| /* Copyright (C) 2006-2021 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| Contributed by MontaVista Software, Inc. (written by Nicolas Pitre) |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library. If not, see |
| <https://www.gnu.org/licenses/>. */ |
| |
| /* Thumb requires excessive IT insns here. */ |
| #define NO_THUMB |
| #include <sysdep.h> |
| #include <arm-features.h> |
| |
| /* |
| * Data preload for architectures that support it (ARM V5TE and above) |
| */ |
| #if (!defined (__ARM_ARCH_2__) && !defined (__ARM_ARCH_3__) \ |
| && !defined (__ARM_ARCH_3M__) && !defined (__ARM_ARCH_4__) \ |
| && !defined (__ARM_ARCH_4T__) && !defined (__ARM_ARCH_5__) \ |
| && !defined (__ARM_ARCH_5T__)) |
| #define PLD(code...) code |
| #else |
| #define PLD(code...) |
| #endif |
| |
| /* |
| * This can be used to enable code to cacheline align the source pointer. |
| * Experiments on tested architectures (StrongARM and XScale) didn't show |
| * this a worthwhile thing to do. That might be different in the future. |
| */ |
| //#define CALGN(code...) code |
| #define CALGN(code...) |
| |
| /* |
| * Endian independent macros for shifting bytes within registers. |
| */ |
| #ifndef __ARMEB__ |
| #define PULL lsr |
| #define PUSH lsl |
| #else |
| #define PULL lsl |
| #define PUSH lsr |
| #endif |
| |
| .text |
| .syntax unified |
| |
| /* |
| * Prototype: void *memmove(void *dest, const void *src, size_t n); |
| * |
| * Note: |
| * |
| * If the memory regions don't overlap, we simply branch to memcpy which is |
| * normally a bit faster. Otherwise the copy is done going downwards. |
| */ |
| |
| ENTRY(memmove) |
| |
| subs ip, r0, r1 |
| cmphi r2, ip |
| #if !IS_IN (libc) |
| bls memcpy |
| #else |
| bls HIDDEN_JUMPTARGET(memcpy) |
| #endif |
| |
| push {r0, r4, lr} |
| cfi_adjust_cfa_offset (12) |
| cfi_rel_offset (r4, 4) |
| cfi_rel_offset (lr, 8) |
| |
| cfi_remember_state |
| |
| add r1, r1, r2 |
| add r0, r0, r2 |
| subs r2, r2, #4 |
| blo 8f |
| ands ip, r0, #3 |
| PLD( pld [r1, #-4] ) |
| bne 9f |
| ands ip, r1, #3 |
| bne 10f |
| |
| 1: subs r2, r2, #(28) |
| push {r5 - r8} |
| cfi_adjust_cfa_offset (16) |
| cfi_rel_offset (r5, 0) |
| cfi_rel_offset (r6, 4) |
| cfi_rel_offset (r7, 8) |
| cfi_rel_offset (r8, 12) |
| blo 5f |
| |
| CALGN( ands ip, r1, #31 ) |
| CALGN( sbcsne r4, ip, r2 ) @ C is always set here |
| CALGN( bcs 2f ) |
| CALGN( adr r4, 6f ) |
| CALGN( subs r2, r2, ip ) @ C is set here |
| #ifndef ARM_ALWAYS_BX |
| CALGN( add pc, r4, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2)) |
| #else |
| CALGN( add r4, r4, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2)) |
| CALGN( bx r4 ) |
| #endif |
| |
| PLD( pld [r1, #-4] ) |
| 2: PLD( cmp r2, #96 ) |
| PLD( pld [r1, #-32] ) |
| PLD( blo 4f ) |
| PLD( pld [r1, #-64] ) |
| PLD( pld [r1, #-96] ) |
| |
| 3: PLD( pld [r1, #-128] ) |
| 4: ldmdb r1!, {r3, r4, r5, r6, r7, r8, ip, lr} |
| subs r2, r2, #32 |
| stmdb r0!, {r3, r4, r5, r6, r7, r8, ip, lr} |
| bhs 3b |
| |
| 5: ands ip, r2, #28 |
| rsb ip, ip, #32 |
| #ifndef ARM_ALWAYS_BX |
| /* C is always clear here. */ |
| addne pc, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2) |
| b 7f |
| #else |
| beq 7f |
| push {r10} |
| cfi_adjust_cfa_offset (4) |
| cfi_rel_offset (r10, 0) |
| 0: add r10, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2) |
| /* If alignment is not perfect, then there will be some |
| padding (nop) instructions between this BX and label 6. |
| The computation above assumed that two instructions |
| later is exactly the right spot. */ |
| add r10, #(6f - (0b + PC_OFS)) |
| bx r10 |
| #endif |
| .p2align ARM_BX_ALIGN_LOG2 |
| 6: nop |
| .p2align ARM_BX_ALIGN_LOG2 |
| ldr r3, [r1, #-4]! |
| .p2align ARM_BX_ALIGN_LOG2 |
| ldr r4, [r1, #-4]! |
| .p2align ARM_BX_ALIGN_LOG2 |
| ldr r5, [r1, #-4]! |
| .p2align ARM_BX_ALIGN_LOG2 |
| ldr r6, [r1, #-4]! |
| .p2align ARM_BX_ALIGN_LOG2 |
| ldr r7, [r1, #-4]! |
| .p2align ARM_BX_ALIGN_LOG2 |
| ldr r8, [r1, #-4]! |
| .p2align ARM_BX_ALIGN_LOG2 |
| ldr lr, [r1, #-4]! |
| |
| #ifndef ARM_ALWAYS_BX |
| add pc, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2) |
| nop |
| #else |
| 0: add r10, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2) |
| /* If alignment is not perfect, then there will be some |
| padding (nop) instructions between this BX and label 66. |
| The computation above assumed that two instructions |
| later is exactly the right spot. */ |
| add r10, #(66f - (0b + PC_OFS)) |
| bx r10 |
| #endif |
| .p2align ARM_BX_ALIGN_LOG2 |
| 66: nop |
| .p2align ARM_BX_ALIGN_LOG2 |
| str r3, [r0, #-4]! |
| .p2align ARM_BX_ALIGN_LOG2 |
| str r4, [r0, #-4]! |
| .p2align ARM_BX_ALIGN_LOG2 |
| str r5, [r0, #-4]! |
| .p2align ARM_BX_ALIGN_LOG2 |
| str r6, [r0, #-4]! |
| .p2align ARM_BX_ALIGN_LOG2 |
| str r7, [r0, #-4]! |
| .p2align ARM_BX_ALIGN_LOG2 |
| str r8, [r0, #-4]! |
| .p2align ARM_BX_ALIGN_LOG2 |
| str lr, [r0, #-4]! |
| |
| #ifdef ARM_ALWAYS_BX |
| pop {r10} |
| cfi_adjust_cfa_offset (-4) |
| cfi_restore (r10) |
| #endif |
| |
| CALGN( bcs 2b ) |
| |
| 7: pop {r5 - r8} |
| cfi_adjust_cfa_offset (-16) |
| cfi_restore (r5) |
| cfi_restore (r6) |
| cfi_restore (r7) |
| cfi_restore (r8) |
| |
| 8: movs r2, r2, lsl #31 |
| ldrbne r3, [r1, #-1]! |
| ldrbcs r4, [r1, #-1]! |
| ldrbcs ip, [r1, #-1] |
| strbne r3, [r0, #-1]! |
| strbcs r4, [r0, #-1]! |
| strbcs ip, [r0, #-1] |
| |
| #if ((defined (__ARM_ARCH_4T__) && defined (__THUMB_INTERWORK__)) \ |
| || defined (ARM_ALWAYS_BX)) |
| pop {r0, r4, lr} |
| cfi_adjust_cfa_offset (-12) |
| cfi_restore (r4) |
| cfi_restore (lr) |
| bx lr |
| #else |
| pop {r0, r4, pc} |
| #endif |
| |
| cfi_restore_state |
| |
| 9: cmp ip, #2 |
| ldrbgt r3, [r1, #-1]! |
| ldrbge r4, [r1, #-1]! |
| ldrb lr, [r1, #-1]! |
| strbgt r3, [r0, #-1]! |
| strbge r4, [r0, #-1]! |
| subs r2, r2, ip |
| strb lr, [r0, #-1]! |
| blo 8b |
| ands ip, r1, #3 |
| beq 1b |
| |
| 10: bic r1, r1, #3 |
| cmp ip, #2 |
| ldr r3, [r1, #0] |
| beq 17f |
| blt 18f |
| |
| |
| .macro backward_copy_shift push pull |
| |
| subs r2, r2, #28 |
| blo 14f |
| |
| CALGN( ands ip, r1, #31 ) |
| CALGN( rsb ip, ip, #32 ) |
| CALGN( sbcsne r4, ip, r2 ) @ C is always set here |
| CALGN( subcc r2, r2, ip ) |
| CALGN( bcc 15f ) |
| |
| 11: push {r5 - r8, r10} |
| cfi_adjust_cfa_offset (20) |
| cfi_rel_offset (r5, 0) |
| cfi_rel_offset (r6, 4) |
| cfi_rel_offset (r7, 8) |
| cfi_rel_offset (r8, 12) |
| cfi_rel_offset (r10, 16) |
| |
| PLD( pld [r1, #-4] ) |
| PLD( cmp r2, #96 ) |
| PLD( pld [r1, #-32] ) |
| PLD( blo 13f ) |
| PLD( pld [r1, #-64] ) |
| PLD( pld [r1, #-96] ) |
| |
| 12: PLD( pld [r1, #-128] ) |
| 13: ldmdb r1!, {r7, r8, r10, ip} |
| mov lr, r3, PUSH #\push |
| subs r2, r2, #32 |
| ldmdb r1!, {r3, r4, r5, r6} |
| orr lr, lr, ip, PULL #\pull |
| mov ip, ip, PUSH #\push |
| orr ip, ip, r10, PULL #\pull |
| mov r10, r10, PUSH #\push |
| orr r10, r10, r8, PULL #\pull |
| mov r8, r8, PUSH #\push |
| orr r8, r8, r7, PULL #\pull |
| mov r7, r7, PUSH #\push |
| orr r7, r7, r6, PULL #\pull |
| mov r6, r6, PUSH #\push |
| orr r6, r6, r5, PULL #\pull |
| mov r5, r5, PUSH #\push |
| orr r5, r5, r4, PULL #\pull |
| mov r4, r4, PUSH #\push |
| orr r4, r4, r3, PULL #\pull |
| stmdb r0!, {r4 - r8, r10, ip, lr} |
| bhs 12b |
| |
| pop {r5 - r8, r10} |
| cfi_adjust_cfa_offset (-20) |
| cfi_restore (r5) |
| cfi_restore (r6) |
| cfi_restore (r7) |
| cfi_restore (r8) |
| cfi_restore (r10) |
| |
| 14: ands ip, r2, #28 |
| beq 16f |
| |
| 15: mov lr, r3, PUSH #\push |
| ldr r3, [r1, #-4]! |
| subs ip, ip, #4 |
| orr lr, lr, r3, PULL #\pull |
| str lr, [r0, #-4]! |
| bgt 15b |
| CALGN( cmp r2, #0 ) |
| CALGN( bge 11b ) |
| |
| 16: add r1, r1, #(\pull / 8) |
| b 8b |
| |
| .endm |
| |
| |
| backward_copy_shift push=8 pull=24 |
| |
| 17: backward_copy_shift push=16 pull=16 |
| |
| 18: backward_copy_shift push=24 pull=8 |
| |
| |
| END(memmove) |
| libc_hidden_builtin_def (memmove) |