The times when tricky goto's produced better codes are long gone.
This patch should express the same in a better way.
Signed-off-by: Adrian Bunk <[email protected]>
---
This patch was already sent on:
- 30 Apr 2005
- 20 Apr 2005
drivers/net/hamradio/baycom_epp.c | 126 ++++++++----------------------
1 files changed, 36 insertions(+), 90 deletions(-)
--- linux-2.6.12-rc2-mm3/drivers/net/hamradio/baycom_epp.c.old 2005-04-20 16:18:47.000000000 +0200
+++ linux-2.6.12-rc2-mm3/drivers/net/hamradio/baycom_epp.c 2005-04-20 17:14:36.000000000 +0200
@@ -374,29 +374,6 @@
}
/* --------------------------------------------------------------------- */
-/*
- * 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)
{
@@ -405,6 +382,7 @@
int pkt_len;
unsigned bitstream, notbitstream, bitbuf, numbit, crc;
unsigned char crcarr[2];
+ int j;
if (bc->hdlctx.bufcnt > 0)
return;
@@ -429,24 +407,14 @@
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;
@@ -612,37 +580,6 @@
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);
@@ -651,6 +588,7 @@
unsigned char tmp[128];
unsigned char *cp;
int cnt2, ret = 0;
+ int j;
numbits = bc->hdlcrx.numbits;
state = bc->hdlcrx.state;
@@ -671,24 +609,32 @@
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;
-
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