/*
  AngelCode Scripting Library
  Copyright (c) 2003-2009 Andreas Jonsson

  This software is provided 'as-is', without any express or implied
  warranty. In no event will the authors be held liable for any
  damages arising from the use of this software.

  Permission is granted to anyone to use this software for any
  purpose, including commercial applications, and to alter it and
  redistribute it freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you
     must not claim that you wrote the original software. If you use
     this software in a product, an acknowledgment in the product
     documentation would be appreciated but is not required.

  2. Altered source versions must be plainly marked as such, and
     must not be misrepresented as being the original software.

  3. This notice may not be removed or altered from any source
     distribution.

  The original version of this library can be located at:
  http://www.angelcode.com/angelscript/

  Andreas Jonsson
  andreas@angelcode.com
*/


// Assembly routines for the ARM call convention
// Written by Fredrik Ehnbom in June 2009

// Adapted to GNUC by darktemplar216 in September 2009

#if defined(__arm__) || defined(__ARM__)

.global armFunc
.global armFuncR0
.global armFuncR0R1
.global armFuncObjLast
.global armFuncR0ObjLast
    
armFunc:
    stmdb   sp!, {r4-r8, lr}
    mov     r6, r0  // arg table
    movs    r7, r1  // arg size (also set the condition code flags so that we detect if there are no arguments)
    mov     r4, r2  // function address
    mov     r8, #0

    beq     nomoreargs

    // Load the first 4 arguments into r0-r3
    cmp     r7, #4
    ldrge   r0, [r6],#4
    cmp     r7, #2*4
    ldrge   r1, [r6],#4
    cmp     r7, #3*4
    ldrge   r2, [r6],#4
    cmp     r7, #4*4
    ldrge   r3, [r6],#4
    ble     nomoreargs

    // Load the rest of the arguments onto the stack
    sub     r7, r7, #4*4    // skip the 4 registers already loaded into r0-r3
    sub     sp, sp, r7
    mov     r8, r7
stackargsloop:
    ldr     r5, [r6], #4
    str     r5, [sp], #4
    subs    r7, r7, #4
    bne     stackargsloop
nomoreargs:
    sub     sp, sp, r8
    blx     r4
    add     sp, sp, r8
    ldmia   sp!, {r4-r8, pc}

armFuncObjLast:
    stmdb   sp!, {r4-r8, lr}
    mov     r6, r0  // arg table
    movs    r7, r1  // arg size (also set the condition code flags so that we detect if there are no arguments)
    mov     r4, r2  // function address
    mov     r8, #0

    mov     r0, r3          // objlast. might get overwritten
    str     r3, [sp, #-4]!  // objlast again.

    beq     nomoreargsarmFuncObjLast

    // Load the first 4 arguments into r0-r3
    cmp     r7, #4
    ldrge   r0, [r6],#4
    cmp     r7, #2*4
    ldrge   r1, [r6],#4
    ldrlt   r1, [sp]    
    cmp     r7, #3*4
    ldrge   r2, [r6],#4
    ldrlt   r2, [sp]
    cmp     r7, #4*4
    ldrge   r3, [r6],#4
    ldrlt   r3, [sp]
    ble     nomoreargsarmFuncObjLast

    // Load the rest of the arguments onto the stack
    sub     r7, r7, #4*4    // skip the 4 registers already loaded into r0-r3
    sub     sp, sp, r7
    mov     r8, r7
stackargslooparmFuncObjLast:
    ldr     r5, [r6], #4
    str     r5, [sp], #4
    subs    r7, r7, #4
    bne     stackargslooparmFuncObjLast
nomoreargsarmFuncObjLast:
    sub     sp, sp, r8
    blx     r4
    add     sp, sp, r8
    add     sp, sp, #4
    ldmia   sp!, {r4-r8, pc}

armFuncR0ObjLast:
    stmdb   sp!, {r4-r8, lr}
    ldr     r7, [sp,#6*4]
    str     r7, [sp,#-4]!

    mov     r6, r0  // arg table
    movs    r7, r1  // arg size (also set the condition code flags so that we detect if there are no arguments)
    mov     r4, r2  // function address
    mov     r8, #0

    mov     r0, r3      // r0 explicitly set
    ldr     r1, [sp]    // objlast.  might get overwritten

    beq     nomoreargsarmFuncR0ObjLast

    // Load the first 3 arguments into r1-r3
    cmp     r7, #1*4
    ldrge   r1, [r6],#4
    cmp     r7, #2*4
    ldrge   r2, [r6],#4
    ldrlt   r2, [sp]
    cmp     r7, #3*4
    ldrge   r3, [r6],#4
    ldrlt   r3, [sp]
    ble     nomoreargsarmFuncR0ObjLast

    // Load the rest of the arguments onto the stack
    sub     r7, r7, #3*4    // skip the 3 registers already loaded into r1-r3
    sub     sp, sp, r7
    mov     r8, r7
stackargslooparmFuncR0ObjLast:
    ldr     r5, [r6], #4
    str     r5, [sp], #4
    subs    r7, r7, #4
    bne     stackargslooparmFuncR0ObjLast
nomoreargsarmFuncR0ObjLast:
    sub     sp, sp, r8
    blx     r4
    add     sp, sp, r8
    add     sp, sp, #4
    ldmia   sp!, {r4-r8, pc}


armFuncR0:
    stmdb   sp!, {r4-r8, lr}
    mov     r6, r0  // arg table
    movs    r7, r1  // arg size (also set the condition code flags so that we detect if there are no arguments)
    mov     r4, r2  // function address
    mov     r8, #0

    mov     r0, r3  // r0 explicitly set

    beq     nomoreargsarmFuncR0

    // Load the first 3 arguments into r1-r3
    cmp     r7, #1*4
    ldrge   r1, [r6],#4
    cmp     r7, #2*4
    ldrge   r2, [r6],#4
    cmp     r7, #3*4
    ldrge   r3, [r6],#4
    ble     nomoreargsarmFuncR0

    // Load the rest of the arguments onto the stack
    sub     r7, r7, #3*4    // skip the 3 registers already loaded into r1-r3
    sub     sp, sp, r7
    mov     r8, r7
stackargslooparmFuncR0:
    ldr     r5, [r6], #4
    str     r5, [sp], #4
    subs    r7, r7, #4
    bne     stackargslooparmFuncR0
nomoreargsarmFuncR0:
    sub     sp, sp, r8
    blx     r4
    add     sp, sp, r8
    ldmia   sp!, {r4-r8, pc}


armFuncR0R1:
    stmdb   sp!, {r4-r8, lr}
    mov     r6, r0  // arg table
    movs    r7, r1  // arg size (also set the condition code flags so that we detect if there are no arguments)
    mov     r4, r2  // function address
    mov     r8, #0

    mov     r0, r3          // r0 explicitly set
    ldr     r1, [sp, #6*4]  // r1 explicitly set too

    beq     nomoreargsarmFuncR0R1

    // Load the first 2 arguments into r2-r3
    cmp     r7, #1*4
    ldrge   r2, [r6],#4
    cmp     r7, #2*4
    ldrge   r3, [r6],#4
    ble     nomoreargsarmFuncR0R1

    // Load the rest of the arguments onto the stack
    sub     r7, r7, #2*4    // skip the 2 registers already loaded into r2-r3
    sub     sp, sp, r7
    mov     r8, r7
stackargslooparmFuncR0R1:
    ldr     r5, [r6], #4
    str     r5, [sp], #4
    subs    r7, r7, #4
    bne     stackargslooparmFuncR0R1
nomoreargsarmFuncR0R1:
    sub     sp, sp, r8
    blx     r4
    add     sp, sp, r8
    ldmia   sp!, {r4-r8, pc}

#endif
