Re: [PATCH] experimental lookupcar based coverage testing.

[Ludovic Courtès]

Hi,

Han-Wen Nienhuys <address@hidden> writes:

> See attached patch. This still has rough edges. For some reason, I
> don't catch the memoization of display to #<proc: display>.

Overall, as Kevin suggested, I'd be more in favor of using the existing
trap mechanism (possibly extending it if it doesn't provide enough
information to trap handlers).  However, as you already said, the trap
mechanism is damn slow.  I guess it is mostly slow because the evaluator
is slow, but the trap mechanism itself may be optimizable, too.

If you look at `ENTER_APPLY' around line 3025, it makes at least two
function calls: `scm_make_debugobj ()' and `scm_call_3 ()'.  The former
is a one-line function and should really be inlined.  The latter
introduces unnecessary overhead since it ends up calling `SCM_APPLY ()'
which in turns necessarily jumps to the `scm_tcs_closures' case since
trap handlers are always closures.  Thus, at the very least,
`scm_call_3 ()' should be replaced by `SCM_APPLY ()'.

These small optimizations would certainly be worthwhile, although
perhaps not sufficient.

Thanks,
Ludovic.