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-rw-r--r--c/src/lib/libnetworking/netinet/in_cksum_i386.c200
1 files changed, 0 insertions, 200 deletions
diff --git a/c/src/lib/libnetworking/netinet/in_cksum_i386.c b/c/src/lib/libnetworking/netinet/in_cksum_i386.c
deleted file mode 100644
index 0612c5a7c4..0000000000
--- a/c/src/lib/libnetworking/netinet/in_cksum_i386.c
+++ /dev/null
@@ -1,200 +0,0 @@
-/*
- * Checksum routine for Internet Protocol family headers.
- *
- * This routine is very heavily used in the network
- * code and should be modified for each CPU to be as fast as possible.
- *
- * This implementation is 386 version.
- *
- * $Id$
- */
-
-#include <stdio.h> /* for puts */
-
-#undef ADDCARRY
-#define ADDCARRY(x) if ((x) > 0xffff) (x) -= 0xffff
-#define REDUCE {sum = (sum & 0xffff) + (sum >> 16); ADDCARRY(sum);}
-
-/*
- * Thanks to gcc we don't have to guess
- * which registers contain sum & w.
- */
-#define ADD(n) asm("addl " #n "(%2), %0" : "=r" (sum) : "0" (sum), "r" (w))
-#define ADDC(n) asm("adcl " #n "(%2), %0" : "=r" (sum) : "0" (sum), "r" (w))
-#define LOAD(n) asm volatile("movb " #n "(%1), %0" : "=r" (junk) : "r" (w))
-#define MOP asm("adcl $0, %0" : "=r" (sum) : "0" (sum))
-
-int
-in_cksum(m, len)
- register struct mbuf *m;
- register int len;
-{
- register u_short *w;
- register unsigned sum = 0;
- register int mlen = 0;
- int byte_swapped = 0;
- union { char c[2]; u_short s; } su;
-
- for (;m && len; m = m->m_next) {
- if (m->m_len == 0)
- continue;
- w = mtod(m, u_short *);
- if (mlen == -1) {
- /*
- * The first byte of this mbuf is the continuation
- * of a word spanning between this mbuf and the
- * last mbuf.
- */
-
- /* su.c[0] is already saved when scanning previous
- * mbuf. sum was REDUCEd when we found mlen == -1
- */
- su.c[1] = *(u_char *)w;
- sum += su.s;
- w = (u_short *)((char *)w + 1);
- mlen = m->m_len - 1;
- len--;
- } else
- mlen = m->m_len;
- if (len < mlen)
- mlen = len;
- len -= mlen;
- /*
- * Force to long boundary so we do longword aligned
- * memory operations
- */
- if (3 & (int) w) {
- REDUCE;
- if ((1 & (int) w) && (mlen > 0)) {
- sum <<= 8;
- su.c[0] = *(char *)w;
- w = (u_short *)((char *)w + 1);
- mlen--;
- byte_swapped = 1;
- }
- if ((2 & (int) w) && (mlen >= 2)) {
- sum += *w++;
- mlen -= 2;
- }
- }
- /*
- * Advance to a 486 cache line boundary.
- */
- if (4 & (int) w && mlen >= 4) {
- ADD(0);
- MOP;
- w += 2;
- mlen -= 4;
- }
- if (8 & (int) w && mlen >= 8) {
- ADD(0);
- ADDC(4);
- MOP;
- w += 4;
- mlen -= 8;
- }
- /*
- * Do as much of the checksum as possible 32 bits at at time.
- * In fact, this loop is unrolled to make overhead from
- * branches &c small.
- */
- mlen -= 1;
- while ((mlen -= 32) >= 0) {
- u_char junk;
- /*
- * Add with carry 16 words and fold in the last
- * carry by adding a 0 with carry.
- *
- * The early ADD(16) and the LOAD(32) are to load
- * the next 2 cache lines in advance on 486's. The
- * 486 has a penalty of 2 clock cycles for loading
- * a cache line, plus whatever time the external
- * memory takes to load the first word(s) addressed.
- * These penalties are unavoidable. Subsequent
- * accesses to a cache line being loaded (and to
- * other external memory?) are delayed until the
- * whole load finishes. These penalties are mostly
- * avoided by not accessing external memory for
- * 8 cycles after the ADD(16) and 12 cycles after
- * the LOAD(32). The loop terminates when mlen
- * is initially 33 (not 32) to guaranteed that
- * the LOAD(32) is within bounds.
- */
- ADD(16);
- ADDC(0);
- ADDC(4);
- ADDC(8);
- ADDC(12);
- LOAD(32);
- ADDC(20);
- ADDC(24);
- ADDC(28);
- MOP;
- w += 16;
- }
- mlen += 32 + 1;
- if (mlen >= 32) {
- ADD(16);
- ADDC(0);
- ADDC(4);
- ADDC(8);
- ADDC(12);
- ADDC(20);
- ADDC(24);
- ADDC(28);
- MOP;
- w += 16;
- mlen -= 32;
- }
- if (mlen >= 16) {
- ADD(0);
- ADDC(4);
- ADDC(8);
- ADDC(12);
- MOP;
- w += 8;
- mlen -= 16;
- }
- if (mlen >= 8) {
- ADD(0);
- ADDC(4);
- MOP;
- w += 4;
- mlen -= 8;
- }
- if (mlen == 0 && byte_swapped == 0)
- continue; /* worth 1% maybe ?? */
- REDUCE;
- while ((mlen -= 2) >= 0) {
- sum += *w++;
- }
- if (byte_swapped) {
- sum <<= 8;
- byte_swapped = 0;
- if (mlen == -1) {
- su.c[1] = *(char *)w;
- sum += su.s;
- mlen = 0;
- } else
- mlen = -1;
- } else if (mlen == -1)
- /*
- * This mbuf has odd number of bytes.
- * There could be a word split betwen
- * this mbuf and the next mbuf.
- * Save the last byte (to prepend to next mbuf).
- */
- su.c[0] = *(char *)w;
- }
-
- if (len)
- puts("cksum: out of data");
- if (mlen == -1) {
- /* The last mbuf has odd # of bytes. Follow the
- standard (the odd byte is shifted left by 8 bits) */
- su.c[1] = 0;
- sum += su.s;
- }
- REDUCE;
- return (~sum & 0xffff);
-}