On Wed, 2024-02-14 at 09:42 -0800, Yonghong Song wrote:
> > .------------------------------------- Checkpoint / State name
> > | .-------------------------------- Code point number
> > | | .---------------------------- Stack state {ctx.a,ctx.b,ctx.c}
> > | | | .------------------- Callback depth in frame #0
> > v v v v
> > 1 - (0) {7P,7P,7},depth=0
> > 2 - (3) {7P,7P,7},depth=1
> > 3 - (0) {7P,7P,42},depth=1
> > (a) - (3) {7P,7,42},depth=2
> > 4 - (0) {7P,7,42},depth=2 loop terminates because of depth limit
> > 5 - (4) {7P,7,42},depth=0 predicted false, ctx.a marked precise
> > 6 - (6) exit
> > 7 - (2) {7P,7,42},depth=2
> > 8 - (0) {7P,42,42},depth=2 loop terminates because of depth limit
> > 9 - (4) {7P,42,42},depth=0 predicted false, ctx.a marked precise
> > 10 - (6) exit
> > (b) - (1) {7P,7P,42},depth=2
> > 11 - (0) {42P,7P,42},depth=2 loop terminates because of depth limit
> > 12 - (4) {42P,7P,42},depth=0 predicted false, ctx.{a,b} marked precise
> > 13 - (6) exit
> > 14 - (2) {7P,7,7},depth=1
> > 15 - (0) {7P,42,7},depth=1 considered safe, pruned using checkpoint (a)
> > (c) - (1) {7P,7P,7},depth=1 considered safe, pruned using checkpoint (b)
>
> For the above line
> (c) - (1) {7P,7P,7},depth=1 considered safe, pruned using checkpoint (b)
> I would change to
> (c) - (1) {7P,7P,7},depth=1
> - (0) {42P, 7P, 7},depth = 1 considered safe, pruned using checkpoint (11)
At that point:
- there is a checkpoint at (1) with state {7P,7P,42}
- verifier is at (1) in state {7,7,7}
Thus, verifier won't proceed to (0) because {7,7,7} is states_equal to {7P,7P,42}.
> For
> 14 - (2) {7P,7,7},depth=1
> 15 - (0) {7P,42,7},depth=1 considered safe, pruned using checkpoint (a)
> I suspect for line 15, the pruning uses checking point at line (8).
Right, because checkpoints for a particular insn form a stack. My bad.
> Other than the above, the diagram LGTM.
Thank you for the feedback, I'll post v2 shortly.
