📄 emufncalib.s
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movl %edx,%esi andl $0x38000000,%esi addl %esi,%edx addb %bl,%bl cmc notl %eax adcl $0,%eax notl %edx adcl $0,%edx movl $0x3fff,%ecx adcl $0,%ecx orl $0x80000000,%edx xchgl (%edi),%eax #swap arguments xchgl 4(%edi),%edx xchgl 8(%edi),%ecx movl %ecx,%ebx #registers = x-C addw $0xc006,%bx jle log52 xchgl %ecx,%ebx shll %cl,%edx shrl %cl,%edx xchgl %ecx,%ebx jmp log54 # subttl arctangent of x# page# take arctangent of x# input: x in cx:edx:eax and ST# output: atan(x) in cx:edx:eax .globl epatan .balign 16atncon: #coefficients for polynomial .word 0,0x45d1,0x5d17,0xd174,0x1745,0xf45d .word 0,0xe38e,0x8e38,0x38e3,0xe38e,0x0e38 .word 0,0xdb6e,0x6db6,0xb6db,0xdb6d,0xedb6 .word 0,0x999a,0x9999,0x9999,0x9999,0x1999 .word 0,0x5555,0x5555,0x5555,0x5555,0xd555 .word 0,0x0000,0x0000,0x0000,0x0000,0x8000 .word -1 .balign 16attab: #interpolation table for n/32 .word 0x0000,0x0000,0x0000,0x0000,0x0000,1 # atan(0.000000) .word 0x2542,0x4bb1,0xaddd,0xffea,0x3ff9,0 # atan(0.031250) .word 0x4e37,0x67ef,0xddb9,0xffaa,0x3ffa,0 # atan(0.062500) .word 0x7460,0x1788,0xc130,0xbf70,0x3ffb,0 # atan(0.093750) .word 0x6e33,0x617b,0xd4d5,0xfead,0x3ffb,0 # atan(0.125000) .word 0x62c4,0x3313,0x7746,0x9eb7,0x3ffc,0 # atan(0.156250) .word 0x1135,0x72d8,0xda5e,0xbdcb,0x3ffc,0 # atan(0.187500) .word 0x1023,0x9305,0xba94,0xdc86,0x3ffc,0 # atan(0.218750) .word 0xeb16,0x6406,0xafc9,0xfadb,0x3ffc,0 # atan(0.250000) .word 0xc130,0x5f8b,0xad18,0x8c5f,0x3ffd,0 # atan(0.281250) .word 0x5e6a,0x3f5e,0xb9b8,0x9b13,0x3ffd,0 # atan(0.312500) .word 0x4eda,0x8e6a,0x6cca,0xa985,0x3ffd,0 # atan(0.343750) .word 0x8473,0x26f7,0xca0f,0xb7b0,0x3ffd,0 # atan(0.375000) .word 0x2b6d,0x50d9,0x69ca,0xc592,0x3ffd,0 # atan(0.406250) .word 0xe5b6,0x611f,0x761e,0xd327,0x3ffd,0 # atan(0.437500) .word 0x7c68,0x764f,0xa64a,0xe06d,0x3ffd,0 # atan(0.468750) .word 0x7b46,0x0dda,0x382b,0xed63,0x3ffd,0 # atan(0.500000) .word 0xbe5c,0xa0a0,0xe85a,0xfa06,0x3ffd,0 # atan(0.531250) .word 0x7e2a,0xd986,0xf4a6,0x832b,0x3ffe,0 # atan(0.562500) .word 0x47b5,0xde95,0xecdf,0x892a,0x3ffe,0 # atan(0.593750) .word 0x9f9c,0xf7f5,0x5d5e,0x8f00,0x3ffe,0 # atan(0.625000) .word 0x86f6,0x8471,0x72c9,0x94ac,0x3ffe,0 # atan(0.656250) .word 0xda20,0x71bd,0x80e6,0x9a2f,0x3ffe,0 # atan(0.687500) .word 0xa1ed,0xf4b7,0xfdc4,0x9f89,0x3ffe,0 # atan(0.718750) .word 0x0924,0x34f7,0x7d19,0xa4bc,0x3ffe,0 # atan(0.750000) .word 0xf5c8,0x4830,0xabdc,0xa9c7,0x3ffe,0 # atan(0.781250) .word 0xc080,0xb4d8,0x4c38,0xaeac,0x3ffe,0 # atan(0.812500) .word 0x3691,0x1f04,0x31c9,0xb36b,0x3ffe,0 # atan(0.843750) .word 0x9e74,0xc231,0x3e2b,0xb805,0x3ffe,0 # atan(0.875000) .word 0xf281,0xe98a,0x5dea,0xbc7b,0x3ffe,0 # atan(0.906250) .word 0x6640,0xac52,0x85b8,0xc0ce,0x3ffe,0 # atan(0.937500) .word 0xbd54,0xbf8f,0xaffa,0xc4ff,0x3ffe,0 # atan(0.968750)atnw8: movl 8(%edi),%ecx #return 3pi/4 andl $0x80000000,%ecx movw $0x4000,%cx movl $0x96cbe3f9,%edx movl $0x990e91a7,%eax orb $precis,h_stat call exprop ret atnzer: movb 11(%edi),%ch #return signed zero movb $1,%cl shll $16,%ecx xorl %edx,%edx xorl %eax,%eax ret atnw11: orl %ecx,%ecx # INF / INF js atnw8 orb $precis,h_stat call exprop jmp atn90 atnw3: cmpw $0x7fff,%cx # INF / y jz atnw11 atnw9: orb $precis,h_stat call exprop atn82: movl $0x3fff,%ecx #INF returns +- pi/2 jmp atn91 atnw5: orl %ecx,%ecx # y / INF or 0 / x jns atnzer orb $precis,h_stat call exprop atn84: movl $0x4000,%ecx #here return +-pi jmp atn91 atnw: call retnan #proper return for illegal arguments testb $1,10(%edi) #weed out x = 0 jnz atnw5 btl $16,%ecx #weed out y = 0 jc atnw9 cmpw $0x7fff,8(%edi) #weed out x = INF jz atnw3 cmpw $0x7fff,%cx #weed out y = INF jz atnw5 call tnormal #normalize arguments xchgl (%edi),%eax xchgl 4(%edi),%edx xchgl 8(%edi),%ecx call tnormal xchgl (%edi),%eax xchgl 4(%edi),%edx xchgl 8(%edi),%ecx jmp atn2 atn90: orl %ecx,%ecx js atnw8 movl $0x3ffe,%ecx #atan(1) return +-pi/4atn91: movl $0xc90fdaa2,%edx movl $0x2168c235,%eax jmp atn23 atn89: movb s_X+5(%ebp),%bl testb $1,%bl jz atn82 orb %bl,%bl js atn84 call epdiv1 jmp atn23 epatan: shldl $16,%ecx,%ebx #save sign bits movb 11(%edi),%bl movw %bx,s_X+4(%ebp) shldl $16,%ecx,%ebx #weed out special arguments orb 10(%edi),%bl jnz atnw atn2: #PREEXS precis #set precision exception orb $precis,h_stat testb $precis,h_ctrl jnz LL8 orw $0x8080,h_stat movl $exret,-4(%ebp) LL8: cmpw 8(%edi),%cx #compare x and y jl atn5 jnz atn7 cmpl 4(%edi),%edx jc atn5 jnz atn7 cmpl (%edi),%eax jz atn90 jc atn5 atn7: xchgl (%edi),%eax #switch arguments, set flag xchgl 4(%edi),%edx xchgl 8(%edi),%ecx incb s_X+5(%ebp) atn5: movl %ecx,%ebx #underflow here means either addw $tBIAS,%bx # atn(INF) = +-pi/2 or subw 8(%edi),%bx # atn(0) = 0 or pi cmpw $0x3f40,%bx jl atn89 atn6: call epdiv1 #divide x / y andl $0x7fffffff,%ecx #PUTEP movl %eax,(%edi) movl %edx,4(%edi) movl %ecx,8(%edi) xorl %ebx,%ebx #get interpolation interval, 0-31 subw $tBIAS-6,%cx cmpw $9,%cx jc atn4 movw $0,%cx atn4: shldl %cl,%edx,%ebx pushl %ebx shll %cl,%edx #calculate x - C = d shrl %cl,%edx movw 8(%edi),%cx js atn55 jnz atn51 orl %eax,%eax jnz atn51 xorl %ecx,%ecx jmp atn54 atn51: decw %cx addl %eax,%eax adcl %edx,%edx jns atn51 atn55: pushl %eax #push d pushl %edx pushl %ecx rorl $5,%ebx #calculate x * C movl 4(%edi),%eax mull %ebx movl %eax,%ecx xchgl %ebx,%edx movl (%edi),%eax mull %edx addl %edx,%ecx adcl $0,%ebx movl %ebx,%edx #get x * C into right registers xchgl %ecx,%eax xorl %ebx,%ebx movl $0x3fff,%ecx subw 8(%edi),%cx atn11: shrl $1,%edx #normalize x * C to exponent 3fff rcrl $1,%eax loop atn11 orl $0x80000000,%edx #calculate 1 + x*C movw $0x3fff,%cx #PUTEP movl %eax,(%edi) movl %edx,4(%edi) movl %ecx,8(%edi) popl %ecx #calculate d/(1 + x*C) popl %edx popl %eax call epdiv1 addb %bl,%bl adcl $0,%eax adcl $0,%edx #PUTEP movl %eax,(%edi) movl %edx,4(%edi) movl %ecx,8(%edi) call square #polynomial uses x^2 movl $atncon,%ebx #do the polynomial call sigmax addw $0x3ffe,%cx call epmul1 #multiply with xatn54: popl %ebx #then add atan(C) shll $2,%ebx lea attab(%ebx,%ebx,2),%ebx movl %cs:(%ebx),%esi movl %esi,(%edi) movl %cs:4(%ebx),%esi movl %esi,4(%edi) movl %cs:8(%ebx),%esi movl %esi,8(%edi) call epadd1 movb s_X+5(%ebp),%bl #adjust for actual quadrant cmpb $0x01,%bl jz atn23 cmpb $0x80,%bl jz atn25 orl $0x80000000,%ecx atn25: movw $0x4000,8(%edi) cmpb $0x81,%bl jz atn26 movw $0x3fff,8(%edi) atn26: movl $0xc90fdaa2,4(%edi) movl $0x2168c235,0(%edi) call epadd1 atn23: roll $8,%ecx #put in sign movb s_X+4(%ebp),%cl rorl $8,%ecx ret # routine to compute a Taylor polynomial# for speed and accuracy, we perform fixed-point scaled calculations# in ebx = pointer to coefficient table# ecx:edx:eax = EP argument# out ecx:edx:eax = EP resultshf22: movl %edx,%eax #big shift here xorl %edx,%edx subw $32,%cx cmpw $32,%cx jc shf9 xorl %eax,%eax jmp shf19 sigmax: pushl %edi #save registers movl %ecx,%esi subw $0x3ffe,%cx #get the scaling factor negl %ecx cmpw $32,%cx jnc shf22 shf9: shrdl %cl,%edx,%eax #shift x right to scale shrl %cl,%edx shf19: movl %eax,s_A(%ebp) #store x movl %edx,s_A+4(%ebp) movw %cs:2(%ebx),%ax #initial value of sum = first coefficient movl %cs:4(%ebx),%ecx movl %cs:8(%ebx),%edx addl $12,%ebx sig5: pushl %ebx #keep constant pointer on the stack movl %edx,%edi mulw s_A+6(%ebp) #multiply with x01 movw %dx,%si # put result in ebx:ecx:si movl %edi,%eax mull s_A+4(%ebp) movl %edx,%ebx xchgl %ecx,%eax orl %edi,%edi jns sig42 subl s_A(%ebp),%ecx sbbl s_A+4(%ebp),%ebx sig42: pushl %eax mull s_A+4(%ebp) shrl $16,%eax addw %ax,%si adcl %edx,%ecx adcl $0,%ebx popl %eax #multiply with x23 shrl $16,%eax mulw s_A+2(%ebp) addw %dx,%si adcl $0,%ecx adcl $0,%ebx movl %edi,%eax mull s_A(%ebp) shrl $16,%eax addw %si,%ax adcl %edx,%ecx adcl $0,%ebx movl %ebx,%edx #sum now in edx:ecx:ax popl %ebx #address of constant table in bx orl %esi,%esi #we may have to complement the sum jns sig31 notl %edx notl %ecx negw %ax sbbl $-1,%ecx sbbl $-1,%edx sig31: addw %cs:2(%ebx),%ax #add next coefficient to sum adcl %cs:4(%ebx),%ecx adcl %cs:8(%ebx),%edx addl $12,%ebx #proceed to next element cmpb $-1,(%ebx) jnz sig5 movb %ah,%bl #restore registers movl %ecx,%eax popl %edi movl $1,%ecx #normalize number orl %edx,%edx js sig18 decl %ecx addb %bl,%bl adcl %eax,%eax adcl %edx,%edx sig18: ret #routine to raise number to second power# in x in ecx:edx:eax# out x^2 in samesqu80: ret #return unchangedsquare: orw %cx,%cx #may be called with zero jz squ80 pushl %edi #preserve registers pushl %ebx pushl %ebp pushl %ecx movl %edx,%esi #move mantissa movl %eax,%edi shrl $16,%eax #x23 * x23 mulw %ax movb %dh,%bl movl %esi,%eax #x01 * x01 -> bp:cx:bl mull %eax movl %eax,%ecx movl %edx,%ebp movl %esi,%eax #double x01 * x23 mull %edi shrl $16,%eax addb %al,%bl adcl %edx,%ecx adcl $0,%ebp addb %al,%bl adcl %edx,%ecx adcl $0,%ebp movl %ecx,%eax #move mantissa to proper place movl %ebp,%edx popl %ecx #double exponent addl %ecx,%ecx subw $tBIAS-1,%cx addb %bl,%bl #round adcl $0,%eax adcl $0,%edx popl %ebp #restore registers popl %ebx popl %edi ret # routine to reduce the trigonometric argument to between 0 and pi/4# returns octant number (0-7) in cl .globl reductred80: orb $4,h_stat+1 #argument too big addl $4,%esp ret red85: call getqn #here INF orb $invop,h_stat call exproc red99: xorb %bl,%bl ret red96: andl $0x8000ffff,%ecx jmp red99 redw: call chkarg #weed out illegals jc red99 btl $16,%ecx #weed out INF, zero jc red99 cmpw $1,%cx jz red96 orw %cx,%cx jnz red85 btsl $18,%ecx cmpb $7,rmcode(%ebp) jz red99 orb $underf,h_stat call exproc jmp red99 reduct: andb $0x0fb,h_stat+1 #clear reduction bit testl $0x00030000,%ecx #jump if special value jnz redw cmpw $tBIAS-1,%cx #small x, do nothing jc red99 subw $tBIAS-2,%cx #get shift count -> cx cmpw $64,%cx # reduce only up to 63 jg red80 pushl %edi #preserve register movl $0x2168c234,%edi movl $0xc90fdaa2,%esi xorl %ebx,%ebx #divide by subtractionred61: subb $0x0c0,%bh # remainder -> edx:eax:bh sbbl %edi,%eax sbbl %esi,%edx sbbb $0,%ch jnc red63 xorb %ch,%ch addb $0x0c0,%bh adcl %edi,%eax adcl %esi,%edx red63: cmc adcb %bl,%bl decb %cl jle red65 addb %bh,%bh adcl %eax,%eax adcl %edx,%edx adcb $0,%ch jmp red61 red65: andb $7,%bl #octant number -> bh testb $1,%bl #if octant 1 or 3 return pi/4 - x jz red41 negb %bh addb $0x0c0,%bh notl %eax adcl %edi,%eax notl %edx adcl %esi,%edx red41: movl $0x3ffe,%ecx #exponent of pi/4 popl %edi red37: orl %edx,%edx #normalize so bit 31 = 1 js red19 jnz red25 xchgl %eax,%edx xchgb %bh,%al shll $16,%eax #fix 10/28/97# shll $16,%ebx subl $32,%ecx jmp red37 red25: decl %ecx addb %bh,%bh adcl %eax,%eax adcl %edx,%edx jns red25 red19: ret #__lib endp#emuseg ends# end⌨️ 快捷键说明
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