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| Commit | Line | Data |
|---|---|---|
| 8daa8d7c DF |
1 | # |
| 2 | # Copyright (c) 1980 Regents of the University of California. | |
| 3 | # All rights reserved. The Berkeley software License Agreement | |
| 4 | # specifies the terms and conditions for redistribution. | |
| 5 | # | |
| 6 | # @(#)badtan.s 5.1 (Berkeley) %G% | |
| 7 | # | |
| 8 | # | |
| 5eed6277 DF |
9 | # double tan(arg) |
| 10 | # double arg; | |
| 11 | #method: range reduction to [0,pi/4] followed by polynomial | |
| 12 | # approximation: Hart&Cheney TAN 4285 D=19.74 | |
| 13 | .globl _tan | |
| 14 | .text | |
| 15 | .align 1 | |
| 16 | _tan: | |
| 17 | .word 0x07c0 | |
| 18 | bispsw $0xe0 | |
| 19 | clrl r10 # sign flag, !=0 negate result | |
| 20 | movd 4(ap),r0 | |
| 21 | jgeq c1 | |
| 22 | xorw2 $0x8000,r10 | |
| 23 | mnegd r0,r0 | |
| 24 | c1: | |
| 25 | emodd fopi,fopix,r0,r2,r6 | |
| 26 | bicl2 $~3,r2 | |
| 27 | caseb r2,$0,$3 | |
| 28 | a0: .word a1-a0,a2-a0,a3-a0,a4-a0 | |
| 29 | a2: subd3 r6,$0d1.0e+0,r6 | |
| 30 | jbr b1 | |
| 31 | a3: xorw2 $0x8000,r10 | |
| 32 | b1: bsbb rtan | |
| 33 | jneq b2 # tests final result cmptd in rtan | |
| 34 | movd $0d1.7e+38,r0 | |
| 35 | jmp b3 | |
| 36 | b2: divd3 r0,$0d1.0e+0,r0 | |
| 37 | b3: xorw2 r10,r0 # negate result if flag != 0 | |
| 38 | ret | |
| 39 | a4: subd3 r6,$0d1.0e+0,r6 | |
| 40 | xorw2 $0x8000,r10 | |
| 41 | a1: bsbb rtan | |
| 42 | xorw2 r10,r0 | |
| 43 | ret | |
| 44 | rtan: | |
| 45 | muld3 r6,r6,r8 | |
| 46 | polyd r8,$4,pcoef | |
| 47 | muld2 r0,r6 | |
| 48 | polyd r8,$3,qcoef | |
| 49 | divd3 r0,r6,r0 | |
| 50 | rsb | |
| 51 | .data | |
| 52 | .align 2 | |
| 53 | pcoef: | |
| 54 | .double 0d0.33866386426771720960e-4 | |
| 55 | .double 0d0.34225543872410034353e-1 | |
| 56 | .double 0d-0.15506856534832663769e+2 | |
| 57 | .double 0d0.10559709017149531936e+4 | |
| 58 | .double 0d-0.13068202647548256682e+5 | |
| 59 | qcoef: | |
| 60 | .double 0d1.0e+0 | |
| 61 | .double 0d-0.15550331640317099669e+3 | |
| 62 | .double 0d0.47657513629164836989e+4 | |
| 63 | .double 0d-0.16638952389471190018e+5 | |
| 64 | fopi: | |
| 65 | .double 0d1.27323954473516268e+0 | |
| 66 | fopix: .byte 0x29 |