working

13 files changed, 903 insertions, 0 deletions

diff --git a/vere/pkg/noun/v2/allocate.c b/vere/pkg/noun/v2/allocate.c
new file mode 100644
index 0000000..0476f8a
--- /dev/null
+++ b/vere/pkg/noun/v2/allocate.c
@@ -0,0 +1,73 @@
+/// @file
+
+#include "../allocate.h"
+#include "v1/allocate.h"
+#include "v2/allocate.h"
+
+#include "v2/hashtable.h"
+#include "log.h"
+#include "v2/manage.h"
+#include "options.h"
+#include "retrieve.h"
+#include "trace.h"
+#include "vortex.h"
+
+u3a_v2_road* u3a_v2_Road;
+
+u3_noun
+u3a_v2_rewritten_noun(u3_noun som)
+{
+  if ( c3y == u3a_v2_is_cat(som) ) {
+    return som;
+  }
+  u3_post som_p = u3a_v2_rewritten(u3a_v1_to_off(som));
+
+  if ( c3y == u3a_v2_is_pug(som) ) {
+    som_p = u3a_v2_to_pug(som_p);
+  }
+  else {
+    som_p = u3a_v2_to_pom(som_p);
+  }
+
+  return som_p;
+}
+
+/* u3a_v2_mig_rewrite_compact(): rewrite pointers in ad-hoc persistent road structures.
+*/
+void
+u3a_v2_mig_rewrite_compact(void)
+{
+  u3a_v2_rewrite_noun(u3R_v2->ski.gul);
+  u3a_v2_rewrite_noun(u3R_v2->bug.tax);
+  u3a_v2_rewrite_noun(u3R_v2->bug.mer);
+  u3a_v2_rewrite_noun(u3R_v2->pro.don);
+  u3a_v2_rewrite_noun(u3R_v2->pro.day);
+  u3a_v2_rewrite_noun(u3R_v2->pro.trace);
+  u3h_v2_rewrite(u3R_v2->cax.har_p);
+
+  u3R_v2->ski.gul = u3a_v2_rewritten_noun(u3R_v2->ski.gul);
+  u3R_v2->bug.tax = u3a_v2_rewritten_noun(u3R_v2->bug.tax);
+  u3R_v2->bug.mer = u3a_v2_rewritten_noun(u3R_v2->bug.mer);
+  u3R_v2->pro.don = u3a_v2_rewritten_noun(u3R_v2->pro.don);
+  u3R_v2->pro.day = u3a_v2_rewritten_noun(u3R_v2->pro.day);
+  u3R_v2->pro.trace = u3a_v2_rewritten_noun(u3R_v2->pro.trace);
+  u3R_v2->cax.har_p = u3a_v2_rewritten(u3R_v2->cax.har_p);
+}
+
+void
+u3a_v2_rewrite_noun(u3_noun som)
+{
+  if ( c3n == u3a_v2_is_cell(som) ) {
+    return;
+  }
+
+  if ( c3n == u3a_v2_rewrite_ptr(u3a_v1_to_ptr((som))) ) return;
+
+  u3a_v2_cell* cel = (u3a_v2_cell*) u3a_v1_to_ptr(som);
+
+  u3a_v2_rewrite_noun(cel->hed);
+  u3a_v2_rewrite_noun(cel->tel);
+
+  cel->hed = u3a_v2_rewritten_noun(cel->hed);
+  cel->tel = u3a_v2_rewritten_noun(cel->tel);
+}
diff --git a/vere/pkg/noun/v2/allocate.h b/vere/pkg/noun/v2/allocate.h
new file mode 100644
index 0000000..8832977
--- /dev/null
+++ b/vere/pkg/noun/v2/allocate.h
@@ -0,0 +1,134 @@
+#ifndef U3_ALLOCATE_V2_H
+#define U3_ALLOCATE_V2_H
+
+#include "../allocate.h"
+
+#include "v2/manage.h"
+#include "options.h"
+
+  /**  Aliases.
+  **/
+#     define u3a_v2_botox        u3a_botox
+#     define u3a_v2_box          u3a_box
+#     define u3a_v2_cell         u3a_cell
+#     define u3a_v2_fbox         u3a_fbox
+#     define u3a_v2_fbox_no      u3a_fbox_no
+#     define u3a_v2_free         u3a_free
+#     define u3a_v2_heap         u3a_heap
+#     define u3a_v2_into         u3a_into
+#     define u3a_v2_is_cat       u3a_is_cat
+#     define u3a_v2_is_cell      u3a_is_cell
+#     define u3a_v2_is_north     u3a_is_north
+#     define u3a_v2_is_pom       u3a_is_pom
+#     define u3a_v2_is_pug       u3a_is_pug
+#     define u3a_v2_lose         u3a_lose
+#     define u3a_v2_malloc       u3a_malloc
+#     define u3a_v2_minimum      u3a_minimum
+#     define u3a_v2_outa         u3a_outa
+#     define u3a_v2_pack_seek    u3a_pack_seek
+#     define u3a_v2_rewrite      u3a_rewrite
+#     define u3a_v2_rewrite_ptr  u3a_rewrite_ptr
+#     define u3a_v2_rewritten    u3a_rewritten
+#     define u3a_v2_to_off       u3a_to_off
+#     define u3a_v2_to_ptr       u3a_to_ptr
+#     define u3a_v2_to_wtr       u3a_to_wtr
+#     define u3a_v2_to_pug       u3a_to_pug
+#     define u3a_v2_to_pom       u3a_to_pom
+#     define u3a_v2_wfree        u3a_wfree
+
+  /**  Data structures.
+  **/
+    /* u3a_v2_road: contiguous allocation and execution context.
+    */
+      typedef struct _u3a_v2_road {
+        u3p(struct _u3a_v2_road) par_p;          //  parent road
+        u3p(struct _u3a_v2_road) kid_p;          //  child road list
+        u3p(struct _u3a_v2_road) nex_p;          //  sibling road
+
+        u3p(c3_w) cap_p;                      //  top of transient region
+        u3p(c3_w) hat_p;                      //  top of durable region
+        u3p(c3_w) mat_p;                      //  bottom of transient region
+        u3p(c3_w) rut_p;                      //  bottom of durable region
+        u3p(c3_w) ear_p;                      //  original cap if kid is live
+
+        c3_w fut_w[32];                       //  futureproof buffer
+
+        struct {                              //  escape buffer
+          union {
+            jmp_buf buf;
+            c3_w buf_w[256];                  //  futureproofing
+          };
+        } esc;
+
+        struct {                              //  miscellaneous config
+          c3_w fag_w;                         //  flag bits
+        } how;                                //
+
+        struct {                                   //  allocation pools
+          u3p(u3a_v2_fbox) fre_p[u3a_v2_fbox_no];  //  heap by node size log
+          u3p(u3a_fbox) cel_p;                //  custom cell allocator
+          c3_w fre_w;                         //  number of free words
+          c3_w max_w;                         //  maximum allocated
+        } all;
+
+        u3a_jets jed;                         //  jet dashboard
+
+        struct {                              // bytecode state
+          u3p(u3h_root) har_p;                // formula->post of bytecode
+        } byc;
+
+        struct {                              //  namespace
+          u3_noun gul;                        //  (list $+(* (unit (unit)))) now
+        } ski;
+
+        struct {                              //  trace stack
+          u3_noun tax;                        //  (list ,*)
+          u3_noun mer;                        //  emergency buffer to release
+        } bug;
+
+        struct {                              //  profile stack
+          c3_d    nox_d;                      //  nock steps
+          c3_d    cel_d;                      //  cell allocations
+          u3_noun don;                        //  (list batt)
+          u3_noun trace;                      //  (list trace)
+          u3_noun day;                        //  doss, only in u3H (moveme)
+        } pro;
+
+        struct {                              //  memoization
+          u3p(u3h_root) har_p;                //  (map (pair term noun) noun)
+        } cax;
+      } u3a_v2_road;
+
+  /**  Globals.
+  **/
+      /// Current road (thread-local).
+      extern u3a_v2_road* u3a_v2_Road;
+#       define u3R_v2  u3a_v2_Road
+
+  /**  Functions.
+  **/
+    /**  Allocation.
+    **/
+      /* Reference and arena control.
+      */
+        /* u3a_v2_mig_rewrite_compact(): rewrite pointers in ad-hoc persistent road structures.
+        */
+          void
+          u3a_v2_mig_rewrite_compact(void);
+
+        /* u3a_v2_rewrite_noun(): rewrite a noun for compaction.
+        */
+          void
+          u3a_v2_rewrite_noun(u3_noun som);
+
+        /* u3a_v2_rewritten(): rewrite a pointer for compaction.
+        */
+          u3_post
+          u3a_v2_rewritten(u3_post som_p);
+
+        /* u3a_v2_rewritten(): rewritten noun pointer for compaction.
+        */
+          u3_noun
+          u3a_v2_rewritten_noun(u3_noun som);
+
+#endif /* ifndef U3_ALLOCATE_V2_H */
diff --git a/vere/pkg/noun/v2/hashtable.c b/vere/pkg/noun/v2/hashtable.c
new file mode 100644
index 0000000..a4f0291
--- /dev/null
+++ b/vere/pkg/noun/v2/hashtable.c
@@ -0,0 +1,143 @@
+/// @file
+
+#include "../hashtable.h"
+#include "v1/hashtable.h"
+#include "v2/hashtable.h"
+
+#include "../allocate.h"
+#include "v1/allocate.h"
+#include "v2/allocate.h"
+
+/* _ch_v2_popcount(): number of bits set in word.  A standard intrinsic.
+**             NB: copy of _ch_v2_popcount in pkg/noun/hashtable.c
+*/
+static c3_w
+_ch_v2_popcount(c3_w num_w)
+{
+  return __builtin_popcount(num_w);
+}
+
+/* _ch_v2_free_buck(): free bucket
+**              NB: copy of _ch_v2_free_buck in pkg/noun/hashtable.c
+*/
+static void
+_ch_v2_free_buck(u3h_v2_buck* hab_u)
+{
+  c3_w i_w;
+
+  for ( i_w = 0; i_w < hab_u->len_w; i_w++ ) {
+    u3z(u3h_v2_slot_to_noun(hab_u->sot_w[i_w]));
+  }
+  u3a_v2_wfree(hab_u);
+}
+
+/* _ch_v2_free_node(): free node.
+*/
+static void
+_ch_v2_free_node(u3h_v2_node* han_u, c3_w lef_w)
+{
+  c3_w len_w = _ch_v2_popcount(han_u->map_w);
+  c3_w i_w;
+
+  lef_w -= 5;
+
+  for ( i_w = 0; i_w < len_w; i_w++ ) {
+    c3_w sot_w = han_u->sot_w[i_w];
+
+    if ( _(u3h_v2_slot_is_noun(sot_w)) ) {
+      u3z(u3h_v2_slot_to_noun(sot_w));
+    }
+    else {
+      //  NB: u3h_v2_slot_to_node()
+      void* hav_v = u3h_v2_slot_to_node(sot_w);
+
+      if ( 0 == lef_w ) {
+        _ch_v2_free_buck(hav_v);
+      } else {
+        _ch_v2_free_node(hav_v, lef_w);
+      }
+    }
+  }
+  u3a_v2_wfree(han_u);
+}
+
+/* _ch_v2_rewrite_buck(): rewrite buck for compaction.
+*/
+void
+_ch_v2_rewrite_buck(u3h_v2_buck* hab_u)
+{
+  if ( c3n == u3a_v2_rewrite_ptr(hab_u) ) return;
+  c3_w i_w;
+
+  for ( i_w = 0; i_w < hab_u->len_w; i_w++ ) {
+    u3_noun som = u3h_v2_slot_to_noun(hab_u->sot_w[i_w]);
+    hab_u->sot_w[i_w] = u3h_v2_noun_to_slot(u3a_v2_rewritten_noun(som));
+    u3a_v2_rewrite_noun(som);
+  }
+}
+
+/* _ch_v2_rewrite_node(): rewrite node for compaction.
+*/
+void
+_ch_v2_rewrite_node(u3h_v2_node* han_u, c3_w lef_w)
+{
+  if ( c3n == u3a_v2_rewrite_ptr(han_u) ) return;
+
+  c3_w len_w = _ch_v2_popcount(han_u->map_w);
+  c3_w i_w;
+
+  lef_w -= 5;
+
+  for ( i_w = 0; i_w < len_w; i_w++ ) {
+    c3_w sot_w = han_u->sot_w[i_w];
+
+    if ( _(u3h_v2_slot_is_noun(sot_w)) ) {
+      u3_noun kev = u3h_v2_slot_to_noun(sot_w);
+      han_u->sot_w[i_w] = u3h_v2_noun_to_slot(u3a_v2_rewritten_noun(kev));
+
+      u3a_v2_rewrite_noun(kev);
+    }
+    else {
+      void* hav_v = u3h_v1_slot_to_node(sot_w);
+      u3h_v2_node* nod_u = u3to(u3h_v2_node, u3a_v2_rewritten(u3of(u3h_v2_node,hav_v)));
+
+      han_u->sot_w[i_w] = u3h_v2_node_to_slot(nod_u);
+
+      if ( 0 == lef_w ) {
+        _ch_v2_rewrite_buck(hav_v);
+      } else {
+        _ch_v2_rewrite_node(hav_v, lef_w);
+      }
+    }
+  }
+}
+
+/* u3h_v2_rewrite(): rewrite pointers during compaction.
+*/
+void
+u3h_v2_rewrite(u3p(u3h_v2_root) har_p)
+{
+  u3h_v2_root* har_u = u3to(u3h_v2_root, har_p);
+  c3_w        i_w;
+
+  if ( c3n == u3a_v2_rewrite_ptr(har_u) ) return;
+
+  for ( i_w = 0; i_w < 64; i_w++ ) {
+    c3_w sot_w = har_u->sot_w[i_w];
+
+    if ( _(u3h_v2_slot_is_noun(sot_w)) ) {
+      u3_noun kev = u3h_v2_slot_to_noun(sot_w);
+      har_u->sot_w[i_w] = u3h_v2_noun_to_slot(u3a_v2_rewritten_noun(kev));
+
+      u3a_v2_rewrite_noun(kev);
+    }
+    else if ( _(u3h_v2_slot_is_node(sot_w)) ) {
+      u3h_v2_node* han_u = (u3h_v2_node*) u3h_v1_slot_to_node(sot_w);
+      u3h_v2_node* nod_u = u3to(u3h_v2_node, u3a_v2_rewritten(u3of(u3h_v2_node,han_u)));
+
+      har_u->sot_w[i_w] = u3h_v2_node_to_slot(nod_u);
+
+      _ch_v2_rewrite_node(han_u, 25);
+    }
+  }
+}
diff --git a/vere/pkg/noun/v2/hashtable.h b/vere/pkg/noun/v2/hashtable.h
new file mode 100644
index 0000000..2278640
--- /dev/null
+++ b/vere/pkg/noun/v2/hashtable.h
@@ -0,0 +1,42 @@
+#ifndef U3_HASHTABLE_V2_H
+#define U3_HASHTABLE_V2_H
+
+#define u3h_v2_buck          u3h_buck
+#define u3h_v2_free          u3h_free
+#define u3h_v2_new           u3h_new
+#define u3h_v2_node          u3h_node
+#define u3h_v2_noun_to_slot  u3h_noun_to_slot
+#define u3h_v2_root          u3h_root
+#define u3h_v2_slot_is_node  u3h_slot_is_node
+#define u3h_v2_slot_is_noun  u3h_slot_is_noun
+#define u3h_v2_slot_to_noun  u3h_slot_to_noun
+#define u3h_v2_walk          u3h_walk
+#define u3h_v2_walk_with     u3h_walk_with
+
+#include "../hashtable.h"
+
+#include "c3/c3.h"
+#include "types.h"
+
+  /**  Data structures.
+  **/
+
+    /**  HAMT macros.
+    ***
+    ***  Coordinate with u3_noun definition!
+    **/
+      /* u3h_v2_slot_to_node(): slot to node pointer
+      ** u3h_v2_node_to_slot(): node pointer to slot
+      */
+#     define  u3h_v2_slot_to_node(sot)  (u3a_v2_into(((sot) & 0x3fffffff) << u3a_vits))
+#     define  u3h_v2_node_to_slot(ptr)  ((u3a_v2_outa((ptr)) >> u3a_vits) | 0x40000000)
+
+    /**  Functions.
+    ***
+    **/
+      /* u3h_v2_rewrite(): rewrite hashtable for compaction.
+      */
+        void
+        u3h_v2_rewrite(u3p(u3h_root) har_p);
+
+#endif /* U3_HASHTABLE_V2_H */
diff --git a/vere/pkg/noun/v2/jets.c b/vere/pkg/noun/v2/jets.c
new file mode 100644
index 0000000..4d5fa0f
--- /dev/null
+++ b/vere/pkg/noun/v2/jets.c
@@ -0,0 +1,54 @@
+/// @file
+
+#include "../vortex.h"
+
+#include "../jets.h"
+#include "v2/jets.h"
+
+#include "v2/allocate.h"
+#include "v2/hashtable.h"
+#include "v2/vortex.h"
+
+#include "v3/hashtable.h"
+#include "v3/jets.h"
+
+/* u3j_v2_reclaim(): clear ad-hoc persistent caches to reclaim memory.
+*/
+void
+u3j_v2_reclaim(void)
+{
+  //  set globals (required for aliased functions)
+  u3H = (u3v_home*) u3H_v2;
+  u3R = (u3a_road*) u3R_v2;
+
+  //  clear the jet hank cache
+  //
+  u3h_v3_walk(u3R->jed.han_p, u3j_v3_free_hank);
+  u3h_v3_free(u3R->jed.han_p);
+  u3R->jed.han_p = u3h_v3_new();
+}
+
+/* u3j_v2_mig_rewrite_compact(): rewrite jet state for compaction.
+ *
+ * NB: u3R_v2->jed.han_p *must* be cleared (currently via u3j_v2_reclaim above)
+ * since it contains hanks which are not nouns but have loom pointers.
+ * Alternately, rewrite the entries with u3h_v2_walk, using u3j_v2_mark as a
+ * template for how to walk.  There's an untested attempt at this in git
+ * history at e8a307a.
+*/
+void
+u3j_v2_mig_rewrite_compact(void)
+{
+  u3h_v2_rewrite(u3R_v2->jed.war_p);
+  u3h_v2_rewrite(u3R_v2->jed.cod_p);
+  u3h_v2_rewrite(u3R_v2->jed.han_p);
+  u3h_v2_rewrite(u3R_v2->jed.bas_p);
+
+  u3h_v2_rewrite(u3R_v2->jed.hot_p);
+  u3R_v2->jed.hot_p = u3a_v2_rewritten(u3R_v2->jed.hot_p);
+
+  u3R_v2->jed.war_p = u3a_v2_rewritten(u3R_v2->jed.war_p);
+  u3R_v2->jed.cod_p = u3a_v2_rewritten(u3R_v2->jed.cod_p);
+  u3R_v2->jed.han_p = u3a_v2_rewritten(u3R_v2->jed.han_p);
+  u3R_v2->jed.bas_p = u3a_v2_rewritten(u3R_v2->jed.bas_p);
+}
diff --git a/vere/pkg/noun/v2/jets.h b/vere/pkg/noun/v2/jets.h
new file mode 100644
index 0000000..33ac088
--- /dev/null
+++ b/vere/pkg/noun/v2/jets.h
@@ -0,0 +1,35 @@
+/// @file
+
+#ifndef U3_JETS_V2_H
+#define U3_JETS_V2_H
+
+#include "../allocate.h"
+#include "../jets.h"
+
+
+  /**  Aliases.
+  **/
+#     define  u3j_v2_core       u3j_core
+#     define  u3j_v2_fink       u3j_fink
+#     define  u3j_v2_fist       u3j_fist
+#     define  u3j_v2_hank       u3j_hank
+#     define  u3j_v2_free_hank  u3j_free_hank
+#     define  u3j_v2_harm       u3j_harm
+#     define  u3j_v2_rite       u3j_rite
+#     define  u3j_v2_site       u3j_site
+#     define  u3j_v2_rite_lose  u3j_rite_lose
+#     define  u3j_v2_site_lose  u3j_site_lose
+
+  /**  Functions.
+  **/
+    /* u3j_v2_reclaim(): clear ad-hoc persistent caches to reclaim memory.
+    */
+      void
+      u3j_v2_reclaim(void);
+
+    /* u3j_v2_mig_rewrite_compact(): rewrite jet state for compaction.
+    */
+      void
+      u3j_v2_mig_rewrite_compact(void);
+
+#endif /* ifndef U3_JETS_V2_H */
diff --git a/vere/pkg/noun/v2/manage.c b/vere/pkg/noun/v2/manage.c
new file mode 100644
index 0000000..16981d2
--- /dev/null
+++ b/vere/pkg/noun/v2/manage.c
@@ -0,0 +1,174 @@
+/// @file
+
+#include "v2/manage.h"
+
+#include "v1/allocate.h"
+#include "v2/allocate.h"
+#include "v2/hashtable.h"
+#include "v2/jets.h"
+#include "v2/nock.h"
+#include "v2/options.h"
+#include "../vortex.h"
+#include "v1/vortex.h"
+#include "v2/vortex.h"
+
+/* _cm_pack_rewrite(): trace through arena, rewriting pointers.
+*/
+static void
+_cm_pack_rewrite(void)
+{
+  u3v_v2_mig_rewrite_compact();
+  u3j_v2_mig_rewrite_compact();
+  u3n_v2_mig_rewrite_compact();
+  u3a_v2_mig_rewrite_compact();
+}
+
+static void
+_migrate_reclaim(void)
+{
+  //  XX update this and similar printfs
+  fprintf(stderr, "loom: migration reclaim\r\n");
+  u3m_v1_reclaim();
+}
+
+static void
+_migrate_seek(const u3a_v2_road *rod_u)
+{
+  /*
+    very much like u3a_v2_pack_seek with the following changes:
+    - there is no need to account for free space as |pack is performed before
+      the migration
+    - odd sized boxes will be padded by one word to achieve an even size
+    - rut will be moved from one word ahead of u3_Loom to two words ahead
+  */
+  c3_w *    box_w = u3a_v2_into(rod_u->rut_p);
+  c3_w *    end_w = u3a_v2_into(rod_u->hat_p);
+  u3_post   new_p = (rod_u->rut_p + 1 + c3_wiseof(u3a_v2_box));
+  u3a_v2_box * box_u = (void *)box_w;
+
+  fprintf(stderr, "loom: migration seek\r\n");
+
+  for (; box_w < end_w
+         ; box_w += box_u->siz_w
+         , box_u = (void*)box_w)
+    {
+      if (!box_u->use_w)
+        continue;
+      u3_assert(box_u->siz_w);
+      u3_assert(box_u->use_w);
+      box_w[box_u->siz_w - 1] = new_p;
+      new_p = c3_align(new_p + box_u->siz_w, 2, C3_ALGHI);
+    }
+}
+
+static void
+_migrate_rewrite(void)
+{
+  fprintf(stderr, "loom: migration rewrite\r\n");
+
+  _cm_pack_rewrite();
+}
+
+static void
+_migrate_move(u3a_v2_road *rod_u)
+{
+  fprintf(stderr, "loom: migration move\r\n");
+
+  c3_z hiz_z = u3a_v2_heap(rod_u) * sizeof(c3_w);
+
+  /* calculate required shift distance to prevent write head overlapping read head */
+  c3_w  off_w = 1;  /* at least 1 word because u3R_v1->rut_p migrates from 1 to 2 */
+  for (u3a_v2_box *box_u = u3a_v2_into(rod_u->rut_p)
+         ; (void *)box_u < u3a_v2_into(rod_u->hat_p)
+         ; box_u = (void *)((c3_w *)box_u + box_u->siz_w))
+    off_w += box_u->siz_w & 1; /* odd-sized boxes are padded by one word */
+
+  /* shift */
+  memmove(u3a_v2_into(u3H_v2->rod_u.rut_p + off_w),
+          u3a_v2_into(u3H_v2->rod_u.rut_p),
+          hiz_z);
+  /* manually zero the former rut */
+  *(c3_w *)u3a_v2_into(rod_u->rut_p) = 0;
+
+  /* relocate boxes to DWORD-aligned addresses stored in trailing size word */
+  c3_w *box_w = u3a_v2_into(rod_u->rut_p + off_w);
+  c3_w *end_w = u3a_v2_into(rod_u->hat_p + off_w);
+  u3a_v2_box *old_u = (void *)box_w;
+  c3_w siz_w = old_u->siz_w;
+  u3p(c3_w) new_p = rod_u->rut_p + 1 + c3_wiseof(u3a_v2_box);
+  c3_w *new_w;
+
+  for (; box_w < end_w
+         ; box_w += siz_w
+         , old_u = (void *)box_w
+         , siz_w = old_u->siz_w) {
+    old_u->use_w &= 0x7fffffff;
+
+    if (!old_u->use_w)
+      continue;
+
+    new_w = (void *)u3a_v2_botox(u3a_v2_into(new_p));
+    u3_assert(box_w[siz_w - 1] == new_p);
+    u3_assert(new_w <= box_w);
+
+    c3_w i_w;
+    for (i_w = 0; i_w < siz_w - 1; i_w++)
+      new_w[i_w] = box_w[i_w];
+
+    if (siz_w & 1) {
+      new_w[i_w++] = 0;         /* pad odd sized boxes */
+      new_w[i_w++] = siz_w + 1; /* restore trailing size word */
+      new_w[0] = siz_w + 1;     /* and the leading size word */
+    }
+    else {
+      new_w[i_w++] = siz_w;
+    }
+
+    new_p += i_w;
+  }
+
+  /* restore proper heap state */
+  rod_u->rut_p = 2;
+  rod_u->hat_p = new_p - c3_wiseof(u3a_v2_box);
+
+  /* like |pack, clear the free lists and cell allocator */
+  for (c3_w i_w = 0; i_w < u3a_v2_fbox_no; i_w++)
+    u3R_v1->all.fre_p[i_w] = 0;
+
+  u3R_v1->all.fre_w = 0;
+  u3R_v1->all.cel_p = 0;
+}
+
+
+/* u3m_v2_migrate: perform loom migration if necessary.
+*/
+void
+u3m_v2_migrate(void)
+{
+  c3_w len_w = u3C_v2.wor_i - 1;
+  c3_w ver_w = *(u3_Loom + len_w);
+
+  u3_assert( U3V_VER1 == ver_w );
+
+  c3_w* mem_w = u3_Loom + 1;
+  c3_w  siz_w = c3_wiseof(u3v_v1_home);
+  c3_w* mat_w = (mem_w + len_w) - siz_w;
+
+  u3H_v1 = (void *)mat_w;
+  u3R_v1 = &u3H_v1->rod_u;
+
+  u3R_v1->cap_p = u3R_v1->mat_p = u3a_v1_outa(u3H_v1);
+
+  fprintf(stderr, "loom: pointer compression migration running...\r\n");
+
+  /* perform the migration in a pattern similar to |pack */
+  _migrate_reclaim();
+  _migrate_seek(&u3H_v1->rod_u);
+  _migrate_rewrite();
+  _migrate_move(&u3H_v1->rod_u);
+
+  /* finally update the version and commit to disk */
+  u3H_v1->ver_w = U3V_VER2;
+
+  fprintf(stderr, "loom: pointer compression migration done\r\n");
+}
diff --git a/vere/pkg/noun/v2/manage.h b/vere/pkg/noun/v2/manage.h
new file mode 100644
index 0000000..623453e
--- /dev/null
+++ b/vere/pkg/noun/v2/manage.h
@@ -0,0 +1,13 @@
+/// @file
+
+#ifndef U3_MANAGE_V2_H
+#define U3_MANAGE_V2_H
+
+    /**  System management.
+    **/
+      /* u3m_v2_migrate: perform pointer compression loom migration if necessary.
+      */
+        void
+        u3m_v2_migrate(void);
+
+#endif /* ifndef U3_MANAGE_V2_H */
diff --git a/vere/pkg/noun/v2/nock.c b/vere/pkg/noun/v2/nock.c
new file mode 100644
index 0000000..e42221a
--- /dev/null
+++ b/vere/pkg/noun/v2/nock.c
@@ -0,0 +1,92 @@
+/// @file
+
+#include "v2/nock.h"
+
+#include "../vortex.h"
+
+#include "v2/allocate.h"
+#include "v2/hashtable.h"
+#include "v2/vortex.h"
+
+#include "v3/hashtable.h"
+
+/* u3n_v2_reclaim(): clear ad-hoc persistent caches to reclaim memory.
+*/
+void
+u3n_v2_reclaim(void)
+{
+  //  set globals (required for aliased functions)
+  u3H = (u3v_home*) u3H_v2;
+  u3R = (u3a_road*) u3R_v2;
+
+  //  clear the bytecode cache
+  u3n_v2_free();
+  u3R->byc.har_p = u3h_v2_new();
+}
+
+/* _cn_v2_prog_free(): free memory retained by program pog_u
+*/
+static void
+_cn_v2_prog_free(u3n_v2_prog* pog_u)
+{
+  // fix up pointers for loom portability
+  pog_u->byc_u.ops_y = (c3_y*) ((void*) pog_u) + sizeof(u3n_v2_prog);
+  pog_u->lit_u.non   = (u3_noun*) (pog_u->byc_u.ops_y + pog_u->byc_u.len_w);
+  pog_u->mem_u.sot_u = (u3n_v2_memo*) (pog_u->lit_u.non + pog_u->lit_u.len_w);
+  pog_u->cal_u.sit_u = (u3j_v2_site*) (pog_u->mem_u.sot_u + pog_u->mem_u.len_w);
+  pog_u->reg_u.rit_u = (u3j_v2_rite*) (pog_u->cal_u.sit_u + pog_u->cal_u.len_w);
+
+  c3_w dex_w;
+  for (dex_w = 0; dex_w < pog_u->lit_u.len_w; ++dex_w) {
+    u3a_v2_lose(pog_u->lit_u.non[dex_w]);
+  }
+  for (dex_w = 0; dex_w < pog_u->mem_u.len_w; ++dex_w) {
+    u3a_v2_lose(pog_u->mem_u.sot_u[dex_w].key);
+  }
+  for (dex_w = 0; dex_w < pog_u->cal_u.len_w; ++dex_w) {
+    u3j_v2_site_lose(&(pog_u->cal_u.sit_u[dex_w]));
+  }
+  for (dex_w = 0; dex_w < pog_u->reg_u.len_w; ++dex_w) {
+    u3j_v2_rite_lose(&(pog_u->reg_u.rit_u[dex_w]));
+  }
+  u3a_v2_free(pog_u);
+}
+
+/* _n_v2_feb(): u3h_v2_walk helper for u3n_v2_free
+ */
+static void
+_n_v2_feb(u3_noun kev)
+{
+  u3a_v2_cell *cel_u = (u3a_v2_cell*) u3a_v2_to_ptr(kev);
+  _cn_v2_prog_free(u3to(u3n_v2_prog, cel_u->tel));
+}
+
+/* u3n_v2_free(): free bytecode cache
+ */
+void
+u3n_v2_free(void)
+{
+  u3p(u3h_v2_root) har_p = u3R_v2->byc.har_p;
+  u3h_v2_walk(har_p, _n_v2_feb);
+  u3h_v2_free(har_p);
+}
+
+/* u3n_v2_mig_rewrite_compact(): rewrite the bytecode cache for compaction.
+ *
+ * NB: u3R_v2->byc.har_p *must* be cleared (currently via u3n_v2_reclaim above),
+ * since it contains things that look like nouns but aren't.
+ * Specifically, it contains "cells" where the tail is a
+ * pointer to a u3a_v2_malloc'ed block that contains loom pointers.
+ *
+ * You should be able to walk this with u3h_v2_walk and rewrite the
+ * pointers, but you need to be careful to handle that u3a_v2_malloc
+ * pointers can't be turned into a box by stepping back two words. You
+ * must step back one word to get the padding, step then step back that
+ * many more words (plus one?).
+ */
+void
+u3n_v2_mig_rewrite_compact(void)
+{
+  u3h_v2_rewrite(u3R_v2->byc.har_p);
+  u3R_v2->byc.har_p = u3a_v2_rewritten(u3R_v2->byc.har_p);
+}
diff --git a/vere/pkg/noun/v2/nock.h b/vere/pkg/noun/v2/nock.h
new file mode 100644
index 0000000..efb9121
--- /dev/null
+++ b/vere/pkg/noun/v2/nock.h
@@ -0,0 +1,64 @@
+/// @file
+
+#ifndef U3_NOCK_V2_H
+#define U3_NOCK_V2_H
+
+#include "v3/nock.h"
+
+#include "v2/jets.h"
+
+#include "types.h"
+
+  /** Data structures.
+  **/
+    /* u3n_memo: %memo hint space
+     */
+    typedef struct {
+      c3_l    sip_l;
+      u3_noun key;
+    } u3n_v2_memo;
+
+  /* u3n_v2_prog: program compiled from nock
+   */
+  typedef struct _u3n_v2_prog {
+    struct {
+      c3_o      own_o;                // program owns ops_y?
+      c3_w      len_w;                // length of bytecode (bytes)
+      c3_y*     ops_y;                // actual array of bytes
+    } byc_u;                          // bytecode
+    struct {
+      c3_w      len_w;                // number of literals
+      u3_noun*  non;                  // array of literals
+    } lit_u;                          // literals
+    struct {
+      c3_w      len_w;                // number of memo slots
+      u3n_v2_memo* sot_u;             // array of memo slots
+    } mem_u;                          // memo slot data
+    struct {
+      c3_w      len_w;                // number of calls sites
+      u3j_v2_site* sit_u;             // array of sites
+    } cal_u;                          // call site data
+    struct {
+      c3_w      len_w;                // number of registration sites
+      u3j_v2_rite* rit_u;             // array of sites
+    } reg_u;                          // registration site data
+  } u3n_v2_prog;
+
+  /**  Functions.
+  **/
+    /* u3n_v2_reclaim(): clear ad-hoc persistent caches to reclaim memory.
+    */
+      void
+      u3n_v2_reclaim(void);
+
+    /* u3n_v2_free(): free bytecode cache.
+     */
+      void
+      u3n_v2_free(void);
+
+    /* u3n_v2_mig_rewrite_compact(): rewrite bytecode cache for compaction.
+     */
+      void
+      u3n_v2_mig_rewrite_compact(void);
+
+#endif /* ifndef U3_NOCK_V2_H */
diff --git a/vere/pkg/noun/v2/options.h b/vere/pkg/noun/v2/options.h
new file mode 100644
index 0000000..079f766
--- /dev/null
+++ b/vere/pkg/noun/v2/options.h
@@ -0,0 +1,14 @@
+/// @file
+
+#ifndef U3_OPTIONS_V2_H
+#define U3_OPTIONS_V2_H
+
+#include "../options.h"
+
+  /** Globals.
+  **/
+    /* u3_Config / u3C: global memory control.
+    */
+#     define u3C_v2  u3C
+
+#endif /* ifndef U3_OPTIONS_H */
diff --git a/vere/pkg/noun/v2/vortex.c b/vere/pkg/noun/v2/vortex.c
new file mode 100644
index 0000000..9b21d5c
--- /dev/null
+++ b/vere/pkg/noun/v2/vortex.c
@@ -0,0 +1,25 @@
+/// @file
+
+#include "../vortex.h"
+#include "v2/vortex.h"
+
+#include "v2/allocate.h"
+
+u3v_v2_home* u3v_v2_Home;
+
+/* u3v_v2_mig_rewrite_compact(): rewrite arvo kernel for compaction.
+*/
+void
+u3v_v2_mig_rewrite_compact(void)
+{
+  u3v_v2_arvo* arv_u = &(u3H_v2->arv_u);
+
+  u3a_v2_rewrite_noun(arv_u->roc);
+  u3a_v2_rewrite_noun(arv_u->now);
+  u3a_v2_rewrite_noun(arv_u->yot);
+
+  arv_u->roc = u3a_v2_rewritten_noun(arv_u->roc);
+  arv_u->now = u3a_v2_rewritten_noun(arv_u->now);
+  arv_u->yot = u3a_v2_rewritten_noun(arv_u->yot);
+}
+
diff --git a/vere/pkg/noun/v2/vortex.h b/vere/pkg/noun/v2/vortex.h
new file mode 100644
index 0000000..9e04832
--- /dev/null
+++ b/vere/pkg/noun/v2/vortex.h
@@ -0,0 +1,40 @@
+/// @file
+
+#ifndef U3_VORTEX_V2_H
+#define U3_VORTEX_V2_H
+
+#include "../vortex.h"
+
+#include "v2/allocate.h"
+#include "../version.h"
+
+  /**  Aliases.
+  **/
+#     define     u3v_v2_arvo  u3v_arvo
+
+  /**  Data structures.
+  **/
+    /* u3v_v2_home: all internal (within image) state.
+    **       NB: version must be last for discriminability in north road
+    */
+      typedef struct _u3v_v2_home {
+        u3a_v2_road    rod_u;                //  storage state
+        u3v_v2_arvo    arv_u;                //  arvo state
+        u3v_version    ver_w;                //  version number
+      } u3v_v2_home;
+
+  /**  Globals.
+  **/
+      /// Arvo internal state.
+      extern u3v_v2_home* u3v_v2_Home;
+#       define u3H_v2  u3v_v2_Home
+#       define u3A_v2  (&(u3v_v2_Home->arv_u))
+
+  /**  Functions.
+  **/
+    /* u3v_v2_mig_rewrite_compact(): rewrite arvo kernel for compaction.
+    */
+      void
+      u3v_v2_mig_rewrite_compact(void);
+
+#endif /* ifndef U3_VORTEX_V2_H */