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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
| commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
| tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/sparc/lib/memscan_32.S | |
| parent | Initial commit. (diff) | |
| download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip | |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/sparc/lib/memscan_32.S')
| -rw-r--r-- | arch/sparc/lib/memscan_32.S | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/arch/sparc/lib/memscan_32.S b/arch/sparc/lib/memscan_32.S new file mode 100644 index 000000000..c4c2d5b3a --- /dev/null +++ b/arch/sparc/lib/memscan_32.S @@ -0,0 +1,138 @@ +/* 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 |