| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* |
| * memscan.S: Optimized memscan for the Sparc. |
| * |
| * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu) |
| */ |
| |
| #include <asm/export.h> |
| |
| /* In essence, this is just a fancy strlen. */ |
| |
| #define LO_MAGIC 0x01010101 |
| #define HI_MAGIC 0x80808080 |
| |
| .text |
| .align 4 |
| .globl __memscan_zero, __memscan_generic |
| .globl memscan |
| EXPORT_SYMBOL(__memscan_zero) |
| EXPORT_SYMBOL(__memscan_generic) |
| __memscan_zero: |
| /* %o0 = addr, %o1 = size */ |
| cmp %o1, 0 |
| bne,a 1f |
| andcc %o0, 3, %g0 |
| |
| retl |
| nop |
| |
| 1: |
| be mzero_scan_word |
| sethi %hi(HI_MAGIC), %g2 |
| |
| ldsb [%o0], %g3 |
| mzero_still_not_word_aligned: |
| cmp %g3, 0 |
| bne 1f |
| add %o0, 1, %o0 |
| |
| retl |
| sub %o0, 1, %o0 |
| |
| 1: |
| subcc %o1, 1, %o1 |
| bne,a 1f |
| andcc %o0, 3, %g0 |
| |
| retl |
| nop |
| |
| 1: |
| bne,a mzero_still_not_word_aligned |
| ldsb [%o0], %g3 |
| |
| sethi %hi(HI_MAGIC), %g2 |
| mzero_scan_word: |
| or %g2, %lo(HI_MAGIC), %o3 |
| sethi %hi(LO_MAGIC), %g3 |
| or %g3, %lo(LO_MAGIC), %o2 |
| mzero_next_word: |
| ld [%o0], %g2 |
| mzero_next_word_preloaded: |
| sub %g2, %o2, %g2 |
| mzero_next_word_preloaded_next: |
| andcc %g2, %o3, %g0 |
| bne mzero_byte_zero |
| add %o0, 4, %o0 |
| |
| mzero_check_out_of_fuel: |
| subcc %o1, 4, %o1 |
| bg,a 1f |
| ld [%o0], %g2 |
| |
| retl |
| nop |
| |
| 1: |
| b mzero_next_word_preloaded_next |
| sub %g2, %o2, %g2 |
| |
| /* Check every byte. */ |
| mzero_byte_zero: |
| ldsb [%o0 - 4], %g2 |
| cmp %g2, 0 |
| bne mzero_byte_one |
| sub %o0, 4, %g3 |
| |
| retl |
| mov %g3, %o0 |
| |
| mzero_byte_one: |
| ldsb [%o0 - 3], %g2 |
| cmp %g2, 0 |
| bne,a mzero_byte_two_and_three |
| ldsb [%o0 - 2], %g2 |
| |
| retl |
| sub %o0, 3, %o0 |
| |
| mzero_byte_two_and_three: |
| cmp %g2, 0 |
| bne,a 1f |
| ldsb [%o0 - 1], %g2 |
| |
| retl |
| sub %o0, 2, %o0 |
| |
| 1: |
| cmp %g2, 0 |
| bne,a mzero_next_word_preloaded |
| ld [%o0], %g2 |
| |
| retl |
| sub %o0, 1, %o0 |
| |
| mzero_found_it: |
| retl |
| sub %o0, 2, %o0 |
| |
| memscan: |
| __memscan_generic: |
| /* %o0 = addr, %o1 = c, %o2 = size */ |
| cmp %o2, 0 |
| bne,a 0f |
| ldub [%o0], %g2 |
| |
| b,a 2f |
| 1: |
| ldub [%o0], %g2 |
| 0: |
| cmp %g2, %o1 |
| be 2f |
| addcc %o2, -1, %o2 |
| bne 1b |
| add %o0, 1, %o0 |
| 2: |
| retl |
| nop |
