source: trunk/gcc/libffi/src/arm/sysv.S

/* -----------------------------------------------------------------------
   sysv.S - Copyright (c) 1998 Cygnus Solutions
   
   ARM 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 CYGNUS SOLUTIONS 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 <ffi.h>
#ifdef HAVE_MACHINE_ASM_H
#include <machine/asm.h>
#else
#ifdef __USER_LABEL_PREFIX__
#define CONCAT1(a, b) CONCAT2(a, b)
#define CONCAT2(a, b) a ## b

/* Use the right prefix for global labels.  */
#define CNAME(x) CONCAT1 (__USER_LABEL_PREFIX__, x)
#else
#define CNAME(x) x
#endif
#define ENTRY(x) .globl CNAME(x); .type CNAME(x),%function; CNAME(x):
#endif
        
.text

        # a1:   ffi_prep_args
        # a2:   &ecif
        # a3:   cif->bytes
        # a4:   fig->flags
        # sp+0: ecif.rvalue
        # sp+4: fn

        # This assumes we are using gas.
ENTRY(ffi_call_SYSV)
        # Save registers
        stmfd sp!, {a1-a4, fp, lr}
        mov   fp, sp

        # Make room for all of the new args.
        sub   sp, fp, a3

        # Place all of the ffi_prep_args in position
        mov   ip, a1
        mov   a1, sp
        #     a2 already set

        # And call
        mov   lr, pc
        mov   pc, ip

        # move first 4 parameters in registers
        ldr   a1, [sp, #0]
        ldr   a2, [sp, #4]
        ldr   a3, [sp, #8]
        ldr   a4, [sp, #12]

        # and adjust stack
        ldr   ip, [fp, #8]
        cmp   ip, #16
        movge ip, #16
        add   sp, sp, ip

        # call function
        mov   lr, pc
        ldr   pc, [fp, #28]

        # Remove the space we pushed for the args
        mov   sp, fp

        # Load a3 with the pointer to storage for the return value
        ldr   a3, [sp, #24]

        # Load a4 with the return type code 
        ldr   a4, [sp, #12]

        # If the return value pointer is NULL, assume no return value.
        cmp   a3, #0
        beq   epilogue

# return INT
        cmp   a4, #FFI_TYPE_INT
        streq a1, [a3]
        beq   epilogue

# return FLOAT
        cmp     a4, #FFI_TYPE_FLOAT
#ifdef __SOFTFP__
        streq   a1, [a3]
#else
        stfeqs  f0, [a3]
#endif
        beq     epilogue

# return DOUBLE or LONGDOUBLE
        cmp     a4, #FFI_TYPE_DOUBLE
#ifdef __SOFTFP__
        stmeqia a3, {a1, a2}
#else
        stfeqd  f0, [a3]
#endif

epilogue:
        ldmfd sp!, {a1-a4, fp, pc}

.ffi_call_SYSV_end:
        .size    CNAME(ffi_call_SYSV),.ffi_call_SYSV_end-CNAME(ffi_call_SYSV)