1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 4 */ 5 6 /* ARC700 has a relatively long pipeline and branch prediction, so we want 7 to avoid branches that are hard to predict. On the other hand, the 8 presence of the norm instruction makes it easier to operate on whole 9 words branch-free. */ 10 11 #include <linux/linkage.h> 12 13 ENTRY_CFI(strchr) 14 extb_s r1,r1 15 asl r5,r1,8 16 bmsk r2,r0,1 17 or r5,r5,r1 18 mov_s r3,0x01010101 19 breq.d r2,r0,.Laligned 20 asl r4,r5,16 21 sub_s r0,r0,r2 22 asl r7,r2,3 23 ld_s r2,[r0] 24 #ifdef __LITTLE_ENDIAN__ 25 asl r7,r3,r7 26 #else 27 lsr r7,r3,r7 28 #endif 29 or r5,r5,r4 30 ror r4,r3 31 sub r12,r2,r7 32 bic_s r12,r12,r2 33 and r12,r12,r4 34 brne.d r12,0,.Lfound0_ua 35 xor r6,r2,r5 36 ld.a r2,[r0,4] 37 sub r12,r6,r7 38 bic r12,r12,r6 39 #ifdef __LITTLE_ENDIAN__ 40 and r7,r12,r4 41 breq r7,0,.Loop ; For speed, we want this branch to be unaligned. 42 b .Lfound_char ; Likewise this one. 43 #else 44 and r12,r12,r4 45 breq r12,0,.Loop ; For speed, we want this branch to be unaligned. 46 lsr_s r12,r12,7 47 bic r2,r7,r6 48 b.d .Lfound_char_b 49 and_s r2,r2,r12 50 #endif 51 ; /* We require this code address to be unaligned for speed... */ 52 .Laligned: 53 ld_s r2,[r0] 54 or r5,r5,r4 55 ror r4,r3 56 ; /* ... so that this code address is aligned, for itself and ... */ 57 .Loop: 58 sub r12,r2,r3 59 bic_s r12,r12,r2 60 and r12,r12,r4 61 brne.d r12,0,.Lfound0 62 xor r6,r2,r5 63 ld.a r2,[r0,4] 64 sub r12,r6,r3 65 bic r12,r12,r6 66 and r7,r12,r4 67 breq r7,0,.Loop /* ... so that this branch is unaligned. */ 68 ; Found searched-for character. r0 has already advanced to next word. 69 #ifdef __LITTLE_ENDIAN__ 70 /* We only need the information about the first matching byte 71 (i.e. the least significant matching byte) to be exact, 72 hence there is no problem with carry effects. */ 73 .Lfound_char: 74 sub r3,r7,1 75 bic r3,r3,r7 76 norm r2,r3 77 sub_s r0,r0,1 78 asr_s r2,r2,3 79 j.d [blink] 80 sub_s r0,r0,r2 81 82 .balign 4 83 .Lfound0_ua: 84 mov r3,r7 85 .Lfound0: 86 sub r3,r6,r3 87 bic r3,r3,r6 88 and r2,r3,r4 89 or_s r12,r12,r2 90 sub_s r3,r12,1 91 bic_s r3,r3,r12 92 norm r3,r3 93 add_s r0,r0,3 94 asr_s r12,r3,3 95 asl.f 0,r2,r3 96 sub_s r0,r0,r12 97 j_s.d [blink] 98 mov.pl r0,0 99 #else /* BIG ENDIAN */ 100 .Lfound_char: 101 lsr r7,r7,7 102 103 bic r2,r7,r6 104 .Lfound_char_b: 105 norm r2,r2 106 sub_s r0,r0,4 107 asr_s r2,r2,3 108 j.d [blink] 109 add_s r0,r0,r2 110 111 .Lfound0_ua: 112 mov_s r3,r7 113 .Lfound0: 114 asl_s r2,r2,7 115 or r7,r6,r4 116 bic_s r12,r12,r2 117 sub r2,r7,r3 118 or r2,r2,r6 119 bic r12,r2,r12 120 bic.f r3,r4,r12 121 norm r3,r3 122 123 add.pl r3,r3,1 124 asr_s r12,r3,3 125 asl.f 0,r2,r3 126 add_s r0,r0,r12 127 j_s.d [blink] 128 mov.mi r0,0 129 #endif /* ENDIAN */ 130 END_CFI(strchr) 131