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Diffstat (limited to 'newlib/libc/machine/aarch64/memcmp.S')
| -rw-r--r-- | newlib/libc/machine/aarch64/memcmp.S | 167 |
1 files changed, 0 insertions, 167 deletions
diff --git a/newlib/libc/machine/aarch64/memcmp.S b/newlib/libc/machine/aarch64/memcmp.S deleted file mode 100644 index 860384cc8..000000000 --- a/newlib/libc/machine/aarch64/memcmp.S +++ /dev/null @@ -1,167 +0,0 @@ -/* memcmp - compare memory - - Copyright (c) 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 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. */ - -#if (defined (__OPTIMIZE_SIZE__) || defined (PREFER_SIZE_OVER_SPEED)) -/* See memcmp-stub.c */ -#else -/* Assumptions: - * - * ARMv8-a, AArch64 - */ - - .macro def_fn f p2align=0 - .text - .p2align \p2align - .global \f - .type \f, %function -\f: - .endm - -/* Parameters and result. */ -#define src1 x0 -#define src2 x1 -#define limit x2 -#define result x0 - -/* Internal variables. */ -#define data1 x3 -#define data1w w3 -#define data2 x4 -#define data2w w4 -#define has_nul x5 -#define diff x6 -#define endloop x7 -#define tmp1 x8 -#define tmp2 x9 -#define tmp3 x10 -#define pos x11 -#define limit_wd x12 -#define mask x13 - -def_fn memcmp p2align=6 - cbz limit, .Lret0 - eor tmp1, src1, src2 - tst tmp1, #7 - b.ne .Lmisaligned8 - ands tmp1, src1, #7 - b.ne .Lmutual_align - add limit_wd, limit, #7 - lsr limit_wd, limit_wd, #3 - /* Start of performance-critical section -- one 64B cache line. */ -.Lloop_aligned: - ldr data1, [src1], #8 - ldr data2, [src2], #8 -.Lstart_realigned: - subs limit_wd, limit_wd, #1 - eor diff, data1, data2 /* Non-zero if differences found. */ - csinv endloop, diff, xzr, ne /* Last Dword or differences. */ - cbz endloop, .Lloop_aligned - /* End of performance-critical section -- one 64B cache line. */ - - /* Not reached the limit, must have found a diff. */ - cbnz limit_wd, .Lnot_limit - - /* Limit % 8 == 0 => all bytes significant. */ - ands limit, limit, #7 - b.eq .Lnot_limit - - lsl limit, limit, #3 /* Bits -> bytes. */ - mov mask, #~0 -#ifdef __AARCH64EB__ - lsr mask, mask, limit -#else - lsl mask, mask, limit -#endif - bic data1, data1, mask - bic data2, data2, mask - - orr diff, diff, mask -.Lnot_limit: - -#ifndef __AARCH64EB__ - rev diff, diff - rev data1, data1 - rev data2, data2 -#endif - /* The MS-non-zero bit of DIFF marks either the first bit - that is different, or the end of the significant data. - Shifting left now will bring the critical information into the - top bits. */ - clz pos, diff - lsl data1, data1, pos - lsl data2, data2, pos - /* But we need to zero-extend (char is unsigned) the value and then - perform a signed 32-bit subtraction. */ - lsr data1, data1, #56 - sub result, data1, data2, lsr #56 - ret - -.Lmutual_align: - /* Sources are mutually aligned, but are not currently at an - alignment boundary. Round down the addresses and then mask off - the bytes that precede the start point. */ - bic src1, src1, #7 - bic src2, src2, #7 - add limit, limit, tmp1 /* Adjust the limit for the extra. */ - lsl tmp1, tmp1, #3 /* Bytes beyond alignment -> bits. */ - ldr data1, [src1], #8 - neg tmp1, tmp1 /* Bits to alignment -64. */ - ldr data2, [src2], #8 - mov tmp2, #~0 -#ifdef __AARCH64EB__ - /* Big-endian. Early bytes are at MSB. */ - lsl tmp2, tmp2, tmp1 /* Shift (tmp1 & 63). */ -#else - /* Little-endian. Early bytes are at LSB. */ - lsr tmp2, tmp2, tmp1 /* Shift (tmp1 & 63). */ -#endif - add limit_wd, limit, #7 - orr data1, data1, tmp2 - orr data2, data2, tmp2 - lsr limit_wd, limit_wd, #3 - b .Lstart_realigned - -.Lret0: - mov result, #0 - ret - - .p2align 6 -.Lmisaligned8: - sub limit, limit, #1 -1: - /* Perhaps we can do better than this. */ - ldrb data1w, [src1], #1 - ldrb data2w, [src2], #1 - subs limit, limit, #1 - ccmp data1w, data2w, #0, cs /* NZCV = 0b0000. */ - b.eq 1b - sub result, data1, data2 - ret - .size memcmp, . - memcmp - -#endif
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