+++ /dev/null
-/*
- * Copyright (c) 2006, 2009 Apple Inc. All rights reserved.
- *
- * @APPLE_LICENSE_HEADER_START@
- *
- * This file contains Original Code and/or Modifications of Original Code
- * as defined in and that are subject to the Apple Public Source License
- * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
- * limitations under the License.
- *
- * @APPLE_LICENSE_HEADER_END@
- */
-
-#include <arm/arch.h>
-#if !defined _ARM_ARCH_7 || defined VARIANT_DYLD
-
-#include <mach/machine/asm.h>
-#include <architecture/arm/asm_help.h>
-
-/*
- * A reasonably well-optimized bzero/memset. Should work equally well on arm11 and arm9 based
- * cores.
- *
- * The algorithm is to align the destination pointer on a 32 byte boundary and then
- * blast data 64 bytes at a time, in two stores of 32 bytes per loop.
- */
- .text
- .align 2
-
- .globl _memset
-/* void *memset(void *ptr, int c, size_t len); */
-_memset:
- /* move len into r1, unpack c into r2 */
- mov r3, r2
- and r1, r1, #0xff
- orr r1, r1, r1, lsl #8
- orr r2, r1, r1, lsl #16
- mov r1, r3
- b Lbzeroengine
-
- .globl _bzero
-/* void bzero(void *ptr, size_t len); */
-_bzero:
- /* zero out r2 so we can be just like memset(0) */
- mov r2, #0
-
-Lbzeroengine:
- /* move the base pointer into r12 and leave r0 alone so that we return the original pointer */
- mov r12, r0
-
- /* copy r2 into r3 for 64-bit stores */
- mov r3, r2
-
- /* check for zero len */
- cmp r1, #0
- bxeq lr
-
- /* fall back to a bytewise store for less than 32 bytes */
- cmp r1, #32
- blt L_bytewise
-
- /* check for 32 byte unaligned ptr */
- tst r12, #0x1f
- bne L_unaligned
-
- /* make sure we have more than 64 bytes to zero */
- cmp r1, #64
- blt L_lessthan64aligned
-
- /* >= 64 bytes of len, 32 byte aligned */
-L_64ormorealigned:
-
- /* we need some registers, avoid r7 (frame pointer) and r9 (thread register) */
- stmfd sp!, { r4-r6, r8, r10-r11 }
- mov r4, r2
- mov r5, r2
- mov r6, r2
- mov r8, r2
- mov r10, r2
- mov r11, r2
-
- /* pre-subtract 64 from the len to avoid an extra compare in the loop */
- sub r1, r1, #64
-
-L_64loop:
- stmia r12!, { r2-r6, r8, r10-r11 }
- subs r1, r1, #64
- stmia r12!, { r2-r6, r8, r10-r11 }
- bge L_64loop
-
- /* restore the saved regs */
- ldmfd sp!, { r4-r6, r8, r10-r11 }
-
- /* check for completion (had previously subtracted an extra 64 from len) */
- adds r1, r1, #64
- bxeq lr
-
-L_lessthan64aligned:
- /* do we have 16 or more bytes left */
- cmp r1, #16
- stmgeia r12!, { r2-r3 }
- stmgeia r12!, { r2-r3 }
- subges r1, r1, #16
- bgt L_lessthan64aligned
- bxeq lr
-
-L_lessthan16aligned:
- /* store 0 to 15 bytes */
- mov r1, r1, lsl #28 /* move the remaining len bits [3:0] to the flags area of cpsr */
- msr cpsr_f, r1
-
- stmmiia r12!, { r2-r3 } /* n is set, store 8 bytes */
- streq r2, [r12], #4 /* z is set, store 4 bytes */
- strcsh r2, [r12], #2 /* c is set, store 2 bytes */
- strvsb r2, [r12], #1 /* v is set, store 1 byte */
- bx lr
-
-L_bytewise:
- /* bytewise copy, 2 bytes at a time, alignment not guaranteed */
- subs r1, r1, #2
- strb r2, [r12], #1
- strplb r2, [r12], #1
- bhi L_bytewise
- bx lr
-
-L_unaligned:
- /* unaligned on 32 byte boundary, store 1-15 bytes until we're 16 byte aligned */
- mov r3, r12, lsl #28
- rsb r3, r3, #0x00000000
- msr cpsr_f, r3
-
- strvsb r2, [r12], #1 /* v is set, unaligned in the 1s column */
- strcsh r2, [r12], #2 /* c is set, unaligned in the 2s column */
- streq r2, [r12], #4 /* z is set, unaligned in the 4s column */
- strmi r2, [r12], #4 /* n is set, unaligned in the 8s column */
- strmi r2, [r12], #4
-
- subs r1, r1, r3, lsr #28
- bxeq lr
-
- /* we had previously trashed r3, restore it */
- mov r3, r2
-
- /* now make sure we're 32 byte aligned */
- tst r12, #(1 << 4)
- stmneia r12!, { r2-r3 }
- stmneia r12!, { r2-r3 }
- subnes r1, r1, #16
-
- /* we're now aligned, check for >= 64 bytes left */
- cmp r1, #64
- bge L_64ormorealigned
- b L_lessthan64aligned
-
-X_LEAF(___bzero, _bzero)
-
-#endif // !defined _ARM_ARCH_7 || defined VARIANT_DYLD
projects / apple / libc.git / blobdiff