/*?Copyright?（C）?2009?Sun?Microsystems?Inc
?
?This?program?is?free?software;?you?can?redistribute?it?and/or?modify
?it?under?the?terms?of?the?GNU?General?Public?License?as?published?by
?the?Free?Software?Foundation;?version?2?of?the?License.

?This?program?is?distributed?in?the?hope?that?it?will?be?useful
?but?WITHOUT?ANY?WARRANTY;?without?even?the?implied?warranty?of
?MERCHANTABILITY?or?FITNESS?FOR?A?PARTICULAR?PURPOSE.??See?the
?GNU?General?Public?License?for?more?details.

?You?should?have?received?a?copy?of?the?GNU?General?Public?License
?along?with?this?program;?if?not?write?to?the?Free?Software
?Foundation?Inc.?51?Franklin?St?Fifth?Floor?Boston?MA??02110-1301??USA?*/

/*?Check?stack?direction?（0-down?1-up）?*/
int?f（int?*a）?
{
??int?b;
??return（&b?>?a）?1:0;?
}
/*
?Prevent?compiler?optimizations?by?calling?function?
?through?pointer.
*/
volatile?int?（*ptr_f）（int?*）?=?f;
int?main（）?
{
??int?a;
??return?ptr_f（&a）;
}