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/*  This file contains the exception-handling save_world and
 *  restore_world routines, which need to do a run-time check to see if
 *  they should save and restore the vector registers.
 *
 *   Copyright (C) 2004 Free Software Foundation, Inc.
 * 
 * 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 2, or (at your option) any
 * later version.
 * 
 * In addition to the permissions in the GNU General Public License, the
 * Free Software Foundation gives you unlimited permission to link the
 * compiled version of this file with other programs, and to distribute
 * those programs without any restriction coming from the use of this
 * file.  (The General Public License restrictions do apply in other
 * respects; for example, they cover modification of the file, and
 * distribution when not linked into another program.)
 * 
 * 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.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 * 
 *  As a special exception, if you link this library with files
 *  compiled with GCC to produce an executable, this does not cause the
 *  resulting executable to be covered by the GNU General Public License.
 *  This exception does not however invalidate any other reasons why the
 *  executable file might be covered by the GNU General Public License.
 */ 

        .machine ppc7400
.data
        .align 2

#ifdef __DYNAMIC__

.non_lazy_symbol_pointer
L_has_vec$non_lazy_ptr:
        .indirect_symbol __cpu_has_altivec
#ifdef __ppc64__
        .quad   0
#else
        .long   0
#endif

#else

/* For static, "pretend" we have a non-lazy-pointer.  */

L_has_vec$non_lazy_ptr:
        .long __cpu_has_altivec

#endif


.text
        .align 2

/* save_world and rest_world save/restore F14-F31 and possibly V20-V31
   (assuming you have a CPU with vector registers; we use a global var
   provided by the System Framework to determine this.)

   SAVE_WORLD takes R0 (the caller`s caller`s return address) and R11
   (the stack frame size) as parameters.  It returns VRsave in R0 if
   we`re on a CPU with vector regs.

   With gcc3, we now need to save and restore CR as well, since gcc3's
   scheduled prologs can cause comparisons to be moved before calls to
   save_world!

   USES: R0 R11 R12  */

.private_extern save_world
save_world:
        stw r0,8(r1)
        mflr r0
        bcl 20,31,Ls$pb
Ls$pb:  mflr r12
        addis r12,r12,ha16(L_has_vec$non_lazy_ptr-Ls$pb)
        lwz r12,lo16(L_has_vec$non_lazy_ptr-Ls$pb)(r12)
        mtlr r0
        lwz r12,0(r12)
                                /* grab CR  */
        mfcr r0 
                                /* test HAS_VEC  */
        cmpwi r12,0
        stfd f14,-144(r1)
        stfd f15,-136(r1)
        stfd f16,-128(r1)
        stfd f17,-120(r1)
        stfd f18,-112(r1)
        stfd f19,-104(r1)
        stfd f20,-96(r1)
        stfd f21,-88(r1)
        stfd f22,-80(r1)
        stfd f23,-72(r1)
        stfd f24,-64(r1)
        stfd f25,-56(r1)
        stfd f26,-48(r1)
        stfd f27,-40(r1)
        stfd f28,-32(r1)
        stfd f29,-24(r1)
        stfd f30,-16(r1)
        stfd f31,-8(r1)
        stmw r13,-220(r1)
                                /* stash CR  */
        stw r0,4(r1)
                                /* set R12 pointing at Vector Reg save area  */
        addi r12,r1,-224
                                /* allocate stack frame  */
        stwux r1,r1,r11
                                /* ...but return if HAS_VEC is zero   */
        bne+ L$saveVMX
                                /* Not forgetting to restore CR.  */
        mtcr r0
        blr

L$saveVMX:
                                /* We're saving Vector regs too.  */
                                /* Restore CR from R0.  No More Branches!  */
        mtcr r0

        /* We should really use VRSAVE to figure out which vector regs
           we actually need to save and restore.  Some other time :-/  */

        li r11,-192
        stvx v20,r11,r12
        li r11,-176
        stvx v21,r11,r12
        li r11,-160
        stvx v22,r11,r12
        li r11,-144
        stvx v23,r11,r12
        li r11,-128
        stvx v24,r11,r12
        li r11,-112
        stvx v25,r11,r12
        li r11,-96
        stvx v26,r11,r12
        li r11,-80
        stvx v27,r11,r12
        li r11,-64
        stvx v28,r11,r12
        li r11,-48
        stvx v29,r11,r12
        li r11,-32
        stvx v30,r11,r12
        mfspr r0,VRsave
        li r11,-16
        stvx v31,r11,r12
                                /* VRsave lives at -224(R1)  */
        stw r0,0(r12)
        blr


/* eh_rest_world_r10 is jumped to, not called, so no need to worry about LR.
   R10 is the C++ EH stack adjust parameter, we return to the caller`s caller.

   USES: R0 R10 R11 R12   and R7 R8
   RETURNS: C++ EH Data registers (R3 - R6.)

   We now set up R7/R8 and jump to rest_world_eh_r7r8.

   rest_world doesn't use the R10 stack adjust parameter, nor does it
   pick up the R3-R6 exception handling stuff.  */

.private_extern rest_world
rest_world:
                                /* Pickup previous SP  */
        lwz r11, 0(r1)
        li r7, 0
        lwz r8, 8(r11)
        li r10, 0
        b rest_world_eh_r7r8

.private_extern eh_rest_world_r10
eh_rest_world_r10:
                                /* Pickup previous SP  */
        lwz r11, 0(r1)
        mr  r7,r10
        lwz r8, 8(r11)
                        /* pickup the C++ EH data regs (R3 - R6.)  */
        lwz r6,-420(r11)
        lwz r5,-424(r11)
        lwz r4,-428(r11)
        lwz r3,-432(r11)

        b rest_world_eh_r7r8

/* rest_world_eh_r7r8 is jumped to -- not called! -- when we're doing
   the exception-handling epilog.  R7 contains the offset to add to
   the SP, and R8 contains the 'real' return address.

   USES: R0 R11 R12  [R7/R8]
   RETURNS: C++ EH Data registers (R3 - R6.)  */

rest_world_eh_r7r8:
        bcl 20,31,Lr7r8$pb
Lr7r8$pb: mflr r12
        lwz r11,0(r1)
                                /* R11 := previous SP  */
        addis r12,r12,ha16(L_has_vec$non_lazy_ptr-Lr7r8$pb)
        lwz r12,lo16(L_has_vec$non_lazy_ptr-Lr7r8$pb)(r12)
        lwz r0,4(r11)
                                /* R0 := old CR  */
        lwz r12,0(r12)
                                /* R12 := HAS_VEC  */
        mtcr r0 
        cmpwi r12,0
        lmw r13,-220(r11)
        beq L.rest_world_fp_eh
                                /* restore VRsave and V20..V31  */
        lwz r0,-224(r11)
        li r12,-416
        mtspr VRsave,r0
        lvx v20,r11,r12
        li r12,-400
        lvx v21,r11,r12
        li r12,-384
        lvx v22,r11,r12
        li r12,-368
        lvx v23,r11,r12
        li r12,-352
        lvx v24,r11,r12
        li r12,-336
        lvx v25,r11,r12
        li r12,-320
        lvx v26,r11,r12
        li r12,-304
        lvx v27,r11,r12
        li r12,-288
        lvx v28,r11,r12
        li r12,-272
        lvx v29,r11,r12
        li r12,-256
        lvx v30,r11,r12
        li r12,-240
        lvx v31,r11,r12

L.rest_world_fp_eh:
        lfd f14,-144(r11)
        lfd f15,-136(r11)
        lfd f16,-128(r11)
        lfd f17,-120(r11)
        lfd f18,-112(r11)
        lfd f19,-104(r11)
        lfd f20,-96(r11)
        lfd f21,-88(r11)
        lfd f22,-80(r11)
        lfd f23,-72(r11)
        lfd f24,-64(r11)
        lfd f25,-56(r11)
        lfd f26,-48(r11)
        lfd f27,-40(r11)
        lfd f28,-32(r11)
        lfd f29,-24(r11)
        lfd f30,-16(r11)
                        /* R8 is the exception-handler's address  */
        mtctr r8
        lfd f31,-8(r11)
                        /* set SP to original value + R7 offset  */
        add r1,r11,r7
        bctr