movl 20(%esp),%eax # Function arg: unsigned int sum
movl 16(%esp),%ecx # Function arg: int len
movl 12(%esp),%esi # Function arg: unsigned char *buff
- testl $2, %esi # Check alignment.
+ testl $3, %esi # Check alignment.
jz 2f # Jump if alignment is ok.
+ testl $1, %esi # Check alignment.
+ jz 10f # Jump if alignment is boundary of 2bytes.
+
+ # buf is odd
+ dec %ecx
+ jl 8f
+ movzbl (%esi), %ebx
+ adcl %ebx, %eax
+ roll $8, %eax
+ inc %esi
+ testl $2, %esi
+ jz 2f
+10:
subl $2, %ecx # Alignment uses up two bytes.
jae 1f # Jump if we had at least two bytes.
addl $2, %ecx # ecx was < 2. Deal with it.
6: addl %ecx,%eax
adcl $0, %eax
7:
+ testl $1, 12(%esp)
+ jz 8f
+ roll $8, %eax
+8:
popl %ebx
popl %esi
ret
movl 16(%esp),%ecx # Function arg: int len
movl 12(%esp),%esi # Function arg: const unsigned char *buf
- testl $2, %esi
- jnz 30f
+ testl $3, %esi
+ jnz 25f
10:
movl %ecx, %edx
movl %ecx, %ebx
lea 2(%esi), %esi
adcl $0, %eax
jmp 10b
+25:
+ testl $1, %esi
+ jz 30f
+ # buf is odd
+ dec %ecx
+ jl 90f
+ movzbl (%esi), %ebx
+ addl %ebx, %eax
+ adcl $0, %eax
+ roll $8, %eax
+ inc %esi
+ testl $2, %esi
+ jz 10b
30: subl $2, %ecx
ja 20b
addl %ebx,%eax
adcl $0,%eax
80:
+ testl $1, 12(%esp)
+ jz 90f
+ roll $8, %eax
+90:
popl %ebx
popl %esi
ret