diff options
Diffstat (limited to 'libc/ports/sysdeps/arm/armv7/multiarch/memcpy_impl.S')
| -rw-r--r-- | libc/ports/sysdeps/arm/armv7/multiarch/memcpy_impl.S | 642 |
1 files changed, 642 insertions, 0 deletions
diff --git a/libc/ports/sysdeps/arm/armv7/multiarch/memcpy_impl.S b/libc/ports/sysdeps/arm/armv7/multiarch/memcpy_impl.S new file mode 100644 index 000000000..f83276a70 --- /dev/null +++ b/libc/ports/sysdeps/arm/armv7/multiarch/memcpy_impl.S @@ -0,0 +1,642 @@ +/* NEON/VFP/ARM version of memcpy optimized for Cortex-A15. + Copyright (C) 2013 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/>. + + This memcpy routine is optimised for Cortex-A15 cores and takes advantage + of VFP or NEON when built with the appropriate flags. + + Assumptions: + + ARMv6 (ARMv7-a if using Neon) + ARM state + Unaligned accesses + LDRD/STRD support unaligned word accesses + + */ + +/* Thumb cannot encode negative immediate offsets in memory operations. */ +#ifndef NO_THUMB +#define NO_THUMB +#endif +#include <sysdep.h> + + .syntax unified + /* This implementation requires ARM state. */ + .arm + +#ifdef MEMCPY_NEON + + .fpu neon + .arch armv7-a +# define FRAME_SIZE 4 +# define USE_VFP +# define USE_NEON + +#elif defined (MEMCPY_VFP) + + .arch armv6 + .fpu vfpv2 +# define FRAME_SIZE 32 +# define USE_VFP + +#else + .arch armv6 +# define FRAME_SIZE 32 + +#endif + +#define ALIGN(addr, align) addr:align + +#define INSN_SIZE 4 + +/* Call parameters. */ +#define dstin r0 +#define src r1 +#define count r2 + +/* Locals. */ +#define tmp1 r3 +#define dst ip +#define tmp2 r10 + +#ifndef USE_NEON +/* For bulk copies using GP registers. */ +#define A_l r2 /* Call-clobbered. */ +#define A_h r3 /* Call-clobbered. */ +#define B_l r4 +#define B_h r5 +#define C_l r6 +#define C_h r7 +#define D_l r8 +#define D_h r9 +#endif + +/* Number of lines ahead to pre-fetch data. If you change this the code + below will need adjustment to compensate. */ + +#define prefetch_lines 5 + +#ifdef USE_VFP + .macro cpy_line_vfp vreg, base + vstr \vreg, [dst, #\base] + vldr \vreg, [src, #\base] + vstr d0, [dst, #\base + 8] + vldr d0, [src, #\base + 8] + vstr d1, [dst, #\base + 16] + vldr d1, [src, #\base + 16] + vstr d2, [dst, #\base + 24] + vldr d2, [src, #\base + 24] + vstr \vreg, [dst, #\base + 32] + vldr \vreg, [src, #\base + prefetch_lines * 64 - 32] + vstr d0, [dst, #\base + 40] + vldr d0, [src, #\base + 40] + vstr d1, [dst, #\base + 48] + vldr d1, [src, #\base + 48] + vstr d2, [dst, #\base + 56] + vldr d2, [src, #\base + 56] + .endm + + .macro cpy_tail_vfp vreg, base + vstr \vreg, [dst, #\base] + vldr \vreg, [src, #\base] + vstr d0, [dst, #\base + 8] + vldr d0, [src, #\base + 8] + vstr d1, [dst, #\base + 16] + vldr d1, [src, #\base + 16] + vstr d2, [dst, #\base + 24] + vldr d2, [src, #\base + 24] + vstr \vreg, [dst, #\base + 32] + vstr d0, [dst, #\base + 40] + vldr d0, [src, #\base + 40] + vstr d1, [dst, #\base + 48] + vldr d1, [src, #\base + 48] + vstr d2, [dst, #\base + 56] + vldr d2, [src, #\base + 56] + .endm +#endif + + .p2align 6 +ENTRY(memcpy) + + mov dst, dstin /* Preserve dstin, we need to return it. */ + cmp count, #64 + bge .Lcpy_not_short + /* Deal with small copies quickly by dropping straight into the + exit block. */ + +.Ltail63unaligned: +#ifdef USE_NEON + and tmp1, count, #0x38 + rsb tmp1, tmp1, #(56 - PC_OFS + INSN_SIZE) + add pc, pc, tmp1 + vld1.8 {d0}, [src]! /* 14 words to go. */ + vst1.8 {d0}, [dst]! + vld1.8 {d0}, [src]! /* 12 words to go. */ + vst1.8 {d0}, [dst]! + vld1.8 {d0}, [src]! /* 10 words to go. */ + vst1.8 {d0}, [dst]! + vld1.8 {d0}, [src]! /* 8 words to go. */ + vst1.8 {d0}, [dst]! + vld1.8 {d0}, [src]! /* 6 words to go. */ + vst1.8 {d0}, [dst]! + vld1.8 {d0}, [src]! /* 4 words to go. */ + vst1.8 {d0}, [dst]! + vld1.8 {d0}, [src]! /* 2 words to go. */ + vst1.8 {d0}, [dst]! + + tst count, #4 + ldrne tmp1, [src], #4 + strne tmp1, [dst], #4 +#else + /* Copy up to 15 full words of data. May not be aligned. */ + /* Cannot use VFP for unaligned data. */ + and tmp1, count, #0x3c + add dst, dst, tmp1 + add src, src, tmp1 + rsb tmp1, tmp1, #(60 - PC_OFS/2 + INSN_SIZE/2) + /* Jump directly into the sequence below at the correct offset. */ + add pc, pc, tmp1, lsl #1 + + ldr tmp1, [src, #-60] /* 15 words to go. */ + str tmp1, [dst, #-60] + + ldr tmp1, [src, #-56] /* 14 words to go. */ + str tmp1, [dst, #-56] + ldr tmp1, [src, #-52] + str tmp1, [dst, #-52] + + ldr tmp1, [src, #-48] /* 12 words to go. */ + str tmp1, [dst, #-48] + ldr tmp1, [src, #-44] + str tmp1, [dst, #-44] + + ldr tmp1, [src, #-40] /* 10 words to go. */ + str tmp1, [dst, #-40] + ldr tmp1, [src, #-36] + str tmp1, [dst, #-36] + + ldr tmp1, [src, #-32] /* 8 words to go. */ + str tmp1, [dst, #-32] + ldr tmp1, [src, #-28] + str tmp1, [dst, #-28] + + ldr tmp1, [src, #-24] /* 6 words to go. */ + str tmp1, [dst, #-24] + ldr tmp1, [src, #-20] + str tmp1, [dst, #-20] + + ldr tmp1, [src, #-16] /* 4 words to go. */ + str tmp1, [dst, #-16] + ldr tmp1, [src, #-12] + str tmp1, [dst, #-12] + + ldr tmp1, [src, #-8] /* 2 words to go. */ + str tmp1, [dst, #-8] + ldr tmp1, [src, #-4] + str tmp1, [dst, #-4] +#endif + + lsls count, count, #31 + ldrhcs tmp1, [src], #2 + ldrbne src, [src] /* Src is dead, use as a scratch. */ + strhcs tmp1, [dst], #2 + strbne src, [dst] + bx lr + +.Lcpy_not_short: + /* At least 64 bytes to copy, but don't know the alignment yet. */ + str tmp2, [sp, #-FRAME_SIZE]! + cfi_adjust_cfa_offset (FRAME_SIZE) + cfi_rel_offset (tmp2, 0) + cfi_remember_state + and tmp2, src, #3 + and tmp1, dst, #3 + cmp tmp1, tmp2 + bne .Lcpy_notaligned + +#ifdef USE_VFP + /* Magic dust alert! Force VFP on Cortex-A9. Experiments show + that the FP pipeline is much better at streaming loads and + stores. This is outside the critical loop. */ + vmov.f32 s0, s0 +#endif + + /* SRC and DST have the same mutual 32-bit alignment, but we may + still need to pre-copy some bytes to get to natural alignment. + We bring DST into full 64-bit alignment. */ + lsls tmp2, dst, #29 + beq 1f + rsbs tmp2, tmp2, #0 + sub count, count, tmp2, lsr #29 + ldrmi tmp1, [src], #4 + strmi tmp1, [dst], #4 + lsls tmp2, tmp2, #2 + ldrhcs tmp1, [src], #2 + ldrbne tmp2, [src], #1 + strhcs tmp1, [dst], #2 + strbne tmp2, [dst], #1 + +1: + subs tmp2, count, #64 /* Use tmp2 for count. */ + blt .Ltail63aligned + + cmp tmp2, #512 + bge .Lcpy_body_long + +.Lcpy_body_medium: /* Count in tmp2. */ +#ifdef USE_VFP +1: + vldr d0, [src, #0] + subs tmp2, tmp2, #64 + vldr d1, [src, #8] + vstr d0, [dst, #0] + vldr d0, [src, #16] + vstr d1, [dst, #8] + vldr d1, [src, #24] + vstr d0, [dst, #16] + vldr d0, [src, #32] + vstr d1, [dst, #24] + vldr d1, [src, #40] + vstr d0, [dst, #32] + vldr d0, [src, #48] + vstr d1, [dst, #40] + vldr d1, [src, #56] + vstr d0, [dst, #48] + add src, src, #64 + vstr d1, [dst, #56] + add dst, dst, #64 + bge 1b + tst tmp2, #0x3f + beq .Ldone + +.Ltail63aligned: /* Count in tmp2. */ + and tmp1, tmp2, #0x38 + add dst, dst, tmp1 + add src, src, tmp1 + rsb tmp1, tmp1, #(56 - PC_OFS + INSN_SIZE) + add pc, pc, tmp1 + + vldr d0, [src, #-56] /* 14 words to go. */ + vstr d0, [dst, #-56] + vldr d0, [src, #-48] /* 12 words to go. */ + vstr d0, [dst, #-48] + vldr d0, [src, #-40] /* 10 words to go. */ + vstr d0, [dst, #-40] + vldr d0, [src, #-32] /* 8 words to go. */ + vstr d0, [dst, #-32] + vldr d0, [src, #-24] /* 6 words to go. */ + vstr d0, [dst, #-24] + vldr d0, [src, #-16] /* 4 words to go. */ + vstr d0, [dst, #-16] + vldr d0, [src, #-8] /* 2 words to go. */ + vstr d0, [dst, #-8] +#else + sub src, src, #8 + sub dst, dst, #8 +1: + ldrd A_l, A_h, [src, #8] + strd A_l, A_h, [dst, #8] + ldrd A_l, A_h, [src, #16] + strd A_l, A_h, [dst, #16] + ldrd A_l, A_h, [src, #24] + strd A_l, A_h, [dst, #24] + ldrd A_l, A_h, [src, #32] + strd A_l, A_h, [dst, #32] + ldrd A_l, A_h, [src, #40] + strd A_l, A_h, [dst, #40] + ldrd A_l, A_h, [src, #48] + strd A_l, A_h, [dst, #48] + ldrd A_l, A_h, [src, #56] + strd A_l, A_h, [dst, #56] + ldrd A_l, A_h, [src, #64]! + strd A_l, A_h, [dst, #64]! + subs tmp2, tmp2, #64 + bge 1b + tst tmp2, #0x3f + bne 1f + ldr tmp2,[sp], #FRAME_SIZE + cfi_adjust_cfa_offset (-FRAME_SIZE) + cfi_restore (tmp2) + bx lr + + cfi_restore_state + cfi_remember_state +1: + add src, src, #8 + add dst, dst, #8 + +.Ltail63aligned: /* Count in tmp2. */ + /* Copy up to 7 d-words of data. Similar to Ltail63unaligned, but + we know that the src and dest are 32-bit aligned so we can use + LDRD/STRD to improve efficiency. */ + /* TMP2 is now negative, but we don't care about that. The bottom + six bits still tell us how many bytes are left to copy. */ + + and tmp1, tmp2, #0x38 + add dst, dst, tmp1 + add src, src, tmp1 + rsb tmp1, tmp1, #(56 - PC_OFS + INSN_SIZE) + add pc, pc, tmp1 + ldrd A_l, A_h, [src, #-56] /* 14 words to go. */ + strd A_l, A_h, [dst, #-56] + ldrd A_l, A_h, [src, #-48] /* 12 words to go. */ + strd A_l, A_h, [dst, #-48] + ldrd A_l, A_h, [src, #-40] /* 10 words to go. */ + strd A_l, A_h, [dst, #-40] + ldrd A_l, A_h, [src, #-32] /* 8 words to go. */ + strd A_l, A_h, [dst, #-32] + ldrd A_l, A_h, [src, #-24] /* 6 words to go. */ + strd A_l, A_h, [dst, #-24] + ldrd A_l, A_h, [src, #-16] /* 4 words to go. */ + strd A_l, A_h, [dst, #-16] + ldrd A_l, A_h, [src, #-8] /* 2 words to go. */ + strd A_l, A_h, [dst, #-8] + +#endif + tst tmp2, #4 + ldrne tmp1, [src], #4 + strne tmp1, [dst], #4 + lsls tmp2, tmp2, #31 /* Count (tmp2) now dead. */ + ldrhcs tmp1, [src], #2 + ldrbne tmp2, [src] + strhcs tmp1, [dst], #2 + strbne tmp2, [dst] + +.Ldone: + ldr tmp2, [sp], #FRAME_SIZE + cfi_adjust_cfa_offset (-FRAME_SIZE) + cfi_restore (tmp2) + bx lr + + cfi_restore_state + cfi_remember_state + +.Lcpy_body_long: /* Count in tmp2. */ + + /* Long copy. We know that there's at least (prefetch_lines * 64) + bytes to go. */ +#ifdef USE_VFP + /* Don't use PLD. Instead, read some data in advance of the current + copy position into a register. This should act like a PLD + operation but we won't have to repeat the transfer. */ + + vldr d3, [src, #0] + vldr d4, [src, #64] + vldr d5, [src, #128] + vldr d6, [src, #192] + vldr d7, [src, #256] + + vldr d0, [src, #8] + vldr d1, [src, #16] + vldr d2, [src, #24] + add src, src, #32 + + subs tmp2, tmp2, #prefetch_lines * 64 * 2 + blt 2f +1: + cpy_line_vfp d3, 0 + cpy_line_vfp d4, 64 + cpy_line_vfp d5, 128 + add dst, dst, #3 * 64 + add src, src, #3 * 64 + cpy_line_vfp d6, 0 + cpy_line_vfp d7, 64 + add dst, dst, #2 * 64 + add src, src, #2 * 64 + subs tmp2, tmp2, #prefetch_lines * 64 + bge 1b + +2: + cpy_tail_vfp d3, 0 + cpy_tail_vfp d4, 64 + cpy_tail_vfp d5, 128 + add src, src, #3 * 64 + add dst, dst, #3 * 64 + cpy_tail_vfp d6, 0 + vstr d7, [dst, #64] + vldr d7, [src, #64] + vstr d0, [dst, #64 + 8] + vldr d0, [src, #64 + 8] + vstr d1, [dst, #64 + 16] + vldr d1, [src, #64 + 16] + vstr d2, [dst, #64 + 24] + vldr d2, [src, #64 + 24] + vstr d7, [dst, #64 + 32] + add src, src, #96 + vstr d0, [dst, #64 + 40] + vstr d1, [dst, #64 + 48] + vstr d2, [dst, #64 + 56] + add dst, dst, #128 + add tmp2, tmp2, #prefetch_lines * 64 + b .Lcpy_body_medium +#else + /* Long copy. Use an SMS style loop to maximize the I/O + bandwidth of the core. We don't have enough spare registers + to synthesise prefetching, so use PLD operations. */ + /* Pre-bias src and dst. */ + sub src, src, #8 + sub dst, dst, #8 + pld [src, #8] + pld [src, #72] + subs tmp2, tmp2, #64 + pld [src, #136] + ldrd A_l, A_h, [src, #8] + strd B_l, B_h, [sp, #8] + cfi_rel_offset (B_l, 8) + cfi_rel_offset (B_h, 12) + ldrd B_l, B_h, [src, #16] + strd C_l, C_h, [sp, #16] + cfi_rel_offset (C_l, 16) + cfi_rel_offset (C_h, 20) + ldrd C_l, C_h, [src, #24] + strd D_l, D_h, [sp, #24] + cfi_rel_offset (D_l, 24) + cfi_rel_offset (D_h, 28) + pld [src, #200] + ldrd D_l, D_h, [src, #32]! + b 1f + .p2align 6 +2: + pld [src, #232] + strd A_l, A_h, [dst, #40] + ldrd A_l, A_h, [src, #40] + strd B_l, B_h, [dst, #48] + ldrd B_l, B_h, [src, #48] + strd C_l, C_h, [dst, #56] + ldrd C_l, C_h, [src, #56] + strd D_l, D_h, [dst, #64]! + ldrd D_l, D_h, [src, #64]! + subs tmp2, tmp2, #64 +1: + strd A_l, A_h, [dst, #8] + ldrd A_l, A_h, [src, #8] + strd B_l, B_h, [dst, #16] + ldrd B_l, B_h, [src, #16] + strd C_l, C_h, [dst, #24] + ldrd C_l, C_h, [src, #24] + strd D_l, D_h, [dst, #32] + ldrd D_l, D_h, [src, #32] + bcs 2b + /* Save the remaining bytes and restore the callee-saved regs. */ + strd A_l, A_h, [dst, #40] + add src, src, #40 + strd B_l, B_h, [dst, #48] + ldrd B_l, B_h, [sp, #8] + cfi_restore (B_l) + cfi_restore (B_h) + strd C_l, C_h, [dst, #56] + ldrd C_l, C_h, [sp, #16] + cfi_restore (C_l) + cfi_restore (C_h) + strd D_l, D_h, [dst, #64] + ldrd D_l, D_h, [sp, #24] + cfi_restore (D_l) + cfi_restore (D_h) + add dst, dst, #72 + tst tmp2, #0x3f + bne .Ltail63aligned + ldr tmp2, [sp], #FRAME_SIZE + cfi_adjust_cfa_offset (-FRAME_SIZE) + cfi_restore (tmp2) + bx lr +#endif + + cfi_restore_state + cfi_remember_state + +.Lcpy_notaligned: + pld [src] + pld [src, #64] + /* There's at least 64 bytes to copy, but there is no mutual + alignment. */ + /* Bring DST to 64-bit alignment. */ + lsls tmp2, dst, #29 + pld [src, #(2 * 64)] + beq 1f + rsbs tmp2, tmp2, #0 + sub count, count, tmp2, lsr #29 + ldrmi tmp1, [src], #4 + strmi tmp1, [dst], #4 + lsls tmp2, tmp2, #2 + ldrbne tmp1, [src], #1 + ldrhcs tmp2, [src], #2 + strbne tmp1, [dst], #1 + strhcs tmp2, [dst], #2 +1: + pld [src, #(3 * 64)] + subs count, count, #64 + ldrmi tmp2, [sp], #FRAME_SIZE + bmi .Ltail63unaligned + pld [src, #(4 * 64)] + +#ifdef USE_NEON + vld1.8 {d0-d3}, [src]! + vld1.8 {d4-d7}, [src]! + subs count, count, #64 + bmi 2f +1: + pld [src, #(4 * 64)] + vst1.8 {d0-d3}, [ALIGN (dst, 64)]! + vld1.8 {d0-d3}, [src]! + vst1.8 {d4-d7}, [ALIGN (dst, 64)]! + vld1.8 {d4-d7}, [src]! + subs count, count, #64 + bpl 1b +2: + vst1.8 {d0-d3}, [ALIGN (dst, 64)]! + vst1.8 {d4-d7}, [ALIGN (dst, 64)]! + ands count, count, #0x3f +#else + /* Use an SMS style loop to maximize the I/O bandwidth. */ + sub src, src, #4 + sub dst, dst, #8 + subs tmp2, count, #64 /* Use tmp2 for count. */ + ldr A_l, [src, #4] + ldr A_h, [src, #8] + strd B_l, B_h, [sp, #8] + cfi_rel_offset (B_l, 8) + cfi_rel_offset (B_h, 12) + ldr B_l, [src, #12] + ldr B_h, [src, #16] + strd C_l, C_h, [sp, #16] + cfi_rel_offset (C_l, 16) + cfi_rel_offset (C_h, 20) + ldr C_l, [src, #20] + ldr C_h, [src, #24] + strd D_l, D_h, [sp, #24] + cfi_rel_offset (D_l, 24) + cfi_rel_offset (D_h, 28) + ldr D_l, [src, #28] + ldr D_h, [src, #32]! + b 1f + .p2align 6 +2: + pld [src, #(5 * 64) - (32 - 4)] + strd A_l, A_h, [dst, #40] + ldr A_l, [src, #36] + ldr A_h, [src, #40] + strd B_l, B_h, [dst, #48] + ldr B_l, [src, #44] + ldr B_h, [src, #48] + strd C_l, C_h, [dst, #56] + ldr C_l, [src, #52] + ldr C_h, [src, #56] + strd D_l, D_h, [dst, #64]! + ldr D_l, [src, #60] + ldr D_h, [src, #64]! + subs tmp2, tmp2, #64 +1: + strd A_l, A_h, [dst, #8] + ldr A_l, [src, #4] + ldr A_h, [src, #8] + strd B_l, B_h, [dst, #16] + ldr B_l, [src, #12] + ldr B_h, [src, #16] + strd C_l, C_h, [dst, #24] + ldr C_l, [src, #20] + ldr C_h, [src, #24] + strd D_l, D_h, [dst, #32] + ldr D_l, [src, #28] + ldr D_h, [src, #32] + bcs 2b + + /* Save the remaining bytes and restore the callee-saved regs. */ + strd A_l, A_h, [dst, #40] + add src, src, #36 + strd B_l, B_h, [dst, #48] + ldrd B_l, B_h, [sp, #8] + cfi_restore (B_l) + cfi_restore (B_h) + strd C_l, C_h, [dst, #56] + ldrd C_l, C_h, [sp, #16] + cfi_restore (C_l) + cfi_restore (C_h) + strd D_l, D_h, [dst, #64] + ldrd D_l, D_h, [sp, #24] + cfi_restore (D_l) + cfi_restore (D_h) + add dst, dst, #72 + ands count, tmp2, #0x3f +#endif + ldr tmp2, [sp], #FRAME_SIZE + cfi_adjust_cfa_offset (-FRAME_SIZE) + cfi_restore (tmp2) + bne .Ltail63unaligned + bx lr + +END(memcpy) +libc_hidden_builtin_def (memcpy) |