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Rework the in4_cksum() code a bit.

This commit is contained in:
mycroft 2001-03-06 19:14:37 +00:00
parent f208d4f546
commit f7a6910822
1 changed files with 28 additions and 31 deletions
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59
sys/arch/i386/i386/in_cksum.s
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@ -1,7 +1,7 @@
/* $NetBSD: in_cksum.s,v 1.10 2001/03/06 14:55:14 fvdl Exp $ */
/* $NetBSD: in_cksum.s,v 1.11 2001/03/06 19:14:37 mycroft Exp $ */
/*-
* Copyright (c) 1998 The NetBSD Foundation, Inc.
* Copyright (c) 1998, 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
@ -125,46 +125,43 @@ ENTRY(in4_cksum)
pushl %esi
movl 16(%esp), %ebp
movzbl 20(%esp), %eax
shl $8, %eax /* sum = w[0] (== nxt << 8) */
movzwl 28(%esp), %ebx
rorw $8, %bx
addl %ebx, %eax /* sum += htons(len) */
movzbl 20(%esp), %eax /* sum = nxt */
movl 28(%esp), %esi
movl M_DATA(%ebp), %ebx
ADC(IP_SRC) /* sum += mtod(m,struct ip *)->ip_src */
ADC(IP_DST)
addl %esi, %eax /* sum += len */
movl 24(%esp), %edx /* %edx = off */
shll $8, %eax /* sum = htons(sum) */
ADD(IP_SRC) /* sum += ip->ip_src */
ADC(IP_DST) /* sum += ip->ip_dst */
MOP
movl 24(%esp), %esi
mbuf_loop_0:
testl %ebp, %ebp
jz skip_done
cmpl $0, %esi
jae skip_done
movl M_LEN(%ebp), %edx
cmpl %edx, %esi
ja skip_done
subl %edx, %esi
jz out_of_mbufs
movl M_LEN(%ebp), %ecx /* %ecx = m_len */
subl %ecx, %edx /* %edx = off - m_len */
jb skip_done
movl M_NEXT(%ebp), %ebp
jmp mbuf_loop_0
skip_done:
testl %ebp, %ebp
jz out_of_mbufs
movl M_DATA(%ebp), %ebx
movl M_LEN(%ebp), %edx
addl %esi, %ebx
subl %esi, %edx
skip_done:
movl M_DATA(%ebp), %ebx /* %ebx = m_data */
movl M_NEXT(%ebp), %ebp
addl %edx, %ebx /* %ebx = m_data + off - m_len */
negl %edx /* %edx = m_len - off */
addl %ecx, %ebx /* %ebx = m_data + off */
xorb %cl, %cl
movl 28(%esp), %esi
testl %esi, %esi
jz done
/*
* The len == 0 case is handled really inefficiently, by going through
* the whole short_mbuf path once to get back to mbuf_loop_1 -- but
* this case never happens in practice, so it's sufficient that it
* doesn't explode.
*/
jmp in4_entry
ENTRY(in_cksum)
pushl %ebp
pushl %ebx
@ -185,9 +182,9 @@ mbuf_loop_2:
movl M_DATA(%ebp), %ebx
movl M_LEN(%ebp), %edx
in4_entry:
movl M_NEXT(%ebp), %ebp
in4_entry:
cmpl %esi, %edx
jbe 1f
movl %esi, %edx