/// @file
///  Contains an implementation of setjmp and longjmp for the
///  Itanium-based architecture.
///
/// Copyright (c) 2006, Intel Corporation                                                         
/// All rights reserved. This program and the accompanying materials                          
/// are licensed and made available under the terms and conditions of the BSD License         
/// which accompanies this distribution.  The full text of the license may be found at        
/// http://opensource.org/licenses/bsd-license.php                                            
///                                                                                           
/// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
/// WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             
/// 
/// Module Name: setjmp.s
///
///

  .file  "setjmp.s"

#include  "asm.h"
#include  "ia_64gen.h"

/// int SetJump(struct jmp_buffer save)
///
///  Setup a non-local goto.
///
/// Description:
///
///  SetJump stores the current register set in the area pointed to
///  by "save".  It returns zero.  Subsequent calls to "LongJump" will
///  restore the registers and return non-zero to the same location.
///
/// On entry, r32 contains the pointer to the jmp_buffer
///

PROCEDURE_ENTRY(SetJump)
  //
  //  Make sure buffer is aligned at 16byte boundary
  //
  mov    r32 = r33        

    add     r10 = -0x10,r0  ;;  // mask the lower 4 bits
    and     r32 = r32, r10;; 
    add     r32 = 0x10, r32;;   // move to next 16 byte boundary

    add    r10 = J_PREDS, r32  // skip Unats & pfs save area
  add    r11 = J_BSP, r32
  //
  //  save immediate context
  //
  mov    r2 = ar.bsp     // save backing store pointer
  mov    r3 = pr         // save predicates
  ;;
  //
  // save user Unat register
  //
  mov    r16 = ar.lc        // save loop count register
  mov    r14 = ar.unat     // save user Unat register

  st8    [r10] = r3, J_LC-J_PREDS
  st8    [r11] = r2, J_R4-J_BSP
  ;;
  st8    [r10] = r16, J_R5-J_LC
  st8    [r32] = r14, J_NATS  // Note: Unat at the 
                    // beginning of the save area
  mov    r15 = ar.pfs
  ;;
  //
  //  save preserved general registers & NaT's
  //
  st8.spill  [r11] = r4, J_R6-J_R4
  ;;
  st8.spill  [r10] = r5, J_R7-J_R5 
    ;;
  st8.spill  [r11] = r6, J_SP-J_R6
  ;;
  st8.spill  [r10] = r7, J_F3-J_R7 
    ;;
  st8.spill  [r11] = sp, J_F2-J_SP
  ;;
  //
  // save spilled Unat and pfs registers
  //
  mov    r2 = ar.unat       // save Unat register after spill
  ;;
  st8    [r32] = r2, J_PFS-J_NATS  // save unat for spilled regs
  ;;
  st8    [r32] = r15          // save pfs
  //
  //  save floating registers 
  //
  stf.spill  [r11] = f2, J_F4-J_F2
  stf.spill  [r10] = f3, J_F5-J_F3 
  ;;
  stf.spill  [r11] = f4, J_F16-J_F4
  stf.spill  [r10] = f5, J_F17-J_F5 
  ;;
  stf.spill  [r11] = f16, J_F18-J_F16
  stf.spill  [r10] = f17, J_F19-J_F17 
  ;;
  stf.spill  [r11] = f18, J_F20-J_F18
  stf.spill  [r10] = f19, J_F21-J_F19 
  ;;
  stf.spill  [r11] = f20, J_F22-J_F20
  stf.spill  [r10] = f21, J_F23-J_F21 
  ;;
  stf.spill  [r11] = f22, J_F24-J_F22
  stf.spill  [r10] = f23, J_F25-J_F23 
  ;;
  stf.spill  [r11] = f24, J_F26-J_F24
  stf.spill  [r10] = f25, J_F27-J_F25 
  ;;
  stf.spill  [r11] = f26, J_F28-J_F26
  stf.spill  [r10] = f27, J_F29-J_F27 
  ;;
  stf.spill  [r11] = f28, J_F30-J_F28
  stf.spill  [r10] = f29, J_F31-J_F29 
  ;;
  stf.spill  [r11] = f30, J_FPSR-J_F30
  stf.spill  [r10] = f31, J_B0-J_F31    // size of f31 + fpsr
  //
  // save FPSR register & branch registers
  //
  mov    r2 = ar.fpsr  // save fpsr register
  mov    r3 = b0 
  ;;
  st8    [r11] = r2, J_B1-J_FPSR
  st8    [r10] = r3, J_B2-J_B0
  mov    r2 = b1
  mov    r3 = b2 
  ;;
  st8    [r11] = r2, J_B3-J_B1
  st8    [r10] = r3, J_B4-J_B2
  mov    r2 = b3
  mov    r3 = b4 
  ;;
  st8    [r11] = r2, J_B5-J_B3
  st8    [r10] = r3
  mov    r2 = b5 
  ;;
  st8    [r11] = r2
  ;;
  //
  // return
  //
  mov    r8 = r0        // return 0 from setjmp
  mov    ar.unat = r14  // restore unat
  br.ret.sptk  b0

PROCEDURE_EXIT(SetJump)


//
// void _LongJump(struct jmp_buffer *)
//
//  Perform a non-local goto.
//
// Description:
//
//  LongJump initializes the register set to the values saved by a
//  previous 'SetJump' and jumps to the return location saved by that
//  'SetJump'.  This has the effect of unwinding the stack and returning
//  for a second time to the 'SetJump'.
//

PROCEDURE_ENTRY(_LongJump)
  //
  //  Make sure buffer is aligned at 16byte boundary
  //
  mov    r32 = r33        

    add     r10 = -0x10,r0  ;;  // mask the lower 4 bits
    and     r32 = r32, r10;; 
    add     r32 = 0x10, r32;;   // move to next 16 byte boundary

  //
  // caching the return value as we do invala in the end
  //
///  mov    r8 = r33          // return value
  mov    r8 = 1              // For now return hard coded 1

  //
  //  get immediate context
  //
  mov    r14 = ar.rsc    // get user RSC conf 
  add    r10 = J_PFS, r32  // get address of pfs
  add    r11 = J_NATS, r32
  ;;
  ld8    r15 = [r10], J_BSP-J_PFS  // get pfs
  ld8    r2 = [r11], J_LC-J_NATS      // get unat for spilled regs
  ;;
  mov    ar.unat = r2
  ;;
  ld8    r16 = [r10], J_PREDS-J_BSP  // get backing store pointer
  mov    ar.rsc = r0        // put RSE in enforced lazy 
  mov    ar.pfs = r15
  ;;
  
  //
  // while returning from longjmp the BSPSTORE and BSP needs to be
  // same and discard all the registers allocated after we did
  // setjmp. Also, we need to generate the RNAT register since we
  // did not flushed the RSE on setjmp.
  //
  mov    r17 = ar.bspstore  // get current BSPSTORE
  ;;
    cmp.ltu  p6,p7 = r17, r16  // is it less than BSP of 
(p6)  br.spnt.few  .flush_rse
  mov    r19 = ar.rnat    // get current RNAT
  ;;
  loadrs              // invalidate dirty regs
  br.sptk.many  .restore_rnat    // restore RNAT

.flush_rse:
  flushrs
  ;;
  mov    r19 = ar.rnat    // get current RNAT
  mov    r17 = r16      // current BSPSTORE
  ;;
.restore_rnat:
  //
  // check if RNAT is saved between saved BSP and curr BSPSTORE
  //
  dep    r18 = 1,r16,3,6   // get RNAT address
  ;;
  cmp.ltu  p8,p9 = r18, r17  // RNAT saved on RSE
  ;;
(p8)  ld8    r19 = [r18]    // get RNAT from RSE
  ;;
  mov    ar.bspstore = r16  // set new BSPSTORE  
  ;;
  mov    ar.rnat = r19    // restore RNAT
  mov    ar.rsc = r14    // restore RSC conf


  ld8    r3 = [r11], J_R4-J_LC    // get lc register
  ld8    r2 = [r10], J_R5-J_PREDS   // get predicates
  ;;
  mov    pr = r2, -1
  mov    ar.lc = r3
  //
  //  restore preserved general registers & NaT's
  //
  ld8.fill  r4 = [r11], J_R6-J_R4
  ;;
  ld8.fill  r5 = [r10], J_R7-J_R5 
  ld8.fill  r6 = [r11], J_SP-J_R6
  ;;
  ld8.fill  r7 = [r10], J_F2-J_R7
  ld8.fill  sp = [r11], J_F3-J_SP
  ;;
  //
  //  restore floating registers 
  //
  ldf.fill  f2 = [r10], J_F4-J_F2
  ldf.fill  f3 = [r11], J_F5-J_F3 
  ;;
  ldf.fill  f4 = [r10], J_F16-J_F4
  ldf.fill  f5 = [r11], J_F17-J_F5 
  ;;
  ldf.fill  f16 = [r10], J_F18-J_F16
  ldf.fill  f17 = [r11], J_F19-J_F17
  ;;
  ldf.fill  f18 = [r10], J_F20-J_F18
  ldf.fill  f19 = [r11], J_F21-J_F19
  ;;
  ldf.fill  f20 = [r10], J_F22-J_F20
  ldf.fill  f21 = [r11], J_F23-J_F21
  ;;
  ldf.fill  f22 = [r10], J_F24-J_F22
  ldf.fill  f23 = [r11], J_F25-J_F23 
  ;;
  ldf.fill  f24 = [r10], J_F26-J_F24
  ldf.fill  f25 = [r11], J_F27-J_F25
  ;;
  ldf.fill  f26 = [r10], J_F28-J_F26
  ldf.fill  f27 = [r11], J_F29-J_F27
  ;;
  ldf.fill  f28 = [r10], J_F30-J_F28
  ldf.fill  f29 = [r11], J_F31-J_F29 
  ;;
  ldf.fill  f30 = [r10], J_FPSR-J_F30
  ldf.fill  f31 = [r11], J_B0-J_F31 ;;

    //
  // restore branch registers and fpsr
  //
  ld8    r16 = [r10], J_B1-J_FPSR  // get fpsr
  ld8    r17 = [r11], J_B2-J_B0    // get return pointer
  ;;
  mov    ar.fpsr = r16
  mov    b0 = r17
  ld8    r2 = [r10], J_B3-J_B1
  ld8    r3 = [r11], J_B4-J_B2
  ;;
  mov    b1 = r2
  mov    b2 = r3
  ld8    r2 = [r10], J_B5-J_B3
  ld8    r3 = [r11]
  ;;
  mov    b3 = r2
  mov    b4 = r3 
  ld8    r2 = [r10]
  ld8    r21 = [r32]      // get user unat
  ;;
  mov    b5 = r2
  mov    ar.unat = r21

  //
  // invalidate ALAT
  //
  invala ;;

  br.ret.sptk  b0
PROCEDURE_EXIT(_LongJump)