It looks like my bound for last time was too conservative,
in that I looked for the lowest number that didn't seem
to fail in 10.6. The range of failing values is apparently
not continuous.
I've tightened the bound to match the lowest
number that produces a useful result on my 10.7 machine,
assuming that it works for a continuous range there.
(The new bound is higher than the number previously used as
a lower bound.)
Merge to 5.2.1
Setting the environment variable causes the bytecode compiler to run
the bytecode validator (which is normally applied to input from a
bytecode file) immediately on all of the compiler's own results.
Certain `lambda'-lifting operations can cause information
about the flonumness of a variable to get lost, leading
to a mismatch between the closure's flags and flags on
a variable reference. (The bytecode validator could detect the
bug when loading the broken bytecode. The broken information,
meanwhile, was only used by the JIT.)
For numbers around -67768122973228093, localtime() doesn't return in
10.6.8, while it returns NULL for 10.7.2. Work around the bug by
setting a lower bound that seems to be high enough to avoid the
problem (and that's lower than the lowest value that succeeds, so no
results are lost, at least for now).
Merge to 5.2.1
If a function with a rest arg is called with argv not at the
start of the runstack, then space is allocated for the rest-arg list
on the runstack without clearing the allocated slot. The value in
the slot could be a pointer that wasn't traversed by the most recent
GC, so it could crash a GC during allocation of the rest-arg list.
Also, tweak setup code for a function of no arguments, and improve
comments in the code.
Merge to 5.2.1
The generated code was checking arity after potentially copying
arguments to the start of the runstack (i.e., if the arguments
were not already there). If too few arguments are provided, then
the copy might access past the end of the given array.
The redundant arity check removed in commit f7c506471b
had previously masked this problem. (Or the check wasn't redundant
in that sense, but it's better this way.)
Merge to 5.2.1
The problem is related to marks that should cancel eagerly when
a form passes through many layers of macro expansion, such as in
the sieve stress test for `syntax-rules'.
There's no particular reason that any one format will have all
the information that other formats need, but it conveniently works
for now that HTML info can subsume Latex info.
Certain unsafe operations were allowed to propagate across a
`lambda' boundary (where space safety is known not to be an issue),
which could lead to duplicate uses of a "once used" variable if
the relevant `lambda' is inlined.
Furthermore, `lambda' boundary crossing wasn't detected in the case
that the operation to propagate was propagated through an intermediate
variable without a `lambda' crossing.
Merge to 5.2.1
I'm fairly certain that the change in commit 25e9bd2a190acf861 isn't
right, but I'm having trouble generating tests to demonstrate the
original bug or this correction.
First use of the function was determining a single arity for
the enclosing module, and that arity could trigger warnings
in addition to failures to inline. For example, using `map'
on 3 arguments would trigger incorrect warnings for later
uses of `map' on 2 arguments.
Rename `read-intern-literal' to `datum-intern-literal'.
Interning is needed only in `read-syntax' or `datum->syntax' to
set up the invariants that the bytecode compiler needs for cross-module
optimization. When `read'ing numbers from a data file, meanwhile,
interning slows things down a lot and doesn't seem worthwhile.
