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; Zilog eZ80 ANSI C Compiler Release 3.4
; -optsize -nomodsect -peephole -globalopt -localcse
; -const=ROM
FILE "..\LOG.C"
.assume ADL=1
SEGMENT CODE
; 1 /************************************************************************/
; 2 /* */
; 3 /* Copyright (C)1999-2008 by Zilog, Inc. */
; 4 /* */
; 5 /************************************************************************/
; 6 /*
; 7 log returns the natural logarithm of its floating
; 8 point argument.
; 9
; 10 The coefficients are #2705 from Hart & Cheney. (19.38D)
; 11
; 12 It calls frexp.
; 13 */
; 14
; 15 #include <errno.h>
; 16 #include <math.h>
; 17
; 18 #define log2 0.693147180559945e0
; 19 #define ln10 2.30258509299404
; 20 #define sqrto2 0.707106781186548e0
; 21 #define p0 -0.240139179559211e2
; 22 #define p1 0.309572928215377e2
; 23 #define p2 -0.963769093368687e1
; 24 #define p3 0.421087371217980e0
; 25 #define q0 -0.120069589779605e2
; 26 #define q1 0.194809660700890e2
; 27 #define q2 -0.891110902798312e1
; 28
; 29 double log( double arg )
; 30 {
_log:
LD HL,-27
CALL __frameset
OR A,A
; 31 double x,z, zsq, temp;
; 32 int exp;
; 33
; 34 if ( arg <= 0.0 ){
SBC HL,HL
LD E,0
LD BC,(IX+6)
LD A,(IX+9)
CALL __fcmp
JP M,L_1
; 35 errno = EDOM;
LD BC,4
LD (_errno),BC
; 36 return -HUGE_VAL;
LD BC,(__huge_val)
LD A,(__huge_val+3)
CALL __fneg
LD E,A
LD HL,BC
JR L_5
; 37 }
L_1:
; 38 x = frexp( arg, & exp );
PEA IX+-15
LD C,(IX+9)
LD B,0
PUSH BC
LD BC,(IX+6)
PUSH BC
CALL _frexp
POP BC
POP BC
POP BC
LD (IX+-8),HL
LD (IX+-5),E
; 39 if ( x < sqrto2 ){
LD HL,(IX+-8)
LD E,(IX+-5)
LD BC,3474675
LD A,63
CALL __fcmp
JP P,L_4
OR A,A
; 40 x *= 2;
SBC HL,HL
LD E,64
LD BC,(IX+-8)
LD A,(IX+-5)
CALL __fmul
LD (IX+-8),BC
LD (IX+-5),A
; 41 exp--;
LD BC,(IX+-15)
DEC BC
LD (IX+-15),BC
; 42 }
L_4:
; 43
; 44 z = (x-1)/(x+1);
LD HL,8388608
LD E,63
LD BC,(IX+-8)
LD A,(IX+-5)
CALL __fsub
LD (IX+-27),BC
LD (IX+-24),A
LD A,(IX+-5)
LD BC,(IX+-8)
LD HL,8388608
LD E,63
CALL __fadd
LD E,A
LD HL,BC
LD BC,(IX+-27)
LD A,(IX+-24)
CALL __fdiv
LD (IX+-19),BC
LD (IX+-16),A
; 45 zsq = z*z;
LD E,(IX+-16)
LD A,(IX+-16)
LD HL,BC
CALL __fmul
LD (IX+-4),BC
LD (IX+-1),A
; 46
; 47 temp = ((p3*zsq + p2)*zsq + p1)*zsq + p0;
LD HL,14129348
LD E,62
CALL __fmul
LD HL,1717243
LD E,193
CALL __fadd
LD HL,(IX+-4)
LD E,(IX+-1)
CALL __fmul
LD HL,16230537
LD E,65
CALL __fadd
LD HL,(IX+-4)
LD E,(IX+-1)
CALL __fmul
LD HL,12590209
LD E,193
CALL __fadd
LD (IX+-12),BC
LD (IX+-9),A
; 48 temp = temp/(((1.0*zsq + q2)*zsq + q1)*zsq + q0);
LD BC,(IX+-4)
LD A,(IX+-1)
LD HL,955367
LD E,193
CALL __fadd
LD HL,(IX+-4)
LD E,(IX+-1)
CALL __fmul
LD HL,10213637
LD E,65
CALL __fadd
LD HL,(IX+-4)
LD E,(IX+-1)
CALL __fmul
LD HL,4201601
LD E,193
CALL __fadd
LD E,A
LD HL,BC
LD BC,(IX+-12)
LD A,(IX+-9)
CALL __fdiv
LD (IX+-12),BC
LD (IX+-9),A
; 49 temp = temp*z + exp*log2;
LD HL,(IX+-19)
LD E,(IX+-16)
LD A,(IX+-9)
CALL __fmul
LD (IX+-23),BC
LD BC,(IX+-15)
LD (IX+-20),A
CALL __itol
CALL __ltof
LD HL,3240472
LD E,63
CALL __fmul
LD E,A
LD HL,BC
LD BC,(IX+-23)
LD A,(IX+-20)
CALL __fadd
LD (IX+-12),BC
LD (IX+-9),A
; 50 return temp;
LD E,(IX+-9)
LD HL,BC
; 51 }
L_5:
LD SP,IX
POP IX
RET
;**************************** _log ***************************
;Name Addr/Register Size Type
;_frexp IMPORT ----- function
;__huge_val IMPORT 4 variable
;_errno IMPORT 3 variable
;z IX-19 4 variable
;exp IX-15 3 variable
;temp IX-12 4 variable
;x IX-8 4 variable
;zsq IX-4 4 variable
;arg IX+6 4 parameter
; Stack Frame Size: 39 (bytes)
; Spill Code: 0 (instruction)
XREF _frexp:ROM
XREF __huge_val:ROM
XREF _errno:ROM
XREF __fadd:ROM
XREF __fsub:ROM
XREF __fmul:ROM
XREF __fdiv:ROM
XREF __fneg:ROM
XREF __fcmp:ROM
XREF __ltof:ROM
XREF __itol:ROM
XREF __frameset:ROM
XDEF _log
END
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