- else if( strmatch(next, "gte" ) ) d= d >= d2 ? 1.0 : 0.0;
- else if( strmatch(next, "lt" ) ) d= d > d2 ? 0.0 : 1.0;
- else if( strmatch(next, "lte" ) ) d= d >= d2 ? 0.0 : 1.0;
- else if( strmatch(next, "eq" ) ) d= d == d2 ? 1.0 : 0.0;
- else if( strmatch(next, "(" ) ) d= d;
-// else if( strmatch(next, "l1" ) ) d= 1 + d2*(d - 1);
-// else if( strmatch(next, "sq01" ) ) d= (d >= 0.0 && d <=1.0) ? 1.0 : 0.0;
+ if( strmatch(next, "sinh" ) ) d->func0 = sinh;
+ else if( strmatch(next, "cosh" ) ) d->func0 = cosh;
+ else if( strmatch(next, "tanh" ) ) d->func0 = tanh;
+ else if( strmatch(next, "sin" ) ) d->func0 = sin;
+ else if( strmatch(next, "cos" ) ) d->func0 = cos;
+ else if( strmatch(next, "tan" ) ) d->func0 = tan;
+ else if( strmatch(next, "atan" ) ) d->func0 = atan;
+ else if( strmatch(next, "asin" ) ) d->func0 = asin;
+ else if( strmatch(next, "acos" ) ) d->func0 = acos;
+ else if( strmatch(next, "exp" ) ) d->func0 = exp;
+ else if( strmatch(next, "log" ) ) d->func0 = log;
+ else if( strmatch(next, "squish") ) d->func0 = evalsquish;
+ else if( strmatch(next, "gauss" ) ) d->func0 = evalgauss;
+ else if( strmatch(next, "abs" ) ) d->func0 = fabs;
+ else if( strmatch(next, "mod" ) ) d->func2 = evalmod;
+ else if( strmatch(next, "max" ) ) d->func2 = evalmax;
+ else if( strmatch(next, "min" ) ) d->func2 = evalmin;
+ else if( strmatch(next, "gt" ) ) d->func2 = evalgt;
+ else if( strmatch(next, "gte" ) ) d->func2 = evalgte;
+ else if( strmatch(next, "lt" ) ) { expr_t * tmp = d->param[1]; d->func2 = evalgte; d->param[1] = d->param[0]; d->param[0] = tmp; }
+ else if( strmatch(next, "lte" ) ) { expr_t * tmp = d->param[1]; d->func2 = evalgt; d->param[1] = d->param[0]; d->param[0] = tmp; }
+ else if( strmatch(next, "eq" ) ) d->func2 = evaleq;
else{
for(i=0; p->func1_name && p->func1_name[i]; i++){
if(strmatch(next, p->func1_name[i])){
- return p->func1[i](p->opaque, d);
+ d->func1 = p->func1[i];
+ d->type = 3;
+ return d;
}
}
for(i=0; p->func2_name && p->func2_name[i]; i++){
if(strmatch(next, p->func2_name[i])){
- return p->func2[i](p->opaque, d, d2);
+ d->func2 = p->func2[i];
+ d->type = 4;
+ return d;
}
}
*p->error = "unknown function";
- return NAN;
+ return NULL;
}
+ if (d->func0) d->type = 2;
+ if (d->func1) d->type = 3;
+ if (d->func2) d->type = 4;
return d;
}
-static double evalPow(Parser *p, int *sign){
+static expr_t * parse_pow(Parser *p, int *sign){
*sign= (*p->s == '+') - (*p->s == '-');
p->s += *sign&1;
- return evalPrimary(p);
+ return parse_primary(p);
}
-static double evalFactor(Parser *p){
+static expr_t * parse_factor(Parser *p){
int sign, sign2;
- double ret, e;
- ret= evalPow(p, &sign);
+ expr_t * e = parse_pow(p, &sign);
while(p->s[0]=='^'){
+ expr_t * tmp = calloc(1, sizeof(expr_t));
+
p->s++;
- e= evalPow(p, &sign2);
- ret= pow(ret, (sign2|1) * e);
+
+ tmp->type = 4;
+ tmp->func2 = &evalpow;
+ tmp->value = 1.;
+ tmp->param[0] = e;
+ tmp->param[1] = parse_pow(p, &sign2);
+ tmp->param[1]->value *= (sign2|1);
+ e = tmp;
}
- return (sign|1) * ret;
+ e->value *= (sign|1);
+ return e;
}
-static double evalTerm(Parser *p){
- double ret= evalFactor(p);
+static expr_t * parse_term(Parser *p){
+ expr_t * e = parse_factor(p);
while(p->s[0]=='*' || p->s[0]=='/'){
- if(*p->s++ == '*') ret*= evalFactor(p);
- else ret/= evalFactor(p);
+ expr_t * tmp = calloc(1, sizeof(expr_t));
+ tmp->type = 4;
+ if(*p->s++ == '*') tmp->func2 = &evalmul;
+ else tmp->func2 = &evaldiv;
+ tmp->value = 1.;
+ tmp->param[0] = e;
+ tmp->param[1] = parse_factor(p);
+ e = tmp;
}
- return ret;
+ return e;
}
-static double evalExpression(Parser *p){
- double ret= 0;
+static expr_t * parse_expr(Parser *p) {
+ expr_t * e;
if(p->stack_index <= 0) //protect against stack overflows
- return NAN;
+ return NULL;
p->stack_index--;
- do{
- ret += evalTerm(p);
- }while(*p->s == '+' || *p->s == '-');
+ e = parse_term(p);
+ while(*p->s == '+' || *p->s == '-') {
+ expr_t * tmp = calloc(1, sizeof(expr_t));
+ tmp->type = 4;
+ tmp->func2 = &evaladd;
+ tmp->value = 1.;
+ tmp->param[0] = e;
+ tmp->param[1] = parse_term(p);
+ e = tmp;
+ };
+
p->stack_index++;
- return ret;
+ return e;
}
-double ff_eval2(char *s, double *const_value, const char **const_name,
+expr_t * ff_parse(char *s, const char **const_name,
double (**func1)(void *, double), const char **func1_name,
double (**func2)(void *, double, double), char **func2_name,
- void *opaque, char **error){
+ char **error){
Parser p;
p.stack_index=100;
p.s= s;
- p.const_value= const_value;
p.const_name = const_name;
p.func1 = func1;
p.func1_name = func1_name;
p.func2 = func2;
p.func2_name = func2_name;
- p.opaque = opaque;
p.error= error;
- return evalExpression(&p);
+ return parse_expr(&p);
}
+double ff_parse_eval(expr_t * e, double *const_value, void *opaque) {
+ Parser p;
-#if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0)
-attribute_deprecated double ff_eval(char *s, double *const_value, const char **const_name,
- double (**func1)(void *, double), const char **func1_name,
- double (**func2)(void *, double, double), char **func2_name,
- void *opaque){
- char *error=NULL;
- double ret;
- ret = ff_eval2(s, const_value, const_name, func1, func1_name, func2, func2_name, opaque, &error);
- if (error)
- av_log(NULL, AV_LOG_ERROR, "Error evaluating \"%s\": %s\n", s, error);
- return ret;
+ p.const_value= const_value;
+ p.opaque = opaque;
+ return eval_expr(&p, e);
}
-#endif
#ifdef TEST
#undef printf
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