projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 6b92951c KT |
1 | .globl exp, _exp |
| 2 | / | |
| 3 | ldfps = 170100^tst | |
| 4 | stfps = 170200^tst | |
| 5 | ldexp = 176400^movif | |
| 6 | stexp = 175000^movfi | |
| 7 | / | |
| 8 | / exp accepts its argument and returns its result | |
| 9 | / in fr0. The carry bit is set if the result overflows. | |
| 10 | / The coefficients are #1067 from Hart & Cheney. | |
| 11 | / | |
| 12 | / movf arg,fr0 | |
| 13 | / jsr pc,exp | |
| 14 | / movf fr0,result | |
| 15 | / | |
| 16 | _exp: | |
| 17 | mov r5,-(sp) | |
| 18 | mov sp,r5 | |
| 19 | mov 4(r5),fr0 | |
| 20 | jsr pc,exp | |
| 21 | mov (sp)+,r5 | |
| 22 | rts pc | |
| 23 | ||
| 24 | exp: | |
| 25 | stfps -(sp) | |
| 26 | ldfps $200 /di mode | |
| 27 | movf fr2,-(sp) | |
| 28 | movf fr1,-(sp) | |
| 29 | tstf fr0 | |
| 30 | cfcc | |
| 31 | bne 1f | |
| 32 | movf $one,fr0 /exp(0) | |
| 33 | clc | |
| 34 | br out | |
| 35 | 1: | |
| 36 | modf log2e,fr0 /exp(x) = 2^(x*log2(e)) | |
| 37 | cfcc | |
| 38 | bmi 2f | |
| 39 | movfi fr1,-(sp) /save integer part | |
| 40 | subf $half,fr0 | |
| 41 | br 3f | |
| 42 | 2: | |
| 43 | movfi fr1,-(sp) | |
| 44 | dec (sp) | |
| 45 | addf $half,fr0 | |
| 46 | 3: | |
| 47 | movf fr0,fr1 / -.5 < x < +.5 | |
| 48 | mulf fr1,fr1 /arg**2 | |
| 49 | / | |
| 50 | movf P2,fr2 | |
| 51 | mulf fr1,fr2 | |
| 52 | addf P1,fr2 | |
| 53 | mulf fr1,fr2 | |
| 54 | addf P0,fr2 | |
| 55 | mulf fr2,fr0 /xP(x**2) | |
| 56 | / | |
| 57 | movf fr1,fr2 | |
| 58 | addf Q1,fr2 | |
| 59 | mulf fr1,fr2 | |
| 60 | addf Q0,fr2 /Q(x**2) | |
| 61 | / | |
| 62 | movf fr2,fr1 | |
| 63 | subf fr0,fr1 | |
| 64 | addf fr2,fr0 | |
| 65 | divf fr1,fr0 /(Q+xP)/(Q-xP) | |
| 66 | mulf sqrt2,fr0 | |
| 67 | / | |
| 68 | stexp fr0,-(sp) | |
| 69 | add (sp)+,(sp) | |
| 70 | / | |
| 71 | cmp (sp),$177 | |
| 72 | ble 2f | |
| 73 | tst (sp)+ | |
| 74 | movf big,fr0 /overflow | |
| 75 | sec | |
| 76 | br 1f | |
| 77 | 2: | |
| 78 | cmp (sp),$-177 | |
| 79 | bge 2f | |
| 80 | tst (sp)+ | |
| 81 | clrf fr0 /underflow | |
| 82 | clc | |
| 83 | br 1f | |
| 84 | 2: | |
| 85 | ldexp (sp)+,fr0 | |
| 86 | clc | |
| 87 | 1: | |
| 88 | out: | |
| 89 | movf (sp)+,fr1 | |
| 90 | movf (sp)+,fr2 | |
| 91 | ldfps (sp)+ | |
| 92 | rts pc | |
| 93 | / | |
| 94 | / | |
| 95 | .data | |
| 96 | P0: 42675; 36404; 77563; 46675 | |
| 97 | P1: 41241; 116724; 114237; 60333 | |
| 98 | P2: 36675; 27102; 125560; 136652 | |
| 99 | Q0: 43210; 100661; 76072; 62453 | |
| 100 | Q1: 42151; 27450; 75350; 112503 | |
| 101 | log2e: 40270; 125073; 24534; 13761 | |
| 102 | sqrt2: 40265; 02363; 31771; 157144 | |
| 103 | half = 40000 | |
| 104 | one = 40200 | |
| 105 | / | |
| 106 | big: 77777; 177777; 177777; 177777 | |
| 107 | / | |
| 108 | / P0 = .15139 06799 05433 89158 94328 d4 | |
| 109 | / P1 = .20202 06565 12869 27227 886 d2 | |
| 110 | / P2 = .23093 34775 37502 33624 d-1 | |
| 111 | / | |
| 112 | / Q0 = .43682 11662 72755 84984 96814 d4 | |
| 113 | / Q1 = .23318 42114 27481 62379 0295 d3 | |
| 114 | / Q2 = .1 d1 | |
| 115 | / | |
| 116 | / log2e = 1.44269 50408 88963 40735 99246 | |
| 117 | / sqrt2 = 1.41421 35623 73095 04880 16887 |