diff options
Diffstat (limited to 'arch/cris/arch-v10/lib/checksum.S')
-rw-r--r-- | arch/cris/arch-v10/lib/checksum.S | 119 |
1 files changed, 0 insertions, 119 deletions
diff --git a/arch/cris/arch-v10/lib/checksum.S b/arch/cris/arch-v10/lib/checksum.S deleted file mode 100644 index a3b96391706f..000000000000 --- a/arch/cris/arch-v10/lib/checksum.S +++ /dev/null @@ -1,119 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * A fast checksum routine using movem - * Copyright (c) 1998-2001 Axis Communications AB - * - * csum_partial(const unsigned char * buff, int len, unsigned int sum) - */ - - .globl csum_partial -csum_partial: - - ;; r10 - src - ;; r11 - length - ;; r12 - checksum - - ;; check for breakeven length between movem and normal word looping versions - ;; we also do _NOT_ want to compute a checksum over more than the - ;; actual length when length < 40 - - cmpu.w 80,$r11 - blo _word_loop - nop - - ;; need to save the registers we use below in the movem loop - ;; this overhead is why we have a check above for breakeven length - ;; only r0 - r8 have to be saved, the other ones are clobber-able - ;; according to the ABI - - subq 9*4,$sp - movem $r8,[$sp] - - ;; do a movem checksum - - subq 10*4,$r11 ; update length for the first loop - -_mloop: movem [$r10+],$r9 ; read 10 longwords - - ;; perform dword checksumming on the 10 longwords - - add.d $r0,$r12 - ax - add.d $r1,$r12 - ax - add.d $r2,$r12 - ax - add.d $r3,$r12 - ax - add.d $r4,$r12 - ax - add.d $r5,$r12 - ax - add.d $r6,$r12 - ax - add.d $r7,$r12 - ax - add.d $r8,$r12 - ax - add.d $r9,$r12 - - ;; fold the carry into the checksum, to avoid having to loop the carry - ;; back into the top - - ax - addq 0,$r12 - - subq 10*4,$r11 - bge _mloop - nop - - addq 10*4,$r11 ; compensate for last loop underflowing length - - movem [$sp+],$r8 ; restore regs - -_word_loop: - ;; only fold if there is anything to fold. - - cmpq 0,$r12 - beq _no_fold - - ;; fold 32-bit checksum into a 16-bit checksum, to avoid carries below. - ;; r9 and r13 can be used as temporaries. - - moveq -1,$r9 ; put 0xffff in r9, faster than move.d 0xffff,r9 - lsrq 16,$r9 - - move.d $r12,$r13 - lsrq 16,$r13 ; r13 = checksum >> 16 - and.d $r9,$r12 ; checksum = checksum & 0xffff - add.d $r13,$r12 ; checksum += r13 - -_no_fold: - cmpq 2,$r11 - blt _no_words - nop - - ;; checksum the rest of the words - - subq 2,$r11 - -_wloop: subq 2,$r11 - bge _wloop - addu.w [$r10+],$r12 - - addq 2,$r11 - -_no_words: - ;; see if we have one odd byte more - cmpq 1,$r11 - beq _do_byte - nop - ret - move.d $r12, $r10 - -_do_byte: - ;; copy and checksum the last byte - addu.b [$r10],$r12 - ret - move.d $r12, $r10 - |