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[PATCH] drivers/net/hamradio/baycom_epp.c: cleanups
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The times when tricky goto's produced better codes are long gone.

This patch should express the same in a better way.

(Also fixes the final gcc-4.0 x86 compile error)

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Adrian Bunk authored and Linus Torvalds committed Jun 2, 2005
1 parent c4eb2a9 commit 0fd56f6
Showing 1 changed file with 36 additions and 90 deletions.
126 changes: 36 additions & 90 deletions drivers/net/hamradio/baycom_epp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -374,29 +374,6 @@ static inline void do_kiss_params(struct baycom_state *bc,
}

/* --------------------------------------------------------------------- */
/*
* high performance HDLC encoder
* yes, it's ugly, but generates pretty good code
*/

#define ENCODEITERA(j) \
({ \
if (!(notbitstream & (0x1f0 << j))) \
goto stuff##j; \
encodeend##j: ; \
})

#define ENCODEITERB(j) \
({ \
stuff##j: \
bitstream &= ~(0x100 << j); \
bitbuf = (bitbuf & (((2 << j) << numbit) - 1)) | \
((bitbuf & ~(((2 << j) << numbit) - 1)) << 1); \
numbit++; \
notbitstream = ~bitstream; \
goto encodeend##j; \
})


static void encode_hdlc(struct baycom_state *bc)
{
Expand All @@ -405,6 +382,7 @@ static void encode_hdlc(struct baycom_state *bc)
int pkt_len;
unsigned bitstream, notbitstream, bitbuf, numbit, crc;
unsigned char crcarr[2];
int j;

if (bc->hdlctx.bufcnt > 0)
return;
Expand All @@ -429,24 +407,14 @@ static void encode_hdlc(struct baycom_state *bc)
pkt_len--;
if (!pkt_len)
bp = crcarr;
ENCODEITERA(0);
ENCODEITERA(1);
ENCODEITERA(2);
ENCODEITERA(3);
ENCODEITERA(4);
ENCODEITERA(5);
ENCODEITERA(6);
ENCODEITERA(7);
goto enditer;
ENCODEITERB(0);
ENCODEITERB(1);
ENCODEITERB(2);
ENCODEITERB(3);
ENCODEITERB(4);
ENCODEITERB(5);
ENCODEITERB(6);
ENCODEITERB(7);
enditer:
for (j = 0; j < 8; j++)
if (unlikely(!(notbitstream & (0x1f0 << j)))) {
bitstream &= ~(0x100 << j);
bitbuf = (bitbuf & (((2 << j) << numbit) - 1)) |
((bitbuf & ~(((2 << j) << numbit) - 1)) << 1);
numbit++;
notbitstream = ~bitstream;
}
numbit += 8;
while (numbit >= 8) {
*wp++ = bitbuf;
Expand Down Expand Up @@ -610,37 +578,6 @@ static void do_rxpacket(struct net_device *dev)
bc->stats.rx_packets++;
}

#define DECODEITERA(j) \
({ \
if (!(notbitstream & (0x0fc << j))) /* flag or abort */ \
goto flgabrt##j; \
if ((bitstream & (0x1f8 << j)) == (0xf8 << j)) /* stuffed bit */ \
goto stuff##j; \
enditer##j: ; \
})

#define DECODEITERB(j) \
({ \
flgabrt##j: \
if (!(notbitstream & (0x1fc << j))) { /* abort received */ \
state = 0; \
goto enditer##j; \
} \
if ((bitstream & (0x1fe << j)) != (0x0fc << j)) /* flag received */ \
goto enditer##j; \
if (state) \
do_rxpacket(dev); \
bc->hdlcrx.bufcnt = 0; \
bc->hdlcrx.bufptr = bc->hdlcrx.buf; \
state = 1; \
numbits = 7-j; \
goto enditer##j; \
stuff##j: \
numbits--; \
bitbuf = (bitbuf & ((~0xff) << j)) | ((bitbuf & ~((~0xff) << j)) << 1); \
goto enditer##j; \
})

static int receive(struct net_device *dev, int cnt)
{
struct baycom_state *bc = netdev_priv(dev);
Expand All @@ -649,6 +586,7 @@ static int receive(struct net_device *dev, int cnt)
unsigned char tmp[128];
unsigned char *cp;
int cnt2, ret = 0;
int j;

numbits = bc->hdlcrx.numbits;
state = bc->hdlcrx.state;
Expand All @@ -669,24 +607,32 @@ static int receive(struct net_device *dev, int cnt)
bitbuf |= (*cp) << 8;
numbits += 8;
notbitstream = ~bitstream;
DECODEITERA(0);
DECODEITERA(1);
DECODEITERA(2);
DECODEITERA(3);
DECODEITERA(4);
DECODEITERA(5);
DECODEITERA(6);
DECODEITERA(7);
goto enddec;
DECODEITERB(0);
DECODEITERB(1);
DECODEITERB(2);
DECODEITERB(3);
DECODEITERB(4);
DECODEITERB(5);
DECODEITERB(6);
DECODEITERB(7);
enddec:
for (j = 0; j < 8; j++) {

/* flag or abort */
if (unlikely(!(notbitstream & (0x0fc << j)))) {

/* abort received */
if (!(notbitstream & (0x1fc << j)))
state = 0;

/* not flag received */
else if (!(bitstream & (0x1fe << j)) != (0x0fc << j)) {
if (state)
do_rxpacket(dev);
bc->hdlcrx.bufcnt = 0;
bc->hdlcrx.bufptr = bc->hdlcrx.buf;
state = 1;
numbits = 7-j;
}
}

/* stuffed bit */
else if (unlikely((bitstream & (0x1f8 << j)) == (0xf8 << j))) {
numbits--;
bitbuf = (bitbuf & ((~0xff) << j)) | ((bitbuf & ~((~0xff) << j)) << 1);
}
}
while (state && numbits >= 8) {
if (bc->hdlcrx.bufcnt >= TXBUFFER_SIZE) {
state = 0;
Expand Down

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