gcc/config/rs6000/darwin-tramp.asm

   1 /*  Special support for trampolines
   2  *
   3  *   Copyright (C) 1996, 1997, 2000 Free Software Foundation, Inc.
   4  *   Written By Michael Meissner
   5  *
   6  * This file is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2, or (at your option) any
   9  * later version.
  10  *
  11  * In addition to the permissions in the GNU General Public License, the
  12  * Free Software Foundation gives you unlimited permission to link the
  13  * compiled version of this file with other programs, and to distribute
  14  * those programs without any restriction coming from the use of this
  15  * file.  (The General Public License restrictions do apply in other
  16  * respects; for example, they cover modification of the file, and
  17  * distribution when not linked into another program.)
  18  *
  19  * This file is distributed in the hope that it will be useful, but
  20  * WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22  * General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; see the file COPYING.  If not, write to
  26  * the Free Software Foundation, 59 Temple Place - Suite 330,
  27  * Boston, MA 02111-1307, USA.
  28  *
  29  *  As a special exception, if you link this library with files
  30  *  compiled with GCC to produce an executable, this does not cause the
  31  *  resulting executable to be covered by the GNU General Public License.
  32  *  This exception does not however invalidate any other reasons why the
  33  *  executable file might be covered by the GNU General Public License.
  34  */
  35
  36 /* Set up trampolines.  */
  37
  38 .text
  39         .align  2
  40 Ltrampoline_initial:
  41         mflr    r0
  42         bl      1f
  43 Lfunc = .-Ltrampoline_initial
  44         .long   0               /* will be replaced with function address */
  45 Lchain = .-Ltrampoline_initial
  46         .long   0               /* will be replaced with static chain */
  47 1:      mflr    r11
  48         lwz     r12,0(r11)      /* function address */
  49         mtlr    r0
  50         mtctr   r12
  51         lwz     r11,4(r11)      /* static chain */
  52         bctr
  53
  54 trampoline_size = .-Ltrampoline_initial
  55
  56 /* R3 = stack address to store trampoline */
  57 /* R4 = length of trampoline area */
  58 /* R5 = function address */
  59 /* R6 = static chain */
  60
  61         .globl ___trampoline_setup
  62 ___trampoline_setup:
  63         mflr    r0              /* save return address */
  64         bcl 20,31,LCF0          /* load up __trampoline_initial into r7 */
  65 LCF0:
  66         mflr    r11
  67         addi    r7,r11,ha16(LTRAMP-LCF0)
  68         lwz     r7,lo16(LTRAMP-LCF0)(r7)
  69         subi    r7,r7,4
  70         li      r8,trampoline_size      /* verify trampoline big enough */
  71         cmpw    cr1,r8,r4
  72         srwi    r4,r4,2         /* # words to move */
  73         addi    r9,r3,-4        /* adjust pointer for lwzu */
  74         mtctr   r4
  75         blt     cr1,Labort
  76
  77         mtlr    r0
  78
  79         /* Copy the instructions to the stack */
  80 Lmove:
  81         lwzu    r10,4(r7)
  82         stwu    r10,4(r9)
  83         bdnz    Lmove
  84
  85         /* Store correct function and static chain */
  86         stw     r5,Lfunc(r3)
  87         stw     r6,Lchain(r3)
  88
  89         /* Now flush both caches */
  90         mtctr   r4
  91 Lcache:
  92         icbi    0,r3
  93         dcbf    0,r3
  94         addi    r3,r3,4
  95         bdnz    Lcache
  96
  97         /* Finally synchronize things & return */
  98         sync
  99         isync
 100         blr
 101
 102 Labort:
 103 #ifdef __DYNAMIC__
 104         bl      L_abort$stub
 105 .data
 106 .picsymbol_stub
 107 L_abort$stub:
 108         .indirect_symbol _abort
 109         mflr r0
 110         bcl 20,31,L0$_abort
 111 L0$_abort:
 112         mflr r11
 113         addis r11,r11,ha16(L_abort$lazy_ptr-L0$_abort)
 114         mtlr r0
 115         lwz r12,lo16(L_abort$lazy_ptr-L0$_abort)(r11)
 116         mtctr r12
 117         addi r11,r11,lo16(L_abort$lazy_ptr-L0$_abort)
 118         bctr
 119 .data
 120 .lazy_symbol_pointer
 121 L_abort$lazy_ptr:
 122         .indirect_symbol _abort
 123         .long dyld_stub_binding_helper
 124 #else
 125         bl      _abort
 126 #endif
 127 .data
 128         .align 2
 129 LTRAMP:
 130         .long Ltrampoline_initial
 131