84d9c625bf
- Fix for possible unset uid/gid in toproto - Fix for default mtree style - Update libelf - Importing libexecinfo - Resynchronize GCC, mpc, gmp, mpfr - build.sh: Replace params with show-params. This has been done as the make target has been renamed in the same way, while a new target named params has been added. This new target generates a file containing all the parameters, instead of printing it on the console. - Update test48 with new etc/services (Fix by Ben Gras <ben@minix3.org) get getservbyport() out of the inner loop Change-Id: Ie6ad5226fa2621ff9f0dee8782ea48f9443d2091
180 lines
5.7 KiB
ArmAsm
180 lines
5.7 KiB
ArmAsm
/*-
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* Copyright (c) 2012 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Matt Thomas of 3am Software Foundry.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <machine/asm.h>
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RCSID("$NetBSD: strlen_arm.S,v 1.8 2013/09/05 05:15:47 matt Exp $")
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#if defined(__thumb__) && !defined(_ARM_ARCH_T2)
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#error Only Thumb2 or ARM supported
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#endif
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#ifdef __ARMEL__
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#define BYTE0 0x000000ff
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#define BYTE1 0x0000ff00
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#define BYTE2 0x00ff0000
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#define BYTE3 0xff000000
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#else
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#define BYTE0 0xff000000
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#define BYTE1 0x00ff0000
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#define BYTE2 0x0000ff00
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#define BYTE3 0x000000ff
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#endif
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#ifdef STRNLEN
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#define FUNCNAME strnlen
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#else
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#define FUNCNAME strlen
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#endif
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.text
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ENTRY(FUNCNAME)
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#if defined(__ARM_EABI__) && defined(__UNWIND_TABLES__)
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.fnstart
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.cfi_startproc
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#endif
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#ifdef STRNLEN
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push {r4,r5} /* save some registers */
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#if defined(__ARM_EABI__) && defined(__UNWIND_TABLES__)
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.save {r4,r5}
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.cfi_def_cfa_offset 8
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.cfi_offset 5, -4
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.cfi_offset 4, -8
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#endif
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adds r5, r0, r1 /* get ptr to end of string */
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mov r4, r1 /* save maxlen */
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#endif
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adds r2, r0, #4 /* for the final post-inc */
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1: tst r0, #3 /* test for word alignment */
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beq .Lpre_main_loop /* finally word aligned */
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#ifdef STRNLEN
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cmp r0, r5 /* have we gone too far? */
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beq .Lmaxed_out /* yes, return maxlen */
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#endif
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ldrb r3, [r0], #1 /* load a byte */
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cmp r3, #0 /* is it 0? */
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bne 1b /* no, try next byte */
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subs r2, r2, #3 /* subtract (4 - the NUL) */
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subs r0, r0, r2 /* subtract start */
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#ifdef STRNLEN
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pop {r4, r5} /* restore registers */
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#endif
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RET /* return */
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.Lpre_main_loop:
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#if defined(_ARM_ARCH_7)
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movw r1, #0xfefe /* magic constant; 254 in each byte */
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movt r1, #0xfefe /* magic constant; 254 in each byte */
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#elif defined(_ARM_ARCH_6)
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mov r1, #0xfe /* put 254 in low byte */
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orr r1, r1, r1, lsl #8 /* move to next byte */
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orr r1, r1, r1, lsl #16 /* move to next halfword */
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#endif /* _ARM_ARCH_6 */
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.Lmain_loop:
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#ifdef STRNLEN
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cmp r0, r5 /* gone too far? */
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bge .Lmaxed_out /* yes, return maxlen */
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#endif
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ldr r3, [r0], #4 /* load next word */
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#if defined(_ARM_ARCH_6)
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/*
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* Add 254 to each byte using the UQADD8 (unsigned saturating add 8)
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* instruction. For every non-NUL byte, the result for that byte will
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* become 255. For NUL, it will be 254. When we complement the
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* result, if the result is non-0 then we must have encountered a NUL.
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*/
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uqadd8 r3, r3, r1 /* magic happens here */
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mvns r3, r3 /* is the complemented result non-0? */
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beq .Lmain_loop /* no, then we encountered no NULs */
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#else
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/*
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* No fancy shortcuts so just test each byte lane for a NUL.
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* (other tests for NULs in a word take more instructions/cycles).
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*/
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tst r3, #BYTE0 /* is this byte 0? */
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tstne r3, #BYTE1 /* no, is this byte 0? */
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tstne r3, #BYTE2 /* no, is this byte 0? */
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tstne r3, #BYTE3 /* no, is this byte 0? */
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bne .Lmain_loop /* no, then get next word */
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#endif
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#if defined(_ARM_ARCH_6)
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/*
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* We encountered a NUL. Find out where by doing a CLZ and then
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* shifting right by 3. That will be the number of non-NUL bytes.
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*/
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#ifdef __ARMEL__
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rev r3, r3 /* we want this in BE for the CLZ */
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#endif
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clz r3, r3 /* count how many leading zeros */
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#ifdef __thumb__
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lsrs r3, r3, #3
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adds r0, r0, r3 /* divide that by 8 and add to count */
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#else
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add r0, r0, r3, lsr #3 /* divide that by 8 and add to count */
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#endif
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#else
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/*
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* We encountered a NUL.
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*/
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tst r3, #BYTE0 /* 1st byte was NUL? */
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beq 1f /* yes, done adding */
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add r0, r0, #1 /* we have one more non-NUL byte */
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tst r3, #BYTE1 /* 2nd byte was NUL? */
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beq 1f /* yes, done adding */
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add r0, r0, #1 /* we have one more non-NUL byte */
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tst r3, #BYTE2 /* 3rd byte was NUL? */
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addne r0, r0, #1 /* no, we have one more non-NUL byte */
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1:
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#endif /* _ARM_ARCH_6 */
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/*
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* r0 now points to 4 past the NUL due to the post-inc. Subtract the
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* start of the string (which also has 4 added to it to compensate for
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* the post-inc.
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*/
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subs r0, r0, r2 /* subtract start to get length */
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#ifdef STRNLEN
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cmp r0, r4 /* is it larger than maxlen? */
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#ifdef __thumb__
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it gt
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#endif
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movgt r0, r4 /* yes, return maxlen */
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pop {r4, r5} /* restore registers */
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#endif
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RET /* return */
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#ifdef STRNLEN
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.Lmaxed_out:
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mov r0, r4 /* return maxlen */
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pop {r4, r5} /* restore registers */
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RET /* return */
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#endif
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#if defined(__ARM_EABI__) && defined(__UNWIND_TABLES__)
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.cfi_endproc
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.fnend
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#endif
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END(FUNCNAME)
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