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/* -----------------------------------------------------------------------
   o32.S - Copyright (c) 1996, 1998, 2005  Red Hat, Inc.
   
   MIPS 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.
   ----------------------------------------------------------------------- */

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

/* Only build this code if we are compiling for o32 */  

#if defined(FFI_MIPS_O32)
        
#define callback a0
#define bytes    a2
#define flags    a3
                
#define SIZEOF_FRAME    (4 * FFI_SIZEOF_ARG + 2 * FFI_SIZEOF_ARG)
#define A3_OFF          (SIZEOF_FRAME + 3 * FFI_SIZEOF_ARG)
#define FP_OFF          (SIZEOF_FRAME - 2 * FFI_SIZEOF_ARG)
#define RA_OFF          (SIZEOF_FRAME - 1 * FFI_SIZEOF_ARG)

        .abicalls
        .text
        .align  2
        .globl  ffi_call_O32
        .ent    ffi_call_O32
ffi_call_O32:   
$LFB0:
        # Prologue
        SUBU    $sp, SIZEOF_FRAME       # Frame size
$LCFI0:
        REG_S   $fp, FP_OFF($sp)        # Save frame pointer
$LCFI1:
        REG_S   ra, RA_OFF($sp)         # Save return address
$LCFI2:
        move    $fp, $sp

$LCFI3:
        move    t9, callback            # callback function pointer
        REG_S   flags, A3_OFF($fp)      # flags

        # Allocate at least 4 words in the argstack
        LI      v0, 4 * FFI_SIZEOF_ARG
        blt     bytes, v0, sixteen

        ADDU    v0, bytes, 7    # make sure it is aligned 
        and     v0, -8          # to an 8 byte boundry

sixteen:
        SUBU    $sp, v0         # move the stack pointer to reflect the
                                # arg space

        ADDU    a0, $sp, 4 * FFI_SIZEOF_ARG

        jalr    t9
        
        REG_L   t0, A3_OFF($fp)         # load the flags word
        SRL     t2, t0, 4               # shift our arg info
        and     t0, ((1<<4)-1)          # mask out the return type
                
        ADDU    $sp, 4 * FFI_SIZEOF_ARG         # adjust $sp to new args

        bnez    t0, pass_d                      # make it quick for int
        REG_L   a0, 0*FFI_SIZEOF_ARG($sp)       # just go ahead and load the
        REG_L   a1, 1*FFI_SIZEOF_ARG($sp)       # four regs.
        REG_L   a2, 2*FFI_SIZEOF_ARG($sp)
        REG_L   a3, 3*FFI_SIZEOF_ARG($sp)
        b       call_it

pass_d:
        bne     t0, FFI_ARGS_D, pass_f
        l.d     $f12, 0*FFI_SIZEOF_ARG($sp)     # load $fp regs from args
        REG_L   a2,   2*FFI_SIZEOF_ARG($sp)     # passing a double
        REG_L   a3,   3*FFI_SIZEOF_ARG($sp)
        b       call_it

pass_f: 
        bne     t0, FFI_ARGS_F, pass_d_d
        l.s     $f12, 0*FFI_SIZEOF_ARG($sp)     # load $fp regs from args
        REG_L   a1,   1*FFI_SIZEOF_ARG($sp)     # passing a float
        REG_L   a2,   2*FFI_SIZEOF_ARG($sp)
        REG_L   a3,   3*FFI_SIZEOF_ARG($sp)
        b       call_it         

pass_d_d:               
        bne     t0, FFI_ARGS_DD, pass_f_f
        l.d     $f12, 0*FFI_SIZEOF_ARG($sp)     # load $fp regs from args
        l.d     $f14, 2*FFI_SIZEOF_ARG($sp)     # passing two doubles
        b       call_it

pass_f_f:       
        bne     t0, FFI_ARGS_FF, pass_d_f
        l.s     $f12, 0*FFI_SIZEOF_ARG($sp)     # load $fp regs from args
        l.s     $f14, 1*FFI_SIZEOF_ARG($sp)     # passing two floats
        REG_L   a2,   2*FFI_SIZEOF_ARG($sp)
        REG_L   a3,   3*FFI_SIZEOF_ARG($sp)
        b       call_it

pass_d_f:               
        bne     t0, FFI_ARGS_DF, pass_f_d
        l.d     $f12, 0*FFI_SIZEOF_ARG($sp)     # load $fp regs from args
        l.s     $f14, 2*FFI_SIZEOF_ARG($sp)     # passing double and float
        REG_L   a3,   3*FFI_SIZEOF_ARG($sp)
        b       call_it

pass_f_d:               
 # assume that the only other combination must be float then double
 #      bne     t0, FFI_ARGS_F_D, call_it
        l.s     $f12, 0*FFI_SIZEOF_ARG($sp)     # load $fp regs from args
        l.d     $f14, 2*FFI_SIZEOF_ARG($sp)     # passing double and float

call_it:        
        # Load the function pointer
        REG_L   t9, SIZEOF_FRAME + 5*FFI_SIZEOF_ARG($fp)

        # If the return value pointer is NULL, assume no return value.
        REG_L   t1, SIZEOF_FRAME + 4*FFI_SIZEOF_ARG($fp)
        beqz    t1, noretval

        bne     t2, FFI_TYPE_INT, retlonglong
        jalr    t9
        REG_L   t0, SIZEOF_FRAME + 4*FFI_SIZEOF_ARG($fp)
        REG_S   v0, 0(t0)
        b       epilogue

retlonglong:
        # Really any 64-bit int, signed or not.
        bne     t2, FFI_TYPE_UINT64, retfloat
        jalr    t9
        REG_L   t0, SIZEOF_FRAME + 4*FFI_SIZEOF_ARG($fp)
        REG_S   v1, 4(t0)
        REG_S   v0, 0(t0)
        b       epilogue

retfloat:
        bne     t2, FFI_TYPE_FLOAT, retdouble
        jalr    t9
        REG_L   t0, SIZEOF_FRAME + 4*FFI_SIZEOF_ARG($fp)
        s.s     $f0, 0(t0)
        b       epilogue

retdouble:      
        bne     t2, FFI_TYPE_DOUBLE, noretval
        jalr    t9
        REG_L   t0, SIZEOF_FRAME + 4*FFI_SIZEOF_ARG($fp)
        s.d     $f0, 0(t0)
        b       epilogue
        
noretval:       
        jalr    t9
        
        # Epilogue
epilogue:       
        move    $sp, $fp        
        REG_L   $fp, FP_OFF($sp)        # Restore frame pointer
        REG_L   ra, RA_OFF($sp)         # Restore return address
        ADDU    $sp, SIZEOF_FRAME       # Fix stack pointer
        j       ra

$LFE0:
        .end    ffi_call_O32


/* ffi_closure_O32. Expects address of the passed-in ffi_closure
        in t4 ($12). Stores any arguments passed in registers onto the
        stack, then calls ffi_closure_mips_inner_O32, which
        then decodes them.
        
        Stack layout:

         3 - a3 save
         2 - a2 save
         1 - a1 save
         0 - a0 save, original sp
        -1 - ra save
        -2 - fp save
        -3 - $16 (s0) save
        -4 - cprestore
        -5 - return value high (v1)
        -6 - return value low (v0)
        -7 - f14 (le high, be low)
        -8 - f14 (le low, be high)
        -9 - f12 (le high, be low)
       -10 - f12 (le low, be high)
       -11 - Called function a3 save
       -12 - Called function a2 save
       -13 - Called function a1 save
       -14 - Called function a0 save, our sp and fp point here
         */
        
#define SIZEOF_FRAME2   (14 * FFI_SIZEOF_ARG)
#define A3_OFF2         (SIZEOF_FRAME2 + 3 * FFI_SIZEOF_ARG)
#define A2_OFF2         (SIZEOF_FRAME2 + 2 * FFI_SIZEOF_ARG)
#define A1_OFF2         (SIZEOF_FRAME2 + 1 * FFI_SIZEOF_ARG)
#define A0_OFF2         (SIZEOF_FRAME2 + 0 * FFI_SIZEOF_ARG)
#define RA_OFF2         (SIZEOF_FRAME2 - 1 * FFI_SIZEOF_ARG)
#define FP_OFF2         (SIZEOF_FRAME2 - 2 * FFI_SIZEOF_ARG)
#define S0_OFF2         (SIZEOF_FRAME2 - 3 * FFI_SIZEOF_ARG)
#define GP_OFF2         (SIZEOF_FRAME2 - 4 * FFI_SIZEOF_ARG)
#define V1_OFF2         (SIZEOF_FRAME2 - 5 * FFI_SIZEOF_ARG)
#define V0_OFF2         (SIZEOF_FRAME2 - 6 * FFI_SIZEOF_ARG)
#define FA_1_1_OFF2     (SIZEOF_FRAME2 - 7 * FFI_SIZEOF_ARG)
#define FA_1_0_OFF2     (SIZEOF_FRAME2 - 8 * FFI_SIZEOF_ARG)
#define FA_0_1_OFF2     (SIZEOF_FRAME2 - 9 * FFI_SIZEOF_ARG)
#define FA_0_0_OFF2     (SIZEOF_FRAME2 - 10 * FFI_SIZEOF_ARG)

        .text
        .align  2
        .globl  ffi_closure_O32
        .ent    ffi_closure_O32
ffi_closure_O32:
$LFB1:
        # Prologue
        .frame  $fp, SIZEOF_FRAME2, ra
        .set    noreorder
        .cpload t9
        .set    reorder
        SUBU    $sp, SIZEOF_FRAME2
        .cprestore GP_OFF2
$LCFI4:
        REG_S   $16, S0_OFF2($sp)        # Save s0
        REG_S   $fp, FP_OFF2($sp)        # Save frame pointer
        REG_S   ra, RA_OFF2($sp)         # Save return address
$LCFI6:
        move    $fp, $sp

$LCFI7:
        # Store all possible argument registers. If there are more than
        # four arguments, then they are stored above where we put a3.
        REG_S   a0, A0_OFF2($fp)
        REG_S   a1, A1_OFF2($fp)
        REG_S   a2, A2_OFF2($fp)
        REG_S   a3, A3_OFF2($fp)

        # Load ABI enum to s0
        REG_L   $16, 20($12)    # cif pointer follows tramp.
        REG_L   $16, 0($16)     # abi is first member.

        li      $13, 1          # FFI_O32
        bne     $16, $13, 1f    # Skip fp save if FFI_O32_SOFT_FLOAT
        
        # Store all possible float/double registers.
        s.d     $f12, FA_0_0_OFF2($fp)
        s.d     $f14, FA_1_0_OFF2($fp)
1:      
        # Call ffi_closure_mips_inner_O32 to do the work.
        la      t9, ffi_closure_mips_inner_O32
        move    a0, $12  # Pointer to the ffi_closure
        addu    a1, $fp, V0_OFF2
        addu    a2, $fp, A0_OFF2
        addu    a3, $fp, FA_0_0_OFF2
        jalr    t9

        # Load the return value into the appropriate register.
        move    $8, $2
        li      $9, FFI_TYPE_VOID
        beq     $8, $9, closure_done

        li      $13, 1          # FFI_O32
        bne     $16, $13, 1f    # Skip fp restore if FFI_O32_SOFT_FLOAT

        li      $9, FFI_TYPE_FLOAT
        l.s     $f0, V0_OFF2($fp)
        beq     $8, $9, closure_done

        li      $9, FFI_TYPE_DOUBLE
        l.d     $f0, V0_OFF2($fp)
        beq     $8, $9, closure_done
1:      
        REG_L   $3, V1_OFF2($fp)
        REG_L   $2, V0_OFF2($fp)

closure_done:
        # Epilogue
        move    $sp, $fp
        REG_L   $16, S0_OFF2($sp)        # Restore s0
        REG_L   $fp, FP_OFF2($sp)        # Restore frame pointer
        REG_L   ra,  RA_OFF2($sp)        # Restore return address
        ADDU    $sp, SIZEOF_FRAME2
        j       ra
$LFE1:
        .end    ffi_closure_O32

/* DWARF-2 unwind info. */

        .section        .eh_frame,"a",@progbits
$Lframe0:
        .4byte  $LECIE0-$LSCIE0  # Length of Common Information Entry
$LSCIE0:
        .4byte  0x0      # CIE Identifier Tag
        .byte   0x1      # CIE Version
        .ascii "zR\0"    # CIE Augmentation
        .uleb128 0x1     # CIE Code Alignment Factor
        .sleb128 4       # CIE Data Alignment Factor
        .byte   0x1f     # CIE RA Column
        .uleb128 0x1     # Augmentation size
        .byte   0x00     # FDE Encoding (absptr)
        .byte   0xc      # DW_CFA_def_cfa
        .uleb128 0x1d
        .uleb128 0x0
        .align  2
$LECIE0:
$LSFDE0:
        .4byte  $LEFDE0-$LASFDE0         # FDE Length
$LASFDE0:
        .4byte  $LASFDE0-$Lframe0        # FDE CIE offset
        .4byte  $LFB0    # FDE initial location
        .4byte  $LFE0-$LFB0      # FDE address range
        .uleb128 0x0     # Augmentation size
        .byte   0x4      # DW_CFA_advance_loc4
        .4byte  $LCFI0-$LFB0
        .byte   0xe      # DW_CFA_def_cfa_offset
        .uleb128 0x18
        .byte   0x4      # DW_CFA_advance_loc4
        .4byte  $LCFI2-$LCFI0
        .byte   0x11     # DW_CFA_offset_extended_sf
        .uleb128 0x1e    # $fp
        .sleb128 -2      # SIZEOF_FRAME2 - 2*FFI_SIZEOF_ARG($sp)
        .byte   0x11     # DW_CFA_offset_extended_sf
        .uleb128 0x1f    # $ra
        .sleb128 -1      # SIZEOF_FRAME2 - 1*FFI_SIZEOF_ARG($sp)
        .byte   0x4      # DW_CFA_advance_loc4
        .4byte  $LCFI3-$LCFI2
        .byte   0xc      # DW_CFA_def_cfa
        .uleb128 0x1e
        .uleb128 0x18
        .align  2
$LEFDE0:
$LSFDE1:
        .4byte  $LEFDE1-$LASFDE1         # FDE Length
$LASFDE1:
        .4byte  $LASFDE1-$Lframe0        # FDE CIE offset
        .4byte  $LFB1    # FDE initial location
        .4byte  $LFE1-$LFB1      # FDE address range
        .uleb128 0x0     # Augmentation size
        .byte   0x4      # DW_CFA_advance_loc4
        .4byte  $LCFI4-$LFB1
        .byte   0xe      # DW_CFA_def_cfa_offset
        .uleb128 0x38
        .byte   0x4      # DW_CFA_advance_loc4
        .4byte  $LCFI6-$LCFI4
        .byte   0x11     # DW_CFA_offset_extended_sf
        .uleb128 0x10    # $16
        .sleb128 -3      # SIZEOF_FRAME2 - 3*FFI_SIZEOF_ARG($sp)
        .byte   0x11     # DW_CFA_offset_extended_sf
        .uleb128 0x1e    # $fp
        .sleb128 -2      # SIZEOF_FRAME2 - 2*FFI_SIZEOF_ARG($sp)
        .byte   0x11     # DW_CFA_offset_extended_sf
        .uleb128 0x1f    # $ra
        .sleb128 -1      # SIZEOF_FRAME2 - 1*FFI_SIZEOF_ARG($sp)
        .byte   0x4      # DW_CFA_advance_loc4
        .4byte  $LCFI7-$LCFI6
        .byte   0xc      # DW_CFA_def_cfa
        .uleb128 0x1e
        .uleb128 0x38
        .align  2
$LEFDE1:

#endif