print: Fix printing of weak vectors.

* libguile/print.c (print_vector_or_weak_vector): New static function.
  (iprin1): Use 'print_vector_or_weak_vector' in the vector and weak
  vector cases.

build: Clean up rules for meta/{guild,guile-config}.

* meta/Makefile.am (guile-config, guild): Avoid useless 'cat'
  invocation'.  Quote all occurrences of '@'.
  Suggested by Eric Blake <eblake@redhat.com>.

build: Honor program name transformation in 'guild'.

* configure.ac: Remove erroneous 'guile_program_name' substitute; see
  <https://lists.gnu.org/archive/html/autoconf/2014-04/msg00010.html>
  for details.  Remove 'meta/guild' config file.
* meta/Makefile.am (guild): New target.
  (CLEANFILES): Add 'guild'.
* meta/guild.in: Remove 'prefix' and 'exec_prefix' definitions; use
  @installed_guile@.

Set $GC_MARKERS to 1 when libgc 7.4.0 is used.

* libguile/gc.c (scm_storage_prehistory) [GC_VERSION == 7.4.0]: Add
  'setenv' call.

Add make-vector opcode

* libguile/vm-engine.c (make-vector): New opcode.
* module/language/cps/compile-bytecode.scm (compile-fun):
* module/system/vm/assembler.scm (system): Support the new opcode.
  (*bytecode-minor-version*): Bump.

* libguile/_scm.h (SCM_OBJCODE_MINOR_VERSION): Bump.

* test-suite/tests/compiler.test ("limits"): Add vector test.

Operations on 8-bit and 12-bit operands shuffle args into range

* module/language/cps/slot-allocation.scm (allocate-slots): Avoid
  allocating locals in the range [253,255].

* module/system/vm/assembler.scm: List exports explicitly.  For
  operations with limited-range operands, export wrapper assemblers that
  handle shuffling their operands into and out of their range.
  (define-assembler): Get rid of enclosing begin.
  (shuffling-assembler, define-shuffling-assembler): New helpers to
  define shuffling wrapper assemblers.
  (emit-mov*, emit-receive*): New functions.
  (shuffle-up-args): New helper.
  (standard-prelude, opt-prelude, kw-prelude): Call shuffle-up-args
  after finishing.

* test-suite/tests/compiler.test ("limits"): Add test cases.

More expansion-time-only definitions in assembler.scm

* module/system/vm/assembler.scm (define-inline): Change so that the
  defined macro is only defined at expansion-time.
  (u32-ref, u32-set!, s32-ref, s32-set!, pack-arity-flags): Use
  define-inline.
  (pack-flags, assert-match, *block-size*, id-append, assembler)
  (define-assembler, visit-opcodes, define-macro-assembler): Wrap in
  eval-when expand.

define-inline in assembler.scm

* module/system/vm/assembler.scm (define-inline): New local helper.
  Update local users of define-inlinable to use it.

VM opcodes only have <24-bit slot operands in the first word

* libguile/vm-engine.c (make-array): Change to only have
  restricted-width operands in the first word.  This instruction is
  currently unused, however.

* module/system/vm/assembler.scm (assembler):
* module/system/vm/disassembler.scm (disassembler): Disallow
  restricted-width operands in tail words.

Add interface to disable automatic finalization

* libguile/finalizers.h:
* libguile/finalizers.c (run_finalizers_async_thunk)
  (finalization_thread_proc): Call the new scm_run_finalizers helper.
  (scm_i_finalizer_pre_fork): Only spawn the thread if automatic
  finalization is enabled.
  (scm_set_automatic_finalization_enabled, scm_run_finalizers): New
  functions.
  (scm_init_finalizers, scm_init_finalizer_thread): Only set a finalizer
  notifier if automatic finalization is enabled.

* doc/ref/libguile-smobs.texi (Garbage Collecting Smobs): Add discussion
  of concurrency.

* doc/ref/api-smobs.texi (Smobs): Document new functions.

Slot allocation can re-use closure and argument slots

* module/language/cps/slot-allocation.scm (allocate-slots): Allow slot
  allocation to re-use the closure and argument slots.

Remove SCM_FRAME_PROGRAM

* libguile/frames.h: Remove SCM_FRAME_PROGRAM, now unused.

VM robustness for optimized closures

* libguile/vm.c (vm_error_unbound, vm_error_unbound_fluid): Remove proc
  argument.  The value in slot 0 is not necessarily the procedure being
  applied, after the prelude is done.

* libguile/vm-engine.c (vm_engine): Use LOCAL_REF (0) instead of
  SCM_FRAME_PROGRAM, and adapt to above changes.

Fix rewinding continuations when outermost frame has zero locals

* libguile/vm.c (vm_reinstate_partial_continuation_inner): Fix boundary
  condition when the outermost frame has zero locals.

frame-previous, frame-procedure robustness

* libguile/frames.c (scm_c_frame_closure): Don't use SCM_FRAME_PROGRAM,
  as we don't know if the frame actually has any locals.
  (scm_c_frame_previous): More robustly detect end-of-stack.  Allows
  scm_c_frame_previous to work on partial continuations.

make-stack works on delimited continuations

* libguile/stacks.c (scm_make_stack, scm_stack_id):
* libguile/vm.c (scm_i_vm_cont_to_frame): Allow delimited continuations
  as the argument to make-stack.

More robust coverage tests

* test-suite/tests/coverage.test ("line-execution-counts"): Allow zero
  or one count on the loop head.

Change some make-stack tests to use frame-call-representation

* test-suite/tests/eval.test ("stacks"): Use frame-call-representation.

Fix statprof for optimizations

* module/statprof.scm (profile-signal-handler): Bind in a letrec.
  Otherwise the compiler may see the closure slot as dead, and the inner
  stack cut won't work.

Fix a frame-call-representation bug

* module/system/vm/frame.scm (frame-call-representation): Fix logic for
  displaying names of non-procedures and procedures out of arities.

Better backtraces from C, especially for optimized closures

* libguile/frames.h:
* libguile/frames.c (scm_frame_call_representation): New interface;
  dispatches to Scheme.

* libguile/backtrace.c (display_application): Use
  scm_frame_call_representation.  This should be monotonically better,
  given that scm_frame_arguments (which was previously called) also
  dispatched to Scheme and actually ended up calling
  frame-call-representation.

frame-call-representation checks available-bindings, as appropriate

* module/system/vm/frame.scm (available-bindings): Map indexes in such a
  way that the first argument is index 1.
  (frame-call-representation): Update to search the bindings for live
  bindings.

Update frame-bindings interface

* module/system/repl/debug.scm (print-locals): Update to work with new
  interface.
  (frame->module): Update.  Still doesn't work due to lack of
  `program-module', though.

* module/system/vm/program.scm (make-binding, binding:name)
  (binding:definition-offset, program-arity-bindings-for-ip): Remove
  these.

* module/system/vm/frame.scm (<binding>): New type.
  (available-bindings): Return a list of <binding> instances.
  (frame-lookup-binding, frame-binding-set!, frame-binding-ref):
  (frame-environment, frame-object-name): Adapt.

Implement frame-bindings

* module/system/vm/frame.scm (parse-code, compute-predecessors):
  (compute-genv, compute-defs-by-slot, compute-killv, available-bindings):
  (frame-bindings): Add a bunch of hairy code to compute the set of
  bindings that are live in a frame.

Add arity-code

* module/system/vm/debug.scm (arity-code): New interface.

Add parsing interfaces to the disassembler

* module/system/vm/disassembler.scm (instruction-length):
  (instruction-has-fallthrough?, instruction-relative-jump-targets):
  (instruction-slot-clobbers): New interfaces; to be used when
  determining the bindings available at a given point of a procedure.

Fix up some opcode metadata

* libguile/vm-engine.c (make-long-immediate, static-ref): Mark as "dst"
  instructions.

Add ability to query local definitions for a procedure

* module/system/vm/debug.scm (arity-definitions): New interface.

* module/system/vm/program.scm (make-binding, binding:boxed?)
  (binding:index, binding:start, binding:end): Remove.
  (binding:definition-offset, binding:slot): Add.
  (program-arity-bindings-for-ip): Rename from program-bindings-for-ip,
  as it gives all definitions in an arity.  The user will have to do
  data-flow analysis to recover the set of variables that are actually
  available at any given point.
  (arity->arguments-alist): Remove crufty code.

Fix rtl tests

* module/system/vm/assembler.scm (write-arities): Add a diagnostic.

* test-suite/tests/rtl.test: Fix tests to emit "definition"
  instructions.

Fix frame-call-representation for primitive applications

* module/system/vm/frame.scm (frame-call-representation): Fix to work
  for primitives.

* test-suite/tests/eval.test ("stacks"): Update expected result for
  substring.

Assembler residualizes local variable definition locations

* module/system/vm/assembler.scm (write-arities): Serialize definition
  locations after names.
  (definition): Store definition as a byte offset.

Bump minor objcode version for recent changes

* libguile/_scm.h (SCM_OBJCODE_MINOR_VERSION):
* module/system/vm/assembler.scm (*bytecode-minor-version*): Bump.

Write all local variable names into the arities section

* module/system/vm/assembler.scm (put-uleb128, put-sleb128)
  (port-position): Lift out these helpers.
  (arity-header-len, write-arities, link-arities): Add "nlocals" to the
  arity headers.  Write names of all locals into the arities section,
  not just the arguments.  Write them as uleb128's instead of uint32's,
  to save space.

* module/system/vm/debug.scm (arity-header-len, arity-nlocals*)
  (arity-nlocals, arity-locals, arity-arguments-alist): Adapt to new
  encoding for arities.

Tweak arities debugging representation

* module/system/vm/assembler.scm (meta-arities-size, write-arity-links):
* module/system/vm/debug.scm (arity-keyword-args)
  (arity-arguments-alist): Rewrite to put they keyword literals link
  first.  Unfortunately requires a recompile :/

Beginnings of local variable information

* module/system/vm/assembler.scm (<arity>, begin-kw-arity, end-arity):
  (definition): Add definition macro-instruction.  Arrange to record
  variable definitions.

* module/language/cps/compile-bytecode.scm (compile-fun): Emit
  definition macro-instructions as appropriate.

Remove needless label remapping in slot-allocation

* module/language/cps/slot-allocation.scm (dead-after-def?):
  (dead-after-use?, allocate-slots): Remove some needless remapping
  between label indexes in the CFA, the DFA, and their names.

DFA datums don't rename their labels

* module/language/cps/dfg.scm (analyze-reverse-control-flow): Don't
  compute and return an order vector; it's not needed.
  ($dfa): Remove label renaming.  We can just rename labels before
  returning the DFA.
  (dfa-k-idx, dfa-k-sym, dfa-k-count): Adapt.
  (compute-live-variables): Adapt, and rename labels before returning.

Better backtraces for optimized closures

* module/system/vm/debug.scm (arity-keyword-args, find-program-arity):
  New exports.

* module/system/vm/frame.scm (frame-call-representation): Prefer to use
  the frame IP to get the procedure.

statprof avoids mucking with VM trace levels when not counting calls

* module/statprof.scm (statprof-start, statprof-stop): Don't futz the vm
  trace level when we aren't counting calls.  With this change, statprof
  now imposes no overhead on the measured program.

Better state handling in statprof

* module/statprof.scm (statprof-fold-call-data)
  (statprof-proc-call-data): Add optional state arg.
  (gcprof): Add optional port arg, and pass state arg explicitly.
  (statprof-display-anomalies, statprof-display)
  (statprof-call-data->stats): Pass state explicitly.

Optimize make-stack

* libguile/continuations.h:
* libguile/continuations.c (scm_i_continuation_to_frame): Operate on
  low-level C structures instead of heap objects.

* libguile/frames.h:
* libguile/frames.c (frame_offset, frame_stack_base): Const args.
  (scm_c_frame_closure): New helper.
  (scm_frame_procedure): Use the new helper.

* libguile/stacks.c (stack_depth, narrow_stack, scm_make_stack): Rework
  to avoid allocating frames as we traverse the stack, and to avoid an
  n**2 case where there are outer cuts.

scm_c_make_frame takes struct scm_frame as arg

* libguile/frames.h:
* libguile/frames.c (scm_c_make_frame): Adapt to take a const struct
  scm_frame as the argument.  Adapt callers.

* libguile/continuations.c:
* libguile/stacks.c: Adapt callers.

Refactor to frames code

* libguile/frames.h:
* libguile/frames.c (scm_c_frame_previous): New internal helper.
  (scm_frame_previous): Use the helper.
  (RELOC): Take kind and low-level frame args separately.  Adapt
  callers.
  (frame_stack_base, frame_offset): New helpers.
  (scm_i_frame_offset, scm_i_frame_stack_base): Use low-level helpers.

Optimize make-global-cont-folder

* module/language/cps.scm (make-global-cont-folder): Inline the
  fold-values, as peval doesn't do so.  Allows closure conversion to
  avoid any closure creation.

Improve disassembly for optimized closures

* module/system/vm/disassembler.scm (code-annotation): Add call-label
  and tail-call-label cases.
  (disassemble-addr): With call-label we can see sets of mutually
  recursive functions, so keep a global "visited?" set.

Remove debugging code in closure-conversion

* module/language/cps/closure-conversion.scm (prune-free-vars): Remove
  pk.

Eval has no more free variables

* module/ice-9/eval.scm (primitive-eval): Expand out the call to
  make-general-closure, so that make-general-closure becomes
  well-known.  Now eval has no more free variables!

Closure conversion eliminates self-references introduced by fixpoint

* module/language/cps/closure-conversion.scm (analyze-closures): Build a
  bound-vars set as well, to resolve introduced self-references.
  (prune-free-vars, convert-one): Arrange to eliminate self-references.

Refactor to closure-conversion

* module/language/cps/closure-conversion.scm (convert-one): Refactor to
  pull in helpers locally, as they will need more state.

Avoid consing an unbound-arg marker in the evaluator

* module/ice-9/eval.scm (primitive-eval): Turns out we don't need to
  cons to make the unbound-arg marker.

Optimize closures with one free variable

* module/language/cps/closure-conversion.scm (convert-free-var)
  (allocate-closure, init-closure, prune-free-vars, convert-one)
  (convert-closures): Optimize closures with one free variable.

Well-known closures represented using pairs or vectors

* module/language/cps/closure-conversion.scm (convert-free-var):
  (convert-free-vars): Take self-known? param, to do the right thing for
  well-known closures.
  (allocate-closure): New helper.  Well-known closures are represented
  using pairs or vectors.
  (init-closure): Adapt tpo DTRT for well-known closures.
  (prune-free-vars): Move up.
  (convert-one): Adapt to new well-known closure representation.

Update verify-cps

* module/language/cps/verify.scm (verify-cps): Update for recent CPS
  changes.

Avoid creating closures with no free variables

* module/language/cps/closure-conversion.scm (init-closure): Return just
  one value.
  (analyze-closures): Rewrite the well-known set to key off the label
  instead of the closure identifiers before returning.
  (convert-one): Avoid creating closure objects at runtime or load-time
  when "instantiating" or calling well-known closures with no free
  variables.
  (prune-free-vars): New pass.
  (convert-closures): Adapt.

Hard-wire calls to known procedures

* module/language/cps/closure-conversion.scm (analyze-closures):
  (convert-one, convert-closures): Hard-wire calls to known procedures
  by transforming $call to $callk.

closure conversion computes well-known functions

* module/language/cps/closure-conversion.scm (analyze-closures)
  (convert-closures, convert-one): Adapt to compute well-known
  functions.  We don't yet produce $callk though.

First-order CPS has $program and $closure forms

* module/language/cps.scm ($closure, $program): New CPS types, part of
  low-level (first-order) CPS.
  (build-cps-exp, build-cps-term, parse-cps, unparse-cps)
  (compute-max-label-and-var): Update for new CPS types.

* module/language/cps/closure-conversion.scm: Rewrite to produce a
  $program with $closures, and no $funs.

* module/language/cps/reify-primitives.scm:
* module/language/cps/compile-bytecode.scm (compile-fun):
  (compile-bytecode): Adapt to new first-order format.

* module/language/cps/dfg.scm (compute-dfg): Add $closure case.

* module/language/cps/renumber.scm (renumber): Allow this pass to work
  on either format.

* module/language/cps/slot-allocation.scm (allocate-slots): Add $closure
  case.

Separate make-cont-folder into global and local variants

* module/language/cps.scm (make-global-cont-folder)
  (make-local-cont-folder): Separate this macro in two.  It's hot and
  the difference can be important for perf.

* module/language/cps/dfg.scm (compute-label-and-var-ranges):
* module/language/cps/cse.scm (compute-label-and-var-ranges):
* module/language/cps/dce.scm (compute-live-code): Adapt.

Root higher-order CPS term is always $kfun $cont

* module/language/cps/arities.scm:
* module/language/cps/closure-conversion.scm:
* module/language/cps/compile-bytecode.scm:
* module/language/cps/constructors.scm:
* module/language/cps/contification.scm:
* module/language/cps/cse.scm:
* module/language/cps/dce.scm:
* module/language/cps/elide-values.scm:
* module/language/cps/prune-bailouts.scm:
* module/language/cps/prune-top-level-scopes.scm:
* module/language/cps/renumber.scm:
* module/language/cps/self-references.scm:
* module/language/cps/simplify.scm:
* module/language/cps/specialize-primcalls.scm:
* module/language/tree-il/compile-cps.scm: Adapt to produce and consume
  raw $kfun $cont instances.

* .dir-locals.el: Update $letrec indentation.

Closure conversion, reify-primitives use $kfun $cont

* module/language/cps/closure-conversion.scm: Produce a $kfun $cont.
* module/language/cps/reify-primitives.scm: Produce and consume $kfun
  $cont.
* module/language/cps/compile-bytecode.scm: Adapt.

Preparation for compile-bytecode to work on $kfun $conts

* module/language/cps/compile-bytecode.scm (compile-fun): Change to take
  a $kfun $cont instead of a $fun.
  (visit-funs): Change likewise, and call the proc on $kfun $cont's, not
  $fun's.
  (compile-bytecode): Adapt.

* module/language/cps/dfg.scm (analyze-reverse-control-flow): Adapt to
  expect a $kfun $cont.

compute-dfg takes a $kfun $cont, not a $fun

* module/language/cps/dfg.scm (compute-dfg): Take a $kfun $cont instead
  of a $fun.

* module/language/cps/arities.scm:
* module/language/cps/compile-bytecode.scm:
* module/language/cps/contification.scm:
* module/language/cps/cse.scm:
* module/language/cps/dce.scm:
* module/language/cps/simplify.scm:
* module/language/cps/specialize-primcalls.scm: Adapt callers.

with-fresh-name-state takes a cont, not a $fun

* module/language/cps.scm (with-fresh-name-state): Take a cont instead
  of a fun.

* module/language/cps/closure-conversion.scm:
* module/language/cps/constructors.scm:
* module/language/cps/elide-values.scm:
* module/language/cps/prune-bailouts.scm:
* module/language/cps/reify-primitives.scm: Adapt.

Function defined by make-cont-folder takes a cont, not a $fun

* module/language/cps.scm (make-cont-folder): Take a cont instead of a
  $fun.
  (with-fresh-name-state): Adapt.

* module/language/cps/cse.scm (compute-label-and-var-ranges):
* module/language/cps/dce.scm (compute-live-code):
* module/language/cps/dfg.scm (compute-dfg):
* module/language/cps/elide-values.scm (elide-values):
* module/language/cps/reify-primitives.scm (reify-primitives):
* module/language/cps/renumber.scm (compute-new-labels-and-vars):
  (renumber): Adapt.

Rename $kentry to $kfun

* module/language/cps.scm ($kfun): Rename from $kentry.

* module/language/cps/arities.scm:
* module/language/cps/closure-conversion.scm:
* module/language/cps/compile-bytecode.scm:
* module/language/cps/constructors.scm:
* module/language/cps/contification.scm:
* module/language/cps/cse.scm:
* module/language/cps/dce.scm:
* module/language/cps/dfg.scm:
* module/language/cps/effects-analysis.scm:
* module/language/cps/elide-values.scm:
* module/language/cps/prune-bailouts.scm:
* module/language/cps/prune-top-level-scopes.scm:
* module/language/cps/reify-primitives.scm:
* module/language/cps/renumber.scm:
* module/language/cps/self-references.scm:
* module/language/cps/simplify.scm:
* module/language/cps/slot-allocation.scm:
* module/language/cps/specialize-primcalls.scm:
* module/language/cps/verify.scm:
* module/language/tree-il/compile-cps.scm: Adapt users.

src and meta are fields of $kentry, not $fun

* module/language/cps.scm ($kentry, $fun): Attach "src" and "meta" on
  the $kentry, not the $fun.  This prepares us for $callk to $kentry
  continuations that have no corresponding $fun.

* module/language/cps/arities.scm:
* module/language/cps/closure-conversion.scm:
* module/language/cps/compile-bytecode.scm:
* module/language/cps/constructors.scm:
* module/language/cps/contification.scm:
* module/language/cps/cse.scm:
* module/language/cps/dce.scm:
* module/language/cps/dfg.scm:
* module/language/cps/elide-values.scm:
* module/language/cps/prune-bailouts.scm:
* module/language/cps/prune-top-level-scopes.scm:
* module/language/cps/reify-primitives.scm:
* module/language/cps/renumber.scm:
* module/language/cps/self-references.scm:
* module/language/cps/simplify.scm:
* module/language/cps/slot-allocation.scm:
* module/language/cps/specialize-primcalls.scm:
* module/language/cps/verify.scm:
* module/language/tree-il/compile-cps.scm: Adapt.

Remove tests for old Tree-IL CSE module

* test-suite/tests/cse.test: Remove.
* test-suite/Makefile.am:

Remove obsolete comment in compile-bytecode.scm

* module/language/cps/compile-bytecode.scm (optimize): Remove an
  obsolete comment.

New pass to avoid free variable creation for self-recursion

* module/language/cps/self-references.scm: New pass, avoids the need for
  self-recursion to allocate free variables.

* module/Makefile.am:
* module/language/cps/compile-bytecode.scm: Wire up the new pass.

Compile some standalone tests to bytecode

* test-suite/standalone/test-out-of-memory:
* test-suite/standalone/test-stack-overflow: Compile these files before
  running them.  That way, recursion can check the stack-overflow
  mechanism instead of the memory allocation mechanism.  We compile
  beforehand as a prepass so as not to impose an rlimit on a Guile that
  previously ran auto-compilation.

Remove old Tree-IL CSE pass

* module/language/tree-il/cse.scm: Delete.

* module/language/tree-il/optimize.scm: Remove use of Tree-IL CSE.

* module/Makefile.am: Remove language/tree-il/cse.scm.

* module/language/cps/compile-bytecode.scm: Rename CSE keyword to
  #:cse?.

Flow-sensitive analysis of truth values

* module/language/cps/cse.scm (compute-truthy-expressions):
  (compute-equivalent-subexpressions, apply-cse): Arrange to infer
  truthiness of expressions, and use that information to elide redundant
  tests.

Add effects for specialized primitives

* module/language/cps/effects-analysis.scm (make-vector)
  (make-vector/immediate, vector-ref/immediate, vector-set!/immediate)
  (struct-ref/immediate, struct-set!/immediate): Add effects.

Minor cleanup/optimization in CSE

* module/language/cps/cse.scm (compute-available-expressions): Remove
  needless for-each definition.
  (compute-equivalent-subexpressions): Optimize for-each/2.

Prune bailouts after contification

* module/language/cps/compile-bytecode.scm (optimize): Prune bailouts
  after contifying, so that we return to the tail of the contified
  function.

Match and srfi-9 expose their bailouts to the CSE pass

* module/ice-9/match.upstream.scm (match-next): Inline a call to
  "error", so the new CSE pass will see this case as a bailout.

* module/srfi/srfi-9.scm (throw-bad-struct): Reimplement as a syntax
  rule, so that the CSE pass sees the "throw" call.

Remove &bailout; replace uses of &unknown-effects with &all-effects

* module/language/cps/effects-analysis.scm (&bailout): Remove effect.
  (&unknown-effects): Remove.  Replace uses with &all-effects.
* module/language/cps/cse.scm:

Remove parts of CSE that deal with bailout

* module/language/cps/cse.scm (compute-available-expressions, cse):
  (compute-idoms, compute-equivalent-subexpressions, apply-cse): Remove
  attempts to deal with bailout, as the bailout pass handles that
  already.

Add prune-bailouts pass

* module/language/cps/prune-bailouts.scm: New pass.
* module/language/cps/compile-bytecode.scm: Wire it up.
* module/Makefile.am: Add new file.

Disable Tree-IL CSE

* module/language/tree-il/optimize.scm (optimize): Disable Tree-IL CSE
  by default.

Fix effects analysis for cached-module-box

* module/language/cps/effects-analysis.scm (cached-module-box): Fix
  expected arity.

Fix coverage expectations

* test-suite/tests/coverage.test ("line-execution-counts"): Update
  expectations.  Since there's nothing to do at the loop header and the
  renaming of X happens at the end of the loops, the compiled code only
  sees the loop header once.

More bailout preparation work

* module/language/cps/cse.scm (compute-available-expressions): Compute a
  bailout set -- or at least, set things up so that we can do so.
  (compute-idoms): Don't add predecessors that bail out.
  (apply-cse, cse, compute-equivalent-subexpressions): Thread the
  bailout set through the computations.

Prepare for CSE bailout propagation

* module/language/cps/cse.scm (compute-available-expressions): Prepare
  for being able to prune joins from bailouts.  Always loop after the
  first iteration.

* module/language/cps/effects-analysis.scm: Remove &possible-bailout.
  Rename &definite-bailout to &bailout, and rename
  &all-effects-but-bailout to &unknown-effects.

Add common subexpression elimination pass on CPS

* module/language/cps/cse.scm: New file.
* module/language/cps/compile-bytecode.scm: Wire up CSE, on by default.
  Currently using the #:cps-cse? keyword.

* module/Makefile.am: Add new file.

Effects analysis tweaks

* module/language/cps/effects-analysis.scm: Add &fluid-environment
  effect, a dependency of fluid-ref and fluid-set!, and an effect of
  push-fluid/pop-fluid.
  (list): Depend on &cdr.
  (resolve, cached-toplevel-box, cached-module-box): Don't depend on
  &box.

Fix verify-cps to work

* module/language/cps/verify.scm (verify-cps): Relax requirements for
  variable names to be symbols.

constant-needs-allocation? fix

* module/language/cps/dfg.scm (constant-needs-allocation?): Constants
  need allocation when they are used as a slot-needing operand, not when
  they are not used as an immediate operand.  Fixes the case where one
  var is used in both ways after CSE, in struct-set!/immediate.

Remove variable-set! clause from compile-fun

* module/language/cps/compile-bytecode.scm (compile-fun): Remove
  vestigial `variable-set!' clause.

Effects analysis: define causes-all-effects?

* module/language/cps/effects-analysis.scm (causes-all-effects?): New
  export.

build-cps niceties

* module/language/cps.scm (build-cps-exp, build-cont-body): Respect
  unquote in list builders (kargs, call, callk, primcall, and values).

Minor CSE optimization

* module/language/tree-il/cse.scm (cse): Use hashq instead of modulo to
  convert a full-width hash value to a vector index.

Add with-fresh-name-state-from-dfg

* module/language/cps/dfg.scm (with-fresh-name-state-from-dfg): New
  helper.
  ($dfg, compute-dfg): Store max-var and max-label in the dfg.

* module/language/cps.scm (with-fresh-name-state): Don't raise an error
  on recursive invocation; that was mostly useful when finding a bug.

* module/language/cps/arities.scm (fix-arities):
* module/language/cps/specialize-primcalls.scm (specialize-primcalls):
  Use the new helper.

* .dir-locals.el: Update.

(test-suite lib) uses plain old catch, not stack-catch

* test-suite/test-suite/lib.scm (run-test-exception): Refactor to just
  use "catch" instead of stack-catch.

Refactor toplevel scope name generation in compile-cps

* module/language/tree-il/compile-cps.scm (scope-counter, fresh-scope-id):
  (toplevel-box, capture-toplevel-scope, convert, cps-convert/thunk):
  Refactor to avoid abusing the var counter to generate scope
  identifiers.

compute-max-label-and-var takes letrec vars into account.

* module/language/cps.scm (compute-max-label-and-var): Fix to take
  letrec vars into account.

Fix DCE for refactor-introduced borkage

* module/language/cps/dce.scm ($fun-data, compute-live-code)
  (process-eliminations): Fix clownshoes regarding fun-data field names
  and order.

Fix prune-top-level-scopes to allow collisions between var, scope, cont names

* module/language/cps/prune-top-level-scopes.scm (compute-referenced-scopes):
  Fix to not assume that scope names, continuation names, and var names
  are mutually unique.
  (prune-top-level-scopes): Better variable names.

Update old-style REPL code for deprecation

* module/ice-9/scm-style-repl.scm:
* module/ice-9/save-stack.scm: As the deprecated bindings have been
  removed from the default environment, use #:export instead of
  #:replace.

Remove CFA data type

* module/language/cps/dfg.scm: Remove CFA data type.
  (analyze-reverse-control-flow): Take min-label and label-count as
  args, and return multiple values instead of returning a CFA object.
  (compute-live-variables): Rework to accept multiple values from
  analyze-reverse-control-flow.
  ($dfa): Update comments.