1 /* memcpy.S: optimised assembly memcpy 2 * 3 * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells (at) redhat.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12 13 .text 14 .p2align 4 15 16 ############################################################################### 17 # 18 # void *memcpy(void *to, const char *from, size_t count) 19 # 20 # - NOTE: must not use any stack. exception detection performs function return 21 # to caller's fixup routine, aborting the remainder of the copy 22 # 23 ############################################################################### 24 .globl memcpy,__memcpy_end 25 .type memcpy,@function 26 memcpy: 27 or.p gr8,gr9,gr4 28 orcc gr10,gr0,gr0,icc3 29 or.p gr10,gr4,gr4 30 beqlr icc3,#0 31 32 # optimise based on best common alignment for to, from & count 33 andicc.p gr4,#0x0f,gr0,icc0 34 setlos #8,gr11 35 andicc.p gr4,#0x07,gr0,icc1 36 beq icc0,#0,memcpy_16 37 andicc.p gr4,#0x03,gr0,icc0 38 beq icc1,#0,memcpy_8 39 andicc.p gr4,#0x01,gr0,icc1 40 beq icc0,#0,memcpy_4 41 setlos.p #1,gr11 42 beq icc1,#0,memcpy_2 43 44 # do byte by byte copy 45 sub.p gr8,gr11,gr3 46 sub gr9,gr11,gr9 47 0: ldubu.p @(gr9,gr11),gr4 48 subicc gr10,#1,gr10,icc0 49 stbu.p gr4,@(gr3,gr11) 50 bne icc0,#2,0b 51 bralr 52 53 # do halfword by halfword copy 54 memcpy_2: 55 setlos #2,gr11 56 sub.p gr8,gr11,gr3 57 sub gr9,gr11,gr9 58 0: lduhu.p @(gr9,gr11),gr4 59 subicc gr10,#2,gr10,icc0 60 sthu.p gr4,@(gr3,gr11) 61 bne icc0,#2,0b 62 bralr 63 64 # do word by word copy 65 memcpy_4: 66 setlos #4,gr11 67 sub.p gr8,gr11,gr3 68 sub gr9,gr11,gr9 69 0: ldu.p @(gr9,gr11),gr4 70 subicc gr10,#4,gr10,icc0 71 stu.p gr4,@(gr3,gr11) 72 bne icc0,#2,0b 73 bralr 74 75 # do double-word by double-word copy 76 memcpy_8: 77 sub.p gr8,gr11,gr3 78 sub gr9,gr11,gr9 79 0: lddu.p @(gr9,gr11),gr4 80 subicc gr10,#8,gr10,icc0 81 stdu.p gr4,@(gr3,gr11) 82 bne icc0,#2,0b 83 bralr 84 85 # do quad-word by quad-word copy 86 memcpy_16: 87 sub.p gr8,gr11,gr3 88 sub gr9,gr11,gr9 89 0: lddu @(gr9,gr11),gr4 90 lddu.p @(gr9,gr11),gr6 91 subicc gr10,#16,gr10,icc0 92 stdu gr4,@(gr3,gr11) 93 stdu.p gr6,@(gr3,gr11) 94 bne icc0,#2,0b 95 bralr 96 __memcpy_end: 97 98 .size memcpy, __memcpy_end-memcpy 99 100 ############################################################################### 101 # 102 # copy to/from userspace 103 # - return the number of bytes that could not be copied (0 on complete success) 104 # 105 # long __memcpy_user(void *dst, const void *src, size_t count) 106 # 107 ############################################################################### 108 .globl __memcpy_user, __memcpy_user_error_lr, __memcpy_user_error_handler 109 .type __memcpy_user,@function 110 __memcpy_user: 111 movsg lr,gr7 112 subi.p sp,#8,sp 113 add gr8,gr10,gr6 ; calculate expected end address 114 stdi gr6,@(sp,#0) 115 116 # abuse memcpy to do the dirty work 117 call memcpy 118 __memcpy_user_error_lr: 119 ldi.p @(sp,#4),gr7 120 setlos #0,gr8 121 jmpl.p @(gr7,gr0) 122 addi sp,#8,sp 123 124 # deal any exception generated by memcpy 125 # GR8 - memcpy's current dest address 126 # GR11 - memset's step value (index register for store insns) 127 __memcpy_user_error_handler: 128 lddi.p @(sp,#0),gr4 ; load GR4 with dst+count, GR5 with ret addr 129 add gr11,gr3,gr7 130 sub.p gr4,gr7,gr8 131 132 addi sp,#8,sp 133 jmpl @(gr5,gr0) 134 135 .size __memcpy_user, .-__memcpy_user 136
