attack the biggest stack users:

-mkfs_minix_main [busybox_unstripped]:                  4288
-mkfs_minix_main [busybox_unstripped]:                  4276
-grave [busybox_unstripped]:                            4260
(bzip2 users too - not listed)

price we pay in code size increase:
mainSort                                            2458    2515     +57
grave                                               1005    1058     +53
sendMTFValues                                       2177    2195     +18
BZ2_blockSort                                        122     125      +3
mkfs_minix_main                                     3070    3022     -48
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/1 up/down: 131/-48)            Total: 83 bytes

1 files changed, 8 insertions, 2 deletions

diff --git a/archival/bz/compress.c b/archival/bz/compress.c
index b72edbbd4..640b8872b 100644
--- a/archival/bz/compress.c
+++ b/archival/bz/compress.c
@@ -264,13 +264,16 @@ void sendMTFValues(EState* s)
          * are also globals only used in this proc.
          * Made global to keep stack frame size small.
          */
+#define code     sendMTFValues__code
+#define rfreq    sendMTFValues__rfreq
+#define len_pack sendMTFValues__len_pack
 
         uint16_t cost[BZ_N_GROUPS];
         int32_t  fave[BZ_N_GROUPS];
 
         uint16_t* mtfv = s->mtfv;
 
-        alphaSize = s->nInUse+2;
+        alphaSize = s->nInUse + 2;
         for (t = 0; t < BZ_N_GROUPS; t++)
                 for (v = 0; v < alphaSize; v++)
                         s->len[t][v] = BZ_GREATER_ICOST;
@@ -453,7 +456,7 @@ void sendMTFValues(EState* s)
                 /* maxLen was changed from 20 to 17 in bzip2-1.0.3.  See
                  * comment in huffman.c for details. */
                 for (t = 0; t < nGroups; t++)
-                        BZ2_hbMakeCodeLengths(&(s->len[t][0]), &(s->rfreq[t][0]), alphaSize, 17 /*20*/);
+                        BZ2_hbMakeCodeLengths(s, &(s->len[t][0]), &(s->rfreq[t][0]), alphaSize, 17 /*20*/);
         }
 
         AssertH(nGroups < 8, 3002);
@@ -602,6 +605,9 @@ void sendMTFValues(EState* s)
                 selCtr++;
         }
         AssertH(selCtr == nSelectors, 3007);
+#undef code
+#undef rfreq
+#undef len_pack
 }