lavu/eval: add bitor and bitand functions

Warning note suggested by Reimar.
This commit is contained in:
Stefano Sabatini 2013-03-13 14:09:10 +01:00
parent d8dccf69ff
commit b2098d2417
4 changed files with 29 additions and 2 deletions

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@ -32,6 +32,17 @@ Compute arcsine of @var{x}.
@item atan(x)
Compute arctangent of @var{x}.
@item bitand(x, y)
@item bitor(x, y)
Compute bitwise and/or operation on @var{x} and @var{y}.
The results of the evaluation of @var{x} and @var{y} are converted to
integers before executing the bitwise operation.
Note that both the conversion to integer and the conversion back to
floating point can lose precision. Beware of unexpected results for
large numbers (usually 2^53 and larger).
@item ceil(expr)
Round the value of expression @var{expr} upwards to the nearest
integer. For example, "ceil(1.5)" is "2.0".

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@ -145,7 +145,7 @@ struct AVExpr {
e_pow, e_mul, e_div, e_add,
e_last, e_st, e_while, e_taylor, e_root, e_floor, e_ceil, e_trunc,
e_sqrt, e_not, e_random, e_hypot, e_gcd,
e_if, e_ifnot, e_print,
e_if, e_ifnot, e_print, e_bitand, e_bitor,
} type;
double value; // is sign in other types
union {
@ -284,6 +284,8 @@ static double eval_expr(Parser *p, AVExpr *e)
case e_last:return e->value * d2;
case e_st : return e->value * (p->var[av_clip(d, 0, VARS-1)]= d2);
case e_hypot:return e->value * (sqrt(d*d + d2*d2));
case e_bitand: return isnan(d) || isnan(d2) ? NAN : e->value * ((long int)d & (long int)d2);
case e_bitor: return isnan(d) || isnan(d2) ? NAN : e->value * ((long int)d | (long int)d2);
}
}
}
@ -424,6 +426,8 @@ static int parse_primary(AVExpr **e, Parser *p)
else if (strmatch(next, "gcd" )) d->type = e_gcd;
else if (strmatch(next, "if" )) d->type = e_if;
else if (strmatch(next, "ifnot" )) d->type = e_ifnot;
else if (strmatch(next, "bitand")) d->type = e_bitand;
else if (strmatch(next, "bitor" )) d->type = e_bitor;
else {
for (i=0; p->func1_names && p->func1_names[i]; i++) {
if (strmatch(next, p->func1_names[i])) {
@ -809,6 +813,9 @@ int main(int argc, char **argv)
"gauss(0.1)",
"hypot(4,3)",
"gcd(30,55)*print(min(9,1))",
"bitor(42, 12)",
"bitand(42, 12)",
"bitand(NAN, 1)",
NULL
};

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@ -76,7 +76,7 @@
#define LIBAVUTIL_VERSION_MAJOR 52
#define LIBAVUTIL_VERSION_MINOR 19
#define LIBAVUTIL_VERSION_MICRO 100
#define LIBAVUTIL_VERSION_MICRO 101
#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
LIBAVUTIL_VERSION_MINOR, \

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@ -252,3 +252,12 @@ Evaluating 'gcd(30,55)*print(min(9,1))'
12.700000 == 12.7
0.931323 == 0.931322575
Evaluating 'bitor(42, 12)'
'bitor(42, 12)' -> 46.000000
Evaluating 'bitand(42, 12)'
'bitand(42, 12)' -> 8.000000
Evaluating 'bitand(NAN, 1)'
'bitand(NAN, 1)' -> nan