/**************************************************************************** * libs/libc/machine/arm/armv7-m/gnu/arch_memset.S * * Copyright (c) 2015 ARM Ltd * All rights reserved. * * 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. * 3. The name of the company may not be used to endorse or promote * products derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY ARM LTD ``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 ARM LTD 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 "libc.h" #ifdef LIBC_BUILD_STRING #include "arm_asm.h" .thumb .syntax unified .global memset .type memset, %function .fnstart .cfi_startproc memset: prologue 4 6 lsls r4, r0, #30 beq 10f subs r4, r2, #1 cmp r2, #0 beq 9f uxtb r5, r1 mov r3, r0 b 2f 1: subs r2, r4, #1 cbz r4, 9f mov r4, r2 2: strb r5, [r3], #1 lsls r2, r3, #30 bne 1b 3: cmp r4, #3 bls 7f uxtb r5, r1 orr r5, r5, r5, lsl #8 cmp r4, #15 orr r5, r5, r5, lsl #16 bls 5f mov r6, r4 add r2, r3, #16 4: subs r6, r6, #16 cmp r6, #15 str r5, [r2, #-16] str r5, [r2, #-12] str r5, [r2, #-8] str r5, [r2, #-4] add r2, r2, #16 bhi 4b sub r2, r4, #16 bic r2, r2, #15 and r4, r4, #15 adds r2, r2, #16 cmp r4, #3 add r3, r3, r2 bls 7f 5: mov r6, r3 mov r2, r4 6: subs r2, r2, #4 cmp r2, #3 str r5, [r6], #4 bhi 6b subs r2, r4, #4 bic r2, r2, #3 adds r2, r2, #4 add r3, r3, r2 and r4, r4, #3 7: cbz r4, 9f uxtb r1, r1 add r4, r4, r3 8: strb r1, [r3], #1 cmp r3, r4 bne 8b 9: .cfi_remember_state epilogue 4 6 10: .cfi_restore_state mov r4, r2 mov r3, r0 b 3b .cfi_endproc .cantunwind .fnend .size memset, . - memset #endif