Re: register allocation: basic blocks, liveness and next use

On Mar 22, 8:22 pm, kphillips <kevin.phillip...@[EMAIL PROTECTED]
> wrote:
> The TAC would be something of this sort:
>
> == Block 1 =========
> PUSHPARAM 2
> CALL t1 A                       //call A and store the return value in
> t1
> == Block 2 =========
> PUSHPARAM -3
> CALL t2 A
> == Block 3 =========
> ADD t3 = t1, t2
> PRINT t3
> =================
>
> The problem is that the tem****aries in both block 1 (t1) and block 2
> (t2) would be discarded (assumed dead since they are at the end of the
> block) and block 3 can't compute the addition.
>
> Am I missing something here?

Perhaps the definition of a basic block.

The definition of a tem****ary requires that none of its defs can reach
the end of the corresponding block.  Obviously your t1..3 don't meet
this requirement.