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#
# Copyright (C) 2005 Jakub Jermar
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# - Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
# - Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
# - The name of the author may not be used to endorse or promote products
#   derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

.text

.global context_save
.global context_restore

context_save:
    alloc loc0 = ar.pfs, 1, 10, 0, 0
    mov loc1 = ar.unat  ;;
    
    st8 [in0] = loc0, 8 ;;  /* save ar.pfs */
    st8 [in0] = loc1, 8 ;;  /* save ar.unat (caller) */
    mov loc2 = in0      ;;
    add in0 = 8, in0    ;;  /* skip ar.unat (callee) */
    
    /*
     * TODO: save the rest of the context registers.
     */

    /*
     * Save general registers including NaT bits
     */
    st8.spill [in0] = r1, 8     ;;
    st8.spill [in0] = r2, 8     ;;
    st8.spill [in0] = r3, 8     ;;
    st8.spill [in0] = r4, 8     ;;
    st8.spill [in0] = r5, 8     ;;
    st8.spill [in0] = r6, 8     ;;
    st8.spill [in0] = r7, 8     ;;
    st8.spill [in0] = r8, 8     ;;
    st8.spill [in0] = r9, 8     ;;
    st8.spill [in0] = r10, 8    ;;
    st8.spill [in0] = r11, 8    ;;
    st8.spill [in0] = r12, 8    ;;  /* save sp */
    st8.spill [in0] = r13, 8    ;;
    st8.spill [in0] = r14, 8    ;;
    st8.spill [in0] = r15, 8    ;;
    st8.spill [in0] = r16, 8    ;;
    st8.spill [in0] = r17, 8    ;;
    st8.spill [in0] = r18, 8    ;;
    st8.spill [in0] = r19, 8    ;;
    st8.spill [in0] = r20, 8    ;;
    st8.spill [in0] = r21, 8    ;;
    st8.spill [in0] = r22, 8    ;;
    st8.spill [in0] = r23, 8    ;;
    st8.spill [in0] = r24, 8    ;;
    st8.spill [in0] = r25, 8    ;;
    st8.spill [in0] = r26, 8    ;;
    st8.spill [in0] = r27, 8    ;;
    st8.spill [in0] = r28, 8    ;;
    st8.spill [in0] = r29, 8    ;;
    st8.spill [in0] = r30, 8    ;;
    st8.spill [in0] = r31, 8    ;;

    mov loc3 = ar.unat      ;;
    st8 [loc2] = loc3       /* save ar.unat (callee) */

    /*
     * Save branch registers
     */
    mov loc2 = b0       ;;
    st8 [in0] = loc2, 8     /* save pc */
    mov loc3 = b1       ;;
    st8 [in0] = loc3, 8
    mov loc4 = b2       ;;
    st8 [in0] = loc4, 8
    mov loc5 = b3       ;;
    st8 [in0] = loc5, 8
    mov loc6 = b4       ;;
    st8 [in0] = loc6, 8
    mov loc7 = b5       ;;
    st8 [in0] = loc7, 8
    mov loc8 = b6       ;;
    st8 [in0] = loc8, 8
    mov loc9 = b7       ;;
    st8 [in0] = loc9, 8

    /*
     * Save predicate registers
     */
    mov loc2 = pr       ;;
    st8 [in0] = loc2, 8
    
    mov ar.pfs = loc0
    mov ar.unat = loc1
    
    add r8 = r0, r0, 1      /* context_save returns 1 */
    br.ret.sptk.many b0

context_restore:
    alloc loc0 = ar.pfs, 1, 10, 0, 0    ;;

    /*
     * TODO: restore the rest of the context registers.
     */
    
    ld8 loc0 = [in0], 8 ;;  /* load pfs */
    ld8 loc1 = [in0], 8 ;;  /* load unat (caller) */
    ld8 loc2 = [in0], 8 ;;  /* load unat (callee) */
    
    mov ar.unat = loc2  ;;
    
    /*
     * Restore general registers including NaT bits
     */
    ld8.fill r1 = [in0], 8  ;;
    ld8.fill r2 = [in0], 8  ;;
    ld8.fill r3 = [in0], 8  ;;
    ld8.fill r4 = [in0], 8  ;;
    ld8.fill r5 = [in0], 8  ;;
    ld8.fill r6 = [in0], 8  ;;
    ld8.fill r7 = [in0], 8  ;;
    ld8.fill r8 = [in0], 8  ;;
    ld8.fill r9 = [in0], 8  ;;
    ld8.fill r10 = [in0], 8 ;;
    ld8.fill r11 = [in0], 8 ;;
    ld8.fill r12 = [in0], 8 ;;  /* restore sp */
    ld8.fill r13 = [in0], 8 ;;
    ld8.fill r14 = [in0], 8 ;;
    ld8.fill r15 = [in0], 8 ;;
    ld8.fill r16 = [in0], 8 ;;
    ld8.fill r17 = [in0], 8 ;;
    ld8.fill r18 = [in0], 8 ;;
    ld8.fill r19 = [in0], 8 ;;
    ld8.fill r20 = [in0], 8 ;;
    ld8.fill r21 = [in0], 8 ;;
    ld8.fill r22 = [in0], 8 ;;
    ld8.fill r23 = [in0], 8 ;;
    ld8.fill r24 = [in0], 8 ;;
    ld8.fill r25 = [in0], 8 ;;
    ld8.fill r26 = [in0], 8 ;;
    ld8.fill r27 = [in0], 8 ;;
    ld8.fill r28 = [in0], 8 ;;
    ld8.fill r29 = [in0], 8 ;;
    ld8.fill r30 = [in0], 8 ;;
    ld8.fill r31 = [in0], 8 ;;

    /* 
     * Restore branch registers
     */
    ld8 loc2 = [in0], 8 ;;  /* restore pc */
    mov b0 = loc2
    ld8 loc3 = [in0], 8 ;;
    mov b1 = loc3
    ld8 loc4 = [in0], 8 ;;
    mov b2 = loc4
    ld8 loc5 = [in0], 8 ;;
    mov b3 = loc5
    ld8 loc6 = [in0], 8 ;;
    mov b4 = loc6
    ld8 loc7 = [in0], 8 ;;
    mov b5 = loc7
    ld8 loc8 = [in0], 8 ;;
    mov b6 = loc8
    ld8 loc9 = [in0], 8 ;;
    mov b7 = loc9

    /*
     * Restore predicate registers
     */
    ld8 loc2 = [in0], 8 ;;
    mov pr = loc2, ~0
    
    mov ar.pfs = loc0
    mov ar.unat = loc1
    
    mov r8 = r0         /* context_restore returns 0 */
    br.ret.sptk.many b0