[git commit] bzip2: code shrink

[Denys Vlasenko]

commit: https://git.busybox.net/busybox/commit/?id=e594fb2171a40d6d8f438140440b6c6b1dad5c41
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master

function                                             old     new   delta
BZ2_compressBlock                                    225     230      +5
handle_compress                                      356     355      -1
bsW16                                                 59      56      -3
bsW                                                   64      61      -3
bsFinishWrite                                         37      32      -5
prepare_new_block                                     48      34     -14
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/5 up/down: 5/-26)             Total: -21 bytes

Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 archival/libarchive/bz/bzlib.c         | 18 +++++++++---------
 archival/libarchive/bz/bzlib_private.h |  5 +++--
 archival/libarchive/bz/compress.c      | 13 ++++++-------
 3 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/archival/libarchive/bz/bzlib.c b/archival/libarchive/bz/bzlib.c
index 5f7db747a..3572474f4 100644
--- a/archival/libarchive/bz/bzlib.c
+++ b/archival/libarchive/bz/bzlib.c
@@ -55,8 +55,9 @@ void prepare_new_block(EState* s)
 {
 	int i;
 	s->nblock = 0;
-	s->numZ = 0;
-	s->state_out_pos = 0;
+	//indexes inot s->zbits[], initialzation moved to init of s->zbits
+	//s->posZ = s->zbits; // was: s->numZ = 0;
+	//s->state_out_pos = s->zbits;
 	BZ_INITIALISE_CRC(s->blockCRC);
 	/* inlined memset would be nice to have here */
 	for (i = 0; i < 256; i++)
@@ -237,11 +238,10 @@ void /*Bool*/ copy_output_until_stop(EState* s)
 		if (s->strm->avail_out == 0) break;
 
 		/*-- block done? --*/
-		if (s->state_out_pos >= s->numZ) break;
+		if (s->state_out_pos >= s->posZ) break;
 
 		/*progress_out = True;*/
-		*(s->strm->next_out) = s->zbits[s->state_out_pos];
-		s->state_out_pos++;
+		*(s->strm->next_out) = *s->state_out_pos++;
 		s->strm->avail_out--;
 		s->strm->next_out++;
 		s->strm->total_out++;
@@ -261,7 +261,7 @@ void /*Bool*/ handle_compress(bz_stream *strm)
 	while (1) {
 		if (s->state == BZ_S_OUTPUT) {
 			/*progress_out |=*/ copy_output_until_stop(s);
-			if (s->state_out_pos < s->numZ) break;
+			if (s->state_out_pos < s->posZ) break;
 			if (s->mode == BZ_M_FINISHING
 			//# && s->avail_in_expect == 0
 			 && s->strm->avail_in == 0
@@ -336,7 +336,7 @@ int BZ2_bzCompress(bz_stream *strm, int action)
 			/*if (s->avail_in_expect != s->strm->avail_in)
 				return BZ_SEQUENCE_ERROR;*/
 			/*progress =*/ handle_compress(strm);
-			if (s->avail_in_expect > 0 || !isempty_RL(s) || s->state_out_pos < s->numZ)
+			if (s->avail_in_expect > 0 || !isempty_RL(s) || s->state_out_pos < s->posZ)
 				return BZ_FLUSH_OK;
 			s->mode = BZ_M_RUNNING;
 			return BZ_RUN_OK;
@@ -349,9 +349,9 @@ int BZ2_bzCompress(bz_stream *strm, int action)
 				return BZ_SEQUENCE_ERROR;*/
 			/*progress =*/ handle_compress(strm);
 			/*if (!progress) return BZ_SEQUENCE_ERROR;*/
-			//#if (s->avail_in_expect > 0 || !isempty_RL(s) || s->state_out_pos < s->numZ)
+			//#if (s->avail_in_expect > 0 || !isempty_RL(s) || s->state_out_pos < s->posZ)
 			//#	return BZ_FINISH_OK;
-			if (s->strm->avail_in > 0 || !isempty_RL(s) || s->state_out_pos < s->numZ)
+			if (s->strm->avail_in > 0 || !isempty_RL(s) || s->state_out_pos < s->posZ)
 				return BZ_FINISH_OK;
 			/*s->mode = BZ_M_IDLE;*/
 			return BZ_STREAM_END;
diff --git a/archival/libarchive/bz/bzlib_private.h b/archival/libarchive/bz/bzlib_private.h
index 43e674bec..8e44a8e64 100644
--- a/archival/libarchive/bz/bzlib_private.h
+++ b/archival/libarchive/bz/bzlib_private.h
@@ -150,8 +150,9 @@ typedef struct EState {
 	/* input and output limits and current posns */
 	int32_t  nblock;
 	int32_t  nblockMAX;
-	int32_t  numZ;
-	int32_t  state_out_pos;
+	//int32_t  numZ; // index into s->zbits[], replaced by pointer:
+	uint8_t *posZ;
+	uint8_t *state_out_pos;
 
 	/* the buffer for bit stream creation */
 	uint32_t bsBuff;
diff --git a/archival/libarchive/bz/compress.c b/archival/libarchive/bz/compress.c
index c640173e5..534cf665a 100644
--- a/archival/libarchive/bz/compress.c
+++ b/archival/libarchive/bz/compress.c
@@ -50,8 +50,7 @@ static NOINLINE
 void bsFinishWrite(EState* s)
 {
 	while (s->bsLive > 0) {
-		s->zbits[s->numZ] = (uint8_t)(s->bsBuff >> 24);
-		s->numZ++;
+		*s->posZ++ = (uint8_t)(s->bsBuff >> 24);
 		s->bsBuff <<= 8;
 		s->bsLive -= 8;
 	}
@@ -67,8 +66,7 @@ ALWAYS_INLINE
 void bsW(EState* s, int32_t n, uint32_t v)
 {
 	while (s->bsLive >= 8) {
-		s->zbits[s->numZ] = (uint8_t)(s->bsBuff >> 24);
-		s->numZ++;
+		*s->posZ++ = (uint8_t)(s->bsBuff >> 24);
 		s->bsBuff <<= 8;
 		s->bsLive -= 8;
 	}
@@ -83,8 +81,7 @@ ALWAYS_INLINE
 void bsW16(EState* s, uint32_t v)
 {
 	while (s->bsLive >= 8) {
-		s->zbits[s->numZ] = (uint8_t)(s->bsBuff >> 24);
-		s->numZ++;
+		*s->posZ++ = (uint8_t)(s->bsBuff >> 24);
 		s->bsBuff <<= 8;
 		s->bsLive -= 8;
 	}
@@ -624,12 +621,14 @@ void BZ2_compressBlock(EState* s, int is_last_block)
 		s->combinedCRC = (s->combinedCRC << 1) | (s->combinedCRC >> 31);
 		s->combinedCRC ^= s->blockCRC;
 		if (s->blockNo > 1)
-			s->numZ = 0;
+			s->posZ = s->zbits; // was: s->numZ = 0;
 
 		BZ2_blockSort(s);
 	}
 
 	s->zbits = &((uint8_t*)s->arr2)[s->nblock];
+	s->posZ = s->zbits;
+	s->state_out_pos = s->zbits;
 
 	/*-- If this is the first block, create the stream header. --*/
 	if (s->blockNo == 1) {