-----------------------------------------------------------------------
darwin64.S - Copyright (c) 2006 Free Software Foundation, Inc.
             Copyright (c) 2008 Red Hat, Inc.
derived from unix64.S

x86-64 Foreign Function Interface for Darwin.

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
``Software''), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.
-----------------------------------------------------------------------

ifdef x86_64 define LIBFFI_ASM include <fficonfig.h> include <ffi.h>

.file "darwin64.S"

.text

ffi_call_unix64 (void *args, unsigned long bytes, unsigned flags,
                 void *raddr, void (*fnaddr)(void));

Bit o trickiness here -- ARGS+BYTES is the base of the stack frame
for this function.  This has been allocated by ffi_call.  We also
deallocate some of the stack that has been alloca'd.    

     .align  3
     .globl  _ffi_call_unix64

_ffi_call_unix64: LUW0:

movq    (%rsp), %r10            /* Load return address.  */
leaq    (%rdi, %rsi), %rax      /* Find local stack base.  */
movq    %rdx, (%rax)            /* Save flags.  */
movq    %rcx, 8(%rax)           /* Save raddr.  */
movq    %rbp, 16(%rax)          /* Save old frame pointer.  */
movq    %r10, 24(%rax)          /* Relocate return address.  */
movq    %rax, %rbp              /* Finalize local stack frame.  */

LUW1:

movq    %rdi, %r10              /* Save a copy of the register area. */
movq    %r8, %r11               /* Save a copy of the target fn.  */
movl    %r9d, %eax              /* Set number of SSE registers.  */

/* Load up all argument registers.  */
movq    (%r10), %rdi
movq    8(%r10), %rsi
movq    16(%r10), %rdx
movq    24(%r10), %rcx
movq    32(%r10), %r8
movq    40(%r10), %r9
testl   %eax, %eax
jnz     Lload_sse

Lret_from_load_sse:

/* Deallocate the reg arg area.  */
leaq    176(%r10), %rsp

/* Call the user function.  */
call    *%r11

/* Deallocate stack arg area; local stack frame in redzone.  */
leaq    24(%rbp), %rsp

movq    0(%rbp), %rcx           /* Reload flags.  */
movq    8(%rbp), %rdi           /* Reload raddr.  */
movq    16(%rbp), %rbp          /* Reload old frame pointer.  */

LUW2:

/* The first byte of the flags contains the FFI_TYPE.  */
movzbl  %cl, %r10d
leaq    Lstore_table(%rip), %r11
movslq  (%r11, %r10, 4), %r10
addq    %r11, %r10
jmp     *%r10

Lstore_table:

.long   Lst_void-Lstore_table           /* FFI_TYPE_VOID */
.long   Lst_sint32-Lstore_table         /* FFI_TYPE_INT */
.long   Lst_float-Lstore_table          /* FFI_TYPE_FLOAT */
.long   Lst_double-Lstore_table         /* FFI_TYPE_DOUBLE */
.long   Lst_ldouble-Lstore_table        /* FFI_TYPE_LONGDOUBLE */
.long   Lst_uint8-Lstore_table          /* FFI_TYPE_UINT8 */
.long   Lst_sint8-Lstore_table          /* FFI_TYPE_SINT8 */
.long   Lst_uint16-Lstore_table         /* FFI_TYPE_UINT16 */
.long   Lst_sint16-Lstore_table         /* FFI_TYPE_SINT16 */
.long   Lst_uint32-Lstore_table         /* FFI_TYPE_UINT32 */
.long   Lst_sint32-Lstore_table         /* FFI_TYPE_SINT32 */
.long   Lst_int64-Lstore_table          /* FFI_TYPE_UINT64 */
.long   Lst_int64-Lstore_table          /* FFI_TYPE_SINT64 */
.long   Lst_struct-Lstore_table         /* FFI_TYPE_STRUCT */
.long   Lst_int64-Lstore_table          /* FFI_TYPE_POINTER */

.text
.align  3

Lst_void:

ret
.align  3

Lst_uint8:

movzbq  %al, %rax
movq    %rax, (%rdi)
ret
.align  3

Lst_sint8:

movsbq  %al, %rax
movq    %rax, (%rdi)
ret
.align  3

Lst_uint16:

movzwq  %ax, %rax
movq    %rax, (%rdi)
.align  3

Lst_sint16:

movswq  %ax, %rax
movq    %rax, (%rdi)
ret
.align  3

Lst_uint32:

movl    %eax, %eax
movq    %rax, (%rdi)
.align  3

Lst_sint32:

cltq
movq    %rax, (%rdi)
ret
.align  3

Lst_int64:

movq    %rax, (%rdi)
ret
.align  3

Lst_float:

movss   %xmm0, (%rdi)
ret
.align  3

Lst_double:

movsd   %xmm0, (%rdi)
ret

Lst_ldouble:

fstpt   (%rdi)
ret
.align  3

Lst_struct:

leaq    -20(%rsp), %rsi         /* Scratch area in redzone.  */

/* We have to locate the values now, and since we don't want to
   write too much data into the user's return value, we spill the
   value to a 16 byte scratch area first.  Bits 8, 9, and 10
   control where the values are located.  Only one of the three
   bits will be set; see ffi_prep_cif_machdep for the pattern.  */
movd    %xmm0, %r10
movd    %xmm1, %r11
testl   $0x100, %ecx
cmovnz  %rax, %rdx
cmovnz  %r10, %rax
testl   $0x200, %ecx
cmovnz  %r10, %rdx
testl   $0x400, %ecx
cmovnz  %r10, %rax
cmovnz  %r11, %rdx
movq    %rax, (%rsi)
movq    %rdx, 8(%rsi)

/* Bits 12-31 contain the true size of the structure.  Copy from
   the scratch area to the true destination.  */
shrl    $12, %ecx
rep movsb
ret

/* Many times we can avoid loading any SSE registers at all.
   It's not worth an indirect jump to load the exact set of
   SSE registers needed; zero or all is a good compromise.  */
.align  3

LUW3: Lload_sse:

movdqa  48(%r10), %xmm0
movdqa  64(%r10), %xmm1
movdqa  80(%r10), %xmm2
movdqa  96(%r10), %xmm3
movdqa  112(%r10), %xmm4
movdqa  128(%r10), %xmm5
movdqa  144(%r10), %xmm6
movdqa  160(%r10), %xmm7
jmp     Lret_from_load_sse

LUW4:

.align  3
.globl  _ffi_closure_unix64

_ffi_closure_unix64: LUW5:

/* The carry flag is set by the trampoline iff SSE registers
   are used.  Don't clobber it before the branch instruction.  */
leaq    -200(%rsp), %rsp

LUW6:

movq    %rdi, (%rsp)
movq    %rsi, 8(%rsp)
movq    %rdx, 16(%rsp)
movq    %rcx, 24(%rsp)
movq    %r8, 32(%rsp)
movq    %r9, 40(%rsp)
jc      Lsave_sse

Lret_from_save_sse:

movq    %r10, %rdi
leaq    176(%rsp), %rsi
movq    %rsp, %rdx
leaq    208(%rsp), %rcx
call    _ffi_closure_unix64_inner

/* Deallocate stack frame early; return value is now in redzone.  */
addq    $200, %rsp

LUW7:

/* The first byte of the return value contains the FFI_TYPE.  */
movzbl  %al, %r10d
leaq    Lload_table(%rip), %r11
movslq  (%r11, %r10, 4), %r10
addq    %r11, %r10
jmp     *%r10

Lload_table:

.long   Lld_void-Lload_table            /* FFI_TYPE_VOID */
.long   Lld_int32-Lload_table           /* FFI_TYPE_INT */
.long   Lld_float-Lload_table           /* FFI_TYPE_FLOAT */
.long   Lld_double-Lload_table          /* FFI_TYPE_DOUBLE */
.long   Lld_ldouble-Lload_table         /* FFI_TYPE_LONGDOUBLE */
.long   Lld_int8-Lload_table            /* FFI_TYPE_UINT8 */
.long   Lld_int8-Lload_table            /* FFI_TYPE_SINT8 */
.long   Lld_int16-Lload_table           /* FFI_TYPE_UINT16 */
.long   Lld_int16-Lload_table           /* FFI_TYPE_SINT16 */
.long   Lld_int32-Lload_table           /* FFI_TYPE_UINT32 */
.long   Lld_int32-Lload_table           /* FFI_TYPE_SINT32 */
.long   Lld_int64-Lload_table           /* FFI_TYPE_UINT64 */
.long   Lld_int64-Lload_table           /* FFI_TYPE_SINT64 */
.long   Lld_struct-Lload_table          /* FFI_TYPE_STRUCT */
.long   Lld_int64-Lload_table           /* FFI_TYPE_POINTER */

.text
.align  3

Lld_void:

ret
.align  3

Lld_int8:

movzbl  -24(%rsp), %eax
ret
.align  3

Lld_int16:

movzwl  -24(%rsp), %eax
ret
.align  3

Lld_int32:

movl    -24(%rsp), %eax
ret
.align  3

Lld_int64:

movq    -24(%rsp), %rax
ret
.align  3

Lld_float:

movss   -24(%rsp), %xmm0
ret
.align  3

Lld_double:

movsd   -24(%rsp), %xmm0
ret
.align  3

Lld_ldouble:

fldt    -24(%rsp)
ret
.align  3

Lld_struct:

/* There are four possibilities here, %rax/%rdx, %xmm0/%rax,
   %rax/%xmm0, %xmm0/%xmm1.  We collapse two by always loading
   both rdx and xmm1 with the second word.  For the remaining,
   bit 8 set means xmm0 gets the second word, and bit 9 means
   that rax gets the second word.  */
movq    -24(%rsp), %rcx
movq    -16(%rsp), %rdx
movq    -16(%rsp), %xmm1
testl   $0x100, %eax
cmovnz  %rdx, %rcx
movd    %rcx, %xmm0
testl   $0x200, %eax
movq    -24(%rsp), %rax
cmovnz  %rdx, %rax
ret

/* See the comment above Lload_sse; the same logic applies here.  */
.align  3

LUW8: Lsave_sse:

movdqa  %xmm0, 48(%rsp)
movdqa  %xmm1, 64(%rsp)
movdqa  %xmm2, 80(%rsp)
movdqa  %xmm3, 96(%rsp)
movdqa  %xmm4, 112(%rsp)
movdqa  %xmm5, 128(%rsp)
movdqa  %xmm6, 144(%rsp)
movdqa  %xmm7, 160(%rsp)
jmp     Lret_from_save_sse

LUW9: .section __TEXT,__eh_frame,coalesced,no_toc+strip_static_syms+live_support EH_frame1:

.set    L$set$0,LECIE1-LSCIE1           /* CIE Length */
.long   L$set$0

LSCIE1:

.long   0x0             /* CIE Identifier Tag */
.byte   0x1             /* CIE Version */
.ascii  "zR\0"          /* CIE Augmentation */
.byte   0x1             /* uleb128 0x1; CIE Code Alignment Factor */
.byte   0x78            /* sleb128 -8; CIE Data Alignment Factor */
.byte   0x10            /* CIE RA Column */
.byte   0x1             /* uleb128 0x1; Augmentation size */
.byte   0x10            /* FDE Encoding (pcrel sdata4) */
.byte   0xc             /* DW_CFA_def_cfa, %rsp offset 8 */
.byte   0x7             /* uleb128 0x7 */
.byte   0x8             /* uleb128 0x8 */
.byte   0x90            /* DW_CFA_offset, column 0x10 */
.byte   0x1
.align  3

LECIE1:

.globl _ffi_call_unix64.eh

_ffi_call_unix64.eh: LSFDE1:

.set    L$set$1,LEFDE1-LASFDE1  /* FDE Length */
.long   L$set$1

LASFDE1:

.long   LASFDE1-EH_frame1       /* FDE CIE offset */
.quad   LUW0-.                  /* FDE initial location */
.set    L$set$2,LUW4-LUW0       /* FDE address range */
.quad   L$set$2
.byte   0x0                     /* Augmentation size */
.byte   0x4                     /* DW_CFA_advance_loc4 */
.set    L$set$3,LUW1-LUW0
.long   L$set$3

/* New stack frame based off rbp.  This is a itty bit of unwind
   trickery in that the CFA *has* changed.  There is no easy way
   to describe it correctly on entry to the function.  Fortunately,
   it doesn't matter too much since at all points we can correctly
   unwind back to ffi_call.  Note that the location to which we
   moved the return address is (the new) CFA-8, so from the
   perspective of the unwind info, it hasn't moved.  */
.byte   0xc                     /* DW_CFA_def_cfa, %rbp offset 32 */
.byte   0x6
.byte   0x20
.byte   0x80+6                  /* DW_CFA_offset, %rbp offset 2*-8 */
.byte   0x2
.byte   0xa                     /* DW_CFA_remember_state */

.byte   0x4                     /* DW_CFA_advance_loc4 */
.set    L$set$4,LUW2-LUW1
.long   L$set$4
.byte   0xc                     /* DW_CFA_def_cfa, %rsp offset 8 */
.byte   0x7
.byte   0x8
.byte   0xc0+6                  /* DW_CFA_restore, %rbp */

.byte   0x4                     /* DW_CFA_advance_loc4 */
.set    L$set$5,LUW3-LUW2
.long   L$set$5
.byte   0xb                     /* DW_CFA_restore_state */

.align  3

LEFDE1:

.globl _ffi_closure_unix64.eh

_ffi_closure_unix64.eh: LSFDE3:

.set    L$set$6,LEFDE3-LASFDE3  /* FDE Length */
.long   L$set$6

LASFDE3:

.long   LASFDE3-EH_frame1       /* FDE CIE offset */
.quad   LUW5-.                  /* FDE initial location */
.set    L$set$7,LUW9-LUW5       /* FDE address range */
.quad   L$set$7
.byte   0x0                     /* Augmentation size */

.byte   0x4                     /* DW_CFA_advance_loc4 */
.set    L$set$8,LUW6-LUW5
.long   L$set$8
.byte   0xe                     /* DW_CFA_def_cfa_offset */
.byte   208,1                   /* uleb128 208 */
.byte   0xa                     /* DW_CFA_remember_state */

.byte   0x4                     /* DW_CFA_advance_loc4 */
.set    L$set$9,LUW7-LUW6
.long   L$set$9
.byte   0xe                     /* DW_CFA_def_cfa_offset */
.byte   0x8

.byte   0x4                     /* DW_CFA_advance_loc4 */
.set    L$set$10,LUW8-LUW7
.long   L$set$10
.byte   0xb                     /* DW_CFA_restore_state */

.align  3

LEFDE3:

.subsections_via_symbols

endif /* x86_64 */