[gimple] temporary variable

[charfi asma]

Hello,

when generating gimple using gcc 4.4.2 from 

int a =5;
int b=10;
if (a++ +b != 0)
return 0;
else
return 1;

we obtain this code

int a;
int b;
a = 5;
b = 10;
D.1715 = a + b;
retval.0 = D.1715 != 0;
a = a + 1;
if (retval.0 != 0) goto <D.1716>; else goto <D.1717>;
....

why retval.0 is added ? why we do not produce if (D.1715 !=0) directly ?

thank you very much 

Asma