?: expression is converted into an
if statement with
each branch assigning to the same temporary. So,
a = b ? c : d;
if (b == 1) T1 = c; else T1 = d; a = T1;
The GIMPLE level if-conversion pass re-introduces
expression, if appropriate. It is used to vectorize loops with
conditions using vector conditional operations.
Note that in GIMPLE,
if statements are represented using
GIMPLE_COND, as described below.