projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 88278ca2 | 1 | /* |
| 1da177e4 LT |
2 | * memscan.S: Optimized memscan for the Sparc. |
| 3 | * | |
| 4 | * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu) | |
| 5 | */ | |
| 6 | ||
| d3867f04 AV |
7 | #include <asm/export.h> |
| 8 | ||
| 1da177e4 LT |
9 | /* In essence, this is just a fancy strlen. */ |
| 10 | ||
| 11 | #define LO_MAGIC 0x01010101 | |
| 12 | #define HI_MAGIC 0x80808080 | |
| 13 | ||
| 14 | .text | |
| 15 | .align 4 | |
| 16 | .globl __memscan_zero, __memscan_generic | |
| 17 | .globl memscan | |
| d3867f04 AV |
18 | EXPORT_SYMBOL(__memscan_zero) |
| 19 | EXPORT_SYMBOL(__memscan_generic) | |
| 1da177e4 LT |
20 | __memscan_zero: |
| 21 | /* %o0 = addr, %o1 = size */ | |
| 22 | cmp %o1, 0 | |
| 23 | bne,a 1f | |
| 24 | andcc %o0, 3, %g0 | |
| 25 | ||
| 26 | retl | |
| 27 | nop | |
| 28 | ||
| 29 | 1: | |
| 30 | be mzero_scan_word | |
| 31 | sethi %hi(HI_MAGIC), %g2 | |
| 32 | ||
| 33 | ldsb [%o0], %g3 | |
| 34 | mzero_still_not_word_aligned: | |
| 35 | cmp %g3, 0 | |
| 36 | bne 1f | |
| 37 | add %o0, 1, %o0 | |
| 38 | ||
| 39 | retl | |
| 40 | sub %o0, 1, %o0 | |
| 41 | ||
| 42 | 1: | |
| 43 | subcc %o1, 1, %o1 | |
| 44 | bne,a 1f | |
| 45 | andcc %o0, 3, %g0 | |
| 46 | ||
| 47 | retl | |
| 48 | nop | |
| 49 | ||
| 50 | 1: | |
| 51 | bne,a mzero_still_not_word_aligned | |
| 52 | ldsb [%o0], %g3 | |
| 53 | ||
| 54 | sethi %hi(HI_MAGIC), %g2 | |
| 55 | mzero_scan_word: | |
| 56 | or %g2, %lo(HI_MAGIC), %o3 | |
| 57 | sethi %hi(LO_MAGIC), %g3 | |
| 58 | or %g3, %lo(LO_MAGIC), %o2 | |
| 59 | mzero_next_word: | |
| 60 | ld [%o0], %g2 | |
| 61 | mzero_next_word_preloaded: | |
| 62 | sub %g2, %o2, %g2 | |
| 63 | mzero_next_word_preloaded_next: | |
| 64 | andcc %g2, %o3, %g0 | |
| 65 | bne mzero_byte_zero | |
| 66 | add %o0, 4, %o0 | |
| 67 | ||
| 68 | mzero_check_out_of_fuel: | |
| 69 | subcc %o1, 4, %o1 | |
| 70 | bg,a 1f | |
| 71 | ld [%o0], %g2 | |
| 72 | ||
| 73 | retl | |
| 74 | nop | |
| 75 | ||
| 76 | 1: | |
| 77 | b mzero_next_word_preloaded_next | |
| 78 | sub %g2, %o2, %g2 | |
| 79 | ||
| 80 | /* Check every byte. */ | |
| 81 | mzero_byte_zero: | |
| 82 | ldsb [%o0 - 4], %g2 | |
| 83 | cmp %g2, 0 | |
| 84 | bne mzero_byte_one | |
| 85 | sub %o0, 4, %g3 | |
| 86 | ||
| 87 | retl | |
| 88 | mov %g3, %o0 | |
| 89 | ||
| 90 | mzero_byte_one: | |
| 91 | ldsb [%o0 - 3], %g2 | |
| 92 | cmp %g2, 0 | |
| 93 | bne,a mzero_byte_two_and_three | |
| 94 | ldsb [%o0 - 2], %g2 | |
| 95 | ||
| 96 | retl | |
| 97 | sub %o0, 3, %o0 | |
| 98 | ||
| 99 | mzero_byte_two_and_three: | |
| 100 | cmp %g2, 0 | |
| 101 | bne,a 1f | |
| 102 | ldsb [%o0 - 1], %g2 | |
| 103 | ||
| 104 | retl | |
| 105 | sub %o0, 2, %o0 | |
| 106 | ||
| 107 | 1: | |
| 108 | cmp %g2, 0 | |
| 109 | bne,a mzero_next_word_preloaded | |
| 110 | ld [%o0], %g2 | |
| 111 | ||
| 112 | retl | |
| 113 | sub %o0, 1, %o0 | |
| 114 | ||
| 115 | mzero_found_it: | |
| 116 | retl | |
| 117 | sub %o0, 2, %o0 | |
| 118 | ||
| 119 | memscan: | |
| 120 | __memscan_generic: | |
| 121 | /* %o0 = addr, %o1 = c, %o2 = size */ | |
| 122 | cmp %o2, 0 | |
| 123 | bne,a 0f | |
| 124 | ldub [%o0], %g2 | |
| 125 | ||
| 126 | b,a 2f | |
| 127 | 1: | |
| 128 | ldub [%o0], %g2 | |
| 129 | 0: | |
| 130 | cmp %g2, %o1 | |
| 131 | be 2f | |
| 132 | addcc %o2, -1, %o2 | |
| 133 | bne 1b | |
| 134 | add %o0, 1, %o0 | |
| 135 | 2: | |
| 136 | retl | |
| 137 | nop |