658 lines
20 KiB
NASM
658 lines
20 KiB
NASM
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page 78,132
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;*******************************************************************************
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; Copyright (c) Microsoft Corporation 1991
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; All Rights Reserved
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;
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; ke\i386\emxcptn.asm
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;
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; Module to support getting/setting context to and from the R3
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; emulator.
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;
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;Revision History:
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;
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;
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;*******************************************************************************
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.386p
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_TEXT SEGMENT DWORD PUBLIC 'CODE'
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ASSUME DS:FLAT, ES:FLAT, SS:NOTHING, FS:NOTHING, GS:NOTHING
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;;*******************************************************************************
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;;
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;; Include some more macros and constants.
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;;
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;;*******************************************************************************
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;
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NT386 equ 1
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include ks386.inc
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include em387.inc ; Emulator TEB data layout
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include callconv.inc
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EXTRNP _KeGetCurrentIrql,0
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EXTRNP _KeBugCheck,1
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EXTRNP _ExRaiseStatus,1
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extrn _Ki387RoundModeTable:dword
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subttl _KiEm87StateToNpxFrame
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page
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;*** _KiEm87StateToNpxFrames
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;
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; Translates the R3 emulators state to the NpxFrame
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;
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; Returns TRUE if NpxFrame sucessfully completed.
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; else FALSE
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;
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; Warning: This function can only be called at Irql 0 with interrupts
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; enabled. It is intended to be called only to deal with R3 exceptions
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; when the emulator is being used.
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;
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; Revision History:
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;
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;
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;*******************************************************************************
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cPublicProc _KiEm87StateToNpxFrame, 1
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push ebp
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mov ebp, esp
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push ebx ; Save C runtime varibles
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push edi
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push esi
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push esp ; Pass current Esp to handler
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push offset stnpx_30 ; Set Handler address
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push PCR[PcExceptionList] ; Set next pointer
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mov PCR[PcExceptionList],esp ; Link us on
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if DBG
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pushfd ; Sanity check
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pop ecx ; make sure interrupts are enabled
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test ecx, EFLAGS_INTERRUPT_MASK
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jz short stnpx_err
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stdCall _KeGetCurrentIrql ; Sanity check
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cmp al, DISPATCH_LEVEL ; make sure Irql is below DPC level
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jnc short stnpx_err
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endif
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xor eax, eax ; set FALSE
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mov ebx,PCR[PcPrcbData+PbCurrentThread]
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mov ebx,[ebx]+ThApcState+AsProcess
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cmp dword ptr [ebx]+PrVdmObjects,0 ; is this a vdm process?
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jne short stnpx_10 ; Yes, then not supported
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mov ebx, PCR[PcTeb] ; R3 Teb
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cmp [ebx].Einstall, 0 ; Initialized?
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je short stnpx_10 ; No, then don't return NpxFrame
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test [ebx].CURErr, Summary ; Completed?
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jz short stnpx_10 ; No, then don't return NpxFrame
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mov esi, [ebp+8] ; (esi) = NpxFrame
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call SaveState
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mov eax, 1 ; Return TRUE
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stnpx_10:
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pop PCR[PcExceptionList] ; Remove our exception handle
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add esp, 8 ; clear stack
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pop esi
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pop edi
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pop ebx
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pop ebp
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stdRET _KiEm87StateToNpxFrame
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stnpx_30:
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;
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; WARNING: Here we directly unlink the exception handler from the
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; exception registration chain. NO unwind is performed. We can take
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; this short cut because we know that our handler is a leaf-node.
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;
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mov esp, [esp+8] ; (esp)-> ExceptionList
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xor eax, eax ; Return FALSE
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jmp short stnpx_10
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if DBG
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stnpx_err:
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stdCall _KeBugCheck <IRQL_NOT_LESS_OR_EQUAL>
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endif
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_KiEm87StateToNpxFrame ENDP
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;*** SaveEnv
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;
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;
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; ARGUMENTS
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;
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; (esi) = NpxFrame
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; (ebx) = PcTeb
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;
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;
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; DESCRIPTION
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;
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SaveEnv:
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xor ax,ax
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mov [esi].reserved1,ax
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mov [esi].reserved2,ax
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mov [esi].reserved3,ax
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mov [esi].reserved4,ax
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mov [esi].reserved5,ax
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mov ax,[ebx].ControlWord
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mov [esi].E32_ControlWord,ax
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call GetEMSEGStatusWord
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mov [esi].E32_StatusWord,ax
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call GetTagWord
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mov [esi].E32_TagWord,ax
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mov ax,cs
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mov [esi].E32_CodeSeg,ax ; NOTE: Not R0 code & stack
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mov ax,ss
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mov [esi].E32_DataSeg,ax
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mov eax,[ebx].PrevCodeOff
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mov [esi].E32_CodeOff,eax
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mov eax,[ebx].PrevDataOff
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mov [esi].E32_DataOff,eax
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ret
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;*** SaveState -
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;
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; ARGUMENTS
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; (esi) = where to store environment
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; (ebx) = PcTeb
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;
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; DESCRIPTION
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;
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; REGISTERS
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; Destroys ALL, but EBX
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;
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SaveState: ; Enter here for debugger save state
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mov dword ptr [esi].FpCr0NpxState, CR0_EM
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call SaveEnv
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add esi,size Env80x87_32 ;Skip over environment
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mov ebp,NumLev ;Save entire stack
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mov edi,[ebx].CURstk
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ss_loop:
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mov eax,[ebx+edi].ExpSgn
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call StoreTempReal ;in emstore.asm
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add esi,10
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mov edi,[ebx].CURstk
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;;; NextStackElem edi,SaveState
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cmp edi,INITstk
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jae short ss_wrap
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add edi,Reg87Len
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ss_continue:
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mov [ebx].CURstk,edi
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dec ebp
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jnz short ss_loop
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ret
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ss_wrap:
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mov edi, BEGstk
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jmp short ss_continue
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;*** GetTagWord - figures out what the tag word is from the numeric stack
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; and returns the value of the tag word in ax.
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;
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; ARGUMENTS
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; (ebx) = PcTeb
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;
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GetTagWord:
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push esi
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xor eax, eax
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mov ecx, NumLev ; get tags for regs. 0, 7 - 1
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mov esi, INITstk
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GetTagLoop:
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mov dh, [ebx+esi].bTag ; The top 2 bits of Tag are the X87 tag bits.
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shld ax, dx, 2
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sub esi, Reg87Len
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loop GetTagLoop
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rol ax, 2 ; This moves Tag(0) into the low 2 bits
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pop esi
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ret
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;*** GetEMSEGStatusWord
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;
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; User status word returned in ax.
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; Uses status word in per-thread data area, otherwise
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; identical to GetStatusWord
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;
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; ARGUMENTS
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; (ebx) = PcTeb
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GetEMSEGStatusWord:
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mov eax, [ebx].CURstk
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sub eax, BEGstk
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;
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; Make sure the 'div' won't overflowed.
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;
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cmp eax, Reg87Len * (NumLev + 2)
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ja short @f
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mov dl,Reg87Len
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div dl
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inc eax
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and eax, 7 ; eax is now the stack number
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shl ax, 11
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or ax, [ebx].StatusWord ; or in the rest of the status word.
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ret
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@@:
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mov eax, STATUS_INTEGER_OVERFLOW
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stdCall _ExRaiseStatus, <eax>
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ret ; Should never come here ...
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;*** StoreTempReal
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;
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;
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; ARGUMENTS
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; ??
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; (ebx) = PcTeb
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;
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StoreTempReal:
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mov edx,[ebx+edi].lManHi
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mov edi,[ebx+edi].lManLo
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;mantissa in edx:edi, exponent in high eax, sign in ah bit 7, tag in al
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;memory destination is esi
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mov ecx,eax ;get copy of sign and tag
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shr ecx,16 ;Bring exponent down
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cmp al,bTAG_ZERO
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jz short StoreIEEE80 ;Skip bias if zero
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add ecx,IexpBias-TexpBias ;Correct bias
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cmp al,bTAG_DEN
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jz short Denorm80
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StoreIEEE80:
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and eax,bSign shl 8
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or ecx,eax ;Combine sign with exponent
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mov [esi],edi
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mov [esi+4],edx
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mov [esi+8],cx
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ret
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Denorm80:
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;Must change it to a denormal
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dec ecx
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neg ecx ;Use as shift count
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cmp cl,32 ;Long shift?
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jae LongDenorm
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shrd edi,edx,cl
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shr edx,cl
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xor ecx,ecx ;Exponent is zero
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jmp short StoreIEEE80
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LongDenorm:
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;edi must be zero if we have 32 bits to shift
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xchg edx,edi ;32-bit right shift
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shr edi,cl ;shift count is modulo-32
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xor ecx,ecx ;Exponent is zero
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jmp short StoreIEEE80
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;****************************************************
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;****************************************************
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;****************************************************
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;****************************************************
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;*** _KiNpxFrameToEm87State
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;
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; Translates the NpxFrame to the R3 emulators state
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;
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; Returns TRUE if NpxFrame state sucessfully transfered.
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; else FALSE
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;
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; Warning: This function can only be called at Irql 0 with interrupts
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; enabled. It is intended to be called only to deal with R3 exceptions
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; when the emulator is being used.
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;
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; Revision History:
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;
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;
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;*******************************************************************************
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cPublicProc _KiNpxFrameToEm87State, 1
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push ebp
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mov ebp, esp
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push ebx ; Save C runtime varibles
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push edi
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push esi
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push esp ; Pass current Esp to handler
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push offset npxts_30 ; Set Handler address
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push PCR[PcExceptionList] ; Set next pointer
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mov PCR[PcExceptionList],esp ; Link us on
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if DBG
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pushfd ; Sanity check
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pop ecx ; make sure interrupts are enabled
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test ecx, EFLAGS_INTERRUPT_MASK
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jz short npxts_err
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stdCall _KeGetCurrentIrql ; Sanity check
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cmp al, DISPATCH_LEVEL ; make sure Irql is below DPC level
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jnc short npxts_err
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endif
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xor eax, eax ; set FALSE
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mov ebx,PCR[PcPrcbData+PbCurrentThread]
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mov ebx,[ebx]+ThApcState+AsProcess
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cmp dword ptr [ebx]+PrVdmObjects,0 ; is this a vdm process?
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jne short npxts_10 ; Yes, then not supported
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mov ebx, PCR[PcTeb] ; R3 Teb
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cmp [ebx].Einstall, 0 ; Initialized?
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je short npxts_10 ; No, then don't set NpxFrame
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mov esi, [ebp+8] ; (esi) = NpxFrame
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call StorState
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or [ebx].CURErr, Summary ; Set completed
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mov eax, 1 ; Return TRUE
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npxts_10:
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pop PCR[PcExceptionList] ; Remove our exception handle
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add esp, 8 ; clear stack
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pop esi
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pop edi
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pop ebx
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pop ebp
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stdRet _KiNpxFrameToEm87State
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npxts_30:
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;
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; WARNING: Here we directly unlink the exception handler from the
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; exception registration chain. NO unwind is performed. We can take
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; this short cut because we know that our handler is a leaf-node.
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;
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mov esp, [esp+8] ; (esp)-> ExceptionList
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xor eax, eax ; Return FALSE
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jmp short npxts_10
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ret
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if DBG
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npxts_err:
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stdCall _KeBugCheck <IRQL_NOT_LESS_OR_EQUAL>
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endif
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_KiNpxFrameToEm87State ENDP
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;*** StorState - emulate FRSTOR [address]
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;
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; ARGUMENTS
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; (esi) = where to get the environment
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; (ebx) = PcTeb
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;
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;
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; DESCRIPTION
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; This routine emulates an 80387 FRSTOR (restore state)
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StorState:
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;First we set up the status word so that [CURstk] is initialized.
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|
|
;The floating-point registers are stored in logical ST(0) - ST(7) order,
|
||
|
|
;not physical register order. We don't do a full load of the environment
|
||
|
|
;because we're not ready to use the tag word yet.
|
||
|
|
|
||
|
|
mov ax, [esi].E32_StatusWord
|
||
|
|
call SetEmStatusWord ;Initialize [CURstk]
|
||
|
|
add esi,size Env80x87_32 ;Skip over environment
|
||
|
|
|
||
|
|
;Load of temp real has one difference from real math chip: it is an invalid
|
||
|
|
;operation to load an unsupported format. By ensuring the exception is
|
||
|
|
;masked, we will convert unsupported format to Indefinite. Note that the
|
||
|
|
;mask and [CURerr] will be completely restored by the FLDENV at the end.
|
||
|
|
|
||
|
|
mov [ebx].CWmask,3FH ;Mask off invalid operation exception
|
||
|
|
mov edi,[ebx].CURstk
|
||
|
|
mov ebp,NumLev
|
||
|
|
FrstorLoadLoop:
|
||
|
|
push esi
|
||
|
|
call LoadTempReal ;In emload.asm
|
||
|
|
pop esi
|
||
|
|
add esi,10 ;Point to next temp real
|
||
|
|
;;; NextStackElem edi,Frstor
|
||
|
|
cmp edi,INITstk
|
||
|
|
jae short fr_wrap
|
||
|
|
add edi,Reg87Len
|
||
|
|
fr_continue:
|
||
|
|
dec ebp
|
||
|
|
jnz short FrstorLoadLoop
|
||
|
|
sub esi,NumLev*10+size Env80x87_32 ;Point to start of env.
|
||
|
|
;
|
||
|
|
; Stor Enviroment
|
||
|
|
; (esi) = where to get enviroment
|
||
|
|
; (ebx) = PcTeb
|
||
|
|
;
|
||
|
|
|
||
|
|
mov ax, [esi].E32_StatusWord
|
||
|
|
call SetEmStatusWord ; set up status word
|
||
|
|
mov ax, [esi].E32_ControlWord
|
||
|
|
call SetControlWord
|
||
|
|
mov ax, [esi].E32_TagWord
|
||
|
|
call UseTagWord
|
||
|
|
|
||
|
|
mov eax, [esi].E32_CodeOff
|
||
|
|
mov [ebx].PrevCodeOff, eax
|
||
|
|
mov eax, [esi].E32_DataOff
|
||
|
|
mov [ebx].PrevDataOff, eax
|
||
|
|
ret
|
||
|
|
|
||
|
|
fr_wrap:
|
||
|
|
mov edi, BEGstk
|
||
|
|
jmp short fr_continue
|
||
|
|
|
||
|
|
|
||
|
|
;*** SetEmStatusWord -
|
||
|
|
;
|
||
|
|
; Given user status word in ax, set into emulator.
|
||
|
|
; Destroys ebx only.
|
||
|
|
|
||
|
|
|
||
|
|
SetEmStatusWord:
|
||
|
|
and ax,7F7FH
|
||
|
|
mov cx,ax
|
||
|
|
and cx,3FH ; set up CURerr in case user
|
||
|
|
mov [ebx].CURerr,cl ; wants to force an exception
|
||
|
|
mov ecx, eax
|
||
|
|
and ecx, not (7 shl 11) ; remove stack field.
|
||
|
|
mov [ebx].StatusWord, cx
|
||
|
|
|
||
|
|
sub ah, 8 ; adjust for emulator's stack layout
|
||
|
|
and ah, 7 shl 3
|
||
|
|
mov al, ah
|
||
|
|
shr ah, 1
|
||
|
|
add al, ah ; stack field * 3 * 4
|
||
|
|
.erre Reg87Len eq 12
|
||
|
|
and eax, 255 ; eax is now 12*stack number
|
||
|
|
add eax, BEGstk
|
||
|
|
mov [ebx].CURstk, eax
|
||
|
|
ret
|
||
|
|
|
||
|
|
SetControlWord:
|
||
|
|
and ax,0F3FH ; Limit to valid values
|
||
|
|
mov [ebx].ControlWord, ax ; Store in the emulated control word
|
||
|
|
not al ;Flip mask bits for fast compare
|
||
|
|
and al,3FH ;Limit to valid mask bits
|
||
|
|
mov [ebx].ErrMask,al
|
||
|
|
and eax,(RoundControl + PrecisionControl) shl 8
|
||
|
|
.erre RoundControl eq 1100B
|
||
|
|
.erre PrecisionControl eq 0011B
|
||
|
|
shr eax,6 ;Put PC and RC in bits 2-5
|
||
|
|
mov ecx,_Ki387RoundModeTable
|
||
|
|
mov ecx,[ecx+eax] ;Get correct RoundMode vector
|
||
|
|
mov [ebx].RoundMode,ecx
|
||
|
|
mov [ebx].SavedRoundMode,ecx
|
||
|
|
and eax,RoundControl shl (8-6) ;Mask off precision control
|
||
|
|
mov ecx,_Ki387RoundModeTable
|
||
|
|
mov ecx,[ecx+(eax+PC64 shl (8-6))];Get correct RoundMode vector
|
||
|
|
mov [ebx].TransRound,ecx ;Round mode w/o precision
|
||
|
|
ret
|
||
|
|
|
||
|
|
|
||
|
|
;*** UseTagWord - Set up tags using tag word from environment
|
||
|
|
;
|
||
|
|
; ARGUMENTS
|
||
|
|
; ax - should contain the tag word
|
||
|
|
;
|
||
|
|
; Destroys ax,bx,cx,dx,di
|
||
|
|
|
||
|
|
UseTagWord:
|
||
|
|
ror ax, 2 ; mov Tag(0) into top bits of ax
|
||
|
|
mov edi,INITstk
|
||
|
|
mov ecx, NumLev
|
||
|
|
UseTagLoop:
|
||
|
|
mov dl,bTAG_EMPTY
|
||
|
|
cmp ah, 0c0h ;Is register to be tagged Empty?
|
||
|
|
jae short SetTag ;Yes, go mark it
|
||
|
|
mov dl,[ebx+edi].bTag ;Get current tag
|
||
|
|
cmp dl,bTAG_EMPTY ;Is register currently Empty?
|
||
|
|
je short SetTagNotEmpty ;If so, go figure out tag for it
|
||
|
|
SetTag:
|
||
|
|
mov [ebx+edi].bTag,dl
|
||
|
|
UseTagLoopCheck:
|
||
|
|
sub edi, Reg87Len
|
||
|
|
shl eax, 2
|
||
|
|
loop UseTagLoop
|
||
|
|
ret
|
||
|
|
|
||
|
|
SetTagEmpty:
|
||
|
|
mov [ebx+edi].bTag, bTAG_EMPTY
|
||
|
|
jmp short UseTagLoopCheck
|
||
|
|
|
||
|
|
SetTagNotEmpty:
|
||
|
|
;Register is currently tagged empty, but new tag word says it is not empty.
|
||
|
|
;Figure out a new tag for it. The rules are:
|
||
|
|
;
|
||
|
|
;1. Everything is either normalized or zero--unnormalized formats cannot
|
||
|
|
;get in. So if the high half mantissa is zero, the number is zero.
|
||
|
|
;
|
||
|
|
;2. Although the exponent bias is different, NANs and Infinities are in
|
||
|
|
;standard IEEE format - exponent is TexpMax, mantissa indicates NAN vs.
|
||
|
|
;infinity (mantissa for infinity is 800..000H).
|
||
|
|
;
|
||
|
|
;3. Denormals have an exponent less than TexpMin.
|
||
|
|
;
|
||
|
|
;4. If the low half of the mantissa is zero, it is tagged bTAG_SNGL
|
||
|
|
;
|
||
|
|
;5. Everything else is bTAG_VALID
|
||
|
|
|
||
|
|
cmp [ebx+edi].lManHi, 0
|
||
|
|
mov dl,bTAG_ZERO ;Try zero first
|
||
|
|
jz short SetTag ;Is mantissa zero?
|
||
|
|
mov edx,[ebx+edi].ExpSgn
|
||
|
|
mov dl,bTAG_DEN
|
||
|
|
cmp edx,TexpMin shl 16 ;Is it denormal?
|
||
|
|
jl short SetTag
|
||
|
|
cmp [ebx+edi].lManLo,0 ;Is low half zero?
|
||
|
|
.erre bTAG_VALID eq 1
|
||
|
|
.erre bTAG_SNGL eq 0
|
||
|
|
setnz dl ;if low half==0 then dl=0 else dl=1
|
||
|
|
cmp edx,TexpMax shl 16 ;Is it NAN or Infinity?
|
||
|
|
jl short SetTag ;If not, it's valid
|
||
|
|
.erre (bTAG_VALID - bTAG_SNGL) shl TAG_SHIFT eq (bTAG_NAN - bTAG_INF)
|
||
|
|
shl dl,TAG_SHIFT
|
||
|
|
add dl,bTAG_INF - bTAG_SNGL
|
||
|
|
;If the low bits were zero we have just changed bTAG_SNGL to bTAG_INF
|
||
|
|
;If the low bits weren't zero, we changed bTAG_VALID to bTAG_NAN
|
||
|
|
;See if infinity is really possible: is high half 80..00H?
|
||
|
|
cmp [ebx+edi].lManHi,1 shl 31 ;Is it infinity?
|
||
|
|
jz short SetTag ;Store tag for infinity or NAN
|
||
|
|
mov dl,bTAG_NAN
|
||
|
|
jmp short SetTag
|
||
|
|
|
||
|
|
|
||
|
|
;*** LoadTempReal
|
||
|
|
;
|
||
|
|
;
|
||
|
|
;
|
||
|
|
|
||
|
|
LoadTempReal:
|
||
|
|
mov ebx,[esi+4] ;Get high half of mantissa
|
||
|
|
mov cx,[esi+8] ;Get exponent and sign
|
||
|
|
mov esi,[esi] ;Get low half of mantissa
|
||
|
|
mov eax,ecx
|
||
|
|
and ch,7FH ;Mask off sign bit
|
||
|
|
shl ecx,16 ;Move exponent to high end
|
||
|
|
mov ch,ah ;Restore sign
|
||
|
|
jz short ZeroOrDenorm80
|
||
|
|
;Check for unsupported format: unnormals (MSB not set)
|
||
|
|
or ebx,ebx
|
||
|
|
jns short Unsupported
|
||
|
|
sub ecx,(IexpBias-TexpBias) shl 16 ;Correct the bias
|
||
|
|
cmp ecx,TexpMax shl 16
|
||
|
|
jge short NANorInf80
|
||
|
|
SetupTag:
|
||
|
|
or esi,esi ;Any bits in low half?
|
||
|
|
.erre bTAG_VALID eq 1
|
||
|
|
.erre bTAG_SNGL eq 0
|
||
|
|
setnz cl ;if low half==0 then cl=0 else cl=1
|
||
|
|
jmp short SaveStack
|
||
|
|
|
||
|
|
NANorInf80:
|
||
|
|
mov cl,bTAG_NAN
|
||
|
|
cmp ebx,1 shl 31 ;Only 1 bit set means infinity
|
||
|
|
jnz short SaveStack
|
||
|
|
or esi,esi
|
||
|
|
jnz short SaveStack
|
||
|
|
mov cl,bTAG_INF
|
||
|
|
jmp short SaveStack
|
||
|
|
|
||
|
|
ZeroOrDenorm80:
|
||
|
|
;Exponent is zero. Number is either zero or denormalized
|
||
|
|
or ebx,ebx
|
||
|
|
jnz short ShortNorm80 ;Are top 32 bits zero?
|
||
|
|
or esi,esi ;Are low 32 bits zero too?
|
||
|
|
jnz LongNorm80
|
||
|
|
mov cl,bTAG_ZERO
|
||
|
|
jmp short SaveStack
|
||
|
|
|
||
|
|
;This code accepts and works correctly with pseudo-denormals (MSB already set)
|
||
|
|
LongNorm80:
|
||
|
|
xchg ebx,esi ;Shift up 32 bits
|
||
|
|
sub ecx,32 shl 16 ;Correct exponent
|
||
|
|
ShortNorm80:
|
||
|
|
add ecx,(TexpBias-IexpBias+1-31) shl 16 ;Fix up bias
|
||
|
|
bsr edx,ebx ;Scan for MSB
|
||
|
|
;Bit number in edx ranges from 0 to 31
|
||
|
|
mov cl,dl
|
||
|
|
not cl ;Convert bit number to shift count
|
||
|
|
shld ebx,esi,cl
|
||
|
|
shl esi,cl
|
||
|
|
shl edx,16 ;Move exp. adjustment to high end
|
||
|
|
add ecx,edx ;Adjust exponent
|
||
|
|
jmp short SetUpTag
|
||
|
|
|
||
|
|
SaveStack:
|
||
|
|
mov eax, PCR[PcTeb]
|
||
|
|
mov [eax].CURstk,edi
|
||
|
|
mov [eax+edi].lManLo,esi
|
||
|
|
mov [eax+edi].lManHi,ebx
|
||
|
|
mov [eax+edi].ExpSgn,ecx
|
||
|
|
mov ebx, eax ; (ebx) = PcTeb
|
||
|
|
ret
|
||
|
|
|
||
|
|
Unsupported:
|
||
|
|
mov ebx, PCR[PcTeb]
|
||
|
|
or [ebx].CURerr,Invalid ; (assume it's masked?)
|
||
|
|
mov [ebx+edi].lManLo,0
|
||
|
|
mov [ebx+edi].lManHi,0C0000000H
|
||
|
|
mov [ebx+edi].ExpSgn,TexpMax shl 16 + bSign shl 8 + bTAG_NAN
|
||
|
|
mov [ebx].CURstk,edi ;Update top of stack
|
||
|
|
ret
|
||
|
|
|
||
|
|
_TEXT ENDS
|
||
|
|
END
|