1 /* SPDX-License-Identifier: GPL-2.0-only */ !! 1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* !! 2 /* Sparc optimized memcmp code. 3 * Copyright (c) 2013-2021, Arm Limited. << 4 * 3 * 5 * Adapted from the original at: !! 4 * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz) 6 * https://github.com/ARM-software/optimized-r !! 5 * Copyright (C) 2000, 2008 David S. Miller (davem@davemloft.net) 7 */ 6 */ 8 7 9 #include <linux/linkage.h> 8 #include <linux/linkage.h> 10 #include <asm/assembler.h> !! 9 #include <asm/asm.h> >> 10 #include <asm/export.h> 11 11 12 /* Assumptions: !! 12 .text 13 * !! 13 ENTRY(memcmp) 14 * ARMv8-a, AArch64, unaligned accesses. !! 14 cmp %o2, 0 15 */ !! 15 1: BRANCH32(be, pn, 2f) 16 !! 16 nop 17 #define L(label) .L ## label !! 17 ldub [%o0], %g7 18 !! 18 ldub [%o1], %g3 19 /* Parameters and result. */ !! 19 sub %o2, 1, %o2 20 #define src1 x0 !! 20 add %o0, 1, %o0 21 #define src2 x1 !! 21 add %o1, 1, %o1 22 #define limit x2 !! 22 subcc %g7, %g3, %g3 23 #define result w0 !! 23 BRANCH32(be, pt, 1b) 24 !! 24 cmp %o2, 0 25 /* Internal variables. */ !! 25 retl 26 #define data1 x3 !! 26 mov %g3, %o0 27 #define data1w w3 !! 27 2: retl 28 #define data1h x4 !! 28 mov 0, %o0 29 #define data2 x5 !! 29 ENDPROC(memcmp) 30 #define data2w w5 !! 30 EXPORT_SYMBOL(memcmp) 31 #define data2h x6 << 32 #define tmp1 x7 << 33 #define tmp2 x8 << 34 << 35 SYM_FUNC_START(__pi_memcmp) << 36 subs limit, limit, 8 << 37 b.lo L(less8) << 38 << 39 ldr data1, [src1], 8 << 40 ldr data2, [src2], 8 << 41 cmp data1, data2 << 42 b.ne L(return) << 43 << 44 subs limit, limit, 8 << 45 b.gt L(more16) << 46 << 47 ldr data1, [src1, limit] << 48 ldr data2, [src2, limit] << 49 b L(return) << 50 << 51 L(more16): << 52 ldr data1, [src1], 8 << 53 ldr data2, [src2], 8 << 54 cmp data1, data2 << 55 bne L(return) << 56 << 57 /* Jump directly to comparing the last << 58 strings. */ << 59 subs limit, limit, 16 << 60 b.ls L(last_bytes) << 61 << 62 /* We overlap loads between 0-32 bytes << 63 try to align, so limit it only to s << 64 cmp limit, 96 << 65 b.ls L(loop16) << 66 << 67 /* Align src1 and adjust src2 with byt << 68 and tmp1, src1, 15 << 69 add limit, limit, tmp1 << 70 sub src1, src1, tmp1 << 71 sub src2, src2, tmp1 << 72 << 73 /* Loop performing 16 bytes per iterat << 74 Limit is pre-decremented by 16 and << 75 Exit if <= 16 bytes left to do or i << 76 .p2align 4 << 77 L(loop16): << 78 ldp data1, data1h, [src1], 16 << 79 ldp data2, data2h, [src2], 16 << 80 subs limit, limit, 16 << 81 ccmp data1, data2, 0, hi << 82 ccmp data1h, data2h, 0, eq << 83 b.eq L(loop16) << 84 << 85 cmp data1, data2 << 86 bne L(return) << 87 mov data1, data1h << 88 mov data2, data2h << 89 cmp data1, data2 << 90 bne L(return) << 91 << 92 /* Compare last 1-16 bytes using unali << 93 L(last_bytes): << 94 add src1, src1, limit << 95 add src2, src2, limit << 96 ldp data1, data1h, [src1] << 97 ldp data2, data2h, [src2] << 98 cmp data1, data2 << 99 bne L(return) << 100 mov data1, data1h << 101 mov data2, data2h << 102 cmp data1, data2 << 103 << 104 /* Compare data bytes and set return v << 105 L(return): << 106 #ifndef __AARCH64EB__ << 107 rev data1, data1 << 108 rev data2, data2 << 109 #endif << 110 cmp data1, data2 << 111 L(ret_eq): << 112 cset result, ne << 113 cneg result, result, lo << 114 ret << 115 << 116 .p2align 4 << 117 /* Compare up to 8 bytes. Limit is [- << 118 L(less8): << 119 adds limit, limit, 4 << 120 b.lo L(less4) << 121 ldr data1w, [src1], 4 << 122 ldr data2w, [src2], 4 << 123 cmp data1w, data2w << 124 b.ne L(return) << 125 sub limit, limit, 4 << 126 L(less4): << 127 adds limit, limit, 4 << 128 beq L(ret_eq) << 129 L(byte_loop): << 130 ldrb data1w, [src1], 1 << 131 ldrb data2w, [src2], 1 << 132 subs limit, limit, 1 << 133 ccmp data1w, data2w, 0, ne /* NZC << 134 b.eq L(byte_loop) << 135 sub result, data1w, data2w << 136 ret << 137 SYM_FUNC_END(__pi_memcmp) << 138 SYM_FUNC_ALIAS_WEAK(memcmp, __pi_memcmp) << 139 EXPORT_SYMBOL_NOKASAN(memcmp) <<
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