bzip2: eliminate some divisions

1 files changed, 12 insertions, 8 deletions

diff --git a/archival/bz/compress.c b/archival/bz/compress.c
index 3e2fbd867..724474e2d 100644
--- a/archival/bz/compress.c
+++ b/archival/bz/compress.c
@@ -186,7 +186,8 @@ void generateMTFValues(EState* s)
                                                 s->mtfFreq[BZ_RUNA]++;
                                         }
                                         if (zPend < 2) break;
-                                        zPend = (zPend - 2) / 2;
+                                        zPend = (uint32_t)(zPend - 2) / 2;
+                                        /* bbox: unsigned div is easier */
                                 };
                                 zPend = 0;
                         }
@@ -219,15 +220,18 @@ void generateMTFValues(EState* s)
                 zPend--;
                 while (1) {
                         if (zPend & 1) {
-                                mtfv[wr] = BZ_RUNB; wr++;
+                                mtfv[wr] = BZ_RUNB;
+                                wr++;
                                 s->mtfFreq[BZ_RUNB]++;
                         } else {
-                                mtfv[wr] = BZ_RUNA; wr++;
+                                mtfv[wr] = BZ_RUNA;
+                                wr++;
                                 s->mtfFreq[BZ_RUNA]++;
                         }
                         if (zPend < 2)
                                 break;
-                        zPend = (zPend - 2) / 2;
+                        zPend = (uint32_t)(zPend - 2) / 2;
+                        /* bbox: unsigned div is easier */
                 };
                 zPend = 0;
         }
@@ -288,7 +292,7 @@ void sendMTFValues(EState* s)
                 gs = 0;
                 while (nPart > 0) {
                         tFreq = remF / nPart;
-                        ge = gs-1;
+                        ge = gs - 1;
                         aFreq = 0;
                         while (aFreq < tFreq && ge < alphaSize-1) {
                                 ge++;
@@ -297,7 +301,7 @@ void sendMTFValues(EState* s)
 
                         if (ge > gs
                          && nPart != nGroups && nPart != 1
-                         && ((nGroups - nPart) % 2 == 1)
+                         && ((nGroups - nPart) % 2 == 1) /* bbox: can this be replaced by x & 1? */
                         ) {
                                 aFreq -= s->mtfFreq[ge];
                                 ge--;
@@ -310,7 +314,7 @@ void sendMTFValues(EState* s)
                                         s->len[nPart-1][v] = BZ_GREATER_ICOST;
 
                         nPart--;
-                        gs = ge+1;
+                        gs = ge + 1;
                         remF -= aFreq;
                 }
         }
@@ -414,7 +418,7 @@ void sendMTFValues(EState* s)
                         /*
                          * Increment the symbol frequencies for the selected table.
                          */
-/* 1% faster compress. +800 bytes */
+/* 1% faster compress. +800 bytes */ 
 #if CONFIG_BZIP2_FEATURE_SPEED >= 4
                         if (nGroups == 6 && 50 == ge-gs+1) {
                                 /*--- fast track the common case ---*/