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/*  Special support for trampolines
 *
 *   Copyright (C) 1996, 1997, 2000, 2004, 2005, 2009 Free Software Foundation, Inc.
 *   Written By Michael Meissner
 * 
 * This file is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 3, or (at your option) any
 * later version.
 * 
 * This file is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 * 
 * Under Section 7 of GPL version 3, you are granted additional
 * permissions described in the GCC Runtime Library Exception, version
 * 3.1, as published by the Free Software Foundation.
 *
 * You should have received a copy of the GNU General Public License and
 * a copy of the GCC Runtime Library Exception along with this program;
 * see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 * <http://www.gnu.org/licenses/>.
 */ 

#include "darwin-asm.h"

/* Set up trampolines.  */

.text
        .align  LOG2_GPR_BYTES
Ltrampoline_initial:
        mflr    r0
        bl      1f
Lfunc = .-Ltrampoline_initial
        .g_long 0                /* will be replaced with function address */
Lchain = .-Ltrampoline_initial
        .g_long 0                /* will be replaced with static chain */
1:      mflr    r11
        lg      r12,0(r11)      /* function address */
        mtlr    r0
        mtctr   r12
        lg      r11,GPR_BYTES(r11)      /* static chain */
        bctr

trampoline_size = .-Ltrampoline_initial

/* R3 = stack address to store trampoline */
/* R4 = length of trampoline area */
/* R5 = function address */
/* R6 = static chain */

        .globl ___trampoline_setup
___trampoline_setup:
        mflr    r0              /* save return address */
        bcl 20,31,LCF0          /* load up __trampoline_initial into r7 */
LCF0:
        mflr    r11
        addis   r7,r11,ha16(LTRAMP-LCF0)
        lg      r7,lo16(LTRAMP-LCF0)(r7)
        subi    r7,r7,4
        li      r8,trampoline_size      /* verify trampoline big enough */
        cmpg    cr1,r8,r4
        srwi    r4,r4,2                 /* # words to move (insns always 4-byte) */
        addi    r9,r3,-4        /* adjust pointer for lgu */
        mtctr   r4
        blt     cr1,Labort

        mtlr    r0

        /* Copy the instructions to the stack */
Lmove:
        lwzu    r10,4(r7)
        stwu    r10,4(r9)
        bdnz    Lmove

        /* Store correct function and static chain */
        stg     r5,Lfunc(r3)
        stg     r6,Lchain(r3)

        /* Now flush both caches */
        mtctr   r4
Lcache:
        icbi    0,r3
        dcbf    0,r3
        addi    r3,r3,4
        bdnz    Lcache

        /* Ensure cache-flushing has finished.  */
        sync
        isync

        /* Make stack writeable.  */
        b       ___enable_execute_stack

Labort:
#ifdef __DYNAMIC__
        bl      L_abort$stub
.data
.section __TEXT,__picsymbolstub1,symbol_stubs,pure_instructions,32
        .align 2
L_abort$stub:
        .indirect_symbol _abort
        mflr r0
        bcl 20,31,L0$_abort
L0$_abort:
        mflr r11
        addis r11,r11,ha16(L_abort$lazy_ptr-L0$_abort)
        mtlr r0
        lgu r12,lo16(L_abort$lazy_ptr-L0$_abort)(r11)
        mtctr r12
        bctr
.data
.lazy_symbol_pointer
L_abort$lazy_ptr:
        .indirect_symbol _abort
        .g_long dyld_stub_binding_helper
#else
        bl      _abort
#endif
.data
        .align LOG2_GPR_BYTES
LTRAMP:
        .g_long Ltrampoline_initial