/**************************************************************************** * libs/libc/machine/arm/armv8-m/gnu/arch_strlen.S * * Copyright (c) 2010-2011,2013 Linaro Limited * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * * 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. * * * Neither the name of Linaro Limited nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT * HOLDER 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. * * Assumes: * ARMv6T2 or ARMv7E-M, AArch32 * * 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: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 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. * * Neither the name of the Linaro nor the * names of its contributors may be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT * HOLDER 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 "libc.h" #ifdef LIBC_BUILD_STRING #include "arm-acle-compat.h" #include "arm_asm.h" .macro def_fn f p2align=0 .text .p2align \p2align .global \f .type \f, %function \f: .endm #ifdef __ARMEB__ #define S2LO lsl #define S2HI lsr #else #define S2LO lsr #define S2HI lsl #endif /* This code requires Thumb. */ #if __ARM_ARCH_PROFILE == 'M' #if __ARM_ARCH >= 8 /* keep config inherited from -march=. */ #else .arch armv7e-m #endif /* if __ARM_ARCH >= 8 */ #else .arch armv6t2 #endif .eabi_attribute Tag_ARM_ISA_use, 0 .thumb .syntax unified /* Parameters and result. */ #define srcin r0 #define result r0 /* Internal variables. */ #define src r1 #define data1a r2 #define data1b r3 #define const_m1 r12 #define const_0 r4 #define tmp1 r4 /* Overlaps const_0 */ #define tmp2 r5 def_fn strlen p2align=6 .fnstart .cfi_startproc prologue 4 5 push_ip=HAVE_PAC_LEAF pld [srcin, #0] bic src, srcin, #7 mvn const_m1, #0 ands tmp1, srcin, #7 /* (8 - bytes) to alignment. */ pld [src, #32] bne.w .Lmisaligned8 mov const_0, #0 mov result, #-8 .Lloop_aligned: /* Bytes 0-7. */ ldrd data1a, data1b, [src] pld [src, #64] add result, result, #8 .Lstart_realigned: uadd8 data1a, data1a, const_m1 /* Saturating GE<0:3> set. */ sel data1a, const_0, const_m1 /* Select based on GE<0:3>. */ uadd8 data1b, data1b, const_m1 sel data1b, data1a, const_m1 /* Only used if d1a == 0. */ cbnz data1b, .Lnull_found /* Bytes 8-15. */ ldrd data1a, data1b, [src, #8] uadd8 data1a, data1a, const_m1 /* Saturating GE<0:3> set. */ add result, result, #8 sel data1a, const_0, const_m1 /* Select based on GE<0:3>. */ uadd8 data1b, data1b, const_m1 sel data1b, data1a, const_m1 /* Only used if d1a == 0. */ cbnz data1b, .Lnull_found /* Bytes 16-23. */ ldrd data1a, data1b, [src, #16] uadd8 data1a, data1a, const_m1 /* Saturating GE<0:3> set. */ add result, result, #8 sel data1a, const_0, const_m1 /* Select based on GE<0:3>. */ uadd8 data1b, data1b, const_m1 sel data1b, data1a, const_m1 /* Only used if d1a == 0. */ cbnz data1b, .Lnull_found /* Bytes 24-31. */ ldrd data1a, data1b, [src, #24] add src, src, #32 uadd8 data1a, data1a, const_m1 /* Saturating GE<0:3> set. */ add result, result, #8 sel data1a, const_0, const_m1 /* Select based on GE<0:3>. */ uadd8 data1b, data1b, const_m1 sel data1b, data1a, const_m1 /* Only used if d1a == 0. */ cmp data1b, #0 beq .Lloop_aligned .Lnull_found: .cfi_remember_state cmp data1a, #0 itt eq addeq result, result, #4 moveq data1a, data1b #ifndef __ARMEB__ rev data1a, data1a #endif clz data1a, data1a add result, result, data1a, lsr #3 /* Bits -> Bytes. */ epilogue 4 5 push_ip=HAVE_PAC_LEAF .Lmisaligned8: .cfi_restore_state ldrd data1a, data1b, [src] and tmp2, tmp1, #3 rsb result, tmp1, #0 lsl tmp2, tmp2, #3 /* Bytes -> bits. */ tst tmp1, #4 pld [src, #64] S2HI tmp2, const_m1, tmp2 orn data1a, data1a, tmp2 itt ne ornne data1b, data1b, tmp2 movne data1a, const_m1 mov const_0, #0 b .Lstart_realigned .cfi_endproc .cantunwind .fnend .size strlen, . - strlen #endif