[PATCH 05/21] zlib: rename BITS() to LOWBITS()

Yury Norov (NVIDIA)
2025-10-25T16:29:14Z

In preparation from adding generic BITS() macro, rename the local one.

Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
---
lib/zlib_inflate/inflate.c | 48 +++++++++++++++++++-------------------
1 file changed, 24 insertions(+), 24 deletions(-)

diff --git a/lib/zlib_inflate/inflate.c b/lib/zlib_inflate/inflate.c
index d1efad69f02b..3102137b51c2 100644
--- a/lib/zlib_inflate/inflate.c
+++ b/lib/zlib_inflate/inflate.c
@@ -229,7 +229,7 @@ static int zlib_inflateSyncPacket(z_streamp strm)
} while (0)

/* Return the low n bits of the bit accumulator (n < 16) */
-#define BITS(n) \
+#define LOWBITS(n) \
((unsigned)hold & ((1U << (n)) - 1))

/* Remove n bits from the bit accumulator */
@@ -270,16 +270,16 @@ static int zlib_inflateSyncPacket(z_streamp strm)
is:

NEEDBITS(n);
- ... do something with BITS(n) ...
+ ... do something with LOWBITS(n) ...
DROPBITS(n);

where NEEDBITS(n) either returns from inflate() if there isn't enough
- input left to load n bits into the accumulator, or it continues. BITS(n)
+ input left to load n bits into the accumulator, or it continues. LOWBITS(n)
gives the low n bits in the accumulator. When done, DROPBITS(n) drops
the low n bits off the accumulator. INITBITS() clears the accumulator
and sets the number of available bits to zero. BYTEBITS() discards just
enough bits to put the accumulator on a byte boundary. After BYTEBITS()
- and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
+ and a NEEDBITS(8), then LOWBITS(8) would return the next byte in the stream.

NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
if there is no input available. The decoding of variable length codes uses
@@ -295,7 +295,7 @@ static int zlib_inflateSyncPacket(z_streamp strm)
case STATEw:
while (want < need) {
NEEDBITS(n);
- keep[want++] = BITS(n);
+ keep[want++] = LOWBITS(n);
DROPBITS(n);
}
state = STATEx;
@@ -369,18 +369,18 @@ int zlib_inflate(z_streamp strm, int flush)
}
NEEDBITS(16);
if (
- ((BITS(8) << 8) + (hold >> 8)) % 31) {
+ ((LOWBITS(8) << 8) + (hold >> 8)) % 31) {
strm->msg = (char *)"incorrect header check";
state->mode = BAD;
break;
}
- if (BITS(4) != Z_DEFLATED) {
+ if (LOWBITS(4) != Z_DEFLATED) {
strm->msg = (char *)"unknown compression method";
state->mode = BAD;
break;
}
DROPBITS(4);
- len = BITS(4) + 8;
+ len = LOWBITS(4) + 8;
if (len > state->wbits) {
strm->msg = (char *)"invalid window size";
state->mode = BAD;
@@ -416,9 +416,9 @@ int zlib_inflate(z_streamp strm, int flush)
break;
}
NEEDBITS(3);
- state->last = BITS(1);
+ state->last = LOWBITS(1);
DROPBITS(1);
- switch (BITS(2)) {
+ switch (LOWBITS(2)) {
case 0: /* stored block */
state->mode = STORED;
break;
@@ -465,11 +465,11 @@ int zlib_inflate(z_streamp strm, int flush)
break;
case TABLE:
NEEDBITS(14);
- state->nlen = BITS(5) + 257;
+ state->nlen = LOWBITS(5) + 257;
DROPBITS(5);
- state->ndist = BITS(5) + 1;
+ state->ndist = LOWBITS(5) + 1;
DROPBITS(5);
- state->ncode = BITS(4) + 4;
+ state->ncode = LOWBITS(4) + 4;
DROPBITS(4);
#ifndef PKZIP_BUG_WORKAROUND
if (state->nlen > 286 || state->ndist > 30) {
@@ -484,7 +484,7 @@ int zlib_inflate(z_streamp strm, int flush)
case LENLENS:
while (state->have < state->ncode) {
NEEDBITS(3);
- state->lens[order[state->have++]] = (unsigned short)BITS(3);
+ state->lens[order[state->have++]] = (unsigned short)LOWBITS(3);
DROPBITS(3);
}
while (state->have < 19)
@@ -505,7 +505,7 @@ int zlib_inflate(z_streamp strm, int flush)
case CODELENS:
while (state->have < state->nlen + state->ndist) {
for (;;) {
- this = state->lencode[BITS(state->lenbits)];
+ this = state->lencode[LOWBITS(state->lenbits)];
if ((unsigned)(this.bits) <= bits) break;
PULLBYTE();
}
@@ -524,21 +524,21 @@ int zlib_inflate(z_streamp strm, int flush)
break;
}
len = state->lens[state->have - 1];
- copy = 3 + BITS(2);
+ copy = 3 + LOWBITS(2);
DROPBITS(2);
}
else if (this.val == 17) {
NEEDBITS(this.bits + 3);
DROPBITS(this.bits);
len = 0;
- copy = 3 + BITS(3);
+ copy = 3 + LOWBITS(3);
DROPBITS(3);
}
else {
NEEDBITS(this.bits + 7);
DROPBITS(this.bits);
len = 0;
- copy = 11 + BITS(7);
+ copy = 11 + LOWBITS(7);
DROPBITS(7);
}
if (state->have + copy > state->nlen + state->ndist) {
@@ -584,7 +584,7 @@ int zlib_inflate(z_streamp strm, int flush)
break;
}
for (;;) {
- this = state->lencode[BITS(state->lenbits)];
+ this = state->lencode[LOWBITS(state->lenbits)];
if ((unsigned)(this.bits) <= bits) break;
PULLBYTE();
}
@@ -592,7 +592,7 @@ int zlib_inflate(z_streamp strm, int flush)
last = this;
for (;;) {
this = state->lencode[last.val +
- (BITS(last.bits + last.op) >> last.bits)];
+ (LOWBITS(last.bits + last.op) >> last.bits)];
if ((unsigned)(last.bits + this.bits) <= bits) break;
PULLBYTE();
}
@@ -619,14 +619,14 @@ int zlib_inflate(z_streamp strm, int flush)
case LENEXT:
if (state->extra) {
NEEDBITS(state->extra);
- state->length += BITS(state->extra);
+ state->length += LOWBITS(state->extra);
DROPBITS(state->extra);
}
state->mode = DIST;
fallthrough;
case DIST:
for (;;) {
- this = state->distcode[BITS(state->distbits)];
+ this = state->distcode[LOWBITS(state->distbits)];
if ((unsigned)(this.bits) <= bits) break;
PULLBYTE();
}
@@ -634,7 +634,7 @@ int zlib_inflate(z_streamp strm, int flush)
last = this;
for (;;) {
this = state->distcode[last.val +
- (BITS(last.bits + last.op) >> last.bits)];
+ (LOWBITS(last.bits + last.op) >> last.bits)];
if ((unsigned)(last.bits + this.bits) <= bits) break;
PULLBYTE();
}
@@ -653,7 +653,7 @@ int zlib_inflate(z_streamp strm, int flush)
case DISTEXT:
if (state->extra) {
NEEDBITS(state->extra);
- state->offset += BITS(state->extra);
+ state->offset += LOWBITS(state->extra);
DROPBITS(state->extra);
}
#ifdef INFLATE_STRICT
--
2.43.0