projects / pdp8.git / blame
| Commit | Line | Data |
|---|---|---|
| 81e70d48 PH |
1 | / |
| 2 | / | |
| 3 | / | |
| 4 | / A T A N 2 | |
| 5 | / - - - - - | |
| 6 | / | |
| 7 | /SUBROUTINE ATAN2(Y,X) | |
| 8 | / | |
| 9 | / VERSION 5A 4-27-77 PT | |
| 10 | / | |
| 11 | SECT ATAN2 | |
| 12 | JA #ATAN2 | |
| 13 | TEXT +ATAN2 + | |
| 14 | ATN2XR, SETX XRATN2 | |
| 15 | SETB BPATN2 | |
| 16 | BPATN2, FNOP | |
| 17 | 0 | |
| 18 | 0 | |
| 19 | XRATN2, F 0.0 | |
| 20 | YCOR, F 0.0 | |
| 21 | XCOR, F 0.0 | |
| 22 | FPIAT2, 2 /PI | |
| 23 | 3110 | |
| 24 | 3755 | |
| 25 | ATPI, F 1.570796 /PI/2 | |
| 26 | ORG 10*3+BPATN2 | |
| 27 | FNOP | |
| 28 | JA ATN2XR | |
| 29 | 0 | |
| 30 | AT2RTN, JA . | |
| 31 | BASE 0 | |
| 32 | #ATAN2, STARTD | |
| 33 | FLDA 10*3 | |
| 34 | FSTA AT2RTN | |
| 35 | FLDA 0 | |
| 36 | SETX XRATN2 | |
| 37 | SETB BPATN2 | |
| 38 | BASE BPATN2 | |
| 39 | LDX 1,1 | |
| 40 | FSTA BPATN2 | |
| 41 | FLDA% BPATN2,1 /ADDR OF Y | |
| 42 | FSTA YCOR | |
| 43 | FLDA% BPATN2,1+ /ADDR OF X | |
| 44 | FSTA XCOR | |
| 45 | STARTF | |
| 46 | FLDA% YCOR /GET Y - THE TAN | |
| 47 | FSTA YCOR /SAV FOR A SECOND | |
| 48 | LDX 1,2 /POSITIVE X | |
| 49 | JEQ ATN0 | |
| 50 | JGT ATN1 | |
| 51 | LDX 0,2 | |
| 52 | ATN1, FLDA% XCOR /GET X - THE QUADRAND | |
| 53 | FSTA XCOR /+MOVE IT TO A SAFE PLACE | |
| 54 | JEQ ATASP | |
| 55 | FLDA YCOR /Y/X | |
| 56 | FDIV XCOR | |
| 57 | FSTA YCOR | |
| 58 | EXTERN ATAN | |
| 59 | JSR ATAN /CALL ATAN | |
| 60 | JA .+4 /TAKE ARCTAN OF Y/X | |
| 61 | JA YCOR | |
| 62 | FSTA YCOR /SAVE IT AWAY | |
| 63 | JGE A2 /SKIP IF 1 OR 3 Q | |
| 64 | FADD FPIAT2 /ADD PI FOR 4TH Q | |
| 65 | FSTA YCOR | |
| 66 | A2, JXN AT2RTN,2 | |
| 67 | FLDA YCOR | |
| 68 | FSUB FPIAT2 /SUB PI FOR 2ND+3RD QUADS | |
| 69 | JA AT2RTN | |
| 70 | ATASP, FLDA ATPI /X=0 MEANS +-PI/2 | |
| 71 | JXN ATNG,2 | |
| 72 | FNEG | |
| 73 | ATNG, JA AT2RTN | |
| 74 | ATN0, FLDA% XCOR | |
| 75 | JLT POSX /IF X POS,ANS IS 0 | |
| 76 | FCLA | |
| 77 | JA AT2RTN | |
| 78 | POSX, FLDA FPIAT2 /OTHERWISE,ANS IS PI | |
| 79 | JA AT2RTN | |
| 80 | \f |