| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * arch/alpha/lib/csum_ipv6_magic.S |
| 3 | * Contributed by Richard Henderson <rth@tamu.edu> |
| 4 | * |
| 5 | * unsigned short csum_ipv6_magic(struct in6_addr *saddr, |
| 6 | * struct in6_addr *daddr, |
| 7 | * __u32 len, |
| 8 | * unsigned short proto, |
| 9 | * unsigned int csum); |
| 10 | */ |
| 11 | |
| 12 | .globl csum_ipv6_magic |
| 13 | .align 4 |
| 14 | .ent csum_ipv6_magic |
| 15 | .frame $30,0,$26,0 |
| 16 | csum_ipv6_magic: |
| 17 | .prologue 0 |
| 18 | |
| 19 | ldq $0,0($16) # e0 : load src & dst addr words |
| 20 | zapnot $20,15,$20 # .. e1 : zero extend incoming csum |
| 21 | extqh $18,1,$4 # e0 : byte swap len & proto while we wait |
| 22 | ldq $1,8($16) # .. e1 : |
| 23 | |
| 24 | extbl $18,1,$5 # e0 : |
| 25 | ldq $2,0($17) # .. e1 : |
| 26 | extbl $18,2,$6 # e0 : |
| 27 | ldq $3,8($17) # .. e1 : |
| 28 | |
| 29 | extbl $18,3,$18 # e0 : |
| 30 | sra $4,32,$4 # e0 : |
| 31 | sll $5,16,$5 # e0 : |
| 32 | addq $20,$0,$20 # .. e1 : begin summing the words |
| 33 | |
| 34 | sll $6,8,$6 # e0 : |
| 35 | cmpult $20,$0,$0 # .. e1 : |
| 36 | extwh $19,7,$7 # e0 : |
| 37 | or $4,$18,$18 # .. e1 : |
| 38 | |
| 39 | extbl $19,1,$19 # e0 : |
| 40 | or $5,$6,$5 # .. e1 : |
| 41 | or $18,$5,$18 # e0 : len complete |
| 42 | or $19,$7,$19 # .. e1 : |
| 43 | |
| 44 | sll $19,48,$19 # e0 : |
| 45 | addq $20,$1,$20 # .. e1 : |
| 46 | sra $19,32,$19 # e0 : proto complete |
| 47 | cmpult $20,$1,$1 # .. e1 : |
| 48 | |
| 49 | nop # e0 : |
| 50 | addq $20,$2,$20 # .. e1 : |
| 51 | cmpult $20,$2,$2 # e0 : |
| 52 | addq $20,$3,$20 # .. e1 : |
| 53 | |
| 54 | cmpult $20,$3,$3 # e0 : |
| 55 | addq $20,$18,$20 # .. e1 : |
| 56 | cmpult $20,$18,$18 # e0 : |
| 57 | addq $20,$19,$20 # .. e1 : |
| 58 | |
| 59 | cmpult $20,$19,$19 # e0 : |
| 60 | addq $0,$1,$0 # .. e1 : merge the carries back into the csum |
| 61 | addq $2,$3,$2 # e0 : |
| 62 | addq $18,$19,$18 # .. e1 : |
| 63 | |
| 64 | addq $0,$2,$0 # e0 : |
| 65 | addq $20,$18,$20 # .. e1 : |
| 66 | addq $0,$20,$0 # e0 : |
| 67 | unop # : |
| 68 | |
| 69 | extwl $0,2,$2 # e0 : begin folding the 64-bit value |
| 70 | zapnot $0,3,$3 # .. e1 : |
| 71 | extwl $0,4,$1 # e0 : |
| 72 | addq $2,$3,$3 # .. e1 : |
| 73 | |
| 74 | extwl $0,6,$0 # e0 : |
| 75 | addq $3,$1,$3 # .. e1 : |
| 76 | addq $0,$3,$0 # e0 : |
| 77 | unop # : |
| 78 | |
| 79 | extwl $0,2,$1 # e0 : fold 18-bit value |
| 80 | zapnot $0,3,$0 # .. e1 : |
| 81 | addq $0,$1,$0 # e0 : |
| 82 | unop # : |
| 83 | |
| 84 | extwl $0,2,$1 # e0 : fold 17-bit value |
| 85 | zapnot $0,3,$0 # .. e1 : |
| 86 | addq $0,$1,$0 # e0 : |
| 87 | not $0,$0 # e1 : and complement. |
| 88 | |
| 89 | zapnot $0,3,$0 # e0 : |
| 90 | ret # .. e1 : |
| 91 | |
| 92 | .end csum_ipv6_magic |