diff --git a/libc/arch-arm64/arm64.mk b/libc/arch-arm64/arm64.mk index 76c610a72..88da1f354 100644 --- a/libc/arch-arm64/arm64.mk +++ b/libc/arch-arm64/arm64.mk @@ -4,13 +4,8 @@ libc_common_src_files_arm64 := \ bionic/index.cpp \ bionic/memchr.c \ bionic/__memcmp16.cpp \ - bionic/memcmp.c \ - bionic/memcpy.cpp \ - bionic/memmove.c \ bionic/memrchr.c \ - bionic/memset.c \ bionic/strchr.cpp \ - bionic/strnlen.c \ bionic/strrchr.cpp \ upstream-freebsd/lib/libc/string/wcscat.c \ upstream-freebsd/lib/libc/string/wcschr.c \ @@ -21,13 +16,10 @@ libc_common_src_files_arm64 := \ upstream-freebsd/lib/libc/string/wmemcmp.c \ upstream-openbsd/lib/libc/string/bcopy.c \ upstream-openbsd/lib/libc/string/strcat.c \ - upstream-openbsd/lib/libc/string/strcmp.c \ upstream-openbsd/lib/libc/string/strcpy.c \ upstream-openbsd/lib/libc/string/strlcat.c \ upstream-openbsd/lib/libc/string/strlcpy.c \ - upstream-openbsd/lib/libc/string/strlen.c \ upstream-openbsd/lib/libc/string/strncat.c \ - upstream-openbsd/lib/libc/string/strncmp.c \ upstream-openbsd/lib/libc/string/strncpy.c \ # Fortify implementations of libc functions. @@ -62,3 +54,5 @@ libc_crt_target_crtbegin_file_arm64 := \ libc_crt_target_crtbegin_so_file_arm64 := \ $(LOCAL_PATH)/arch-common/bionic/crtbegin_so.c + +include $(LOCAL_PATH)/arch-arm64/generic/generic.mk diff --git a/libc/arch-arm64/generic/bionic/memcmp.S b/libc/arch-arm64/generic/bionic/memcmp.S new file mode 100644 index 000000000..3d08ecdaf --- /dev/null +++ b/libc/arch-arm64/generic/bionic/memcmp.S @@ -0,0 +1,155 @@ +/* Copyright (c) 2014, 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. +*/ + +/* Assumptions: + * + * ARMv8-a, AArch64 + */ + +#include + +/* 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 + +ENTRY(memcmp) + 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 +END(memcmp) diff --git a/libc/arch-arm64/generic/bionic/memcpy.S b/libc/arch-arm64/generic/bionic/memcpy.S new file mode 100644 index 000000000..e1b1a727c --- /dev/null +++ b/libc/arch-arm64/generic/bionic/memcpy.S @@ -0,0 +1,184 @@ +/* Copyright (c) 2012, 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. +*/ + +/* Assumptions: + * + * ARMv8-a, AArch64 + * Unaligned accesses + * + */ + +#include + +#define dstin x0 +#define src x1 +#define count x2 +#define tmp1 x3 +#define tmp1w w3 +#define tmp2 x4 +#define tmp2w w4 +#define tmp3 x5 +#define tmp3w w5 +#define dst x6 + +#define A_l x7 +#define A_h x8 +#define B_l x9 +#define B_h x10 +#define C_l x11 +#define C_h x12 +#define D_l x13 +#define D_h x14 + +ENTRY(memcpy) + + mov dst, dstin + cmp count, #64 + b.ge .Lcpy_not_short + cmp count, #15 + b.le .Ltail15tiny + + /* Deal with small copies quickly by dropping straight into the + * exit block. */ +.Ltail63: + /* Copy up to 48 bytes of data. At this point we only need the + * bottom 6 bits of count to be accurate. */ + ands tmp1, count, #0x30 + b.eq .Ltail15 + add dst, dst, tmp1 + add src, src, tmp1 + cmp tmp1w, #0x20 + b.eq 1f + b.lt 2f + ldp A_l, A_h, [src, #-48] + stp A_l, A_h, [dst, #-48] +1: + ldp A_l, A_h, [src, #-32] + stp A_l, A_h, [dst, #-32] +2: + ldp A_l, A_h, [src, #-16] + stp A_l, A_h, [dst, #-16] + +.Ltail15: + ands count, count, #15 + beq 1f + add src, src, count + ldp A_l, A_h, [src, #-16] + add dst, dst, count + stp A_l, A_h, [dst, #-16] +1: + ret + +.Ltail15tiny: + /* Copy up to 15 bytes of data. Does not assume additional data + being copied. */ + tbz count, #3, 1f + ldr tmp1, [src], #8 + str tmp1, [dst], #8 +1: + tbz count, #2, 1f + ldr tmp1w, [src], #4 + str tmp1w, [dst], #4 +1: + tbz count, #1, 1f + ldrh tmp1w, [src], #2 + strh tmp1w, [dst], #2 +1: + tbz count, #0, 1f + ldrb tmp1w, [src] + strb tmp1w, [dst] +1: + ret + +.Lcpy_not_short: + /* We don't much care about the alignment of DST, but we want SRC + * to be 128-bit (16 byte) aligned so that we don't cross cache line + * boundaries on both loads and stores. */ + neg tmp2, src + ands tmp2, tmp2, #15 /* Bytes to reach alignment. */ + b.eq 2f + sub count, count, tmp2 + /* Copy more data than needed; it's faster than jumping + * around copying sub-Quadword quantities. We know that + * it can't overrun. */ + ldp A_l, A_h, [src] + add src, src, tmp2 + stp A_l, A_h, [dst] + add dst, dst, tmp2 + /* There may be less than 63 bytes to go now. */ + cmp count, #63 + b.le .Ltail63 +2: + subs count, count, #128 + b.ge .Lcpy_body_large + /* Less than 128 bytes to copy, so handle 64 here and then jump + * to the tail. */ + ldp A_l, A_h, [src] + ldp B_l, B_h, [src, #16] + ldp C_l, C_h, [src, #32] + ldp D_l, D_h, [src, #48] + stp A_l, A_h, [dst] + stp B_l, B_h, [dst, #16] + stp C_l, C_h, [dst, #32] + stp D_l, D_h, [dst, #48] + tst count, #0x3f + add src, src, #64 + add dst, dst, #64 + b.ne .Ltail63 + ret + + /* Critical loop. Start at a new cache line boundary. Assuming + * 64 bytes per line this ensures the entire loop is in one line. */ + .p2align 6 +.Lcpy_body_large: + /* There are at least 128 bytes to copy. */ + ldp A_l, A_h, [src, #0] + sub dst, dst, #16 /* Pre-bias. */ + ldp B_l, B_h, [src, #16] + ldp C_l, C_h, [src, #32] + ldp D_l, D_h, [src, #48]! /* src += 64 - Pre-bias. */ +1: + stp A_l, A_h, [dst, #16] + ldp A_l, A_h, [src, #16] + stp B_l, B_h, [dst, #32] + ldp B_l, B_h, [src, #32] + stp C_l, C_h, [dst, #48] + ldp C_l, C_h, [src, #48] + stp D_l, D_h, [dst, #64]! + ldp D_l, D_h, [src, #64]! + subs count, count, #64 + b.ge 1b + stp A_l, A_h, [dst, #16] + stp B_l, B_h, [dst, #32] + stp C_l, C_h, [dst, #48] + stp D_l, D_h, [dst, #64] + add src, src, #16 + add dst, dst, #64 + 16 + tst count, #0x3f + b.ne .Ltail63 + ret +END(memcpy) diff --git a/libc/arch-arm64/generic/bionic/memmove.S b/libc/arch-arm64/generic/bionic/memmove.S new file mode 100644 index 000000000..d6ecb868b --- /dev/null +++ b/libc/arch-arm64/generic/bionic/memmove.S @@ -0,0 +1,319 @@ +/* Copyright (c) 2014, 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. +*/ + +/* Assumptions: + * + * ARMv8-a, AArch64 + * Unaligned accesses + */ + +#include + +/* Parameters and result. */ +#define dstin x0 +#define src x1 +#define count x2 +#define tmp1 x3 +#define tmp1w w3 +#define tmp2 x4 +#define tmp2w w4 +#define tmp3 x5 +#define tmp3w w5 +#define dst x6 + +#define A_l x7 +#define A_h x8 +#define B_l x9 +#define B_h x10 +#define C_l x11 +#define C_h x12 +#define D_l x13 +#define D_h x14 + +ENTRY(memmove) + cmp dstin, src + b.lo .Ldownwards + add tmp1, src, count + cmp dstin, tmp1 + b.hs memcpy /* No overlap. */ + + /* Upwards move with potential overlap. + * Need to move from the tail backwards. SRC and DST point one + * byte beyond the remaining data to move. */ + add dst, dstin, count + add src, src, count + cmp count, #64 + b.ge .Lmov_not_short_up + + /* Deal with small moves quickly by dropping straight into the + * exit block. */ +.Ltail63up: + /* Move up to 48 bytes of data. At this point we only need the + * bottom 6 bits of count to be accurate. */ + ands tmp1, count, #0x30 + b.eq .Ltail15up + sub dst, dst, tmp1 + sub src, src, tmp1 + cmp tmp1w, #0x20 + b.eq 1f + b.lt 2f + ldp A_l, A_h, [src, #32] + stp A_l, A_h, [dst, #32] +1: + ldp A_l, A_h, [src, #16] + stp A_l, A_h, [dst, #16] +2: + ldp A_l, A_h, [src] + stp A_l, A_h, [dst] +.Ltail15up: + /* Move up to 15 bytes of data. Does not assume additional data + * being moved. */ + tbz count, #3, 1f + ldr tmp1, [src, #-8]! + str tmp1, [dst, #-8]! +1: + tbz count, #2, 1f + ldr tmp1w, [src, #-4]! + str tmp1w, [dst, #-4]! +1: + tbz count, #1, 1f + ldrh tmp1w, [src, #-2]! + strh tmp1w, [dst, #-2]! +1: + tbz count, #0, 1f + ldrb tmp1w, [src, #-1] + strb tmp1w, [dst, #-1] +1: + ret + +.Lmov_not_short_up: + /* We don't much care about the alignment of DST, but we want SRC + * to be 128-bit (16 byte) aligned so that we don't cross cache line + * boundaries on both loads and stores. */ + ands tmp2, src, #15 /* Bytes to reach alignment. */ + b.eq 2f + sub count, count, tmp2 + /* Move enough data to reach alignment; unlike memcpy, we have to + * be aware of the overlap, which means we can't move data twice. */ + tbz tmp2, #3, 1f + ldr tmp1, [src, #-8]! + str tmp1, [dst, #-8]! +1: + tbz tmp2, #2, 1f + ldr tmp1w, [src, #-4]! + str tmp1w, [dst, #-4]! +1: + tbz tmp2, #1, 1f + ldrh tmp1w, [src, #-2]! + strh tmp1w, [dst, #-2]! +1: + tbz tmp2, #0, 1f + ldrb tmp1w, [src, #-1]! + strb tmp1w, [dst, #-1]! +1: + + /* There may be less than 63 bytes to go now. */ + cmp count, #63 + b.le .Ltail63up +2: + subs count, count, #128 + b.ge .Lmov_body_large_up + /* Less than 128 bytes to move, so handle 64 here and then jump + * to the tail. */ + ldp A_l, A_h, [src, #-64]! + ldp B_l, B_h, [src, #16] + ldp C_l, C_h, [src, #32] + ldp D_l, D_h, [src, #48] + stp A_l, A_h, [dst, #-64]! + stp B_l, B_h, [dst, #16] + stp C_l, C_h, [dst, #32] + stp D_l, D_h, [dst, #48] + tst count, #0x3f + b.ne .Ltail63up + ret + + /* Critical loop. Start at a new Icache line boundary. Assuming + * 64 bytes per line this ensures the entire loop is in one line. */ + .p2align 6 +.Lmov_body_large_up: + /* There are at least 128 bytes to move. */ + ldp A_l, A_h, [src, #-16] + ldp B_l, B_h, [src, #-32] + ldp C_l, C_h, [src, #-48] + ldp D_l, D_h, [src, #-64]! +1: + stp A_l, A_h, [dst, #-16] + ldp A_l, A_h, [src, #-16] + stp B_l, B_h, [dst, #-32] + ldp B_l, B_h, [src, #-32] + stp C_l, C_h, [dst, #-48] + ldp C_l, C_h, [src, #-48] + stp D_l, D_h, [dst, #-64]! + ldp D_l, D_h, [src, #-64]! + subs count, count, #64 + b.ge 1b + stp A_l, A_h, [dst, #-16] + stp B_l, B_h, [dst, #-32] + stp C_l, C_h, [dst, #-48] + stp D_l, D_h, [dst, #-64]! + tst count, #0x3f + b.ne .Ltail63up + ret + + +.Ldownwards: + /* For a downwards move we can safely use memcpy provided that + * DST is more than 16 bytes away from SRC. */ + sub tmp1, src, #16 + cmp dstin, tmp1 + b.ls memcpy /* May overlap, but not critically. */ + + mov dst, dstin /* Preserve DSTIN for return value. */ + cmp count, #64 + b.ge .Lmov_not_short_down + + /* Deal with small moves quickly by dropping straight into the + * exit block. */ +.Ltail63down: + /* Move up to 48 bytes of data. At this point we only need the + * bottom 6 bits of count to be accurate. */ + ands tmp1, count, #0x30 + b.eq .Ltail15down + add dst, dst, tmp1 + add src, src, tmp1 + cmp tmp1w, #0x20 + b.eq 1f + b.lt 2f + ldp A_l, A_h, [src, #-48] + stp A_l, A_h, [dst, #-48] +1: + ldp A_l, A_h, [src, #-32] + stp A_l, A_h, [dst, #-32] +2: + ldp A_l, A_h, [src, #-16] + stp A_l, A_h, [dst, #-16] +.Ltail15down: + /* Move up to 15 bytes of data. Does not assume additional data + being moved. */ + tbz count, #3, 1f + ldr tmp1, [src], #8 + str tmp1, [dst], #8 +1: + tbz count, #2, 1f + ldr tmp1w, [src], #4 + str tmp1w, [dst], #4 +1: + tbz count, #1, 1f + ldrh tmp1w, [src], #2 + strh tmp1w, [dst], #2 +1: + tbz count, #0, 1f + ldrb tmp1w, [src] + strb tmp1w, [dst] +1: + ret + +.Lmov_not_short_down: + /* We don't much care about the alignment of DST, but we want SRC + * to be 128-bit (16 byte) aligned so that we don't cross cache line + * boundaries on both loads and stores. */ + neg tmp2, src + ands tmp2, tmp2, #15 /* Bytes to reach alignment. */ + b.eq 2f + sub count, count, tmp2 + /* Move enough data to reach alignment; unlike memcpy, we have to + * be aware of the overlap, which means we can't move data twice. */ + tbz tmp2, #3, 1f + ldr tmp1, [src], #8 + str tmp1, [dst], #8 +1: + tbz tmp2, #2, 1f + ldr tmp1w, [src], #4 + str tmp1w, [dst], #4 +1: + tbz tmp2, #1, 1f + ldrh tmp1w, [src], #2 + strh tmp1w, [dst], #2 +1: + tbz tmp2, #0, 1f + ldrb tmp1w, [src], #1 + strb tmp1w, [dst], #1 +1: + + /* There may be less than 63 bytes to go now. */ + cmp count, #63 + b.le .Ltail63down +2: + subs count, count, #128 + b.ge .Lmov_body_large_down + /* Less than 128 bytes to move, so handle 64 here and then jump + * to the tail. */ + ldp A_l, A_h, [src] + ldp B_l, B_h, [src, #16] + ldp C_l, C_h, [src, #32] + ldp D_l, D_h, [src, #48] + stp A_l, A_h, [dst] + stp B_l, B_h, [dst, #16] + stp C_l, C_h, [dst, #32] + stp D_l, D_h, [dst, #48] + tst count, #0x3f + add src, src, #64 + add dst, dst, #64 + b.ne .Ltail63down + ret + + /* Critical loop. Start at a new cache line boundary. Assuming + * 64 bytes per line this ensures the entire loop is in one line. */ + .p2align 6 +.Lmov_body_large_down: + /* There are at least 128 bytes to move. */ + ldp A_l, A_h, [src, #0] + sub dst, dst, #16 /* Pre-bias. */ + ldp B_l, B_h, [src, #16] + ldp C_l, C_h, [src, #32] + ldp D_l, D_h, [src, #48]! /* src += 64 - Pre-bias. */ +1: + stp A_l, A_h, [dst, #16] + ldp A_l, A_h, [src, #16] + stp B_l, B_h, [dst, #32] + ldp B_l, B_h, [src, #32] + stp C_l, C_h, [dst, #48] + ldp C_l, C_h, [src, #48] + stp D_l, D_h, [dst, #64]! + ldp D_l, D_h, [src, #64]! + subs count, count, #64 + b.ge 1b + stp A_l, A_h, [dst, #16] + stp B_l, B_h, [dst, #32] + stp C_l, C_h, [dst, #48] + stp D_l, D_h, [dst, #64] + add src, src, #16 + add dst, dst, #64 + 16 + tst count, #0x3f + b.ne .Ltail63down + ret +END(memmove) diff --git a/libc/arch-arm64/generic/bionic/memset.S b/libc/arch-arm64/generic/bionic/memset.S new file mode 100644 index 000000000..4750fe3f1 --- /dev/null +++ b/libc/arch-arm64/generic/bionic/memset.S @@ -0,0 +1,236 @@ +/* Copyright (c) 2012, 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. +*/ + +/* Assumptions: + * + * ARMv8-a, AArch64 + * Unaligned accesses + * + */ + +#include + +/* By default we assume that the DC instruction can be used to zero + data blocks more efficiently. In some circumstances this might be + unsafe, for example in an asymmetric multiprocessor environment with + different DC clear lengths (neither the upper nor lower lengths are + safe to use). The feature can be disabled by defining DONT_USE_DC. + + If code may be run in a virtualized environment, then define + MAYBE_VIRT. This will cause the code to cache the system register + values rather than re-reading them each call. */ + +#define dstin x0 +#define val w1 +#define count x2 +#define tmp1 x3 +#define tmp1w w3 +#define tmp2 x4 +#define tmp2w w4 +#define zva_len_x x5 +#define zva_len w5 +#define zva_bits_x x6 + +#define A_l x7 +#define A_lw w7 +#define dst x8 +#define tmp3w w9 + +ENTRY(memset) + + mov dst, dstin /* Preserve return value. */ + ands A_lw, val, #255 +#ifndef DONT_USE_DC + b.eq .Lzero_mem +#endif + orr A_lw, A_lw, A_lw, lsl #8 + orr A_lw, A_lw, A_lw, lsl #16 + orr A_l, A_l, A_l, lsl #32 +.Ltail_maybe_long: + cmp count, #64 + b.ge .Lnot_short +.Ltail_maybe_tiny: + cmp count, #15 + b.le .Ltail15tiny +.Ltail63: + ands tmp1, count, #0x30 + b.eq .Ltail15 + add dst, dst, tmp1 + cmp tmp1w, #0x20 + b.eq 1f + b.lt 2f + stp A_l, A_l, [dst, #-48] +1: + stp A_l, A_l, [dst, #-32] +2: + stp A_l, A_l, [dst, #-16] + +.Ltail15: + and count, count, #15 + add dst, dst, count + stp A_l, A_l, [dst, #-16] /* Repeat some/all of last store. */ + ret + +.Ltail15tiny: + /* Set up to 15 bytes. Does not assume earlier memory + being set. */ + tbz count, #3, 1f + str A_l, [dst], #8 +1: + tbz count, #2, 1f + str A_lw, [dst], #4 +1: + tbz count, #1, 1f + strh A_lw, [dst], #2 +1: + tbz count, #0, 1f + strb A_lw, [dst] +1: + ret + + /* Critical loop. Start at a new cache line boundary. Assuming + * 64 bytes per line, this ensures the entire loop is in one line. */ + .p2align 6 +.Lnot_short: + neg tmp2, dst + ands tmp2, tmp2, #15 + b.eq 2f + /* Bring DST to 128-bit (16-byte) alignment. We know that there's + * more than that to set, so we simply store 16 bytes and advance by + * the amount required to reach alignment. */ + sub count, count, tmp2 + stp A_l, A_l, [dst] + add dst, dst, tmp2 + /* There may be less than 63 bytes to go now. */ + cmp count, #63 + b.le .Ltail63 +2: + sub dst, dst, #16 /* Pre-bias. */ + sub count, count, #64 +1: + stp A_l, A_l, [dst, #16] + stp A_l, A_l, [dst, #32] + stp A_l, A_l, [dst, #48] + stp A_l, A_l, [dst, #64]! + subs count, count, #64 + b.ge 1b + tst count, #0x3f + add dst, dst, #16 + b.ne .Ltail63 + ret + +#ifndef DONT_USE_DC + /* For zeroing memory, check to see if we can use the ZVA feature to + * zero entire 'cache' lines. */ +.Lzero_mem: + mov A_l, #0 + cmp count, #63 + b.le .Ltail_maybe_tiny + neg tmp2, dst + ands tmp2, tmp2, #15 + b.eq 1f + sub count, count, tmp2 + stp A_l, A_l, [dst] + add dst, dst, tmp2 + cmp count, #63 + b.le .Ltail63 +1: + /* For zeroing small amounts of memory, it's not worth setting up + * the line-clear code. */ + cmp count, #128 + b.lt .Lnot_short +#ifdef MAYBE_VIRT + /* For efficiency when virtualized, we cache the ZVA capability. */ + adrp tmp2, .Lcache_clear + ldr zva_len, [tmp2, #:lo12:.Lcache_clear] + tbnz zva_len, #31, .Lnot_short + cbnz zva_len, .Lzero_by_line + mrs tmp1, dczid_el0 + tbz tmp1, #4, 1f + /* ZVA not available. Remember this for next time. */ + mov zva_len, #~0 + str zva_len, [tmp2, #:lo12:.Lcache_clear] + b .Lnot_short +1: + mov tmp3w, #4 + and zva_len, tmp1w, #15 /* Safety: other bits reserved. */ + lsl zva_len, tmp3w, zva_len + str zva_len, [tmp2, #:lo12:.Lcache_clear] +#else + mrs tmp1, dczid_el0 + tbnz tmp1, #4, .Lnot_short + mov tmp3w, #4 + and zva_len, tmp1w, #15 /* Safety: other bits reserved. */ + lsl zva_len, tmp3w, zva_len +#endif + +.Lzero_by_line: + /* Compute how far we need to go to become suitably aligned. We're + * already at quad-word alignment. */ + cmp count, zva_len_x + b.lt .Lnot_short /* Not enough to reach alignment. */ + sub zva_bits_x, zva_len_x, #1 + neg tmp2, dst + ands tmp2, tmp2, zva_bits_x + b.eq 1f /* Already aligned. */ + /* Not aligned, check that there's enough to copy after alignment. */ + sub tmp1, count, tmp2 + cmp tmp1, #64 + ccmp tmp1, zva_len_x, #8, ge /* NZCV=0b1000 */ + b.lt .Lnot_short + /* We know that there's at least 64 bytes to zero and that it's safe + * to overrun by 64 bytes. */ + mov count, tmp1 +2: + stp A_l, A_l, [dst] + stp A_l, A_l, [dst, #16] + stp A_l, A_l, [dst, #32] + subs tmp2, tmp2, #64 + stp A_l, A_l, [dst, #48] + add dst, dst, #64 + b.ge 2b + /* We've overrun a bit, so adjust dst downwards. */ + add dst, dst, tmp2 +1: + sub count, count, zva_len_x +3: + dc zva, dst + add dst, dst, zva_len_x + subs count, count, zva_len_x + b.ge 3b + ands count, count, zva_bits_x + b.ne .Ltail_maybe_long + ret +END(memset) + +#ifdef MAYBE_VIRT + .bss + .p2align 2 +.Lcache_clear: + .space 4 +#endif +#endif /* DONT_USE_DC */ diff --git a/libc/arch-arm64/generic/bionic/strcmp.S b/libc/arch-arm64/generic/bionic/strcmp.S new file mode 100644 index 000000000..3cce47817 --- /dev/null +++ b/libc/arch-arm64/generic/bionic/strcmp.S @@ -0,0 +1,162 @@ +/* Copyright (c) 2012, 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. +*/ + +/* Assumptions: + * + * ARMv8-a, AArch64 + */ + +#include + +#define REP8_01 0x0101010101010101 +#define REP8_7f 0x7f7f7f7f7f7f7f7f +#define REP8_80 0x8080808080808080 + +/* Parameters and result. */ +#define src1 x0 +#define src2 x1 +#define result x0 + +/* Internal variables. */ +#define data1 x2 +#define data1w w2 +#define data2 x3 +#define data2w w3 +#define has_nul x4 +#define diff x5 +#define syndrome x6 +#define tmp1 x7 +#define tmp2 x8 +#define tmp3 x9 +#define zeroones x10 +#define pos x11 + + /* Start of performance-critical section -- one 64B cache line. */ +ENTRY(strcmp) + eor tmp1, src1, src2 + mov zeroones, #REP8_01 + tst tmp1, #7 + b.ne .Lmisaligned8 + ands tmp1, src1, #7 + b.ne .Lmutual_align + /* NUL detection works on the principle that (X - 1) & (~X) & 0x80 + (=> (X - 1) & ~(X | 0x7f)) is non-zero iff a byte is zero, and + can be done in parallel across the entire word. */ +.Lloop_aligned: + ldr data1, [src1], #8 + ldr data2, [src2], #8 +.Lstart_realigned: + sub tmp1, data1, zeroones + orr tmp2, data1, #REP8_7f + eor diff, data1, data2 /* Non-zero if differences found. */ + bic has_nul, tmp1, tmp2 /* Non-zero if NUL terminator. */ + orr syndrome, diff, has_nul + cbz syndrome, .Lloop_aligned + /* End of performance-critical section -- one 64B cache line. */ + +#ifndef __AARCH64EB__ + rev syndrome, syndrome + rev data1, data1 + /* The MS-non-zero bit of the syndrome marks either the first bit + that is different, or the top bit of the first zero byte. + Shifting left now will bring the critical information into the + top bits. */ + clz pos, syndrome + rev data2, data2 + 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 +#else + /* For big-endian we cannot use the trick with the syndrome value + as carry-propagation can corrupt the upper bits if the trailing + bytes in the string contain 0x01. */ + /* However, if there is no NUL byte in the dword, we can generate + the result directly. We can't just subtract the bytes as the + MSB might be significant. */ + cbnz has_nul, 1f + cmp data1, data2 + cset result, ne + cneg result, result, lo + ret +1: + /* Re-compute the NUL-byte detection, using a byte-reversed value. */ + rev tmp3, data1 + sub tmp1, tmp3, zeroones + orr tmp2, tmp3, #REP8_7f + bic has_nul, tmp1, tmp2 + rev has_nul, has_nul + orr syndrome, diff, has_nul + clz pos, syndrome + /* The MS-non-zero bit of the syndrome marks either the first bit + that is different, or the top bit of the first zero byte. + Shifting left now will bring the critical information into the + top bits. */ + 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 +#endif + +.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 preceed the start point. */ + bic src1, src1, #7 + bic src2, src2, #7 + 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 + orr data1, data1, tmp2 + orr data2, data2, tmp2 + b .Lstart_realigned + +.Lmisaligned8: + /* We can do better than this. */ + ldrb data1w, [src1], #1 + ldrb data2w, [src2], #1 + cmp data1w, #1 + ccmp data1w, data2w, #0, cs /* NZCV = 0b0000. */ + b.eq .Lmisaligned8 + sub result, data1, data2 + ret +END(strcmp) diff --git a/libc/arch-arm64/generic/bionic/strlen.S b/libc/arch-arm64/generic/bionic/strlen.S new file mode 100644 index 000000000..3bd980935 --- /dev/null +++ b/libc/arch-arm64/generic/bionic/strlen.S @@ -0,0 +1,126 @@ +/* Copyright (c) 2014, 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. +*/ + +/* Assumptions: + * + * ARMv8-a, AArch64 + */ + +#include + +/* Arguments and results. */ +#define srcin x0 +#define len x0 + +/* Locals and temporaries. */ +#define src x1 +#define data1 x2 +#define data2 x3 +#define data2a x4 +#define has_nul1 x5 +#define has_nul2 x6 +#define tmp1 x7 +#define tmp2 x8 +#define tmp3 x9 +#define tmp4 x10 +#define zeroones x11 +#define pos x12 + +#define REP8_01 0x0101010101010101 +#define REP8_7f 0x7f7f7f7f7f7f7f7f +#define REP8_80 0x8080808080808080 + + /* Start of critial section -- keep to one 64Byte cache line. */ +ENTRY(strlen) + mov zeroones, #REP8_01 + bic src, srcin, #15 + ands tmp1, srcin, #15 + b.ne .Lmisaligned + /* NUL detection works on the principle that (X - 1) & (~X) & 0x80 + (=> (X - 1) & ~(X | 0x7f)) is non-zero iff a byte is zero, and + can be done in parallel across the entire word. */ + /* The inner loop deals with two Dwords at a time. This has a + slightly higher start-up cost, but we should win quite quickly, + especially on cores with a high number of issue slots per + cycle, as we get much better parallelism out of the operations. */ +.Lloop: + ldp data1, data2, [src], #16 +.Lrealigned: + sub tmp1, data1, zeroones + orr tmp2, data1, #REP8_7f + sub tmp3, data2, zeroones + orr tmp4, data2, #REP8_7f + bic has_nul1, tmp1, tmp2 + bics has_nul2, tmp3, tmp4 + ccmp has_nul1, #0, #0, eq /* NZCV = 0000 */ + b.eq .Lloop + /* End of critical section -- keep to one 64Byte cache line. */ + + sub len, src, srcin + cbz has_nul1, .Lnul_in_data2 +#ifdef __AARCH64EB__ + mov data2, data1 +#endif + sub len, len, #8 + mov has_nul2, has_nul1 +.Lnul_in_data2: +#ifdef __AARCH64EB__ + /* For big-endian, carry propagation (if the final byte in the + string is 0x01) means we cannot use has_nul directly. The + easiest way to get the correct byte is to byte-swap the data + and calculate the syndrome a second time. */ + rev data2, data2 + sub tmp1, data2, zeroones + orr tmp2, data2, #REP8_7f + bic has_nul2, tmp1, tmp2 +#endif + sub len, len, #8 + rev has_nul2, has_nul2 + clz pos, has_nul2 + add len, len, pos, lsr #3 /* Bits to bytes. */ + ret + +.Lmisaligned: + cmp tmp1, #8 + neg tmp1, tmp1 + ldp data1, data2, [src], #16 + lsl tmp1, tmp1, #3 /* Bytes beyond alignment -> bits. */ + 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 + orr data1, data1, tmp2 + orr data2a, data2, tmp2 + csinv data1, data1, xzr, le + csel data2, data2, data2a, le + b .Lrealigned + +END(strlen) diff --git a/libc/arch-arm64/generic/bionic/strncmp.S b/libc/arch-arm64/generic/bionic/strncmp.S new file mode 100644 index 000000000..267f663ed --- /dev/null +++ b/libc/arch-arm64/generic/bionic/strncmp.S @@ -0,0 +1,217 @@ +/* Copyright (c) 2014, 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. +*/ + +/* Assumptions: + * + * ARMv8-a, AArch64 + */ + +#include + +#define REP8_01 0x0101010101010101 +#define REP8_7f 0x7f7f7f7f7f7f7f7f +#define REP8_80 0x8080808080808080 + +/* 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 syndrome x7 +#define tmp1 x8 +#define tmp2 x9 +#define tmp3 x10 +#define zeroones x11 +#define pos x12 +#define limit_wd x13 +#define mask x14 +#define endloop x15 + + .text + .p2align 6 + .rep 7 + nop /* Pad so that the loop below fits a cache line. */ + .endr +ENTRY(strncmp) + cbz limit, .Lret0 + eor tmp1, src1, src2 + mov zeroones, #REP8_01 + tst tmp1, #7 + b.ne .Lmisaligned8 + ands tmp1, src1, #7 + b.ne .Lmutual_align + /* Calculate the number of full and partial words -1. */ + sub limit_wd, limit, #1 /* limit != 0, so no underflow. */ + lsr limit_wd, limit_wd, #3 /* Convert to Dwords. */ + + /* NUL detection works on the principle that (X - 1) & (~X) & 0x80 + (=> (X - 1) & ~(X | 0x7f)) is non-zero iff a byte is zero, and + can be done in parallel across the entire word. */ + /* 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 + sub tmp1, data1, zeroones + orr tmp2, data1, #REP8_7f + eor diff, data1, data2 /* Non-zero if differences found. */ + csinv endloop, diff, xzr, pl /* Last Dword or differences. */ + bics has_nul, tmp1, tmp2 /* Non-zero if NUL terminator. */ + ccmp endloop, #0, #0, eq + b.eq .Lloop_aligned + /* End of performance-critical section -- one 64B cache line. */ + + /* Not reached the limit, must have found the end or a diff. */ + tbz limit_wd, #63, .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 + + /* Make sure that the NUL byte is marked in the syndrome. */ + orr has_nul, has_nul, mask + +.Lnot_limit: + orr syndrome, diff, has_nul + +#ifndef __AARCH64EB__ + rev syndrome, syndrome + rev data1, data1 + /* The MS-non-zero bit of the syndrome marks either the first bit + that is different, or the top bit of the first zero byte. + Shifting left now will bring the critical information into the + top bits. */ + clz pos, syndrome + rev data2, data2 + 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 +#else + /* For big-endian we cannot use the trick with the syndrome value + as carry-propagation can corrupt the upper bits if the trailing + bytes in the string contain 0x01. */ + /* However, if there is no NUL byte in the dword, we can generate + the result directly. We can't just subtract the bytes as the + MSB might be significant. */ + cbnz has_nul, 1f + cmp data1, data2 + cset result, ne + cneg result, result, lo + ret +1: + /* Re-compute the NUL-byte detection, using a byte-reversed value. */ + rev tmp3, data1 + sub tmp1, tmp3, zeroones + orr tmp2, tmp3, #REP8_7f + bic has_nul, tmp1, tmp2 + rev has_nul, has_nul + orr syndrome, diff, has_nul + clz pos, syndrome + /* The MS-non-zero bit of the syndrome marks either the first bit + that is different, or the top bit of the first zero byte. + Shifting left now will bring the critical information into the + top bits. */ + 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 +#endif + +.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. + We also need to adjust the limit calculations, but without + overflowing if the limit is near ULONG_MAX. */ + bic src1, src1, #7 + bic src2, src2, #7 + ldr data1, [src1], #8 + neg tmp3, tmp1, lsl #3 /* 64 - bits(bytes beyond align). */ + ldr data2, [src2], #8 + mov tmp2, #~0 + sub limit_wd, limit, #1 /* limit != 0, so no underflow. */ +#ifdef __AARCH64EB__ + /* Big-endian. Early bytes are at MSB. */ + lsl tmp2, tmp2, tmp3 /* Shift (tmp1 & 63). */ +#else + /* Little-endian. Early bytes are at LSB. */ + lsr tmp2, tmp2, tmp3 /* Shift (tmp1 & 63). */ +#endif + and tmp3, limit_wd, #7 + lsr limit_wd, limit_wd, #3 + /* Adjust the limit. Only low 3 bits used, so overflow irrelevant. */ + add limit, limit, tmp1 + add tmp3, tmp3, tmp1 + orr data1, data1, tmp2 + orr data2, data2, tmp2 + add limit_wd, limit_wd, tmp3, lsr #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, #1, #0, cs /* NZCV = 0b0000. */ + ccmp data1w, data2w, #0, cs /* NZCV = 0b0000. */ + b.eq 1b + sub result, data1, data2 + ret +END(strncmp) diff --git a/libc/arch-arm64/generic/bionic/strnlen.S b/libc/arch-arm64/generic/bionic/strnlen.S new file mode 100644 index 000000000..0ad446e4f --- /dev/null +++ b/libc/arch-arm64/generic/bionic/strnlen.S @@ -0,0 +1,174 @@ +/* Copyright (c) 2014, 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. +*/ + +/* Assumptions: + * + * ARMv8-a, AArch64 + */ + +#include + +/* Arguments and results. */ +#define srcin x0 +#define len x0 +#define limit x1 + +/* Locals and temporaries. */ +#define src x2 +#define data1 x3 +#define data2 x4 +#define data2a x5 +#define has_nul1 x6 +#define has_nul2 x7 +#define tmp1 x8 +#define tmp2 x9 +#define tmp3 x10 +#define tmp4 x11 +#define zeroones x12 +#define pos x13 +#define limit_wd x14 + +#define REP8_01 0x0101010101010101 +#define REP8_7f 0x7f7f7f7f7f7f7f7f +#define REP8_80 0x8080808080808080 + + .text + .p2align 6 +.Lstart: + /* Pre-pad to ensure critical loop begins an icache line. */ + .rep 7 + nop + .endr + /* Put this code here to avoid wasting more space with pre-padding. */ +.Lhit_limit: + mov len, limit + ret + +ENTRY(strnlen) + cbz limit, .Lhit_limit + mov zeroones, #REP8_01 + bic src, srcin, #15 + ands tmp1, srcin, #15 + b.ne .Lmisaligned + /* Calculate the number of full and partial words -1. */ + sub limit_wd, limit, #1 /* Limit != 0, so no underflow. */ + lsr limit_wd, limit_wd, #4 /* Convert to Qwords. */ + + /* NUL detection works on the principle that (X - 1) & (~X) & 0x80 + (=> (X - 1) & ~(X | 0x7f)) is non-zero iff a byte is zero, and + can be done in parallel across the entire word. */ + /* The inner loop deals with two Dwords at a time. This has a + slightly higher start-up cost, but we should win quite quickly, + especially on cores with a high number of issue slots per + cycle, as we get much better parallelism out of the operations. */ + + /* Start of critial section -- keep to one 64Byte cache line. */ +.Lloop: + ldp data1, data2, [src], #16 +.Lrealigned: + sub tmp1, data1, zeroones + orr tmp2, data1, #REP8_7f + sub tmp3, data2, zeroones + orr tmp4, data2, #REP8_7f + bic has_nul1, tmp1, tmp2 + bic has_nul2, tmp3, tmp4 + subs limit_wd, limit_wd, #1 + orr tmp1, has_nul1, has_nul2 + ccmp tmp1, #0, #0, pl /* NZCV = 0000 */ + b.eq .Lloop + /* End of critical section -- keep to one 64Byte cache line. */ + + orr tmp1, has_nul1, has_nul2 + cbz tmp1, .Lhit_limit /* No null in final Qword. */ + + /* We know there's a null in the final Qword. The easiest thing + to do now is work out the length of the string and return + MIN (len, limit). */ + + sub len, src, srcin + cbz has_nul1, .Lnul_in_data2 +#ifdef __AARCH64EB__ + mov data2, data1 +#endif + sub len, len, #8 + mov has_nul2, has_nul1 +.Lnul_in_data2: +#ifdef __AARCH64EB__ + /* For big-endian, carry propagation (if the final byte in the + string is 0x01) means we cannot use has_nul directly. The + easiest way to get the correct byte is to byte-swap the data + and calculate the syndrome a second time. */ + rev data2, data2 + sub tmp1, data2, zeroones + orr tmp2, data2, #REP8_7f + bic has_nul2, tmp1, tmp2 +#endif + sub len, len, #8 + rev has_nul2, has_nul2 + clz pos, has_nul2 + add len, len, pos, lsr #3 /* Bits to bytes. */ + cmp len, limit + csel len, len, limit, ls /* Return the lower value. */ + ret + +.Lmisaligned: + /* Deal with a partial first word. + We're doing two things in parallel here; + 1) Calculate the number of words (but avoiding overflow if + limit is near ULONG_MAX) - to do this we need to work out + limit + tmp1 - 1 as a 65-bit value before shifting it; + 2) Load and mask the initial data words - we force the bytes + before the ones we are interested in to 0xff - this ensures + early bytes will not hit any zero detection. */ + sub limit_wd, limit, #1 + neg tmp4, tmp1 + cmp tmp1, #8 + + and tmp3, limit_wd, #15 + lsr limit_wd, limit_wd, #4 + mov tmp2, #~0 + + ldp data1, data2, [src], #16 + lsl tmp4, tmp4, #3 /* Bytes beyond alignment -> bits. */ + add tmp3, tmp3, tmp1 + +#ifdef __AARCH64EB__ + /* Big-endian. Early bytes are at MSB. */ + lsl tmp2, tmp2, tmp4 /* Shift (tmp1 & 63). */ +#else + /* Little-endian. Early bytes are at LSB. */ + lsr tmp2, tmp2, tmp4 /* Shift (tmp1 & 63). */ +#endif + add limit_wd, limit_wd, tmp3, lsr #4 + + orr data1, data1, tmp2 + orr data2a, data2, tmp2 + + csinv data1, data1, xzr, le + csel data2, data2, data2a, le + b .Lrealigned +END(strnlen) diff --git a/libc/arch-arm64/generic/generic.mk b/libc/arch-arm64/generic/generic.mk new file mode 100644 index 000000000..14920a695 --- /dev/null +++ b/libc/arch-arm64/generic/generic.mk @@ -0,0 +1,9 @@ +libc_bionic_src_files_arm64 += \ + arch-arm64/generic/bionic/memcmp.S \ + arch-arm64/generic/bionic/memcpy.S \ + arch-arm64/generic/bionic/memmove.S \ + arch-arm64/generic/bionic/memset.S \ + arch-arm64/generic/bionic/strcmp.S \ + arch-arm64/generic/bionic/strlen.S \ + arch-arm64/generic/bionic/strncmp.S \ + arch-arm64/generic/bionic/strnlen.S \