File:  [Qemu by Fabrice Bellard] / qemu / hostregs_helper.h
Revision 1.1.1.3 (vendor branch): download - view: text, annotated - select for diffs
Tue Apr 24 17:20:25 2018 UTC (2 years, 1 month ago) by root
Branches: qemu, MAIN
CVS tags: qemu0111, qemu0110, HEAD
qemu 0.11.0

    1: /*
    2:  *  Save/restore host registrs.
    3:  *
    4:  *  Copyright (c) 2007 CodeSourcery
    5:  *
    6:  * This library is free software; you can redistribute it and/or
    7:  * modify it under the terms of the GNU Lesser General Public
    8:  * License as published by the Free Software Foundation; either
    9:  * version 2 of the License, or (at your option) any later version.
   10:  *
   11:  * This library is distributed in the hope that it will be useful,
   12:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   13:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   14:  * Lesser General Public License for more details.
   15:  *
   16:  * You should have received a copy of the GNU Lesser General Public
   17:  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
   18:  */
   19: 
   20: /* The GCC global register variable extension is used to reserve some
   21:    host registers for use by generated code.  However only the core parts of
   22:    the translation engine are compiled with these settings.  We must manually
   23:    save/restore these registers when called from regular code.
   24:    It is not sufficient to save/restore T0 et. al. as these may be declared
   25:    with a datatype smaller than the actual register.  */
   26: 
   27: #if defined(DECLARE_HOST_REGS)
   28: 
   29: #define DO_REG(REG)					\
   30:     register host_reg_t reg_AREG##REG asm(AREG##REG);	\
   31:     volatile host_reg_t saved_AREG##REG;
   32: 
   33: #elif defined(SAVE_HOST_REGS)
   34: 
   35: #define DO_REG(REG)					\
   36:     __asm__ __volatile__ ("" : "=r" (reg_AREG##REG));	\
   37:     saved_AREG##REG = reg_AREG##REG;
   38: 
   39: #else
   40: 
   41: #define DO_REG(REG)                                     \
   42:     reg_AREG##REG = saved_AREG##REG;		        \
   43:     __asm__ __volatile__ ("" : : "r" (reg_AREG##REG));
   44: 
   45: #endif
   46: 
   47: #ifdef AREG0
   48: DO_REG(0)
   49: #endif
   50: 
   51: #ifdef AREG1
   52: DO_REG(1)
   53: #endif
   54: 
   55: #ifdef AREG2
   56: DO_REG(2)
   57: #endif
   58: 
   59: #undef SAVE_HOST_REGS
   60: #undef DECLARE_HOST_REGS
   61: #undef DO_REG

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