/* $NetBSD: memmove.S,v 1.10.26.1 2024/07/20 14:52:04 martin Exp $ */ /*- * Copyright (c) 1997 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Neil A. Carson and Mark Brinicombe * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include #ifndef _BCOPY /* LINTSTUB: Func: void *memmove(void *, const void *, size_t) */ ENTRY(memmove) #else /* bcopy = memcpy/memmove with arguments reversed. */ /* LINTSTUB: Func: void bcopy(void *, void *, size_t) */ ENTRY(bcopy) /* switch the source and destination registers */ eor r0, r1, r0 eor r1, r0, r1 eor r0, r1, r0 #endif /* Do the buffers overlap? */ cmp r0, r1 RETc(eq) /* Bail now if src/dst are the same */ subhs r3, r0, r1 /* if (dst > src) r3 = dst - src */ sublo r3, r1, r0 /* if (src > dst) r3 = src - dst */ cmp r3, r2 /* if (r3 >= len) we have an overlap */ bhs PLT_SYM(_C_LABEL(memcpy)) /* Determine copy direction */ cmp r1, r0 bcc .Lmemmove_backwards moveq r0, #0 /* Quick abort for len=0 */ RETc(eq) push {r0, lr} /* memmove() returns dest addr */ subs r2, r2, #4 blo .Lmemmove_fl4 /* less than 4 bytes */ ands r12, r0, #3 bne .Lmemmove_fdestul /* oh unaligned destination addr */ ands r12, r1, #3 bne .Lmemmove_fsrcul /* oh unaligned source addr */ .Lmemmove_ft8: /* We have aligned source and destination */ subs r2, r2, #8 blo .Lmemmove_fl12 /* less than 12 bytes (4 from above) */ subs r2, r2, #0x14 blo .Lmemmove_fl32 /* less than 32 bytes (12 from above) */ push {r4} /* borrow r4 */ /* blat 32 bytes at a time */ /* XXX for really big copies perhaps we should use more registers */ .Lmemmove_floop32: ldmia r1!, {r3, r4, r12, lr} stmia r0!, {r3, r4, r12, lr} ldmia r1!, {r3, r4, r12, lr} stmia r0!, {r3, r4, r12, lr} subs r2, r2, #0x20 bhs .Lmemmove_floop32 cmn r2, #0x10 ldmiahs r1!, {r3, r4, r12, lr} /* blat a remaining 16 bytes */ stmiahs r0!, {r3, r4, r12, lr} subhs r2, r2, #0x10 pop {r4} /* return r4 */ .Lmemmove_fl32: adds r2, r2, #0x14 /* blat 12 bytes at a time */ .Lmemmove_floop12: ldmiahs r1!, {r3, r12, lr} stmiahs r0!, {r3, r12, lr} subshs r2, r2, #0x0c bhs .Lmemmove_floop12 .Lmemmove_fl12: adds r2, r2, #8 blo .Lmemmove_fl4 subs r2, r2, #4 ldrlo r3, [r1], #4 strlo r3, [r0], #4 ldmiahs r1!, {r3, r12} stmiahs r0!, {r3, r12} subhs r2, r2, #4 .Lmemmove_fl4: /* less than 4 bytes to go */ adds r2, r2, #4 popeq {r0, pc} /* done */ /* copy the crud byte at a time */ cmp r2, #2 ldrb r3, [r1], #1 strb r3, [r0], #1 ldrbhs r3, [r1], #1 strbhs r3, [r0], #1 ldrbhi r3, [r1], #1 strbhi r3, [r0], #1 pop {r0, pc} /* erg - unaligned destination */ .Lmemmove_fdestul: rsb r12, r12, #4 cmp r12, #2 /* align destination with byte copies */ ldrb r3, [r1], #1 strb r3, [r0], #1 ldrbhs r3, [r1], #1 strbhs r3, [r0], #1 ldrbhi r3, [r1], #1 strbhi r3, [r0], #1 subs r2, r2, r12 blo .Lmemmove_fl4 /* less the 4 bytes */ ands r12, r1, #3 beq .Lmemmove_ft8 /* we have an aligned source */ /* erg - unaligned source */ /* This is where it gets nasty ... */ .Lmemmove_fsrcul: bic r1, r1, #3 ldr lr, [r1], #4 cmp r12, #2 bhi .Lmemmove_fsrcul3 beq .Lmemmove_fsrcul2 cmp r2, #0x0c blo .Lmemmove_fsrcul1loop4 sub r2, r2, #0x0c push {r4, r5} .Lmemmove_fsrcul1loop16: #ifdef __ARMEB__ mov r3, lr, lsl #8 #else mov r3, lr, lsr #8 #endif ldmia r1!, {r4, r5, r12, lr} #ifdef __ARMEB__ orr r3, r3, r4, lsr #24 mov r4, r4, lsl #8 orr r4, r4, r5, lsr #24 mov r5, r5, lsl #8 orr r5, r5, r12, lsr #24 mov r12, r12, lsl #8 orr r12, r12, lr, lsr #24 #else orr r3, r3, r4, lsl #24 mov r4, r4, lsr #8 orr r4, r4, r5, lsl #24 mov r5, r5, lsr #8 orr r5, r5, r12, lsl #24 mov r12, r12, lsr #8 orr r12, r12, lr, lsl #24 #endif stmia r0!, {r3-r5, r12} subs r2, r2, #0x10 bhs .Lmemmove_fsrcul1loop16 pop {r4, r5} adds r2, r2, #0x0c blo .Lmemmove_fsrcul1l4 .Lmemmove_fsrcul1loop4: #ifdef __ARMEB__ mov r12, lr, lsl #8 #else mov r12, lr, lsr #8 #endif ldr lr, [r1], #4 #ifdef __ARMEB__ orr r12, r12, lr, lsr #24 #else orr r12, r12, lr, lsl #24 #endif str r12, [r0], #4 subs r2, r2, #4 bhs .Lmemmove_fsrcul1loop4 .Lmemmove_fsrcul1l4: sub r1, r1, #3 b .Lmemmove_fl4 .Lmemmove_fsrcul2: cmp r2, #0x0c blo .Lmemmove_fsrcul2loop4 sub r2, r2, #0x0c push {r4, r5} .Lmemmove_fsrcul2loop16: #ifdef __ARMEB__ mov r3, lr, lsl #16 #else mov r3, lr, lsr #16 #endif ldmia r1!, {r4, r5, r12, lr} #ifdef __ARMEB__ orr r3, r3, r4, lsr #16 mov r4, r4, lsl #16 orr r4, r4, r5, lsr #16 mov r5, r5, lsl #16 orr r5, r5, r12, lsr #16 mov r12, r12, lsl #16 orr r12, r12, lr, lsr #16 #else orr r3, r3, r4, lsl #16 mov r4, r4, lsr #16 orr r4, r4, r5, lsl #16 mov r5, r5, lsr #16 orr r5, r5, r12, lsl #16 mov r12, r12, lsr #16 orr r12, r12, lr, lsl #16 #endif stmia r0!, {r3-r5, r12} subs r2, r2, #0x10 bhs .Lmemmove_fsrcul2loop16 pop {r4, r5} adds r2, r2, #0x0c blo .Lmemmove_fsrcul2l4 .Lmemmove_fsrcul2loop4: #ifdef __ARMEB__ mov r12, lr, lsl #16 #else mov r12, lr, lsr #16 #endif ldr lr, [r1], #4 #ifdef __ARMEB__ orr r12, r12, lr, lsr #16 #else orr r12, r12, lr, lsl #16 #endif str r12, [r0], #4 subs r2, r2, #4 bhs .Lmemmove_fsrcul2loop4 .Lmemmove_fsrcul2l4: sub r1, r1, #2 b .Lmemmove_fl4 .Lmemmove_fsrcul3: cmp r2, #0x0c blo .Lmemmove_fsrcul3loop4 sub r2, r2, #0x0c push {r4, r5} .Lmemmove_fsrcul3loop16: #ifdef __ARMEB__ mov r3, lr, lsl #24 #else mov r3, lr, lsr #24 #endif ldmia r1!, {r4, r5, r12, lr} #ifdef __ARMEB__ orr r3, r3, r4, lsr #8 mov r4, r4, lsl #24 orr r4, r4, r5, lsr #8 mov r5, r5, lsl #24 orr r5, r5, r12, lsr #8 mov r12, r12, lsl #24 orr r12, r12, lr, lsr #8 #else orr r3, r3, r4, lsl #8 mov r4, r4, lsr #24 orr r4, r4, r5, lsl #8 mov r5, r5, lsr #24 orr r5, r5, r12, lsl #8 mov r12, r12, lsr #24 orr r12, r12, lr, lsl #8 #endif stmia r0!, {r3-r5, r12} subs r2, r2, #0x10 bhs .Lmemmove_fsrcul3loop16 pop {r4, r5} adds r2, r2, #0x0c blo .Lmemmove_fsrcul3l4 .Lmemmove_fsrcul3loop4: #ifdef __ARMEB__ mov r12, lr, lsl #24 #else mov r12, lr, lsr #24 #endif ldr lr, [r1], #4 #ifdef __ARMEB__ orr r12, r12, lr, lsr #8 #else orr r12, r12, lr, lsl #8 #endif str r12, [r0], #4 subs r2, r2, #4 bhs .Lmemmove_fsrcul3loop4 .Lmemmove_fsrcul3l4: sub r1, r1, #1 b .Lmemmove_fl4 .Lmemmove_backwards: add r1, r1, r2 add r0, r0, r2 subs r2, r2, #4 blo .Lmemmove_bl4 /* less than 4 bytes */ ands r12, r0, #3 bne .Lmemmove_bdestul /* oh unaligned destination addr */ ands r12, r1, #3 bne .Lmemmove_bsrcul /* oh unaligned source addr */ .Lmemmove_bt8: /* We have aligned source and destination */ subs r2, r2, #8 blo .Lmemmove_bl12 /* less than 12 bytes (4 from above) */ push {r4, lr} subs r2, r2, #0x14 /* less than 32 bytes (12 from above) */ blo .Lmemmove_bl32 /* blat 32 bytes at a time */ /* XXX for really big copies perhaps we should use more registers */ .Lmemmove_bloop32: ldmdb r1!, {r3, r4, r12, lr} stmdb r0!, {r3, r4, r12, lr} ldmdb r1!, {r3, r4, r12, lr} stmdb r0!, {r3, r4, r12, lr} subs r2, r2, #0x20 bhs .Lmemmove_bloop32 .Lmemmove_bl32: cmn r2, #0x10 ldmdbhs r1!, {r3, r4, r12, lr} /* blat a remaining 16 bytes */ stmdbhs r0!, {r3, r4, r12, lr} subhs r2, r2, #0x10 adds r2, r2, #0x14 ldmdbhs r1!, {r3, r12, lr} /* blat a remaining 12 bytes */ stmdbhs r0!, {r3, r12, lr} subhs r2, r2, #0x0c pop {r4, lr} .Lmemmove_bl12: adds r2, r2, #8 blo .Lmemmove_bl4 subs r2, r2, #4 ldrlo r3, [r1, #-4]! strlo r3, [r0, #-4]! ldmdbhs r1!, {r3, r12} stmdbhs r0!, {r3, r12} subhs r2, r2, #4 .Lmemmove_bl4: /* less than 4 bytes to go */ adds r2, r2, #4 RETc(eq) /* copy the crud byte at a time */ cmp r2, #2 ldrb r3, [r1, #-1]! strb r3, [r0, #-1]! ldrbhs r3, [r1, #-1]! strbhs r3, [r0, #-1]! ldrbhi r3, [r1, #-1]! strbhi r3, [r0, #-1]! RET /* erg - unaligned destination */ .Lmemmove_bdestul: cmp r12, #2 /* align destination with byte copies */ ldrb r3, [r1, #-1]! strb r3, [r0, #-1]! ldrbhs r3, [r1, #-1]! strbhs r3, [r0, #-1]! ldrbhi r3, [r1, #-1]! strbhi r3, [r0, #-1]! subs r2, r2, r12 blo .Lmemmove_bl4 /* less than 4 bytes to go */ ands r12, r1, #3 beq .Lmemmove_bt8 /* we have an aligned source */ /* erg - unaligned source */ /* This is where it gets nasty ... */ .Lmemmove_bsrcul: bic r1, r1, #3 ldr r3, [r1, #0] cmp r12, #2 blo .Lmemmove_bsrcul1 beq .Lmemmove_bsrcul2 cmp r2, #0x0c blo .Lmemmove_bsrcul3loop4 sub r2, r2, #0x0c push {r4, r5, lr} .Lmemmove_bsrcul3loop16: #ifdef __ARMEB__ mov lr, r3, lsr #8 #else mov lr, r3, lsl #8 #endif ldmdb r1!, {r3-r5, r12} #ifdef __ARMEB__ orr lr, lr, r12, lsl #24 mov r12, r12, lsr #8 orr r12, r12, r5, lsl #24 mov r5, r5, lsr #8 orr r5, r5, r4, lsl #24 mov r4, r4, lsr #8 orr r4, r4, r3, lsl #24 #else orr lr, lr, r12, lsr #24 mov r12, r12, lsl #8 orr r12, r12, r5, lsr #24 mov r5, r5, lsl #8 orr r5, r5, r4, lsr #24 mov r4, r4, lsl #8 orr r4, r4, r3, lsr #24 #endif stmdb r0!, {r4, r5, r12, lr} subs r2, r2, #0x10 bhs .Lmemmove_bsrcul3loop16 pop {r4, r5, lr} adds r2, r2, #0x0c blo .Lmemmove_bsrcul3l4 .Lmemmove_bsrcul3loop4: #ifdef __ARMEB__ mov r12, r3, lsr #8 #else mov r12, r3, lsl #8 #endif ldr r3, [r1, #-4]! #ifdef __ARMEB__ orr r12, r12, r3, lsl #24 #else orr r12, r12, r3, lsr #24 #endif str r12, [r0, #-4]! subs r2, r2, #4 bhs .Lmemmove_bsrcul3loop4 .Lmemmove_bsrcul3l4: add r1, r1, #3 b .Lmemmove_bl4 .Lmemmove_bsrcul2: cmp r2, #0x0c blo .Lmemmove_bsrcul2loop4 sub r2, r2, #0x0c push {r4, r5, lr} .Lmemmove_bsrcul2loop16: #ifdef __ARMEB__ mov lr, r3, lsr #16 #else mov lr, r3, lsl #16 #endif ldmdb r1!, {r3-r5, r12} #ifdef __ARMEB__ orr lr, lr, r12, lsl #16 mov r12, r12, lsr #16 orr r12, r12, r5, lsl #16 mov r5, r5, lsr #16 orr r5, r5, r4, lsl #16 mov r4, r4, lsr #16 orr r4, r4, r3, lsl #16 #else orr lr, lr, r12, lsr #16 mov r12, r12, lsl #16 orr r12, r12, r5, lsr #16 mov r5, r5, lsl #16 orr r5, r5, r4, lsr #16 mov r4, r4, lsl #16 orr r4, r4, r3, lsr #16 #endif stmdb r0!, {r4, r5, r12, lr} subs r2, r2, #0x10 bhs .Lmemmove_bsrcul2loop16 pop {r4, r5, lr} adds r2, r2, #0x0c blo .Lmemmove_bsrcul2l4 .Lmemmove_bsrcul2loop4: #ifdef __ARMEB__ mov r12, r3, lsr #16 #else mov r12, r3, lsl #16 #endif ldr r3, [r1, #-4]! #ifdef __ARMEB__ orr r12, r12, r3, lsl #16 #else orr r12, r12, r3, lsr #16 #endif str r12, [r0, #-4]! subs r2, r2, #4 bhs .Lmemmove_bsrcul2loop4 .Lmemmove_bsrcul2l4: add r1, r1, #2 b .Lmemmove_bl4 .Lmemmove_bsrcul1: cmp r2, #0x0c blo .Lmemmove_bsrcul1loop4 sub r2, r2, #0x0c push {r4, r5, lr} .Lmemmove_bsrcul1loop32: #ifdef __ARMEB__ mov lr, r3, lsr #24 #else mov lr, r3, lsl #24 #endif ldmdb r1!, {r3-r5, r12} #ifdef __ARMEB__ orr lr, lr, r12, lsl #8 mov r12, r12, lsr #24 orr r12, r12, r5, lsl #8 mov r5, r5, lsr #24 orr r5, r5, r4, lsl #8 mov r4, r4, lsr #24 orr r4, r4, r3, lsl #8 #else orr lr, lr, r12, lsr #8 mov r12, r12, lsl #24 orr r12, r12, r5, lsr #8 mov r5, r5, lsl #24 orr r5, r5, r4, lsr #8 mov r4, r4, lsl #24 orr r4, r4, r3, lsr #8 #endif stmdb r0!, {r4, r5, r12, lr} subs r2, r2, #0x10 bhs .Lmemmove_bsrcul1loop32 pop {r4, r5, lr} adds r2, r2, #0x0c blo .Lmemmove_bsrcul1l4 .Lmemmove_bsrcul1loop4: #ifdef __ARMEB__ mov r12, r3, lsr #24 #else mov r12, r3, lsl #24 #endif ldr r3, [r1, #-4]! #ifdef __ARMEB__ orr r12, r12, r3, lsl #8 #else orr r12, r12, r3, lsr #8 #endif str r12, [r0, #-4]! subs r2, r2, #4 bhs .Lmemmove_bsrcul1loop4 .Lmemmove_bsrcul1l4: add r1, r1, #1 b .Lmemmove_bl4 #ifndef _BCOPY END(memmove) #else END(bcopy) #endif #if defined(__ARM_EABI__) && !defined(BCOPY) && !defined(_RUMPKERNEL) STRONG_ALIAS(__aeabi_memmove, memmove) STRONG_ALIAS(__aeabi_memmove4, memmove) STRONG_ALIAS(__aeabi_memmove8, memmove) #endif