gcc/config/rs6000/darwin-tramp.asm

   1 /*  Special support for trampolines
   2  *
   3  *   Copyright (C) 1996, 1997, 2000, 2004, 2005 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 #include "darwin-asm.h"
  37
  38 /* Set up trampolines.  */
  39
  40 .text
  41         .align  LOG2_GPR_BYTES
  42 Ltrampoline_initial:
  43         mflr    r0
  44         bl      1f
  45 Lfunc = .-Ltrampoline_initial
  46         .g_long 0               /* will be replaced with function address */
  47 Lchain = .-Ltrampoline_initial
  48         .g_long 0               /* will be replaced with static chain */
  49 1:      mflr    r11
  50         lg      r12,0(r11)      /* function address */
  51         mtlr    r0
  52         mtctr   r12
  53         lg      r11,GPR_BYTES(r11)      /* static chain */
  54         bctr
  55
  56 trampoline_size = .-Ltrampoline_initial
  57
  58 /* R3 = stack address to store trampoline */
  59 /* R4 = length of trampoline area */
  60 /* R5 = function address */
  61 /* R6 = static chain */
  62
  63         .globl ___trampoline_setup
  64 ___trampoline_setup:
  65         mflr    r0              /* save return address */
  66         bcl 20,31,LCF0          /* load up __trampoline_initial into r7 */
  67 LCF0:
  68         mflr    r11
  69         addis   r7,r11,ha16(LTRAMP-LCF0)
  70         lg      r7,lo16(LTRAMP-LCF0)(r7)
  71         subi    r7,r7,4
  72         li      r8,trampoline_size      /* verify trampoline big enough */
  73         cmpg    cr1,r8,r4
  74         srwi    r4,r4,2                 /* # words to move (insns always 4-byte) */
  75         addi    r9,r3,-4        /* adjust pointer for lgu */
  76         mtctr   r4
  77         blt     cr1,Labort
  78
  79         mtlr    r0
  80
  81         /* Copy the instructions to the stack */
  82 Lmove:
  83         lwzu    r10,4(r7)
  84         stwu    r10,4(r9)
  85         bdnz    Lmove
  86
  87         /* Store correct function and static chain */
  88         stg     r5,Lfunc(r3)
  89         stg     r6,Lchain(r3)
  90
  91         /* Now flush both caches */
  92         mtctr   r4
  93 Lcache:
  94         icbi    0,r3
  95         dcbf    0,r3
  96         addi    r3,r3,4
  97         bdnz    Lcache
  98
  99         /* Finally synchronize things & return */
 100         sync
 101         isync
 102         blr
 103
 104 Labort:
 105 #ifdef __DYNAMIC__
 106         bl      L_abort$stub
 107 .data
 108 .section __TEXT,__picsymbolstub1,symbol_stubs,pure_instructions,32
 109         .align 2
 110 L_abort$stub:
 111         .indirect_symbol _abort
 112         mflr r0
 113         bcl 20,31,L0$_abort
 114 L0$_abort:
 115         mflr r11
 116         addis r11,r11,ha16(L_abort$lazy_ptr-L0$_abort)
 117         mtlr r0
 118         lgu r12,lo16(L_abort$lazy_ptr-L0$_abort)(r11)
 119         mtctr r12
 120         bctr
 121 .data
 122 .lazy_symbol_pointer
 123 L_abort$lazy_ptr:
 124         .indirect_symbol _abort
 125         .g_long dyld_stub_binding_helper
 126 #else
 127         bl      _abort
 128 #endif
 129 .data
 130         .align LOG2_GPR_BYTES
 131 LTRAMP:
 132         .g_long Ltrampoline_initial
 133