* module/language/cps/dfg.scm (dead-after-use?): Don't kill a variable
if it was defined outside the current loop.
(dead-after-branch?): Likewise, but I don't think this helper is
correct yet :/
* module/language/cps/dfg.scm ($block): Add pdom and pdom-level fields,
for post-dominators.
(reverse-post-order, convert-predecessors): Arrange to work either
way: for dominators or for post-dominators.
(analyze-control-flow!): Compute post-dominators.
(dominates?): Refactor.
(post-dominates?): New helper.
* module/language/cps/dfg.scm ($block): Add "irreducible" field, format
TBD.
(reverse-post-order): Return a vector directly.
(convert-predecessors, compute-dom-levels, compute-idoms):
(analyze-control-flow!): Factor out control flow analsysis a bit
better.
(identify-loops): New helper. Currently a NOP.
(visit-fun): Adapt to compute-dominator-tree rename to
analyze-control-flow!.
* module/language/cps/dfg.scm (reverse-post-order, for-each/enumerate)
(convert-predecessors, finish-idoms, compute-dominator-tree): Compute
a dominator tree. We don't use it yet.
* module/language/cps/dfg.scm: Refactor so that we can think about
building a dominator tree. Split continuations out of use maps and
put them in a separate table, which will have more flow information.
(visit-fun): Mark clauses as using their bodies.
(lookup-predecessors, lookup-successors): New exports.
(find-defining-expression): Add an exception for clauses, now that
clauses are in the flow graph.
(continuation-bound-in?): Rename from variable-bound-in?, as it can
currently only be used for continuations.
* module/language/cps/contification.scm (contify): Adapt to use
lookup-predecessors and continuation-bound-in?.
* module/language/cps/contification.scm (contify): Exhaustively replace
contified tail continuations, to fix a bug in nested tail-recursive
contifications. Likewise, call lookup-return-cont when searching for
common return continuations.
* module/language/cps/dfg.scm (variable-free-in?): Rename from
variable-used-in?, to match CWCC language.
(variable-bound-in?): New interface.
* module/language/cps/contification.scm (contify): Adapt caller. Add
more comments.
* module/language/tree-il/compile-cps.scm: New module implementing CPS
conversion of Tree-IL.
* module/Makefile.am:
* module/language/tree-il/spec.scm:
* module/language/cps/spec.scm: Integrate CPS in the build and language
system.
