projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 6b92951c KT |
1 | .globl log, _log |
| 2 | ldfps = 170100^tst | |
| 3 | stfps = 170200^tst | |
| 4 | ldexp = 176400^movif | |
| 5 | stexp = 175000^movfi | |
| 6 | / | |
| 7 | / log accepts its argument and returns its result | |
| 8 | / in fr0. The carry bit is set if the argument is | |
| 9 | / zero or negative. | |
| 10 | / The coefficients are #2705 from Hart & Cheney. | |
| 11 | / | |
| 12 | / movf arg,fr0 | |
| 13 | / jsr pc,log | |
| 14 | / movf fr0,... | |
| 15 | / | |
| 16 | _log: | |
| 17 | mov r5,-(sp) | |
| 18 | mov sp,r5 | |
| 19 | movf 4(r5),fr0 | |
| 20 | jsr pc,log | |
| 21 | mov (sp)+,r5 | |
| 22 | rts pc | |
| 23 | ||
| 24 | log: | |
| 25 | tstf fr0 | |
| 26 | cfcc | |
| 27 | bgt 1f | |
| 28 | movf $bigneg,fr0 /return -(big) on error | |
| 29 | sec | |
| 30 | rts pc | |
| 31 | 1: | |
| 32 | stfps -(sp) | |
| 33 | ldfps $200 /di mode | |
| 34 | movf fr2,-(sp) | |
| 35 | movf fr1,-(sp) | |
| 36 | / | |
| 37 | stexp fr0,-(sp) /scale | |
| 38 | ldexp $0,fr0 | |
| 39 | cmpf sqrt2o2,fr0 | |
| 40 | cfcc | |
| 41 | blt 1f | |
| 42 | ldexp $1,fr0 | |
| 43 | dec (sp) | |
| 44 | 1: | |
| 45 | movf fr0,fr1 /(1/2)^(1/2) < x < 2^(1/2) | |
| 46 | subf $one,fr0 | |
| 47 | addf $one,fr1 | |
| 48 | divf fr1,fr0 /z = (x-1)/(x+1) | |
| 49 | movf fr0,fr1 | |
| 50 | mulf fr0,fr1 /z^2 | |
| 51 | / | |
| 52 | movf p3,fr2 | |
| 53 | mulf fr1,fr2 | |
| 54 | addf p2,fr2 | |
| 55 | mulf fr1,fr2 | |
| 56 | addf p1,fr2 | |
| 57 | mulf fr1,fr2 | |
| 58 | addf p0,fr2 | |
| 59 | mulf fr2,fr0 /zP(z) | |
| 60 | / | |
| 61 | movf fr1,fr2 | |
| 62 | addf q2,fr2 | |
| 63 | mulf fr1,fr2 | |
| 64 | addf q1,fr2 | |
| 65 | mulf fr1,fr2 | |
| 66 | addf q0,fr2 /Q(z) | |
| 67 | / | |
| 68 | divf fr2,fr0 /zP(z)/Q(z) | |
| 69 | movif (sp)+,fr1 | |
| 70 | mulf log2,fr1 | |
| 71 | addf fr1,fr0 | |
| 72 | / | |
| 73 | movf (sp)+,fr1 | |
| 74 | movf (sp)+,fr2 | |
| 75 | ldfps (sp)+ | |
| 76 | rts pc | |
| 77 | / | |
| 78 | / | |
| 79 | one = 40200 | |
| 80 | bigneg = 177777 | |
| 81 | / | |
| 82 | .data | |
| 83 | sqrt2o2: 40065; 02363; 31771; 157145 | |
| 84 | log2: 40061; 71027;173721;147572 | |
| 85 | / | |
| 86 | p0: 141300; 16201; 02154; 10216 | |
| 87 | p1: 41367;124211; 21611;114442 | |
| 88 | p2: 141032; 31773; 64222; 40261 | |
| 89 | p3: 37727;114303;110107;114145 | |
| 90 | / | |
| 91 | q0: 141100; 16201; 02154; 10216 | |
| 92 | q1: 41233;154404;136454; 22153 | |
| 93 | q2: 141016;111747; 07541; 52530 | |
| 94 | / | |
| 95 | / | |
| 96 | /p0 = -.24013 91795 59210 50986 8484 d2 | |
| 97 | /p1 = .30957 29282 15376 50062 264 d2 | |
| 98 | /p2 = -.96376 90933 68686 59324 d1 | |
| 99 | /p3 = .42108 73712 17979 7145 d0 | |
| 100 | / | |
| 101 | /q0 = -.12006 95897 79605 25471 7525 d2 | |
| 102 | /q1 = .19480 96607 00889 73051 623 d2 | |
| 103 | /q2 = -.89111 09027 93783 12337 d1 | |
| 104 | /q3 = .1 d1 | |
| 105 | / |