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/* -----------------------------------------------------------------------
   darwin.S - Copyright (c) 2000 John Hornkvist
              Copyright (c) 2004, 2010 Free Software Foundation, Inc.

   PowerPC Assembly glue.

   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.
   ----------------------------------------------------------------------- */

#define LIBFFI_ASM
#if defined(__ppc64__)
#define MODE_CHOICE(x, y) y
#else
#define MODE_CHOICE(x, y) x
#endif

#define machine_choice  MODE_CHOICE(ppc7400,ppc64)

; Define some pseudo-opcodes for size-independent load & store of GPRs ...
#define lgu             MODE_CHOICE(lwzu, ldu)
#define lg              MODE_CHOICE(lwz,ld)
#define sg              MODE_CHOICE(stw,std)
#define sgu             MODE_CHOICE(stwu,stdu)
#define sgux            MODE_CHOICE(stwux,stdux)

; ... and the size of GPRs and their storage indicator.
#define GPR_BYTES       MODE_CHOICE(4,8)
#define LOG2_GPR_BYTES  MODE_CHOICE(2,3)        /* log2(GPR_BYTES) */
#define g_long          MODE_CHOICE(long, quad) /* usage is ".g_long" */

; From the ABI doc: "Mac OS X ABI Function Call Guide" Version 2009-02-04.
#define LINKAGE_SIZE    MODE_CHOICE(24,48)
#define PARAM_AREA      MODE_CHOICE(32,64)
#define SAVED_LR_OFFSET MODE_CHOICE(8,16)       /* save position for lr */

/* If there is any FP stuff we make space for all of the regs.  */
#define SAVED_FPR_COUNT 13
#define FPR_SIZE        8
#define RESULT_BYTES    16

/* This should be kept in step with the same value in ffi_darwin.c.  */
#define ASM_NEEDS_REGISTERS 4
#define SAVE_REGS_SIZE (ASM_NEEDS_REGISTERS * GPR_BYTES)

#include <fficonfig.h>
#include <ffi.h>

#define JUMPTARGET(name) name
#define L(x) x

        .text
        .align 2
        .globl _ffi_prep_args

        .align 2
        .globl _ffi_call_DARWIN

        /* We arrive here with:
           r3 = ptr to extended cif.
           r4 = -bytes.
           r5 = cif flags.
           r6 = ptr to return value.
           r7 = fn pointer (user func).
           r8 = fn pointer (ffi_prep_args).
           r9 = ffi_type* for the ret val.  */

_ffi_call_DARWIN:
Lstartcode:
        mr      r12,r8  /* We only need r12 until the call,
                           so it does not have to be saved.  */
LFB1:
        /* Save the old stack pointer as AP.  */
        mr      r8,r1
LCFI0:
        
        /* Save the retval type in parents frame.  */
        sg      r9,(LINKAGE_SIZE+6*GPR_BYTES)(r8)

        /* Allocate the stack space we need.  */
        sgux    r1,r1,r4

        /* Save registers we use.  */
        mflr    r9
        sg      r9,SAVED_LR_OFFSET(r8)

        sg      r28,-(4 * GPR_BYTES)(r8)        
        sg      r29,-(3 * GPR_BYTES)(r8)
        sg      r30,-(2 * GPR_BYTES)(r8)
        sg      r31,-(    GPR_BYTES)(r8)

#if !defined(POWERPC_DARWIN)
        /* The TOC slot is reserved in the Darwin ABI and r2 is volatile.  */
        sg      r2,(5 * GPR_BYTES)(r1)
#endif

LCFI1:

        /* Save arguments over call.  */
        mr      r31,r5  /* flags,  */
        mr      r30,r6  /* rvalue,  */
        mr      r29,r7  /* function address,  */
        mr      r28,r8  /* our AP.  */
LCFI2:
        /* Call ffi_prep_args. r3 = extended cif, r4 = stack ptr copy.  */
        mr      r4,r1
        li      r9,0

        mtctr   r12 /* r12 holds address of _ffi_prep_args.  */
        bctrl

#if !defined(POWERPC_DARWIN)
        /* The TOC slot is reserved in the Darwin ABI and r2 is volatile.  */
        lg     r2,(5 * GPR_BYTES)(r1)
#endif
        /* Now do the call.
           Set up cr1 with bits 4-7 of the flags.  */
        mtcrf   0x40,r31
        /* Get the address to call into CTR.  */
        mtctr   r29
        /* Load all those argument registers.
           We have set up a nice stack frame, just load it into registers.  */
        lg     r3, (LINKAGE_SIZE                )(r1)
        lg     r4, (LINKAGE_SIZE +     GPR_BYTES)(r1)
        lg     r5, (LINKAGE_SIZE + 2 * GPR_BYTES)(r1)
        lg     r6, (LINKAGE_SIZE + 3 * GPR_BYTES)(r1)
        nop
        lg     r7, (LINKAGE_SIZE + 4 * GPR_BYTES)(r1)
        lg     r8, (LINKAGE_SIZE + 5 * GPR_BYTES)(r1)
        lg     r9, (LINKAGE_SIZE + 6 * GPR_BYTES)(r1)
        lg     r10,(LINKAGE_SIZE + 7 * GPR_BYTES)(r1)

L1:
        /* ... Load all the FP registers.  */
        bf      6,L2    /* No floats to load.  */
        lfd     f1, -SAVE_REGS_SIZE-(13*FPR_SIZE)(r28)
        lfd     f2, -SAVE_REGS_SIZE-(12*FPR_SIZE)(r28)
        lfd     f3, -SAVE_REGS_SIZE-(11*FPR_SIZE)(r28)
        lfd     f4, -SAVE_REGS_SIZE-(10*FPR_SIZE)(r28)
        nop
        lfd     f5, -SAVE_REGS_SIZE-( 9*FPR_SIZE)(r28)
        lfd     f6, -SAVE_REGS_SIZE-( 8*FPR_SIZE)(r28)
        lfd     f7, -SAVE_REGS_SIZE-( 7*FPR_SIZE)(r28)
        lfd     f8, -SAVE_REGS_SIZE-( 6*FPR_SIZE)(r28)
        nop
        lfd     f9, -SAVE_REGS_SIZE-( 5*FPR_SIZE)(r28)
        lfd     f10,-SAVE_REGS_SIZE-( 4*FPR_SIZE)(r28)
        lfd     f11,-SAVE_REGS_SIZE-( 3*FPR_SIZE)(r28)
        lfd     f12,-SAVE_REGS_SIZE-( 2*FPR_SIZE)(r28)
        nop
        lfd     f13,-SAVE_REGS_SIZE-( 1*FPR_SIZE)(r28)

L2:
        mr      r12,r29 /* Put the target address in r12 as specified.  */
        mtctr   r12
        nop
        nop

        /* Make the call.  */
        bctrl

        /* Now, deal with the return value.  */

        /* m64 structure returns can occupy the same set of registers as
           would be used to pass such a structure as arg0 - so take care 
           not to step on any possibly hot regs.  */

        /* Get the flags.. */
        mtcrf   0x03,r31 ; we need c6 & cr7 now.
        ; FLAG_RETURNS_NOTHING also covers struct ret-by-ref.
        bt      30,L(done_return_value)   ; FLAG_RETURNS_NOTHING
        bf      27,L(scalar_return_value) ; not FLAG_RETURNS_STRUCT
        
        /* OK, so we have a struct.  */
#if defined(__ppc64__)
        bt      31,L(maybe_return_128) ; FLAG_RETURNS_128BITS, special case 

        /* OK, we have to map the return back to a mem struct.
           We are about to trample the parents param area, so recover the
           return type.  r29 is free, since the call is done.  */
        lg      r29,(LINKAGE_SIZE + 6 * GPR_BYTES)(r28)

        sg      r3, (LINKAGE_SIZE                )(r28)
        sg      r4, (LINKAGE_SIZE +     GPR_BYTES)(r28)
        sg      r5, (LINKAGE_SIZE + 2 * GPR_BYTES)(r28)
        sg      r6, (LINKAGE_SIZE + 3 * GPR_BYTES)(r28)
        nop
        sg      r7, (LINKAGE_SIZE + 4 * GPR_BYTES)(r28)
        sg      r8, (LINKAGE_SIZE + 5 * GPR_BYTES)(r28)
        sg      r9, (LINKAGE_SIZE + 6 * GPR_BYTES)(r28)
        sg      r10,(LINKAGE_SIZE + 7 * GPR_BYTES)(r28)
        /* OK, so do the block move - we trust that memcpy will not trample
           the fprs...  */
        mr      r3,r30 ; dest
        addi    r4,r28,LINKAGE_SIZE ; source
        /* The size is a size_t, should be long.  */
        lg      r5,0(r29)
        /* Figure out small structs */
        cmpi    0,r5,4
        bgt     L3      ; 1, 2 and 4 bytes have special rules.
        cmpi    0,r5,3
        beq     L3      ; not 3
        addi    r4,r4,8
        subf    r4,r5,r4
L3:
        bl      _memcpy
        
        /* ... do we need the FP registers? - recover the flags.. */
        mtcrf   0x03,r31 ; we need c6 & cr7 now.
        bf      29,L(done_return_value) /* No floats in the struct.  */
        stfd    f1, -SAVE_REGS_SIZE-(13*FPR_SIZE)(r28)
        stfd    f2, -SAVE_REGS_SIZE-(12*FPR_SIZE)(r28)
        stfd    f3, -SAVE_REGS_SIZE-(11*FPR_SIZE)(r28)
        stfd    f4, -SAVE_REGS_SIZE-(10*FPR_SIZE)(r28)
        nop
        stfd    f5, -SAVE_REGS_SIZE-( 9*FPR_SIZE)(r28)
        stfd    f6, -SAVE_REGS_SIZE-( 8*FPR_SIZE)(r28)
        stfd    f7, -SAVE_REGS_SIZE-( 7*FPR_SIZE)(r28)
        stfd    f8, -SAVE_REGS_SIZE-( 6*FPR_SIZE)(r28)
        nop
        stfd    f9, -SAVE_REGS_SIZE-( 5*FPR_SIZE)(r28)
        stfd    f10,-SAVE_REGS_SIZE-( 4*FPR_SIZE)(r28)
        stfd    f11,-SAVE_REGS_SIZE-( 3*FPR_SIZE)(r28)
        stfd    f12,-SAVE_REGS_SIZE-( 2*FPR_SIZE)(r28)
        nop
        stfd    f13,-SAVE_REGS_SIZE-( 1*FPR_SIZE)(r28)

        mr      r3,r29  ; ffi_type *
        mr      r4,r30  ; dest
        addi    r5,r28,-SAVE_REGS_SIZE-(13*FPR_SIZE) ; fprs
        xor     r6,r6,r6
        sg      r6,(LINKAGE_SIZE + 7 * GPR_BYTES)(r28)
        addi    r6,r28,(LINKAGE_SIZE + 7 * GPR_BYTES) ; point to a zeroed counter.
        bl      _darwin64_struct_floats_to_mem

        b L(done_return_value)
#else
        stw     r3,0(r30) ; m32 the only struct return in reg is 4 bytes.
#endif
        b L(done_return_value)

L(fp_return_value):
        /* Do we have long double to store?  */
        bf      31,L(fd_return_value) ; FLAG_RETURNS_128BITS
        stfd    f1,0(r30)
        stfd    f2,FPR_SIZE(r30)
        b       L(done_return_value)

L(fd_return_value):
        /* Do we have double to store?  */
        bf      28,L(float_return_value)
        stfd    f1,0(r30)
        b       L(done_return_value)

L(float_return_value):
        /* We only have a float to store.  */
        stfs    f1,0(r30)
        b       L(done_return_value)

L(scalar_return_value):
        bt      29,L(fp_return_value)   ; FLAG_RETURNS_FP
        ; ffi_arg is defined as unsigned long. 
        sg      r3,0(r30)               ; Save the reg.
        bf      28,L(done_return_value) ; not FLAG_RETURNS_64BITS 

#if defined(__ppc64__)
L(maybe_return_128):
        std     r3,0(r30)
        bf      31,L(done_return_value) ; not FLAG_RETURNS_128BITS 
        std     r4,8(r30)
#else
        stw     r4,4(r30)
#endif

        /* Fall through.  */
        /* We want this at the end to simplify eh epilog computation.  */

L(done_return_value):
        /* Restore the registers we used and return.  */
        lg      r29,SAVED_LR_OFFSET(r28)
        ; epilog
        lg      r31,-(1 * GPR_BYTES)(r28)
        mtlr    r29
        lg      r30,-(2 * GPR_BYTES)(r28)
        lg      r29,-(3 * GPR_BYTES)(r28)
        lg      r28,-(4 * GPR_BYTES)(r28)
        lg      r1,0(r1)
        blr
LFE1:
        .align  1
/* END(_ffi_call_DARWIN)  */

/* Provide a null definition of _ffi_call_AIX.  */
        .text
        .globl _ffi_call_AIX
        .align 2
_ffi_call_AIX:
        blr
/* END(_ffi_call_AIX)  */

/* EH stuff.  */

#define EH_DATA_ALIGN_FACT MODE_CHOICE(0x7c,0x78)

        .static_data
        .align LOG2_GPR_BYTES
LLFB0$non_lazy_ptr:
        .g_long Lstartcode

        .section __TEXT,__eh_frame,coalesced,no_toc+strip_static_syms+live_support
EH_frame1:
        .set    L$set$0,LECIE1-LSCIE1
        .long   L$set$0 ; Length of Common Information Entry
LSCIE1:
        .long   0x0     ; CIE Identifier Tag
        .byte   0x1     ; CIE Version
        .ascii  "zR\0"  ; CIE Augmentation
        .byte   0x1     ; uleb128 0x1; CIE Code Alignment Factor
        .byte   EH_DATA_ALIGN_FACT ; sleb128 -4; CIE Data Alignment Factor
        .byte   0x41    ; CIE RA Column
        .byte   0x1     ; uleb128 0x1; Augmentation size
        .byte   0x90    ; FDE Encoding (indirect pcrel)
        .byte   0xc     ; DW_CFA_def_cfa
        .byte   0x1     ; uleb128 0x1
        .byte   0x0     ; uleb128 0x0
        .align  LOG2_GPR_BYTES
LECIE1:

        .globl _ffi_call_DARWIN.eh
_ffi_call_DARWIN.eh:
LSFDE1:
        .set    L$set$1,LEFDE1-LASFDE1
        .long   L$set$1 ; FDE Length
LASFDE1:
        .long   LASFDE1-EH_frame1 ; FDE CIE offset
        .g_long LLFB0$non_lazy_ptr-.    ; FDE initial location
        .set    L$set$3,LFE1-Lstartcode
        .g_long L$set$3 ; FDE address range
        .byte   0x0     ; uleb128 0x0; Augmentation size
        .byte   0x4     ; DW_CFA_advance_loc4
        .set    L$set$4,LCFI0-Lstartcode
        .long   L$set$4
        .byte   0xd     ; DW_CFA_def_cfa_register
        .byte   0x08    ; uleb128 0x08
        .byte   0x4     ; DW_CFA_advance_loc4
        .set    L$set$5,LCFI1-LCFI0
        .long   L$set$5
        .byte   0x11    ; DW_CFA_offset_extended_sf
        .byte   0x41    ; uleb128 0x41
        .byte   0x7e    ; sleb128 -2
        .byte   0x9f    ; DW_CFA_offset, column 0x1f
        .byte   0x1     ; uleb128 0x1
        .byte   0x9e    ; DW_CFA_offset, column 0x1e
        .byte   0x2     ; uleb128 0x2
        .byte   0x9d    ; DW_CFA_offset, column 0x1d
        .byte   0x3     ; uleb128 0x3
        .byte   0x9c    ; DW_CFA_offset, column 0x1c
        .byte   0x4     ; uleb128 0x4
        .byte   0x4     ; DW_CFA_advance_loc4
        .set    L$set$6,LCFI2-LCFI1
        .long   L$set$6
        .byte   0xd     ; DW_CFA_def_cfa_register
        .byte   0x1c    ; uleb128 0x1c
        .align LOG2_GPR_BYTES
LEFDE1:
        .align 1