| /* checksum.S: Sparc V9 optimized checksum code. |
| * |
| * Copyright(C) 1995 Linus Torvalds |
| * Copyright(C) 1995 Miguel de Icaza |
| * Copyright(C) 1996, 2000 David S. Miller |
| * Copyright(C) 1997 Jakub Jelinek |
| * |
| * derived from: |
| * Linux/Alpha checksum c-code |
| * Linux/ix86 inline checksum assembly |
| * RFC1071 Computing the Internet Checksum (esp. Jacobsons m68k code) |
| * David Mosberger-Tang for optimized reference c-code |
| * BSD4.4 portable checksum routine |
| */ |
| |
| .text |
| |
| csum_partial_fix_alignment: |
| /* We checked for zero length already, so there must be |
| * at least one byte. |
| */ |
| be,pt %icc, 1f |
| nop |
| ldub [%o0 + 0x00], %o4 |
| add %o0, 1, %o0 |
| sub %o1, 1, %o1 |
| 1: andcc %o0, 0x2, %g0 |
| be,pn %icc, csum_partial_post_align |
| cmp %o1, 2 |
| blu,pn %icc, csum_partial_end_cruft |
| nop |
| lduh [%o0 + 0x00], %o5 |
| add %o0, 2, %o0 |
| sub %o1, 2, %o1 |
| ba,pt %xcc, csum_partial_post_align |
| add %o5, %o4, %o4 |
| |
| .align 32 |
| .globl csum_partial |
| csum_partial: /* %o0=buff, %o1=len, %o2=sum */ |
| prefetch [%o0 + 0x000], #n_reads |
| clr %o4 |
| prefetch [%o0 + 0x040], #n_reads |
| brz,pn %o1, csum_partial_finish |
| andcc %o0, 0x3, %g0 |
| |
| /* We "remember" whether the lowest bit in the address |
| * was set in %g7. Because if it is, we have to swap |
| * upper and lower 8 bit fields of the sum we calculate. |
| */ |
| bne,pn %icc, csum_partial_fix_alignment |
| andcc %o0, 0x1, %g7 |
| |
| csum_partial_post_align: |
| prefetch [%o0 + 0x080], #n_reads |
| andncc %o1, 0x3f, %o3 |
| |
| prefetch [%o0 + 0x0c0], #n_reads |
| sub %o1, %o3, %o1 |
| brz,pn %o3, 2f |
| prefetch [%o0 + 0x100], #n_reads |
| |
| /* So that we don't need to use the non-pairing |
| * add-with-carry instructions we accumulate 32-bit |
| * values into a 64-bit register. At the end of the |
| * loop we fold it down to 32-bits and so on. |
| */ |
| prefetch [%o0 + 0x140], #n_reads |
| 1: lduw [%o0 + 0x00], %o5 |
| lduw [%o0 + 0x04], %g1 |
| lduw [%o0 + 0x08], %g2 |
| add %o4, %o5, %o4 |
| lduw [%o0 + 0x0c], %g3 |
| add %o4, %g1, %o4 |
| lduw [%o0 + 0x10], %o5 |
| add %o4, %g2, %o4 |
| lduw [%o0 + 0x14], %g1 |
| add %o4, %g3, %o4 |
| lduw [%o0 + 0x18], %g2 |
| add %o4, %o5, %o4 |
| lduw [%o0 + 0x1c], %g3 |
| add %o4, %g1, %o4 |
| lduw [%o0 + 0x20], %o5 |
| add %o4, %g2, %o4 |
| lduw [%o0 + 0x24], %g1 |
| add %o4, %g3, %o4 |
| lduw [%o0 + 0x28], %g2 |
| add %o4, %o5, %o4 |
| lduw [%o0 + 0x2c], %g3 |
| add %o4, %g1, %o4 |
| lduw [%o0 + 0x30], %o5 |
| add %o4, %g2, %o4 |
| lduw [%o0 + 0x34], %g1 |
| add %o4, %g3, %o4 |
| lduw [%o0 + 0x38], %g2 |
| add %o4, %o5, %o4 |
| lduw [%o0 + 0x3c], %g3 |
| add %o4, %g1, %o4 |
| prefetch [%o0 + 0x180], #n_reads |
| add %o4, %g2, %o4 |
| subcc %o3, 0x40, %o3 |
| add %o0, 0x40, %o0 |
| bne,pt %icc, 1b |
| add %o4, %g3, %o4 |
| |
| 2: and %o1, 0x3c, %o3 |
| brz,pn %o3, 2f |
| sub %o1, %o3, %o1 |
| 1: lduw [%o0 + 0x00], %o5 |
| subcc %o3, 0x4, %o3 |
| add %o0, 0x4, %o0 |
| bne,pt %icc, 1b |
| add %o4, %o5, %o4 |
| |
| 2: |
| /* fold 64-->32 */ |
| srlx %o4, 32, %o5 |
| srl %o4, 0, %o4 |
| add %o4, %o5, %o4 |
| srlx %o4, 32, %o5 |
| srl %o4, 0, %o4 |
| add %o4, %o5, %o4 |
| |
| /* fold 32-->16 */ |
| sethi %hi(0xffff0000), %g1 |
| srl %o4, 16, %o5 |
| andn %o4, %g1, %g2 |
| add %o5, %g2, %o4 |
| srl %o4, 16, %o5 |
| andn %o4, %g1, %g2 |
| add %o5, %g2, %o4 |
| |
| csum_partial_end_cruft: |
| /* %o4 has the 16-bit sum we have calculated so-far. */ |
| cmp %o1, 2 |
| blu,pt %icc, 1f |
| nop |
| lduh [%o0 + 0x00], %o5 |
| sub %o1, 2, %o1 |
| add %o0, 2, %o0 |
| add %o4, %o5, %o4 |
| 1: brz,pt %o1, 1f |
| nop |
| ldub [%o0 + 0x00], %o5 |
| sub %o1, 1, %o1 |
| add %o0, 1, %o0 |
| sllx %o5, 8, %o5 |
| add %o4, %o5, %o4 |
| 1: |
| /* fold 32-->16 */ |
| sethi %hi(0xffff0000), %g1 |
| srl %o4, 16, %o5 |
| andn %o4, %g1, %g2 |
| add %o5, %g2, %o4 |
| srl %o4, 16, %o5 |
| andn %o4, %g1, %g2 |
| add %o5, %g2, %o4 |
| |
| 1: brz,pt %g7, 1f |
| nop |
| |
| /* We started with an odd byte, byte-swap the result. */ |
| srl %o4, 8, %o5 |
| and %o4, 0xff, %g1 |
| sll %g1, 8, %g1 |
| or %o5, %g1, %o4 |
| |
| 1: addcc %o2, %o4, %o2 |
| addc %g0, %o2, %o2 |
| |
| csum_partial_finish: |
| retl |
| srl %o2, 0, %o0 |
