diff options
author | Steve Ellcey <sellcey@caviumnetworks.com> | 2017-05-24 16:46:48 -0700 |
---|---|---|
committer | Steve Ellcey <sellcey@caviumnetworks.com> | 2017-05-24 16:46:48 -0700 |
commit | 6a2c695266fab34cc057256d1b33d2268183f00e (patch) | |
tree | 320796a70561a5459b120bc2f99b4398dcc4970f /sysdeps/aarch64/multiarch/memcpy_thunderx.S | |
parent | 6edbe546d6ac243a5e3c2610853f2da53f0507b4 (diff) | |
download | glibc-6a2c695266fab34cc057256d1b33d2268183f00e.tar.gz glibc-6a2c695266fab34cc057256d1b33d2268183f00e.tar.xz glibc-6a2c695266fab34cc057256d1b33d2268183f00e.zip |
aarch64: Thunderx specific memcpy and memmove
* sysdeps/aarch64/memcpy.S (MEMMOVE, MEMCPY): New macros. (memmove): Use MEMMOVE for name. (memcpy): Use MEMCPY for name. Change internal labels to external labels. * sysdeps/aarch64/multiarch/Makefile: New file. * sysdeps/aarch64/multiarch/ifunc-impl-list.c: Likewise. * sysdeps/aarch64/multiarch/init-arch.h: Likewise. * sysdeps/aarch64/multiarch/memcpy.c: Likewise. * sysdeps/aarch64/multiarch/memcpy_generic.S: Likewise. * sysdeps/aarch64/multiarch/memcpy_thunderx.S: Likewise. * sysdeps/aarch64/multiarch/memmove.c: Likewise.
Diffstat (limited to 'sysdeps/aarch64/multiarch/memcpy_thunderx.S')
-rw-r--r-- | sysdeps/aarch64/multiarch/memcpy_thunderx.S | 326 |
1 files changed, 326 insertions, 0 deletions
diff --git a/sysdeps/aarch64/multiarch/memcpy_thunderx.S b/sysdeps/aarch64/multiarch/memcpy_thunderx.S new file mode 100644 index 0000000000..5ac9e341bb --- /dev/null +++ b/sysdeps/aarch64/multiarch/memcpy_thunderx.S @@ -0,0 +1,326 @@ +/* A Thunderx Optimized memcpy implementation for AARCH64. + Copyright (C) 2017 Free Software Foundation, Inc. + + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +/* The actual code in this memcpy and memmove should be identical to the + generic version except for the code under '#ifdef THUNDERX'. This is + to make is easier to keep this version and the generic version in sync + for changes that are not specific to thunderx. */ + +#include <sysdep.h> + +/* Assumptions: + * + * ARMv8-a, AArch64, unaligned accesses. + * + */ + +#define dstin x0 +#define src x1 +#define count x2 +#define dst x3 +#define srcend x4 +#define dstend x5 +#define A_l x6 +#define A_lw w6 +#define A_h x7 +#define A_hw w7 +#define B_l x8 +#define B_lw w8 +#define B_h x9 +#define C_l x10 +#define C_h x11 +#define D_l x12 +#define D_h x13 +#define E_l src +#define E_h count +#define F_l srcend +#define F_h dst +#define G_l count +#define G_h dst +#define tmp1 x14 + +/* Copies are split into 3 main cases: small copies of up to 16 bytes, + medium copies of 17..96 bytes which are fully unrolled. Large copies + of more than 96 bytes align the destination and use an unrolled loop + processing 64 bytes per iteration. + In order to share code with memmove, small and medium copies read all + data before writing, allowing any kind of overlap. So small, medium + and large backwards memmoves are handled by falling through into memcpy. + Overlapping large forward memmoves use a loop that copies backwards. +*/ + +#ifndef MEMMOVE +# define MEMMOVE memmove +#endif +#ifndef MEMCPY +# define MEMCPY memcpy +#endif + +#if IS_IN (libc) + +# undef MEMCPY +# define MEMCPY __memcpy_thunderx +# undef MEMMOVE +# define MEMMOVE __memmove_thunderx +# define USE_THUNDERX + +ENTRY_ALIGN (MEMMOVE, 6) + + DELOUSE (0) + DELOUSE (1) + DELOUSE (2) + + sub tmp1, dstin, src + cmp count, 96 + ccmp tmp1, count, 2, hi + b.lo L(move_long) + + /* Common case falls through into memcpy. */ +END (MEMMOVE) +libc_hidden_builtin_def (MEMMOVE) +ENTRY (MEMCPY) + + DELOUSE (0) + DELOUSE (1) + DELOUSE (2) + + prfm PLDL1KEEP, [src] + add srcend, src, count + add dstend, dstin, count + cmp count, 16 + b.ls L(copy16) + cmp count, 96 + b.hi L(copy_long) + + /* Medium copies: 17..96 bytes. */ + sub tmp1, count, 1 + ldp A_l, A_h, [src] + tbnz tmp1, 6, L(copy96) + ldp D_l, D_h, [srcend, -16] + tbz tmp1, 5, 1f + ldp B_l, B_h, [src, 16] + ldp C_l, C_h, [srcend, -32] + stp B_l, B_h, [dstin, 16] + stp C_l, C_h, [dstend, -32] +1: + stp A_l, A_h, [dstin] + stp D_l, D_h, [dstend, -16] + ret + + .p2align 4 + /* Small copies: 0..16 bytes. */ +L(copy16): + cmp count, 8 + b.lo 1f + ldr A_l, [src] + ldr A_h, [srcend, -8] + str A_l, [dstin] + str A_h, [dstend, -8] + ret + .p2align 4 +1: + tbz count, 2, 1f + ldr A_lw, [src] + ldr A_hw, [srcend, -4] + str A_lw, [dstin] + str A_hw, [dstend, -4] + ret + + /* Copy 0..3 bytes. Use a branchless sequence that copies the same + byte 3 times if count==1, or the 2nd byte twice if count==2. */ +1: + cbz count, 2f + lsr tmp1, count, 1 + ldrb A_lw, [src] + ldrb A_hw, [srcend, -1] + ldrb B_lw, [src, tmp1] + strb A_lw, [dstin] + strb B_lw, [dstin, tmp1] + strb A_hw, [dstend, -1] +2: ret + + .p2align 4 + /* Copy 64..96 bytes. Copy 64 bytes from the start and + 32 bytes from the end. */ +L(copy96): + ldp B_l, B_h, [src, 16] + ldp C_l, C_h, [src, 32] + ldp D_l, D_h, [src, 48] + ldp E_l, E_h, [srcend, -32] + ldp F_l, F_h, [srcend, -16] + stp A_l, A_h, [dstin] + stp B_l, B_h, [dstin, 16] + stp C_l, C_h, [dstin, 32] + stp D_l, D_h, [dstin, 48] + stp E_l, E_h, [dstend, -32] + stp F_l, F_h, [dstend, -16] + ret + + /* Align DST to 16 byte alignment so that we don't cross cache line + boundaries on both loads and stores. There are at least 96 bytes + to copy, so copy 16 bytes unaligned and then align. The loop + copies 64 bytes per iteration and prefetches one iteration ahead. */ + + .p2align 4 +L(copy_long): + +# ifdef USE_THUNDERX + + /* On thunderx, large memcpy's are helped by software prefetching. + This loop is identical to the one below it but with prefetching + instructions included. For loops that are less than 32768 bytes, + the prefetching does not help and slow the code down so we only + use the prefetching loop for the largest memcpys. */ + + cmp count, #32768 + b.lo L(copy_long_without_prefetch) + and tmp1, dstin, 15 + bic dst, dstin, 15 + ldp D_l, D_h, [src] + sub src, src, tmp1 + prfm pldl1strm, [src, 384] + add count, count, tmp1 /* Count is now 16 too large. */ + ldp A_l, A_h, [src, 16] + stp D_l, D_h, [dstin] + ldp B_l, B_h, [src, 32] + ldp C_l, C_h, [src, 48] + ldp D_l, D_h, [src, 64]! + subs count, count, 128 + 16 /* Test and readjust count. */ + +L(prefetch_loop64): + tbz src, #6, 1f + prfm pldl1strm, [src, 512] +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.hi L(prefetch_loop64) + b L(last64) + +L(copy_long_without_prefetch): +# endif + + and tmp1, dstin, 15 + bic dst, dstin, 15 + ldp D_l, D_h, [src] + sub src, src, tmp1 + add count, count, tmp1 /* Count is now 16 too large. */ + ldp A_l, A_h, [src, 16] + stp D_l, D_h, [dstin] + ldp B_l, B_h, [src, 32] + ldp C_l, C_h, [src, 48] + ldp D_l, D_h, [src, 64]! + subs count, count, 128 + 16 /* Test and readjust count. */ + b.ls L(last64) +L(loop64): + 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.hi L(loop64) + + /* Write the last full set of 64 bytes. The remainder is at most 64 + bytes, so it is safe to always copy 64 bytes from the end even if + there is just 1 byte left. */ +L(last64): + ldp E_l, E_h, [srcend, -64] + stp A_l, A_h, [dst, 16] + ldp A_l, A_h, [srcend, -48] + stp B_l, B_h, [dst, 32] + ldp B_l, B_h, [srcend, -32] + stp C_l, C_h, [dst, 48] + ldp C_l, C_h, [srcend, -16] + stp D_l, D_h, [dst, 64] + stp E_l, E_h, [dstend, -64] + stp A_l, A_h, [dstend, -48] + stp B_l, B_h, [dstend, -32] + stp C_l, C_h, [dstend, -16] + ret + + .p2align 4 +L(move_long): + cbz tmp1, 3f + + add srcend, src, count + add dstend, dstin, count + + /* Align dstend to 16 byte alignment so that we don't cross cache line + boundaries on both loads and stores. There are at least 96 bytes + to copy, so copy 16 bytes unaligned and then align. The loop + copies 64 bytes per iteration and prefetches one iteration ahead. */ + + and tmp1, dstend, 15 + ldp D_l, D_h, [srcend, -16] + sub srcend, srcend, tmp1 + sub count, count, tmp1 + ldp A_l, A_h, [srcend, -16] + stp D_l, D_h, [dstend, -16] + ldp B_l, B_h, [srcend, -32] + ldp C_l, C_h, [srcend, -48] + ldp D_l, D_h, [srcend, -64]! + sub dstend, dstend, tmp1 + subs count, count, 128 + b.ls 2f + + nop +1: + stp A_l, A_h, [dstend, -16] + ldp A_l, A_h, [srcend, -16] + stp B_l, B_h, [dstend, -32] + ldp B_l, B_h, [srcend, -32] + stp C_l, C_h, [dstend, -48] + ldp C_l, C_h, [srcend, -48] + stp D_l, D_h, [dstend, -64]! + ldp D_l, D_h, [srcend, -64]! + subs count, count, 64 + b.hi 1b + + /* Write the last full set of 64 bytes. The remainder is at most 64 + bytes, so it is safe to always copy 64 bytes from the start even if + there is just 1 byte left. */ +2: + ldp G_l, G_h, [src, 48] + stp A_l, A_h, [dstend, -16] + ldp A_l, A_h, [src, 32] + stp B_l, B_h, [dstend, -32] + ldp B_l, B_h, [src, 16] + stp C_l, C_h, [dstend, -48] + ldp C_l, C_h, [src] + stp D_l, D_h, [dstend, -64] + stp G_l, G_h, [dstin, 48] + stp A_l, A_h, [dstin, 32] + stp B_l, B_h, [dstin, 16] + stp C_l, C_h, [dstin] +3: ret + +END (MEMCPY) +libc_hidden_builtin_def (MEMCPY) + +#endif |