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build/libraries/libffi/src/arm/sysv.S

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/* -----------------------------------------------------------------------
   sysv.S - Copyright (c) 1998, 2008, 2011 Red Hat, Inc.
        Copyright (c) 2011 Plausible Labs Cooperative, Inc.
   
   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 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>
#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
#ifdef __APPLE__
#define ENTRY(x) .globl _##x; _##x:
#else
#define ENTRY(x) .globl CNAME(x); .type CNAME(x),%function; CNAME(x):
#endif /* __APPLE__ */
#endif

#ifdef __ELF__
#define LSYM(x) .x
#else
#define LSYM(x) x
#endif

/* Use the SOFTFP return value ABI on macOS, as per the iOS ABI
  Function Call Guide */
#ifdef __APPLE__
#define __SOFTFP__
#endif

/* We need a better way of testing for this, but for now, this is all 
   we can do.  */
@ This selects the minimum architecture level required.
#define __ARM_ARCH__ 3

#if defined(__ARM_ARCH_4__) || defined(__ARM_ARCH_4T__)
# undef __ARM_ARCH__
# define __ARM_ARCH__ 4
#endif
        
#if defined(__ARM_ARCH_5__) || defined(__ARM_ARCH_5T__) \
    || defined(__ARM_ARCH_5E__) || defined(__ARM_ARCH_5TE__) \
    || defined(__ARM_ARCH_5TEJ__)
# undef __ARM_ARCH__
# define __ARM_ARCH__ 5
#endif

#if defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) \
        || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) \
        || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) \
    || defined(__ARM_ARCH_6M__)
# undef __ARM_ARCH__
# define __ARM_ARCH__ 6
#endif

#if defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) \
        || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) \
    || defined(__ARM_ARCH_7EM__)
# undef __ARM_ARCH__
# define __ARM_ARCH__ 7
#endif

#if __ARM_ARCH__ >= 5
# define call_reg(x)    blx    x
#elif defined (__ARM_ARCH_4T__)
# define call_reg(x)    mov    lr, pc ; bx    x
# if defined(__thumb__) || defined(__THUMB_INTERWORK__)
#  define __INTERWORKING__
# endif
#else
# define call_reg(x)    mov    lr, pc ; mov    pc, x
#endif

/* Conditionally compile unwinder directives.  */
#ifdef __ARM_EABI__
#define UNWIND
#else
#define UNWIND @
#endif    

.syntax unified

#if defined(__thumb__) && !defined(__THUMB_INTERWORK__)
#define ARM_FUNC_START(name) \
    .text; \
    .align 2; \
    .thumb; \
    .thumb_func; \
    ENTRY(name); \
    bx pc; \
    nop; \
    .arm; \
    UNWIND .fnstart; \
_L__##name:
#else
#define ARM_FUNC_START(name) \
    .text; \
    .align 2; \
    .arm; \
    ENTRY(name); \
    UNWIND .fnstart
#endif

.macro    RETLDM    regs=, cond=, dirn=ia
#if defined (__INTERWORKING__)
    .ifc "\regs",""
    ldr\cond    lr, [sp], #4
    .else
    ldm\cond\dirn    sp!, {\regs, lr}
    .endif
    bx\cond    lr
#else
    .ifc "\regs",""
    ldr\cond    pc, [sp], #4
    .else
    ldm\cond\dirn    sp!, {\regs, pc}
    .endif
#endif
.endm

    @ r0:   ffi_prep_args
    @ r1:   &ecif
    @ r2:   cif->bytes
    @ r3:   fig->flags
    @ sp+0: ecif.rvalue

    @ This assumes we are using gas.
ARM_FUNC_START(ffi_call_SYSV)
    @ Save registers
        stmfd    sp!, {r0-r3, fp, lr}
    UNWIND .save    {r0-r3, fp, lr}
    mov    fp, sp

    UNWIND .setfp    fp, sp

    @ Make room for all of the new args.
    sub    sp, fp, r2

    @ Place all of the ffi_prep_args in position
    mov    r0, sp
    @     r1 already set

    @ Call ffi_prep_args(stack, &ecif)
    bl    CNAME(ffi_prep_args_SYSV)

    @ move first 4 parameters in registers
    ldmia    sp, {r0-r3}

    @ and adjust stack
    sub    lr, fp, sp    @ cif->bytes == fp - sp
    ldr    ip, [fp]    @ load fn() in advance
    cmp    lr, #16
    movhs    lr, #16
    add    sp, sp, lr

    @ call (fn) (...)
    call_reg(ip)
    
    @ Remove the space we pushed for the args
    mov    sp, fp

    @ Load r2 with the pointer to storage for the return value
    ldr    r2, [sp, #24]

    @ Load r3 with the return type code 
    ldr    r3, [sp, #12]

    @ If the return value pointer is NULL, assume no return value.
    cmp    r2, #0
    beq    LSYM(Lepilogue)

@ return INT
    cmp    r3, #FFI_TYPE_INT
#if defined(__SOFTFP__) || defined(__ARM_EABI__)
    cmpne    r3, #FFI_TYPE_FLOAT
#endif
    streq    r0, [r2]
    beq    LSYM(Lepilogue)

    @ return INT64
    cmp    r3, #FFI_TYPE_SINT64
#if defined(__SOFTFP__) || defined(__ARM_EABI__)
    cmpne    r3, #FFI_TYPE_DOUBLE
#endif
    stmiaeq    r2, {r0, r1}

#if !defined(__SOFTFP__) && !defined(__ARM_EABI__)
    beq    LSYM(Lepilogue)

@ return FLOAT
    cmp    r3, #FFI_TYPE_FLOAT
    stfeqs    f0, [r2]
    beq    LSYM(Lepilogue)

@ return DOUBLE or LONGDOUBLE
    cmp    r3, #FFI_TYPE_DOUBLE
    stfeqd    f0, [r2]
#endif

LSYM(Lepilogue):
#if defined (__INTERWORKING__)
    ldmia   sp!, {r0-r3,fp, lr}
    bx    lr
#else
    ldmia   sp!, {r0-r3,fp, pc}
#endif

.ffi_call_SYSV_end:
    UNWIND .fnend
#ifdef __ELF__
        .size    CNAME(ffi_call_SYSV),.ffi_call_SYSV_end-CNAME(ffi_call_SYSV)
#endif


/*
    unsigned int FFI_HIDDEN
    ffi_closure_inner (closure, respp, args)
         ffi_closure *closure;
         void **respp;
           void *args;
*/

ARM_FUNC_START(ffi_closure_SYSV)
    UNWIND .pad #16
    add    ip, sp, #16
    stmfd    sp!, {ip, lr}
    UNWIND .save    {r0, lr}
    add    r2, sp, #8
    UNWIND .pad #16
    sub    sp, sp, #16
    str    sp, [sp, #8]
    add    r1, sp, #8
    bl    CNAME(ffi_closure_inner)
    cmp    r0, #FFI_TYPE_INT
    beq    .Lretint

    cmp    r0, #FFI_TYPE_FLOAT
#if defined(__SOFTFP__) || defined(__ARM_EABI__)
    beq    .Lretint
#else
    beq    .Lretfloat
#endif

    cmp    r0, #FFI_TYPE_DOUBLE
#if defined(__SOFTFP__) || defined(__ARM_EABI__)
    beq    .Lretlonglong
#else
    beq    .Lretdouble
#endif

    cmp    r0, #FFI_TYPE_LONGDOUBLE
#if defined(__SOFTFP__) || defined(__ARM_EABI__)
    beq    .Lretlonglong
#else
    beq    .Lretlongdouble
#endif

    cmp    r0, #FFI_TYPE_SINT64
    beq    .Lretlonglong
.Lclosure_epilogue:
    add    sp, sp, #16
    ldmfd    sp, {sp, pc}
.Lretint:
    ldr    r0, [sp]
    b    .Lclosure_epilogue
.Lretlonglong:
    ldr    r0, [sp]
    ldr    r1, [sp, #4]
    b    .Lclosure_epilogue

#if !defined(__SOFTFP__) && !defined(__ARM_EABI__)
.Lretfloat:
    ldfs    f0, [sp]
    b    .Lclosure_epilogue
.Lretdouble:
    ldfd    f0, [sp]
    b    .Lclosure_epilogue
.Lretlongdouble:
    ldfd    f0, [sp]
    b    .Lclosure_epilogue
#endif

.ffi_closure_SYSV_end:
    UNWIND .fnend
#ifdef __ELF__
        .size    CNAME(ffi_closure_SYSV),.ffi_closure_SYSV_end-CNAME(ffi_closure_SYSV)
#endif


/* Below are VFP hard-float ABI call and closure implementations.
   Add VFP FPU directive here. This is only compiled into the library
   under EABI.  */
#ifdef __ARM_EABI__
    .fpu    vfp

    @ r0:   fn
    @ r1:   &ecif
    @ r2:   cif->bytes
    @ r3:   fig->flags
    @ sp+0: ecif.rvalue

ARM_FUNC_START(ffi_call_VFP)
    @ Save registers
        stmfd    sp!, {r0-r3, fp, lr}
    UNWIND .save    {r0-r3, fp, lr}
    mov    fp, sp
    UNWIND .setfp    fp, sp

    @ Make room for all of the new args.
    sub    sp, sp, r2

    @ Make room for loading VFP args
    sub    sp, sp, #64

    @ Place all of the ffi_prep_args in position
    mov    r0, sp
    @     r1 already set
    sub    r2, fp, #64   @ VFP scratch space

    @ Call ffi_prep_args(stack, &ecif, vfp_space)
    bl    CNAME(ffi_prep_args_VFP)

    @ Load VFP register args if needed
    cmp    r0, #0
    mov    ip, fp
    beq    LSYM(Lbase_args)

    @ Load only d0 if possible
    cmp    r0, #3
    sub    ip, fp, #64
    flddle    d0, [ip]
    fldmiadgt    ip, {d0-d7}

LSYM(Lbase_args):
    @ move first 4 parameters in registers
    ldmia    sp, {r0-r3}

    @ and adjust stack
    sub    lr, ip, sp    @ cif->bytes == (fp - 64) - sp
    ldr    ip, [fp]    @ load fn() in advance
        cmp    lr, #16
    movhs    lr, #16
        add    sp, sp, lr

    @ call (fn) (...)
    call_reg(ip)

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

    @ Load r2 with the pointer to storage for
    @ the return value
    ldr    r2, [sp, #24]

    @ Load r3 with the return type code 
    ldr    r3, [sp, #12]

    @ If the return value pointer is NULL,
    @ assume no return value.
    cmp    r2, #0
    beq    LSYM(Lepilogue_vfp)

    cmp    r3, #FFI_TYPE_INT
    streq    r0, [r2]
    beq    LSYM(Lepilogue_vfp)

    cmp    r3, #FFI_TYPE_SINT64
    stmiaeq r2, {r0, r1}
    beq    LSYM(Lepilogue_vfp)

    cmp    r3, #FFI_TYPE_FLOAT
    fstseq    s0, [r2]
    beq    LSYM(Lepilogue_vfp)
    
    cmp    r3, #FFI_TYPE_DOUBLE
    fstdeq    d0, [r2]
    beq    LSYM(Lepilogue_vfp)

    cmp    r3, #FFI_TYPE_STRUCT_VFP_FLOAT
    cmpne    r3, #FFI_TYPE_STRUCT_VFP_DOUBLE
    fstmiadeq    r2, {d0-d3}

LSYM(Lepilogue_vfp):
    RETLDM    "r0-r3,fp"

.ffi_call_VFP_end:
    UNWIND .fnend
        .size    CNAME(ffi_call_VFP),.ffi_call_VFP_end-CNAME(ffi_call_VFP)


ARM_FUNC_START(ffi_closure_VFP)
    fstmfdd    sp!, {d0-d7}
    @ r0-r3, then d0-d7
    UNWIND .pad #80
    add    ip, sp, #80
    stmfd    sp!, {ip, lr}
    UNWIND .save    {r0, lr}
    add    r2, sp, #72
    add    r3, sp, #8
    UNWIND .pad #72
    sub    sp, sp, #72
    str    sp, [sp, #64]
    add    r1, sp, #64
    bl    CNAME(ffi_closure_inner)

    cmp    r0, #FFI_TYPE_INT
    beq    .Lretint_vfp

    cmp    r0, #FFI_TYPE_FLOAT
    beq    .Lretfloat_vfp

    cmp    r0, #FFI_TYPE_DOUBLE
    cmpne    r0, #FFI_TYPE_LONGDOUBLE
    beq    .Lretdouble_vfp

    cmp    r0, #FFI_TYPE_SINT64
    beq    .Lretlonglong_vfp

    cmp    r0, #FFI_TYPE_STRUCT_VFP_FLOAT
    beq    .Lretfloat_struct_vfp

    cmp    r0, #FFI_TYPE_STRUCT_VFP_DOUBLE
    beq    .Lretdouble_struct_vfp
    
.Lclosure_epilogue_vfp:
    add    sp, sp, #72
    ldmfd    sp, {sp, pc}

.Lretfloat_vfp:
    flds    s0, [sp]
    b    .Lclosure_epilogue_vfp
.Lretdouble_vfp:
    fldd    d0, [sp]
    b    .Lclosure_epilogue_vfp
.Lretint_vfp:
    ldr    r0, [sp]
    b    .Lclosure_epilogue_vfp
.Lretlonglong_vfp:
    ldmia    sp, {r0, r1}
    b    .Lclosure_epilogue_vfp
.Lretfloat_struct_vfp:
    fldmiad    sp, {d0-d1}
    b    .Lclosure_epilogue_vfp
.Lretdouble_struct_vfp:
    fldmiad    sp, {d0-d3}
    b    .Lclosure_epilogue_vfp

.ffi_closure_VFP_end:
    UNWIND .fnend
        .size    CNAME(ffi_closure_VFP),.ffi_closure_VFP_end-CNAME(ffi_closure_VFP)
#endif

ENTRY(ffi_arm_trampoline)
    stmfd sp!, {r0-r3}
    ldr r0, [pc]
    ldr pc, [pc]

#if defined __ELF__ && defined __linux__
    .section    .note.GNU-stack,"",%progbits
#endif