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// TITLE("Set Jump")//++//// Copyright (c) 1993 Digital Equipment Corporation//// Module Name://// otsjmp.s//// Abstract://// This module implements the Alpha C8/GEM C compiler specific routine to// perform a setjmp.//// N.B. This module conditionally provides UNSAFE handling of setjmp and// which is NOT integrated with structured exception handling. The// determination is made based on whether an uninitialized variable// has been set to a nonzero value.//// Author://// Thomas Van Baak (tvb) 22-Apr-1993//// Environment://// Any mode.//// Revision History:////--
#include "ksalpha.h"
//// Define variable that will cause setjmp/longjmp to be safe or unsafe with// respect to structured exception handling.//
.globl _Otssetjmpexused .comm _Otssetjmpexused, 4 SBTTL("Set Jump - GEM version")//++//// int// _Otssetjmp3 (// IN OUT jmp_buf JumpBuffer,// IN PVOID RealFramePointer,// IN PVOID SebPointer// )//// Routine Description://// This function saves the current nonvolatile register state in the// specified jump buffer and returns a function value of zero.//// N.B. The name `_Otssetjmp3' was chosen to avoid collision with an// earlier implementation named _Otssetjmp. This version has three// arguments.//// Arguments://// JumpBuffer (a0) - Supplies the address of a jump buffer to store the// jump information.//// RealFramePointer (a1) - Supplies the real frame pointer value.//// SebPointer (a2) - Supplies the pointer to the current SEB or NULL// if the call was made outside of any SEH scope.//// Return Value://// A value of zero is returned.////--
LEAF_ENTRY(_Otssetjmp3)
ldl v0, _Otssetjmpexused // get value of switch variable bne v0, 10f // if ne, provide safe setjmp
//// Provide unsafe handling of setjmp.//
stt f2, JbFltF2(a0) // save floating registers f2 - f9 stt f3, JbFltF3(a0) // stt f4, JbFltF4(a0) // stt f5, JbFltF5(a0) // stt f6, JbFltF6(a0) // stt f7, JbFltF7(a0) // stt f8, JbFltF8(a0) // stt f9, JbFltF9(a0) //
stq s0, JbIntS0(a0) // save integer registers s0 - s6/fp stq s1, JbIntS1(a0) // stq s2, JbIntS2(a0) // stq s3, JbIntS3(a0) // stq s4, JbIntS4(a0) // stq s5, JbIntS5(a0) // stq fp, JbIntS6(a0) //
ldil t0, 1 // get unsafe setjmp flag stl t0, JbType(a0) // set jump buffer context type stq sp, JbIntSp(a0) // save stack pointer stq ra, JbFir(a0) // get setjmp return address
mov zero, v0 // set zero return value ret zero, (ra) // return
//// Provide safe handling of setjmp.//
10: jmp zero, (v0) // finish in _setjmpex code
.end _Otssetjmp3
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