[444] | 1 | /* |
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| 2 | * (c) Copyright 1986 HEWLETT-PACKARD COMPANY |
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| 3 | * |
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| 4 | * To anyone who acknowledges that this file is provided "AS IS" |
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| 5 | * without any express or implied warranty: |
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| 6 | * permission to use, copy, modify, and distribute this file |
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| 7 | * for any purpose is hereby granted without fee, provided that |
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| 8 | * the above copyright notice and this notice appears in all |
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| 9 | * copies, and that the name of Hewlett-Packard Company not be |
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| 10 | * used in advertising or publicity pertaining to distribution |
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| 11 | * of the software without specific, written prior permission. |
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| 12 | * Hewlett-Packard Company makes no representations about the |
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| 13 | * suitability of this software for any purpose. |
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| 14 | */ |
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| 15 | |
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| 16 | /* |
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| 17 | A faster strcpy. |
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| 18 | |
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| 19 | by |
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| 20 | |
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| 21 | Jerry Huck (aligned case) |
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| 22 | Daryl Odnert (equal-alignment case) |
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| 23 | Edgar Circenis (non-aligned case) |
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| 24 | */ |
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| 25 | /* |
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| 26 | * strcpy(s1, s2) |
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| 27 | * |
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| 28 | * Copy string s2 to s1. s1 must be large enough. |
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| 29 | * return s1 |
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| 30 | */ |
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| 31 | |
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| 32 | #include "DEFS.h" |
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| 33 | |
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| 34 | #define d_addr r26 |
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| 35 | #define s_addr r25 |
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| 36 | #define tmp6 r24 |
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| 37 | #define tmp1 r19 |
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| 38 | #define evenside r19 |
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| 39 | #define tmp2 r20 |
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| 40 | #define oddside r20 |
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| 41 | #define tmp3 r21 |
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| 42 | #define tmp4 r22 |
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| 43 | #define tmp5 arg3 |
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| 44 | #define save r1 |
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| 45 | |
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| 46 | |
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| 47 | ENTRY(strcpy) |
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| 48 | /* Do some quick alignment checking on and fast path both word aligned */ |
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| 49 | extru,<> s_addr,31,2,tmp6 /*Is source word aligned? */ |
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| 50 | ldwm 4(0,s_addr),oddside /*Assume yes and guess that it |
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| 51 | is double-word aligned. */ |
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| 52 | dep,= d_addr,29,2,tmp6 /*Is target word aligned? */ |
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| 53 | b case_analysis |
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| 54 | copy d_addr,ret0 |
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| 55 | /* Both are aligned. First source word already loaded assuming that |
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| 56 | source was oddword aligned. Fall through (therefore fastest) code |
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| 57 | shuffles the registers to join the main loop */ |
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| 58 | bothaligned: |
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| 59 | bb,>= s_addr,29,twoatatime /*Branch if source was odd aligned*/ |
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| 60 | uxor,nbz oddside,r0,save |
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| 61 | |
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| 62 | /* Even aligned source. save holds that operand. |
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| 63 | Do one iteration of the main copy loop juggling the registers to avoid |
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| 64 | one copy. */ |
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| 65 | b,n nullfound |
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| 66 | ldwm 4(s_addr),oddside |
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| 67 | stwm save,4(d_addr) |
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| 68 | uxor,nbz oddside,r0,save |
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| 69 | b,n nullfound |
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| 70 | ldwm 4(s_addr),evenside |
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| 71 | stwm oddside,4(d_addr) |
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| 72 | uxor,nbz evenside,r0,save |
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| 73 | b,n nullfound |
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| 74 | ldwm 4(s_addr),oddside |
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| 75 | |
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| 76 | /* Main loop body. Entry expects evenside still to be stored, oddside |
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| 77 | just loaded. */ |
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| 78 | loop: |
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| 79 | stwm evenside,4(d_addr) |
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| 80 | uxor,nbz oddside,r0,save |
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| 81 | |
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| 82 | /* mid loop entry */ |
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| 83 | twoatatime: |
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| 84 | b,n nullfound |
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| 85 | ldwm 4(s_addr),evenside |
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| 86 | stwm oddside,4(d_addr) |
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| 87 | uxor,sbz evenside,r0,save |
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| 88 | b loop |
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| 89 | ldwm 4(s_addr),oddside |
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| 90 | |
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| 91 | /* fall through when null found in evenside. oddside actually loaded */ |
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| 92 | nullfound: /* adjust d_addr and store final word */ |
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| 93 | |
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| 94 | extru,<> save,7,8,r0 /* pick up leftmost byte */ |
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| 95 | addib,tr,n 1,d_addr,store_final |
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| 96 | extru,<> save,15,8,r0 |
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| 97 | addib,tr,n 2,d_addr,store_final |
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| 98 | extru,<> save,23,8,r0 |
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| 99 | addib,tr 3,d_addr,store_final2 |
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| 100 | bv 0(rp) |
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| 101 | stw save,0(d_addr) |
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| 102 | |
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| 103 | store_final: |
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| 104 | bv 0(rp) |
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| 105 | store_final2: |
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| 106 | stbys,e save,0(d_addr) /* delay slot */ |
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| 107 | |
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| 108 | case_analysis: |
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| 109 | |
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| 110 | blr tmp6,r0 |
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| 111 | nop |
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| 112 | |
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| 113 | /* NOTE: the delay slots for the non-aligned cases load a */ |
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| 114 | /* shift quantity which is TGT-SRC into tmp3. */ |
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| 115 | /* Note also, the case for both strings being word aligned */ |
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| 116 | /* is already checked before the BLR is executed, so that */ |
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| 117 | /* case can never occur. */ |
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| 118 | |
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| 119 | /* TGT SRC */ |
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| 120 | nop /* 00 00 can't happen */ |
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| 121 | nop |
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| 122 | b neg_aligned_copy /* 00 01 */ |
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| 123 | ldi -1,tmp3 /* load shift quantity. delay slot */ |
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| 124 | b neg_aligned_copy /* 00 10 */ |
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| 125 | ldi -2,tmp3 /* load shift quantity. delay slot */ |
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| 126 | b neg_aligned_copy /* 00 11 */ |
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| 127 | ldi -3,tmp3 /* load shift quantity. delay slot */ |
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| 128 | b pos_aligned_copy0 /* 01 00 */ |
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| 129 | ldi 1,tmp3 /* load shift quantity. delay slot */ |
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| 130 | b equal_alignment_1 /* 01 01 */ |
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| 131 | ldbs,ma 1(s_addr),tmp1 |
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| 132 | b neg_aligned_copy /* 01 10 */ |
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| 133 | ldi -1,tmp3 /* load shift quantity. delay slot */ |
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| 134 | b neg_aligned_copy /* 01 11 */ |
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| 135 | ldi -2,tmp3 /* load shift quantity. delay slot */ |
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| 136 | b pos_aligned_copy0 /* 10 00 */ |
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| 137 | ldi 2,tmp3 /* load shift quantity. delay slot */ |
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| 138 | b pos_aligned_copy /* 10 01 */ |
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| 139 | ldi 1,tmp3 /* load shift quantity. delay slot */ |
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| 140 | b equal_alignment_2 /* 10 10 */ |
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| 141 | ldhs,ma 2(s_addr),tmp1 |
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| 142 | b neg_aligned_copy /* 10 11 */ |
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| 143 | ldi -1,tmp3 /* load shift quantity. delay slot */ |
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| 144 | b pos_aligned_copy0 /* 11 00 */ |
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| 145 | ldi 3,tmp3 /* load shift quantity. delay slot */ |
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| 146 | b pos_aligned_copy /* 11 01 */ |
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| 147 | ldi 2,tmp3 /* load shift quantity. delay slot */ |
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| 148 | b pos_aligned_copy /* 11 10 */ |
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| 149 | ldi 1,tmp3 /* load shift quantity. delay slot */ |
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| 150 | ldbs,ma 1(s_addr),tmp1 /* 11 11 */ |
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| 151 | comiclr,<> r0,tmp1,r0 |
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| 152 | bv 0(rp) /* return if 1st byte was null */ |
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| 153 | stbs,ma tmp1,1(d_addr) /* store a byte to dst string */ |
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| 154 | b bothaligned /* can now goto word_aligned */ |
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| 155 | ldwm 4(s_addr),oddside /* load next word of source */ |
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| 156 | |
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| 157 | equal_alignment_1: |
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| 158 | comiclr,<> r0,tmp1,r0 /* nullify next if tmp1 <> 0 */ |
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| 159 | bv 0(rp) /* return if null byte found */ |
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| 160 | stbs,ma tmp1,1(d_addr) /* store a byte to dst string */ |
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| 161 | ldhs,ma 2(s_addr),tmp1 /* load next halfword */ |
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| 162 | equal_alignment_2: |
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| 163 | extru,<> tmp1,23,8,tmp6 /* look at left byte of halfword */ |
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| 164 | bv 0(rp) /* return if 1st byte was null */ |
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| 165 | stbs,ma tmp6,1(d_addr) |
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| 166 | extru,<> tmp1,31,8,r0 |
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| 167 | bv 0(rp) /* return if 2nd byte was null */ |
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| 168 | stbs,ma tmp1,1(d_addr) |
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| 169 | b bothaligned |
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| 170 | ldwm 4(s_addr),oddside /* load next word */ |
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| 171 | |
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| 172 | /* source and destination are not aligned, so we do it the hard way. */ |
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| 173 | |
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| 174 | /* target alignment is greater than source alignment */ |
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| 175 | pos_aligned_copy0: |
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| 176 | addi -4,s_addr,s_addr |
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| 177 | pos_aligned_copy: |
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| 178 | extru d_addr,31,2,tmp6 /* Extract low 2 bits of the dest addr */ |
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| 179 | extru s_addr,31,2,tmp1 /* Extract low 2 bits of the src addr */ |
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| 180 | dep r0,31,2,s_addr /* Compute word address of the source. */ |
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| 181 | sh3add tmp3,r0,tmp4 /* compute shift amt */ |
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| 182 | ldwm 4(0,s_addr),tmp2 /* get 1st source word */ |
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| 183 | sh3add tmp1,r0,save /* setup mask shift amount */ |
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| 184 | mtctl save,r11 /* set-up cr11 for mask */ |
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| 185 | zvdepi -2,32,save /* create mask */ |
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| 186 | or save,tmp2,tmp2 /* mask unused bytes in src */ |
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| 187 | ldi -1,tmp1 /* load tmp1 with 0xffffffff */ |
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| 188 | mtctl tmp4,r11 /* shift count -> shift count reg */ |
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| 189 | vshd tmp1,tmp2,tmp3 /* position data ! */ |
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| 190 | uxor,nbz tmp3,r0,save |
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| 191 | b,n first_null |
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| 192 | uxor,nbz tmp2,r0,save |
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| 193 | b nullfound1 |
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| 194 | mtctl tmp4,r11 /* re-load shift cnt (delay slot) */ |
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| 195 | b loop_entry |
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| 196 | ldwm 4(0,s_addr),tmp1 /* get next word. delay slot */ |
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| 197 | |
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| 198 | neg_aligned_copy: |
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| 199 | extru d_addr,31,2,tmp6 /* Extract low 2 bits of the dest addr */ |
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| 200 | extru s_addr,31,2,tmp2 /* Extract low 2 bits of the src addr */ |
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| 201 | dep r0,31,2,s_addr /* Compute word address of the source. */ |
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| 202 | sh3add tmp3,r0,tmp4 /* compute shift amt */ |
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| 203 | ldwm 4(0,s_addr),tmp1 /* load first word from source. */ |
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| 204 | /* check to see if next word can be read safely */ |
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| 205 | sh3add tmp2,r0,save |
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| 206 | mtctl save,r11 /* shift count -> shift count reg */ |
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| 207 | zvdepi -2,32,save |
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| 208 | or save, tmp1, tmp1 |
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| 209 | uxor,nbz tmp1,r0,save /* any nulls in first word? */ |
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| 210 | b first_null0 |
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| 211 | mtctl tmp4,r11 |
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| 212 | ldwm 4(0,s_addr),tmp2 /* load second word from source */ |
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| 213 | combt,= tmp6,r0,chunk1 /* don't mask if whole word valid */ |
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| 214 | vshd tmp1,tmp2,tmp3 /* position data ! */ |
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| 215 | sh3add tmp6,r0,save /* setup r1 */ |
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| 216 | mtctl save,r11 /* set-up cr11 for mask */ |
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| 217 | zvdepi -2,32,save |
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| 218 | or save, tmp3, tmp3 |
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| 219 | uxor,nbz tmp3,r0,save |
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| 220 | b,n first_null |
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| 221 | uxor,nbz tmp2,r0,save |
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| 222 | b nullfound1 |
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| 223 | mtctl tmp4,r11 /* re-load shift cnt (delay slot) */ |
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| 224 | b loop_entry |
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| 225 | ldwm 4(0,s_addr),tmp1 /* get next word. delay slot */ |
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| 226 | |
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| 227 | chunk1: |
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| 228 | uxor,nbz tmp2,r0,save |
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| 229 | b nullfound0 |
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| 230 | vshd tmp1,tmp2,tmp3 |
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| 231 | did_mask: |
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| 232 | ldwm 4(0,s_addr),tmp1 /* get next word ! */ |
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| 233 | loop_entry: |
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| 234 | stbys,b,m tmp3,4(0,d_addr) /* store ! */ |
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| 235 | |
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| 236 | uxor,nbz tmp1, r0, save |
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| 237 | b nullfound2 |
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| 238 | vshd tmp2,tmp1,tmp3 /* position data ! */ |
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| 239 | ldwm 4(s_addr),tmp2 |
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| 240 | stwm tmp3,4(d_addr) |
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| 241 | uxor,sbz tmp2,r0,save |
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| 242 | b did_mask |
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| 243 | nullfound0: |
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| 244 | vshd tmp1,tmp2,tmp3 /* delay slot */ |
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| 245 | uxor,nbz tmp3,r0,save |
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| 246 | b,n nullfound |
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| 247 | nullfound1: |
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| 248 | stbys,b,m tmp3,4(0,d_addr) |
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| 249 | b nullfound |
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| 250 | vshd tmp2,r0,save /* delay slot */ |
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| 251 | |
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| 252 | nullfound2: |
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| 253 | uxor,nbz tmp3,r0,save |
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| 254 | b,n nullfound |
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| 255 | stwm tmp3,4(d_addr) |
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| 256 | b nullfound |
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| 257 | /* notice that delay slot is in next routine */ |
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| 258 | |
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| 259 | first_null0: /* null found in first word of non-aligned (wrt d_addr) */ |
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| 260 | vshd tmp1,r0,save /* delay slot */ |
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| 261 | combt,= tmp6,r0,check4 |
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| 262 | extru save,7,8,tmp4 |
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| 263 | first_null: |
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| 264 | addibt,= -1,tmp6,check3 /* check last 3 bytes of word */ |
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| 265 | extru save,15,8,tmp4 |
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| 266 | addibt,=,n -1,tmp6,check2 /* check last 2 bytes */ |
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| 267 | bv 0(rp) /* null in last byte--store and exit */ |
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| 268 | stbys,b save, 0(d_addr) |
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| 269 | |
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| 270 | check4: |
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| 271 | combt,= tmp4,r0,done |
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| 272 | stbs,ma tmp4,1(d_addr) |
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| 273 | extru,<> save,15,8,tmp4 |
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| 274 | check3: |
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| 275 | combt,= tmp4,r0,done |
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| 276 | stbs,ma tmp4,1(d_addr) |
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| 277 | check2: |
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| 278 | extru,<> save,23,8,tmp4 |
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| 279 | bv 0(rp) |
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| 280 | stbs,ma tmp4,1(d_addr) |
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| 281 | bv 0(rp) |
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| 282 | stbs r0,0(d_addr) |
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| 283 | |
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| 284 | done: |
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| 285 | EXIT(strcpy) |
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