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183 lines
3.4 KiB
183 lines
3.4 KiB
page ,132
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subttl emlstmp.asm - Load/Store Temp Real Numbers
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;***
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;emlstmp.asm - Load/Store Temp Real Numbers
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;
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; Copyright (c) 1986-89, Microsoft Corporation
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;
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;Purpose:
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; Load/Store Temp Real Numbers
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;
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; This Module contains Proprietary Information of Microsoft
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; Corporation and should be treated as Confidential.
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;
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;Revision History:
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; See emulator.hst
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;
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;*******************************************************************************
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ProfBegin LSTMP
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;*********************************************************************;
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; ;
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; Load 80 Bit Temp Real ;
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; ;
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;*********************************************************************;
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;
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; ES:SI: memory address of 80 bit tempreal
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pub eFLDtemp
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MOV edi,esi ; Get a new stack element and leave
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PUSHST
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XCHG edi,esi
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mov ax,es
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mov dx,ds
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mov es,dx
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mov ds,ax
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MVUS2DI ; Move 8 bytes of mantissa to TOS
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MVUS2DI
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MVUS2DI
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MVUS2DI
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mov ax,es
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mov dx,ds
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mov es,dx
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mov ds,ax
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LDUS2AX ; Fetch exponent
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SUB edi,8 ; Reset pointer to TOS
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XCHG esi,edi ; Now DS:SI points to TOS
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MOV DH,AH ; Exponent and Sign to DX
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AND DH,Sign ; Mask to Sign only
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MOV Flag[esi],DH
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AND AH,7FH ; Mask out sign
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XOR DH,DH ; Set Tag to valid non-zero
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CMP AX,IexpMax
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JE short TNANorInf
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CMP AX,IexpMin
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JE short TZeroOrDenorm
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SUB AX,IexpBias
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pub TStoreExpnTag
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MOV Expon[esi],AX
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MOV Tag[esi],DH
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RET
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pub TNANorInf
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MOV AX,IexpMax - IexpBias
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MOV DH,Special
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CMP MB6[esi],8000H ; Test for Infinity
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JNE short TStoreExpnTag
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MOV BP,MB4[esi]
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OR BP,MB2[esi]
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OR BP,MB0[esi]
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JNZ TStoreExpnTag
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OR DH,ZROorINF
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JMP TStoreExpnTag
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pub TZeroOrDenorm
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MOV BP,MB6[esi]
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OR BP,MB4[esi]
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OR BP,MB2[esi]
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OR BP,MB0[esi]
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JNZ short TDenormal
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pub TZero
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MOV AX,IexpMin - IexpBias
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MOV DH,ZROorINF
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JMP TStoreExpnTag
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pub TDenormal
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OR [CURerr],Underflow+Precision ; Say it underflowed - set it to 0
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XOR BP,BP
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MOV MB0[esi],BP
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MOV MB2[esi],BP
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MOV MB4[esi],BP
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MOV MB6[esi],BP
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JMP TZero
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PAGE
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;*********************************************************************;
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; ;
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; Store 80 Bit Temp Real (& POP since only FSTP supported for temp) ;
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; ;
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;*********************************************************************;
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;
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; ES:SI: memory address of 80 bit tempreal
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pub TNANorINFST
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TEST BH,ZROorINF
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JNZ short TInfST
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pub TNANST
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MVSI2US ; copy mantissa
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MVSI2US
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MVSI2US
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MVSI2US
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MOV AX,IexpMax ; Set maximum mantissa
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OR AH,DH ; Overstore proper sign
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STAX2US
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POPST
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RET
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pub TInfST
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XOR AX,AX
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STAX2US
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STAX2US
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STAX2US
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MOV AX,8000H
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STAX2US
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MOV AX,IexpMax ; Set maximum mantissa
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OR AH,DH ; Overstore proper sign
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STAX2US
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POPST
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RET
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pub TSpecialST
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TEST BH,Special
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JNZ TNANorINFST
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pub TzeroST
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XOR AX,AX
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STAX2US
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STAX2US
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STAX2US
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STAX2US
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STAX2US
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POPST
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RET
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pub eFSTtemp
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MOV edi,esi
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MOV esi,[CURstk]
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MOV AX,Expon[esi] ; Adjust exponent of TOS
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ADD AX,IexpBias
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MOV DH,Flag[esi]
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if fastSP
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TEST DH,Single
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JZ TD1
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MOV word ptr MB0[esi],0
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MOV word ptr MB2[esi],0
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MOV byte ptr MB4[esi],0
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TD1:
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endif
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AND DH,Sign ; Mask to sign only
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OR AH,DH
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MOV BH,Tag[esi] ; See if it is a special case
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OR BH,BH
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JNZ TSpecialST
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MVSI2US ; Move Mantissa
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MVSI2US
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MVSI2US
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MVSI2US
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STAX2US ; Move Exponent & Sign
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SUB esi,8 ; Reset pointer to TOS
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POPSTsi
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RET
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ProfEnd LSTMP
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