diff options
Diffstat (limited to 'sysdeps/aarch64/memset.S')
| -rw-r--r-- | sysdeps/aarch64/memset.S | 194 |
1 files changed, 83 insertions, 111 deletions
diff --git a/sysdeps/aarch64/memset.S b/sysdeps/aarch64/memset.S index 7ef77ee8c9..b76dde1557 100644 --- a/sysdeps/aarch64/memset.S +++ b/sysdeps/aarch64/memset.S @@ -1,4 +1,5 @@ -/* Copyright (C) 2012-2024 Free Software Foundation, Inc. +/* Generic optimized memset using SIMD. + Copyright (C) 2012-2024 Free Software Foundation, Inc. This file is part of the GNU C Library. @@ -17,7 +18,6 @@ <https://www.gnu.org/licenses/>. */ #include <sysdep.h> -#include "memset-reg.h" #ifndef MEMSET # define MEMSET memset @@ -25,130 +25,131 @@ /* Assumptions: * - * ARMv8-a, AArch64, unaligned accesses + * ARMv8-a, AArch64, Advanced SIMD, unaligned accesses. * */ -ENTRY (MEMSET) +#define dstin x0 +#define valw w1 +#define count x2 +#define dst x3 +#define dstend x4 +#define zva_val x5 +#define off x3 +#define dstend2 x5 +ENTRY (MEMSET) PTR_ARG (0) SIZE_ARG (2) dup v0.16B, valw + cmp count, 16 + b.lo L(set_small) + add dstend, dstin, count + cmp count, 64 + b.hs L(set_128) - cmp count, 96 - b.hi L(set_long) - cmp count, 16 - b.hs L(set_medium) - mov val, v0.D[0] + /* Set 16..63 bytes. */ + mov off, 16 + and off, off, count, lsr 1 + sub dstend2, dstend, off + str q0, [dstin] + str q0, [dstin, off] + str q0, [dstend2, -16] + str q0, [dstend, -16] + ret + .p2align 4 /* Set 0..15 bytes. */ - tbz count, 3, 1f - str val, [dstin] - str val, [dstend, -8] - ret - nop -1: tbz count, 2, 2f - str valw, [dstin] - str valw, [dstend, -4] +L(set_small): + add dstend, dstin, count + cmp count, 4 + b.lo 2f + lsr off, count, 3 + sub dstend2, dstend, off, lsl 2 + str s0, [dstin] + str s0, [dstin, off, lsl 2] + str s0, [dstend2, -4] + str s0, [dstend, -4] ret + + /* Set 0..3 bytes. */ 2: cbz count, 3f + lsr off, count, 1 strb valw, [dstin] - tbz count, 1, 3f - strh valw, [dstend, -2] + strb valw, [dstin, off] + strb valw, [dstend, -1] 3: ret - /* Set 17..96 bytes. */ -L(set_medium): - str q0, [dstin] - tbnz count, 6, L(set96) - str q0, [dstend, -16] - tbz count, 5, 1f - str q0, [dstin, 16] - str q0, [dstend, -32] -1: ret - .p2align 4 - /* Set 64..96 bytes. Write 64 bytes from the start and - 32 bytes from the end. */ -L(set96): - str q0, [dstin, 16] +L(set_128): + bic dst, dstin, 15 + cmp count, 128 + b.hi L(set_long) + stp q0, q0, [dstin] stp q0, q0, [dstin, 32] + stp q0, q0, [dstend, -64] stp q0, q0, [dstend, -32] ret - .p2align 3 - nop + .p2align 4 L(set_long): - and valw, valw, 255 - bic dst, dstin, 15 str q0, [dstin] - cmp count, 256 - ccmp valw, 0, 0, cs - b.eq L(try_zva) -L(no_zva): - sub count, dstend, dst /* Count is 16 too large. */ - sub dst, dst, 16 /* Dst is biased by -32. */ - sub count, count, 64 + 16 /* Adjust count and bias for loop. */ -1: stp q0, q0, [dst, 32] - stp q0, q0, [dst, 64]! -L(tail64): - subs count, count, 64 - b.hi 1b -2: stp q0, q0, [dstend, -64] + str q0, [dst, 16] + tst valw, 255 + b.ne L(no_zva) +#ifndef ZVA64_ONLY + mrs zva_val, dczid_el0 + and zva_val, zva_val, 31 + cmp zva_val, 4 /* ZVA size is 64 bytes. */ + b.ne L(zva_128) +#endif + stp q0, q0, [dst, 32] + bic dst, dstin, 63 + sub count, dstend, dst /* Count is now 64 too large. */ + sub count, count, 64 + 64 /* Adjust count and bias for loop. */ + + /* Write last bytes before ZVA loop. */ + stp q0, q0, [dstend, -64] stp q0, q0, [dstend, -32] + + .p2align 4 +L(zva64_loop): + add dst, dst, 64 + dc zva, dst + subs count, count, 64 + b.hi L(zva64_loop) ret -L(try_zva): -#ifndef ZVA64_ONLY .p2align 3 - mrs tmp1, dczid_el0 - tbnz tmp1w, 4, L(no_zva) - and tmp1w, tmp1w, 15 - cmp tmp1w, 4 /* ZVA size is 64 bytes. */ - b.ne L(zva_128) - nop -#endif - /* Write the first and last 64 byte aligned block using stp rather - than using DC ZVA. This is faster on some cores. - */ - .p2align 4 -L(zva_64): - str q0, [dst, 16] +L(no_zva): + sub count, dstend, dst /* Count is 32 too large. */ + sub count, count, 64 + 32 /* Adjust count and bias for loop. */ +L(no_zva_loop): stp q0, q0, [dst, 32] - bic dst, dst, 63 stp q0, q0, [dst, 64] - stp q0, q0, [dst, 96] - sub count, dstend, dst /* Count is now 128 too large. */ - sub count, count, 128+64+64 /* Adjust count and bias for loop. */ - add dst, dst, 128 -1: dc zva, dst add dst, dst, 64 subs count, count, 64 - b.hi 1b - stp q0, q0, [dst, 0] - stp q0, q0, [dst, 32] + b.hi L(no_zva_loop) stp q0, q0, [dstend, -64] stp q0, q0, [dstend, -32] ret #ifndef ZVA64_ONLY - .p2align 3 + .p2align 4 L(zva_128): - cmp tmp1w, 5 /* ZVA size is 128 bytes. */ - b.ne L(zva_other) + cmp zva_val, 5 /* ZVA size is 128 bytes. */ + b.ne L(no_zva) - str q0, [dst, 16] stp q0, q0, [dst, 32] stp q0, q0, [dst, 64] stp q0, q0, [dst, 96] bic dst, dst, 127 sub count, dstend, dst /* Count is now 128 too large. */ - sub count, count, 128+128 /* Adjust count and bias for loop. */ - add dst, dst, 128 -1: dc zva, dst - add dst, dst, 128 + sub count, count, 128 + 128 /* Adjust count and bias for loop. */ +1: add dst, dst, 128 + dc zva, dst subs count, count, 128 b.hi 1b stp q0, q0, [dstend, -128] @@ -156,35 +157,6 @@ L(zva_128): stp q0, q0, [dstend, -64] stp q0, q0, [dstend, -32] ret - -L(zva_other): - mov tmp2w, 4 - lsl zva_lenw, tmp2w, tmp1w - add tmp1, zva_len, 64 /* Max alignment bytes written. */ - cmp count, tmp1 - blo L(no_zva) - - sub tmp2, zva_len, 1 - add tmp1, dst, zva_len - add dst, dst, 16 - subs count, tmp1, dst /* Actual alignment bytes to write. */ - bic tmp1, tmp1, tmp2 /* Aligned dc zva start address. */ - beq 2f -1: stp q0, q0, [dst], 64 - stp q0, q0, [dst, -32] - subs count, count, 64 - b.hi 1b -2: mov dst, tmp1 - sub count, dstend, tmp1 /* Remaining bytes to write. */ - subs count, count, zva_len - b.lo 4f -3: dc zva, dst - add dst, dst, zva_len - subs count, count, zva_len - b.hs 3b -4: add count, count, zva_len - sub dst, dst, 32 /* Bias dst for tail loop. */ - b L(tail64) #endif END (MEMSET) |