/* * arch/alpha/lib/csum_ipv6_magic.S * Contributed by Richard Henderson <rth@tamu.edu> * * unsigned short csum_ipv6_magic(struct in6_addr *saddr, * struct in6_addr *daddr, * __u32 len, * unsigned short proto, * unsigned int csum); */ .globl csum_ipv6_magic .align 4 .ent csum_ipv6_magic .frame $30,0,$26,0 csum_ipv6_magic: .prologue 0 ldq $0,0($16) # e0 : load src & dst addr words zapnot $20,15,$20 # .. e1 : zero extend incoming csum extqh $18,1,$4 # e0 : byte swap len & proto while we wait ldq $1,8($16) # .. e1 : extbl $18,1,$5 # e0 : ldq $2,0($17) # .. e1 : extbl $18,2,$6 # e0 : ldq $3,8($17) # .. e1 : extbl $18,3,$18 # e0 : sra $4,32,$4 # e0 : sll $5,16,$5 # e0 : addq $20,$0,$20 # .. e1 : begin summing the words sll $6,8,$6 # e0 : cmpult $20,$0,$0 # .. e1 : extwh $19,7,$7 # e0 : or $4,$18,$18 # .. e1 : extbl $19,1,$19 # e0 : or $5,$6,$5 # .. e1 : or $18,$5,$18 # e0 : len complete or $19,$7,$19 # .. e1 : sll $19,48,$19 # e0 : addq $20,$1,$20 # .. e1 : sra $19,32,$19 # e0 : proto complete cmpult $20,$1,$1 # .. e1 : nop # e0 : addq $20,$2,$20 # .. e1 : cmpult $20,$2,$2 # e0 : addq $20,$3,$20 # .. e1 : cmpult $20,$3,$3 # e0 : addq $20,$18,$20 # .. e1 : cmpult $20,$18,$18 # e0 : addq $20,$19,$20 # .. e1 : cmpult $20,$19,$19 # e0 : addq $0,$1,$0 # .. e1 : merge the carries back into the csum addq $2,$3,$2 # e0 : addq $18,$19,$18 # .. e1 : addq $0,$2,$0 # e0 : addq $20,$18,$20 # .. e1 : addq $0,$20,$0 # e0 : unop # : extwl $0,2,$2 # e0 : begin folding the 64-bit value zapnot $0,3,$3 # .. e1 : extwl $0,4,$1 # e0 : addq $2,$3,$3 # .. e1 : extwl $0,6,$0 # e0 : addq $3,$1,$3 # .. e1 : addq $0,$3,$0 # e0 : unop # : extwl $0,2,$1 # e0 : fold 18-bit value zapnot $0,3,$0 # .. e1 : addq $0,$1,$0 # e0 : unop # : extwl $0,2,$1 # e0 : fold 17-bit value zapnot $0,3,$0 # .. e1 : addq $0,$1,$0 # e0 : not $0,$0 # e1 : and complement. zapnot $0,3,$0 # e0 : ret # .. e1 : .end csum_ipv6_magic