;*****************************************************************************
;*
;* Open Watcom Project
;*
;* Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
;*
;* ========================================================================
;*
;* This file contains Original Code and/or Modifications of Original
;* Code as defined in and that are subject to the Sybase Open Watcom
;* Public License version 1.0 (the 'License'). You may not use this file
;* except in compliance with the License. BY USING THIS FILE YOU AGREE TO
;* ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
;* provided with the Original Code and Modifications, and is also
;* available at www.sybase.com/developer/opensource.
;*
;* The Original Code and all software distributed under the License are
;* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
;* EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
;* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
;* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
;* NON-INFRINGEMENT. Please see the License for the specific language
;* governing rights and limitations under the License.
;*
;* ========================================================================
;*
;* Description: 80x87 interrupt handler.
;*
;*****************************************************************************
;;; //e:\watcom\src\bld\watcom\h;E:\WATCOM\H;E:\WATCOM\H\NT
.8087
.386p
include struct.inc
include mdef.inc
include stword.inc
include env387.inc
include fstatus.inc
ifndef __NETWARE__
xref __GETDS
endif
xref __8087 ; indicate that NDP instructions are present
modstart fpeinth
datasegment
extrn __FPE_exception_: proc
extrn "C",_STACKLOW : dword
TInf db 00h,00h,00h,00h,00h,00h,00h,80h,0ffh,7fh
F8Inf db 0ffh,0ffh,0ffh,0ffh,0ffh,0ffh,0efh,7fh
F4Inf db 0ffh,0ffh,7fh,7fh
db 512 dup(0)
FPEStk label byte
SaveSS dw 0
SaveESP dd 0
enddata
; Interrupt handler for 80x87 exceptions.
xdefp __FPEHandler_
defp __FPEHandler_
public "C",__FPEHandlerStart_
__FPEHandlerStart_ label byte
push EAX ; save reg
mov AL,20h ; issue EOI to 8259 controller
out 20h,AL ; ...
out 0a0h,AL ; issue EOI to slave 8259
xor AX,AX ; clear busy signal
out 0f0h,AL ; ...
pop EAX ; restore regs
public __FPE2Handler_
__FPE2Handler_ label byte
push EAX ; save regs
push EBX ; ...
push ECX ; ...
push EDX ; ...
push ESI ; ...
push EDI ; ...
push EBP ; ...
push DS ; ...
push ES ; ...
sub ESP,ENV_SIZE ; make room for environment information
mov EBP,ESP ; point to buffer for 80x87 environment
fnstenv [EBP] ; get 80x87 environment
fwait ; wait for 80x87
fdisi ; disable interrupts
sti ; enable CPU interrupts
ifndef __NETWARE__
; call __GETDS ; load DS
endif
ifdef __NETWARE__
; push SS ; load DS
; pop DS ; ...
endif
mov EDX,ENV_CW[EBP] ; get control word
not EDX ; flip the mask bits
mov DH,0FFh ; turn on top byte
and EDX,ENV_SW[EBP] ; get status word
; mov ES,ENV_IP+4[EBP] ; get intruction address
mov EDI,ENV_IP[EBP] ; ...
opcode: mov BX,[EDI] ; get opcode
inc EDI ; point to next opcode
cmp BL,0d8h ; check if its the opcode
jb opcode ; ...
cmp BL,0dfh ; ...
ja opcode ; ...
; mov ES,ENV_OP+4[EBP] ; get pointer to operand
mov EDI,ENV_OP[EBP] ; ...
xchg BL,BH ; get opcode in right position
mov CL,FPE_OK ; assume exception to be ignored
_guess ; guess precision exception
test DL,ST_EF_PR ; - check for precision exception
_quif e ; - quit if not precision exception
mov CL,FPE_INEXACT ; - indicate precision exception
_admit ; guess stack under/overflow
test DL,ST_EF_SF ; - check for stack under/overflow
_quif e ; - quit if not stack under/overflow
test DX,ST_C1 ; - check if underflow
_if e ; - if underflow
mov CL,FPE_STACKUNDERFLOW ; - - indicate stack underflow
_else ; - else
mov CL,FPE_STACKOVERFLOW ; - - indicate stack overflow
_endif ; - endif
_admit ; guess invalid operation
test DL,ST_EF_IO ; - check for invalid operation
_quif e ; - quit if not invalid operation
call InvalidOp ; - process invalid operation
_admit ; guess denormal operand
test DL,ST_EF_DO ; - check for denormal operand
_quif e ; - quit if not denormal operand
mov CL,FPE_DENORMAL ; - indicate underflow
_admit ; guess overflow
test DL,ST_EF_OF ; - check for overflow
_quif e ; - quit if not overflow
call KOOverFlow ; - process overflow exception
mov CL,FPE_OVERFLOW ; - set floating point error code
_admit ; guess underflow
test DL,ST_EF_UF ; - check for underflow
_quif e ; - quit if not underflow
mov CL,FPE_UNDERFLOW ; - indicate underflow
_admit ; guess divide by 0
test DL,ST_EF_ZD ; - check for divide by zero
_quif e ; - quit if not divide by zero
call GetInf ; - process divide by zero
mov CL,FPE_ZERODIVIDE ; - indicate divide by zero
_endguess ; endguess
_guess ; guess exception to be handled
cmp CL,FPE_OK ; - check if exception allowed
_quif e ; - quit if exception not allowed
; cmp SaveSS,0 ; - check if already in handler
; _quif ne ; - quit if already in handler
push _STACKLOW ; - save old stack low
mov SaveSS,SS ; - save current stack pointer
mov SaveESP,ESP ; - ...
push DS ; - get new stack pointer
pop SS ; - ...
lea ESP,FPEStk ; - ...
lea EAX,FPEStk-512 ; - set stack low variable
mov _STACKLOW,EAX ; - set stack low variable
movzx EAX,CL ; - set floating point status
call __FPE_exception_ ; - call user's handler
mov SS,SaveSS ; - restore stack pointer
mov ESP,SaveESP ; - ...
pop _STACKLOW ; - restore old stacklow
mov SaveSS,0 ; - indicate handler can be re-entered
_endguess ; endguess
fclex ; clear exceptions that may have
; occurred as a result of handling the
; exception
and word ptr ENV_CW[EBP],0FF72h
fldcw word ptr ENV_CW[EBP] ; enable interrupts
fwait ; ...
add ESP,ENV_SIZE ; clean up stack
pop ES ; restore registers
pop DS ; ...
pop EBP ; ...
pop EDI ; ...
pop ESI ; ...
pop EDX ; ...
pop ECX ; ...
pop EBX ; ...
pop EAX ; ...
iretd ; return from interrupt handler
public "C",__FPEHandlerEnd_
__FPEHandlerEnd_ label byte
endproc __FPEHandler_
; Process invalid operation.
InvalidOp proc near
mov CL,FPE_INVALID ; assume invalid operation
_guess ; guess it's square root
cmp BX,0D9FAh ; - ...
_quif ne ; - quit if it's not that instruction
mov CL,FPE_SQRTNEG ; - indicate sqrt(negative number)
ret ; - return
_endguess ; endguess
_guess ; guess it's square root
cmp BX,0D9F1h ; - ...
_quif ne ; - quit if it's not that instruction
mov CL,FPE_LOGERR ; - indicate sqrt(negative number)
ret ; - return
_endguess ; endguess
_guess ; guess: 'fprem' instruction
cmp BX,0D9F8h ; - check for 'fprem' 10-may-90
_if ne ; - if not 'fprem'
cmp BX,0D9F5h ; - - check for 'fprem1'
_endif ; - endif
_quif ne ; - quit if not 'fprem' or 'fprem1'
mov CL,FPE_MODERR ; - indicate mod(negative number)
_admit ; guess: integer overflow
mov DX,BX ; - save op code
and DX,0310h ; - check for fist/fistp instruction
cmp DX,0310h ; - ...
_quif ne ; - quit if its not that instruction
mov CL,FPE_IOVERFLOW ; - indicate integer overflow
_admit ; guess it's floating point underflow
;; mov DX,BX ; - save op code
and DX,0110h ; - check if fst or fstp instruction
cmp DX,0110h ; - ...
_quif ne ; - quit if it's not that instruction
; Destination is short or long real and source register is an unnormal
; with exponent in range.
fstp st(0) ; - pop old result
fldz ; - load zero
mov DL,BL ; - save op code
and DL,0C0h ; - check the MOD bits of instruction
cmp DL,0C0h ; - ...
_if ne ; - if result to be placed in memory
call Store ; - - store result in memory
_endif ; - endif
test BL,08h ; - check if result to be popped
_if ne ; - if result to be popped
fstp st(0) ; - - pop the result
_endif ; - endif
mov CL,FPE_UNDERFLOW ; - indicate underflow
_admit ; guess it's divide
mov DX,BX ; - save op code
and DX,0130h ; - check for fdiv/fidiv instruction
cmp DX,0030h ; - ...
_quif ne ; - quit if it's not that instruction
mov DX,ENV_TW[EBP] ; - get tag word
mov CL,AH ; - get stack pointer
and CL,38h ; - ...
shr CL,2 ; - ...
ror DX,CL ; - make stack top low order bits
and DL,05h ; - check if top two elements are 0
cmp DL,05h ; - ...
_quif ne ; - quif if they are not 0
mov CL,FPE_ZERODIVIDE ; - indicate divide by zero
_endguess ; endguess
ret
endproc InvalidOp
; Process overflow exception (note that only floating point overflows
; are handled - integer overflows are invalid operations).
KOOverFlow proc near
_guess ; guess: fscale instruction 10-may-90
cmp BX,0D9FDh ; - quit if not 'fscale' instruction
_quif ne ; - ...
_admit ; guess: fst/fstp instruction
mov DX,BX ; - save op code
and DX,0110h ; - check if fst or fstp instruction
cmp DX,0110h ; - ...
_quif ne ; - quit if not an fst/fstp instr.
call GetInf ; - load infinity
mov DL,BL ; - save op code
and DL,0C0h ; - check the MOD bits of instruction
cmp DL,0C0h ; - ...
_if ne ; - if result to be placed in memory
call Store ; - - store infinity
_endif ; - endif
test BL,08h ; - check if result to be popped
_if ne ; - if result to be popped
fstp st(0) ; - - pop result
_endif ; - endif
_admit ; admit arithmetic operation
mov DL,BL ; - save op code
and DL,0C0h ; - check if both operands on stack
cmp DL,0C0h ; - ...
_quif ne ; - quif both operands not on stack
;
; This code handles overflow on the following intructions:
; fxxx ST,ST(i)
; fxxx ST(i),ST where xxx is one of mul,div,sub or add
; fxxxp ST(i),ST
;
lea ESI,TInf ; - load internal infinity
call Load ; - ...
_admit ; admit
;
; This admit block is to handle overflow on the following intructions:
; fxxx short real
; fxxx long real where xxx is one of mul,div,sub or add
;
call GetInf ; - load infinity
_endguess ; endguess
ret ; return
endproc KOOverFlow
; Replace the top element of the stack with the appropriate signed
; infinity.
GetInf proc near
ftst ; get sign of result
fstsw word ptr ENV_OP[EBP]
fstp st(0) ; pop argument off stack (does fwait)
test BH,04h ; check if single or double
_if ne ; if double
fld qword ptr F8Inf ; - load double precision infinity
_else ; else
fld dword ptr F4Inf ; - load single precision infinity
_endif ; endif
test word ptr ENV_OP[EBP],ST_C0
_if ne ; if argument is negative
fchs ; - return negative infinity
_endif ; endif
ret ; return
endproc GetInf
; Replace an element on the stack with internal zero or infinity.
Load proc near
test BH,04h ; check if result is top element
_if e ; if result is not top element
mov DL,0 ; - indicate we are at the top
_else ; else
mov DL,BL ; - get st(i)
and DL,07h ; - . . .
_endif ; endif
push EDX ; save st(i)
_loop ; loop
dec DL ; - decrement counter
_quif l ; - quit if we are at st(i)
fincstp ; - increment stack pointer
_endloop ; endloop
fstp st(0) ; free the stack element
fld tbyte ptr [ESI] ; load internal zero
pop EDX ; get st(i)
_loop ; loop
dec DL ; - decrement counter
_quif l ; - quit if we are at st(i)
fdecstp ; - decrement stack pointer
_endloop ; endloop
ret ; return
endproc Load
; Store the top element of the stack at ES:EDI.
Store proc near
test BH,04h
_if ne ; if double
fst qword ptr ES:[EDI] ; - store as double precision result
_else ; else
fst dword ptr ES:[EDI] ; - store as single precision result
_endif ; endif
ret ; return
endproc Store
endmod
end