# 

# Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.

# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

#

# This code is free software; you can redistribute it and/or modify it

# under the terms of the GNU General Public License version 2 only, as

# published by the Free Software Foundation.

#

# This code 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 General Public License

# version 2 for more details (a copy is included in the LICENSE file that

# accompanied this code).

#

# You should have received a copy of the GNU General Public License version

# 2 along with this work; if not, write to the Free Software Foundation,

# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

#

# Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

# or visit www.oracle.com if you need additional information or have any

# questions.

# 

        # TODO-AARCH64

        # NOTE WELL!  The _Copy functions are called directly

        # from server-compiler-generated code via CallLeafNoFP,

        # which means that they *must* either not use floating

        # point or use it in the same manner as does the server

        # compiler.

        .globl _Copy_conjoint_bytes

        .type _Copy_conjoint_bytes, %function

        .globl _Copy_arrayof_conjoint_bytes

        .type _Copy_arrayof_conjoint_bytes, %function

        .globl _Copy_disjoint_words

        .type _Copy_disjoint_words, %function

        .globl _Copy_conjoint_words

        .type _Copy_conjoint_words, %function

        .globl _Copy_conjoint_jshorts_atomic

        .type _Copy_conjoint_jshorts_atomic, %function

        .globl _Copy_arrayof_conjoint_jshorts

        .type _Copy_arrayof_conjoint_jshorts, %function

        .globl _Copy_conjoint_jints_atomic

        .type _Copy_conjoint_jints_atomic, %function

        .globl _Copy_arrayof_conjoint_jints

        .type _Copy_arrayof_conjoint_jints, %function

        .globl _Copy_conjoint_jlongs_atomic

        .type _Copy_conjoint_jlongs_atomic, %function

        .globl _Copy_arrayof_conjoint_jlongs

        .type _Copy_arrayof_conjoint_jlongs, %function

        .text

        .globl  SpinPause

        .type SpinPause, %function

SpinPause:

        yield

        ret

        # Support for void Copy::conjoint_bytes(void* from,

        #                                       void* to,

        #                                       size_t count)

_Copy_conjoint_bytes:

        hlt 1002

        # Support for void Copy::arrayof_conjoint_bytes(void* from,

        #                                               void* to,

        #                                               size_t count)

_Copy_arrayof_conjoint_bytes:

        hlt 1003

        # Support for void Copy::disjoint_words(void* from,

        #                                       void* to,

        #                                       size_t count)

_Copy_disjoint_words:

        # These and further memory prefetches may hit out of array ranges.

        # Experiments showed that prefetching of inaccessible memory doesn't result in exceptions.

        prfm    pldl1keep,  [x0, #0]

        prfm    pstl1keep,  [x1, #0]

        prfm    pldl1keep,  [x0, #64]

        prfm    pstl1keep,  [x1, #64]

        subs    x18, x2,  #128

        b.ge    dw_large

dw_lt_128:

        # Copy [x0, x0 + x2) to [x1, x1 + x2)

        adr     x15,  dw_tail_table_base

        and     x16,  x2,  #~8

        # Calculate address to jump and store it to x15:

        #   Each pair of instructions before dw_tail_table_base copies 16 bytes.

        #   x16 is count of bytes to copy aligned down by 16.

        #   So x16/16 pairs of instructions should be executed. 

        #   Each pair takes 8 bytes, so x15 = dw_tail_table_base - (x16/16)*8 = x15 - x16/2

        sub     x15,  x15, x16, lsr #1

        prfm    plil1keep, [x15]

        add     x17,  x0,  x2

        add     x18,  x1,  x2

        # If x2 = x16 + 8, then copy 8 bytes and x16 bytes after that.

        # Otherwise x2 = x16, so proceed to copy x16 bytes.

        tbz     x2, #3, dw_lt_128_even

        ldr     x3, [x0]

        str     x3, [x1]

dw_lt_128_even:

        # Copy [x17 - x16, x17) to [x18 - x16, x18)

        # x16 is aligned by 16 and less than 128

        # Execute (x16/16) ldp-stp pairs; each pair copies 16 bytes

        br      x15

        ldp     x3,  x4,  [x17, #-112]

        stp     x3,  x4,  [x18, #-112]

        ldp     x5,  x6,  [x17, #-96]

        stp     x5,  x6,  [x18, #-96]

        ldp     x7,  x8,  [x17, #-80]

        stp     x7,  x8,  [x18, #-80]

        ldp     x9,  x10, [x17, #-64]

        stp     x9,  x10, [x18, #-64]

        ldp     x11, x12, [x17, #-48]

        stp     x11, x12, [x18, #-48]

        ldp     x13, x14, [x17, #-32]

        stp     x13, x14, [x18, #-32]

        ldp     x15, x16, [x17, #-16]

        stp     x15, x16, [x18, #-16]

dw_tail_table_base:

        ret

.p2align  6

.rept   12

        nop

.endr

dw_large:

        # x18 >= 0;

        # Copy [x0, x0 + x18 + 128) to [x1, x1 + x18 + 128)

        ldp     x3,  x4,  [x0], #64

        ldp     x5,  x6,  [x0, #-48]

        ldp     x7,  x8,  [x0, #-32]

        ldp     x9,  x10, [x0, #-16]

        # Before and after each iteration of loop registers x3-x10 contain [x0 - 64, x0),

        # and x1 is a place to copy this data;

        # x18 contains number of bytes to be stored minus 128

        # Exactly 16 instructions from p2align, so dw_loop starts from cache line boundary

        # Checking it explictly by aligning with "hlt 1000" instructions 

.p2alignl  6, 0xd4407d00

dw_loop:

        prfm    pldl1keep,  [x0, #64]

        # Next line actually hurted memory copy performance (for interpreter) - JDK-8078120

        # prfm    pstl1keep,  [x1, #64]

        subs    x18, x18, #64

        stp     x3,  x4,  [x1, #0]

        ldp     x3,  x4,  [x0, #0]

        stp     x5,  x6,  [x1, #16]

        ldp     x5,  x6,  [x0, #16]

        stp     x7,  x8,  [x1, #32]

        ldp     x7,  x8,  [x0, #32]

        stp     x9,  x10, [x1, #48]

        ldp     x9,  x10, [x0, #48]

        add     x1,  x1,  #64

        add     x0,  x0,  #64

        b.ge    dw_loop

        # 13 instructions from dw_loop, so the loop body hits into one cache line

dw_loop_end:

        adds    x2,  x18, #64

        stp     x3,  x4,  [x1], #64

        stp     x5,  x6,  [x1, #-48]

        stp     x7,  x8,  [x1, #-32]

        stp     x9,  x10, [x1, #-16]

        # Increased x18 by 64, but stored 64 bytes, so x2 contains exact number of bytes to be stored

        # If this number is not zero, also copy remaining bytes

        b.ne    dw_lt_128

        ret

        # Support for void Copy::conjoint_words(void* from,

        #                                       void* to,

        #                                       size_t count)

_Copy_conjoint_words:

        subs    x3, x1, x0

        # hi condition is met <=> from < to

        ccmp    x2, x3, #0, hi

        # hi condition is met <=> (from < to) and (to - from < count)

        # otherwise _Copy_disjoint_words may be used, because it performs forward copying,

        # so it also works when ranges overlap but to <= from

        b.ls    _Copy_disjoint_words

        # Overlapping case should be the rare one, it does not worth optimizing

        ands    x3,  x2,  #~8

        # x3 is count aligned down by 2*wordSize

        add     x0,  x0,  x2

        add     x1,  x1,  x2

        sub     x3,  x3,  #16

        # Skip loop if 0 or 1 words

        b.eq    cw_backward_loop_end

        # x3 >= 0

        # Copy [x0 - x3 - 16, x0) to [x1 - x3 - 16, x1) backward

cw_backward_loop:

        subs    x3,  x3,  #16

        ldp     x4,  x5,  [x0, #-16]!

        stp     x4,  x5,  [x1, #-16]!

        b.ge    cw_backward_loop

cw_backward_loop_end:

        # Copy remaining 0 or 1 words

        tbz     x2,  #3,  cw_finish

        ldr     x3, [x0, #-8]

        str     x3, [x1, #-8]

cw_finish:

        ret

        # Support for void Copy::conjoint_jshorts_atomic(void* from,

        #                                                void* to,

        #                                                size_t count)

_Copy_conjoint_jshorts_atomic:

        add     x17, x0, x2

        add     x18, x1, x2

        subs    x3, x1, x0

        # hi is met <=> (from < to) and (to - from < count)

        ccmp    x2, x3, #0, hi

        b.hi    cs_backward

        subs    x3, x2, #14

        b.ge    cs_forward_loop

        # Copy x2 < 14 bytes from x0 to x1

cs_forward_lt14:

        ands    x7, x2, #7

        tbz     x2, #3, cs_forward_lt8

        ldrh    w3, [x0, #0]

        ldrh    w4, [x0, #2]

        ldrh    w5, [x0, #4]

        ldrh    w6, [x0, #6]

        strh    w3, [x1, #0]

        strh    w4, [x1, #2]

        strh    w5, [x1, #4]

        strh    w6, [x1, #6]

        # Copy x7 < 8 bytes from x17 - x7 to x18 - x7

cs_forward_lt8:

        b.eq    cs_forward_0

        cmp     x7, #4

        b.lt    cs_forward_2

        b.eq    cs_forward_4

cs_forward_6:

        ldrh    w3, [x17, #-6]

        strh    w3, [x18, #-6]

cs_forward_4:

        ldrh    w4, [x17, #-4]

        strh    w4, [x18, #-4]

cs_forward_2:

        ldrh    w5, [x17, #-2]

        strh    w5, [x18, #-2]

cs_forward_0:

        ret

        # Copy [x0, x0 + x3 + 14) to [x1, x1 + x3 + 14)

        # x3 >= 0

.p2align 6

cs_forward_loop:

        subs    x3, x3, #14

        ldrh    w4, [x0], #14

        ldrh    w5, [x0, #-12]

        ldrh    w6, [x0, #-10]

        ldrh    w7, [x0, #-8]

        ldrh    w8, [x0, #-6]

        ldrh    w9, [x0, #-4]

        ldrh    w10, [x0, #-2]

        strh    w4, [x1], #14

        strh    w5, [x1, #-12]

        strh    w6, [x1, #-10]

        strh    w7, [x1, #-8]

        strh    w8, [x1, #-6]

        strh    w9, [x1, #-4]

        strh    w10, [x1, #-2]

        b.ge    cs_forward_loop

        # Exactly 16 instruction from cs_forward_loop, so loop fits into one cache line

        adds    x2, x3, #14

        # x2 bytes should be copied from x0 to x1

        b.ne    cs_forward_lt14

        ret

        # Very similar to forward copying

cs_backward:

        subs    x3, x2, #14

        b.ge    cs_backward_loop

cs_backward_lt14:

        ands    x7, x2, #7

        tbz     x2, #3, cs_backward_lt8

        ldrh    w3, [x17, #-8]

        ldrh    w4, [x17, #-6]

        ldrh    w5, [x17, #-4]

        ldrh    w6, [x17, #-2]

        strh    w3, [x18, #-8]

        strh    w4, [x18, #-6]

        strh    w5, [x18, #-4]

        strh    w6, [x18, #-2]

cs_backward_lt8:

        b.eq    cs_backward_0

        cmp     x7, #4

        b.lt    cs_backward_2

        b.eq    cs_backward_4

cs_backward_6:

        ldrh    w3, [x0, #4]

        strh    w3, [x1, #4]

cs_backward_4:

        ldrh    w4, [x0, #2]

        strh    w4, [x1, #2]

cs_backward_2:

        ldrh    w5, [x0, #0]

        strh    w5, [x1, #0]

cs_backward_0:

        ret

.p2align 6

cs_backward_loop:

        subs    x3, x3, #14

        ldrh    w4, [x17, #-14]!

        ldrh    w5, [x17, #2]

        ldrh    w6, [x17, #4]

        ldrh    w7, [x17, #6]

        ldrh    w8, [x17, #8]

        ldrh    w9, [x17, #10]

        ldrh    w10, [x17, #12]

        strh    w4, [x18, #-14]!

        strh    w5, [x18, #2]

        strh    w6, [x18, #4]

        strh    w7, [x18, #6]

        strh    w8, [x18, #8]

        strh    w9, [x18, #10]

        strh    w10, [x18, #12]

        b.ge    cs_backward_loop

        adds    x2, x3, #14

        b.ne    cs_backward_lt14

        ret

        # Support for void Copy::arrayof_conjoint_jshorts(void* from,

        #                                                 void* to,

        #                                                 size_t count)

_Copy_arrayof_conjoint_jshorts:

        hlt 1007

        # Support for void Copy::conjoint_jlongs_atomic(jlong* from,

        #                                               jlong* to,

        #                                               size_t count)

_Copy_conjoint_jlongs_atomic:

_Copy_arrayof_conjoint_jlongs:

        hlt 1009

        # Support for void Copy::conjoint_jints_atomic(void* from,

        #                                              void* to,

        #                                              size_t count)

_Copy_conjoint_jints_atomic:

_Copy_arrayof_conjoint_jints:

        # These and further memory prefetches may hit out of array ranges.

        # Experiments showed that prefetching of inaccessible memory doesn't result in exceptions.

        prfm    pldl1keep,  [x0, #0]

        prfm    pstl1keep,  [x1, #0]

        prfm    pldl1keep,  [x0, #32]

        prfm    pstl1keep,  [x1, #32]

        subs    x3, x1, x0

        # hi condition is met <=> from < to

        ccmp    x2, x3, #0, hi

        # hi condition is met <=> (from < to) and (to - from < count)

        b.hi    ci_backward

        subs    x18, x2,  #64

        b.ge    ci_forward_large

ci_forward_lt_64:

        # Copy [x0, x0 + x2) to [x1, x1 + x2)

        adr     x15,  ci_forward_tail_table_base

        and     x16,  x2,  #~4

        # Calculate address to jump and store it to x15:

        #   Each pair of instructions before ci_forward_tail_table_base copies 8 bytes.

        #   x16 is count of bytes to copy aligned down by 8.

        #   So x16/8 pairs of instructions should be executed. 

        #   Each pair takes 8 bytes, so x15 = ci_forward_tail_table_base - (x16/8)*8 = x15 - x16

        sub     x15,  x15, x16

        prfm    plil1keep, [x15]

        add     x17,  x0,  x2

        add     x18,  x1,  x2

        # If x2 = x16 + 4, then copy 4 bytes and x16 bytes after that.

        # Otherwise x2 = x16, so proceed to copy x16 bytes.

        tbz     x2, #2, ci_forward_lt_64_even

        ldr     w3, [x0]

        str     w3, [x1]

ci_forward_lt_64_even:

        # Copy [x17 - x16, x17) to [x18 - x16, x18)

        # x16 is aligned by 8 and less than 64

        # Execute (x16/8) ldp-stp pairs; each pair copies 8 bytes

        br      x15

        ldp     w3,  w4,  [x17, #-56]

        stp     w3,  w4,  [x18, #-56]

        ldp     w5,  w6,  [x17, #-48]

        stp     w5,  w6,  [x18, #-48]

        ldp     w7,  w8,  [x17, #-40]

        stp     w7,  w8,  [x18, #-40]

        ldp     w9,  w10, [x17, #-32]

        stp     w9,  w10, [x18, #-32]

        ldp     w11, w12, [x17, #-24]

        stp     w11, w12, [x18, #-24]

        ldp     w13, w14, [x17, #-16]

        stp     w13, w14, [x18, #-16]

        ldp     w15, w16, [x17, #-8]

        stp     w15, w16, [x18, #-8]

ci_forward_tail_table_base:

        ret

.p2align  6

.rept   12

        nop

.endr

ci_forward_large:

        # x18 >= 0;

        # Copy [x0, x0 + x18 + 64) to [x1, x1 + x18 + 64)

        ldp     w3,  w4,  [x0], #32

        ldp     w5,  w6,  [x0, #-24]

        ldp     w7,  w8,  [x0, #-16]

        ldp     w9,  w10, [x0, #-8]

        # Before and after each iteration of loop registers w3-w10 contain [x0 - 32, x0),

        # and x1 is a place to copy this data;

        # x18 contains number of bytes to be stored minus 64

        # Exactly 16 instructions from p2align, so ci_forward_loop starts from cache line boundary

        # Checking it explictly by aligning with "hlt 1000" instructions 

.p2alignl  6, 0xd4407d00

ci_forward_loop:

        prfm    pldl1keep,  [x0, #32]

        prfm    pstl1keep,  [x1, #32]

        subs    x18, x18, #32

        stp     w3,  w4,  [x1, #0]

        ldp     w3,  w4,  [x0, #0]

        stp     w5,  w6,  [x1, #8]

        ldp     w5,  w6,  [x0, #8]

        stp     w7,  w8,  [x1, #16]

        ldp     w7,  w8,  [x0, #16]

        stp     w9,  w10, [x1, #24]

        ldp     w9,  w10, [x0, #24]

        add     x1,  x1,  #32

        add     x0,  x0,  #32

        b.ge    ci_forward_loop

        # 14 instructions from ci_forward_loop, so the loop body hits into one cache line

ci_forward_loop_end:

        adds    x2,  x18, #32

        stp     w3,  w4,  [x1], #32

        stp     w5,  w6,  [x1, #-24]

        stp     w7,  w8,  [x1, #-16]

        stp     w9,  w10, [x1, #-8]

        # Increased x18 by 32, but stored 32 bytes, so x2 contains exact number of bytes to be stored

        # If this number is not zero, also copy remaining bytes

        b.ne    ci_forward_lt_64

        ret

ci_backward:

        # Overlapping case should be the rare one, it does not worth optimizing

        ands    x3,  x2,  #~4

        # x3 is count aligned down by 2*jintSize

        add     x0,  x0,  x2

        add     x1,  x1,  x2

        sub     x3,  x3,  #8

        # Skip loop if 0 or 1 jints

        b.eq    ci_backward_loop_end

        # x3 >= 0

        # Copy [x0 - x3 - 8, x0) to [x1 - x3 - 8, x1) backward

ci_backward_loop: