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// TITLE("Miscellaneous Exception Handling")//++//// Module Name://// xcptmisc.s//// Abstract://// This module implements miscellaneous routines that are required to// support exception handling. Functions are provided to call an exception// handler for an exception, call an exception handler for unwinding, call// an exception filter, and call a termination handler.//// Author://// William K. Cheung (wcheung) 15-Jan-1996//// based on the version by David N. Cutler (davec) 12-Sep-1990//// Environment://// Any mode.//// Revision History://// Updated to EAS2.1////--
#include "ksia64.h"
.file "xcptmisc.s" //++//// EXCEPTION_DISPOSITION// RtlpExceptionHandler (// IN PEXCEPTION_RECORD ExceptionRecord,// IN FRAME_POINTERS EstablisherFrame,// IN OUT PCONTEXT ContextRecord,// IN OUT PDISPATCHER_CONTEXT DispatcherContext// )//// Routine Description://// This function is called when a nested exception occurs. Its function// is to retrieve the establisher frame pointer from its establisher's// call frame, store this information in the dispatcher context record,// and return a disposition value of nested exception.//// Arguments://// ExceptionRecord (a0) - Supplies a pointer to an exception record.//// EstablisherFrame (a1,a2) - Supplies the memory stack and backing store// frame pointers of the establisher of this exception handler.//// ContextRecord (a3) - Supplies a pointer to a context record.//// DispatcherContext (a4) - Supplies a pointer to the dispatcher context// record.//// Return Value://// A disposition value ExceptionNestedException is returned if an unwind// is not in progress. Otherwise a value of ExceptionContinueSearch is// returned.////--
LEAF_ENTRY(RtlpExceptionHandler)
// // register aliases //
pUwnd = pt0 pNot = pt1
//// Check if unwind is in progress.//
add t0 = ErExceptionFlags, a0 ;;
ld4.nt1 t0 = [t0] mov t1 = EXCEPTION_UNWIND ;;
add t3 = -8, a1 and t0 = t0, t1 add t2 = DcEstablisherFrame, a4 ;;
ld8.nt1 t4 = [t3] // get dispatcher context addr cmp4.ne pUwnd, pNot = zero, t0 // if ne, unwind in progress ;;
(pNot) add t5 = DcEstablisherFrame, t4 ;;
//// If unwind is not in progress - return nested exception disposition.// And copy the establisher frame pointer structure (i.e. FRAME_POINTERS) // to the current dispatcher context.//// Otherwise, return continue search disposition//
(pNot) ld8.nt1 t6 = [t5], 8 (pNot) mov v0 = ExceptionNestedException // set disposition value(pUwnd) mov v0 = ExceptionContinueSearch // set disposition value ;;
(pNot) ld8.nt1 t7 = [t5] (pNot) st8 [t2] = t6, 8 nop.i 0 ;;
(pNot) st8 [t2] = t7 nop.m 0 br.ret.sptk.clr brp ;;
LEAF_EXIT(RtlpExceptionHandler) //++//// EXCEPTION_DISPOSITION// RtlpExecuteEmHandlerForException (// IN PEXCEPTION_RECORD ExceptionRecord,// IN ULONGLONG MemoryStack,// IN ULONGLONG BackingStore,// IN OUT PCONTEXT ContextRecord,// IN OUT PDISPATCHER_CONTEXT DispatcherContext,// IN ULONGLONG GlobalPointer,// IN PEXCEPTION_ROUTINE ExceptionRoutine// )//// Routine Description://// This function stores the establisher's dispatcher context in the stack// scratch area, establishes an exception handler, and then calls// the specified exception handler as an exception handler. If a nested// exception occurs, then the exception handler of this function is called// and the establisher frame pointer in the saved dispatcher context// is returned to the exception dispatcher via the dispatcher context // parameter of this function's exception handler. If control is returned // to this routine, then the disposition status is returned to the // exception dispatcher.//// Arguments://// ExceptionRecord (a0) - Supplies a pointer to an exception record.//// MemoryStack (a1) - Supplies the memory stack frame pointer of the // activation record whose exception handler is to be called.//// BackingStore (a2) - Supplies the backing store pointer of the // activation record whose exception handler is to be called.//// ContextRecord (a3) - Supplies a pointer to a context record.//// DispatcherContext (a4) - Supplies a pointer to the dispatcher context// record.//// GlobalPointer (a5) - Supplies the global pointer value of the module// to which the function belongs.//// ExceptionRoutine (a6) - supplies a pointer to the exception handler// that is to be called.//// Return Value://// The disposition value returned by the specified exception handler is// returned as the function value.////--
NESTED_ENTRY_EX(RtlpExecuteEmHandlerForException,RtlpExceptionHandler)
// // register aliases //
rpT0 = t8 rpT1 = t9
.prologue .fframe 32, tg30
alloc t1 = ar.pfs, 0, 0, 7, 0 mov t0 = brp mov rpT0 = sp
add rpT1 = 8, sp[tg30:] add sp = -32, sp ;;
.savesp rp, 32 st8 [rpT0] = t0, -8 // save brp .savesp ar.pfs, 32+8 st8 [rpT1] = t1, 8 // save pfs ;;
PROLOGUE_END
//// Setup global pointer and branch register for the except handler//
ld8 t2 = [a6], PlGlobalPointer - PlEntryPoint st8.nta [rpT0] = a4 // save dispatcher context addr ;;
ld8 gp = [a6] mov bt0 = t2 br.call.sptk.many brp = bt0 // call except handler
//// Save swizzled dispatcher context address onto the stack//
.restore tg40[tg40:] add sp = 32, sp // deallocate stack frame ;;
ld8.nt1 t0 = [sp] add rpT1 = 8, sp ;;
ld8.nt1 t1 = [rpT1] nop.f 0 mov brp = t0 // restore return branch ;;
nop.m 0 mov ar.pfs = t1 // restore pfs br.ret.sptk.clr brp // return
NESTED_EXIT(RtlpExecuteEmHandlerForException) //++//// EXCEPTION_DISPOSITION// RtlpEmUnwindHandler (// IN PEXCEPTION_RECORD ExceptionRecord,// IN FRAME_POINTERS EstablisherFrame,// IN OUT PCONTEXT ContextRecord,// IN OUT PVOID DispatcherContext// )//// Routine Description://// This function is called when a collided unwind occurs. Its function// is to retrieve the establisher dispatcher context, copy it to the// current dispatcher context, and return a disposition value of nested// unwind.//// Arguments://// ExceptionRecord (a0) - Supplies a pointer to an exception record.//// EstablisherFrame (a1,a2) - Supplies the memory stack and backing store// frame pointers of the establisher of this exception handler.//// ContextRecord (a3) - Supplies a pointer to a context record.//// DispatcherContext (a4) - Supplies a pointer to the dispatcher context// record.//// Return Value://// A disposition value ExceptionCollidedUnwind is returned if an unwind is// in progress. Otherwise, a value of ExceptionContinueSearch is returned.////--
LEAF_ENTRY(RtlpEmUnwindHandler)
// // register aliases //
pUwnd = pt0 pNot = pt1
//// Check if unwind is in progress.//
add t0 = ErExceptionFlags, a0 ;;
ld4.nt1 t0 = [t0] mov t1 = EXCEPTION_UNWIND ;;
and t0 = t0, t1 ;;
cmp4.eq pNot, pUwnd = zero, t0 // if eq, unwind not in progress (pNot) br.cond.sptk Ruh10
add t2 = -8, a1 add t1 = 8, a4 // -> target dispatch context+8 ;;
ld8.nt1 t2 = [t2] // -> source dispatch context ;;
add t3 = 8, t2 // -> source dispatch context+8 nop.i 0 ;;
//// Copy the establisher dispatcher context (i.e. DISPATCHER_CONTEXT) contents// to the current dispatcher context.//
ld8 t6 = [t2], 16 ld8 t7 = [t3], 16 nop.i 0 ;;
ld8 t8 = [t2], 16 ld8 t9 = [t3], 16 nop.i 0 ;;
st8 [a4] = t6, 16 st8 [t1] = t7, 16 nop.i 0
ld8 t10 = [t2], 16 ld8 t11 = [t3], 16 nop.i 0 ;;
ld8 t12 = [t2], 16 ld8 t13 = [t3] nop.i 0 ;;
st8 [a4] = t8, 16 st8 [t1] = t9, 16 mov v0 = ExceptionCollidedUnwind // set disposition value ;;
ld8 t8 = [t2] st8 [a4] = t10, 16 st8 [t1] = t11, 16 nop.i 0 ;;
st8 [a4] = t12, 16 st8 [t1] = t13 ;;
st8 [a4] = t8 br.ret.sptk.clr brp // return ;;
Ruh10:
//// If branched to here,// unwind is not in progress - return continue search disposition.//
nop.m 0(pNot) mov v0 = ExceptionContinueSearch // set disposition value br.ret.sptk.clr brp // return
LEAF_EXIT(RtlpEmUnwindHandler) //++//// EXCEPTION_DISPOSITION// RtlpExecuteEmHandlerForUnwind (// IN PEXCEPTION_RECORD ExceptionRecord,// IN ULONGLONG MemoryStack,// IN ULONGLONG BackingStore,// IN OUT PCONTEXT ContextRecord,// IN OUT PVOID DispatcherContext,// IN ULONGLONG GlobalPointer,// IN PEXCEPTION_ROUTINE ExceptionRoutine// )//// Routine Description://// This function allocates a call frame, stores the establisher frame// pointer and the context record address in the frame, establishes an// exception handler, and then calls the specified exception handler as// an unwind handler. If a collided unwind occurs, then the exception// handler of of this function is called and the establisher frame pointer// and context record address are returned to the unwind dispatcher via// the dispatcher context parameter. If control is returned to this routine,// then the frame is deallocated and the disposition status is returned to// the unwind dispatcher.//// Arguments://// ExceptionRecord (a0) - Supplies a pointer to an exception record.//// MemoryStack (a1) - Supplies the memory stack frame pointer of the // activation record whose exception handler is to be called.//// BackingStore (a2) - Supplies the backing store pointer of the // activation record whose exception handler is to be called.//// ContextRecord (a3) - Supplies a pointer to a context record.//// DispatcherContext (a4) - Supplies a pointer to the dispatcher context// record.//// GlobalPointer (a5) - Supplies the global pointer value of the module// to which the function belongs.//// ExceptionRoutine (a6) - supplies a pointer to the exception handler// that is to be called.//// Return Value://// The disposition value returned by the specified exception handler is// returned as the function value.////--
NESTED_ENTRY_EX(RtlpExecuteEmHandlerForUnwind, RtlpEmUnwindHandler)
// // register aliases //
.prologue .fframe 32, tg10
rpT0 = t8 rpT1 = t9
alloc t1 = ar.pfs, 0, 0, 7, 0 mov t0 = brp mov rpT0 = sp
add rpT1 = 8, sp[tg10:] add sp = -32, sp ;;
.savepsp rp, 0 st8 [rpT0] = t0, -8 // save brp .savepsp ar.pfs, -8 st8 [rpT1] = t1, 8 // save pfs ;;
PROLOGUE_END
//// Setup global pointer and branch register for the except handler//
ld8 t2 = [a6], PlGlobalPointer - PlEntryPoint st8.nta [rpT0] = a4 // save dispatcher context addr ;;
ld8 gp = [a6] mov bt0 = t2 (p0) br.call.sptk.many brp = bt0 // call except handler
//// Save swizzled dispatcher context address onto the stack//
.restore tg20[tg20:] add sp = 32, sp // deallocate stack frame ;;
ld8.nt1 t0 = [sp] add rpT1 = 8, sp ;;
ld8.nt1 t1 = [rpT1] nop.f 0 mov brp = t0 // restore return branch ;;
nop.m 0 mov ar.pfs = t1 // restore pfs br.ret.sptk.clr brp // return ;;
NESTED_EXIT(RtlpExecuteEmHandlerForUnwind)
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