-----------------------------------------------------------------------
unix64.S - Copyright (c) 2002  Bo Thorsen <bo@suse.de>
           Copyright (c) 2008  Red Hat, Inc

x86-64 Foreign Function Interface 

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 AUTHORS OR COPYRIGHT
HOLDERS 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>

.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  2
     .globl  ffi_call_unix64
     .type   ffi_call_unix64,@function

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 */

.align 2

.Lst_void:

ret
.align 2

.Lst_uint8:

movzbq  %al, %rax
movq    %rax, (%rdi)
ret
.align 2

.Lst_sint8:

movsbq  %al, %rax
movq    %rax, (%rdi)
ret
.align 2

.Lst_uint16:

movzwq  %ax, %rax
movq    %rax, (%rdi)
.align 2

.Lst_sint16:

movswq  %ax, %rax
movq    %rax, (%rdi)
ret
.align 2

.Lst_uint32:

movl    %eax, %eax
movq    %rax, (%rdi)
.align 2

.Lst_sint32:

cltq
movq    %rax, (%rdi)
ret
.align 2

.Lst_int64:

movq    %rax, (%rdi)
ret

.align 2

.Lst_float:

movss   %xmm0, (%rdi)
ret
.align 2

.Lst_double:

movsd   %xmm0, (%rdi)
ret

.Lst_ldouble:

fstpt   (%rdi)
ret

.align 2

.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 2

.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:

.size    ffi_call_unix64,.-ffi_call_unix64

.align  2
.globl ffi_closure_unix64
.type   ffi_closure_unix64,@function

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@PLT

/* 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 */

.align 2

.Lld_void:

ret

.align 2

.Lld_int8:

movzbl  -24(%rsp), %eax
ret
.align 2

.Lld_int16:

movzwl  -24(%rsp), %eax
ret
.align 2

.Lld_int32:

movl    -24(%rsp), %eax
ret
.align 2

.Lld_int64:

movq    -24(%rsp), %rax
ret

.align 2

.Lld_float:

movss   -24(%rsp), %xmm0
ret
.align 2

.Lld_double:

movsd   -24(%rsp), %xmm0
ret
.align 2

.Lld_ldouble:

fldt    -24(%rsp)
ret

.align 2

.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 2

.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:

.size   ffi_closure_unix64,.-ffi_closure_unix64

ifdef HAVE_AS_X86_64_UNWIND_SECTION_TYPE

.section        .eh_frame,"a",@unwind

else

.section        .eh_frame,"a",@progbits

endif .Lframe1:

.long   .LECIE1-.LSCIE1         /* CIE Length */

.LSCIE1:

.long   0                       /* CIE Identifier Tag */
.byte   1                       /* CIE Version */
.ascii "zR\0"                   /* CIE Augmentation */
.uleb128 1                      /* CIE Code Alignment Factor */
.sleb128 -8                     /* CIE Data Alignment Factor */
.byte   0x10                    /* CIE RA Column */
.uleb128 1                      /* Augmentation size */
.byte   0x1b                    /* FDE Encoding (pcrel sdata4) */
.byte   0xc                     /* DW_CFA_def_cfa, %rsp offset 8 */
.uleb128 7
.uleb128 8
.byte   0x80+16                 /* DW_CFA_offset, %rip offset 1*-8 */
.uleb128 1
.align 8

.LECIE1: .LSFDE1:

.long   .LEFDE1-.LASFDE1        /* FDE Length */

.LASFDE1:

.long   .LASFDE1-.Lframe1       /* FDE CIE offset */

if HAVE_AS_X86_PCREL

.long   .LUW0-.                 /* FDE initial location */

else

.long   .LUW0@rel

endif

.long   .LUW4-.LUW0             /* FDE address range */
.uleb128 0x0                    /* Augmentation size */

.byte   0x4                     /* DW_CFA_advance_loc4 */
.long   .LUW1-.LUW0

/* 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 */
.uleb128 6
.uleb128 32
.byte   0x80+6                  /* DW_CFA_offset, %rbp offset 2*-8 */
.uleb128 2
.byte   0xa                     /* DW_CFA_remember_state */

.byte   0x4                     /* DW_CFA_advance_loc4 */
.long   .LUW2-.LUW1
.byte   0xc                     /* DW_CFA_def_cfa, %rsp offset 8 */
.uleb128 7
.uleb128 8
.byte   0xc0+6                  /* DW_CFA_restore, %rbp */

.byte   0x4                     /* DW_CFA_advance_loc4 */
.long   .LUW3-.LUW2
.byte   0xb                     /* DW_CFA_restore_state */

.align 8

.LEFDE1: .LSFDE3:

.long   .LEFDE3-.LASFDE3        /* FDE Length */

.LASFDE3:

.long   .LASFDE3-.Lframe1       /* FDE CIE offset */

if HAVE_AS_X86_PCREL

.long   .LUW5-.                 /* FDE initial location */

else

.long   .LUW5@rel

endif

.long   .LUW9-.LUW5             /* FDE address range */
.uleb128 0x0                    /* Augmentation size */

.byte   0x4                     /* DW_CFA_advance_loc4 */
.long   .LUW6-.LUW5
.byte   0xe                     /* DW_CFA_def_cfa_offset */
.uleb128 208
.byte   0xa                     /* DW_CFA_remember_state */

.byte   0x4                     /* DW_CFA_advance_loc4 */
.long   .LUW7-.LUW6
.byte   0xe                     /* DW_CFA_def_cfa_offset */
.uleb128 8

.byte   0x4                     /* DW_CFA_advance_loc4 */
.long   .LUW8-.LUW7
.byte   0xb                     /* DW_CFA_restore_state */

.align 8

.LEFDE3:

endif /* x86_64 */

if defined __ELF__ && defined __linux__

.section        .note.GNU-stack,"",@progbits

endif