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Linux/arch/m68k/fpsp040/ssin.S

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  1 |
  2 |       ssin.sa 3.3 7/29/91
  3 |
  4 |       The entry point sSIN computes the sine of an input argument
  5 |       sCOS computes the cosine, and sSINCOS computes both. The
  6 |       corresponding entry points with a "d" computes the same
  7 |       corresponding function values for denormalized inputs.
  8 |
  9 |       Input: Double-extended number X in location pointed to
 10 |               by address register a0.
 11 |
 12 |       Output: The function value sin(X) or cos(X) returned in Fp0 if SIN or
 13 |               COS is requested. Otherwise, for SINCOS, sin(X) is returned
 14 |               in Fp0, and cos(X) is returned in Fp1.
 15 |
 16 |       Modifies: Fp0 for SIN or COS; both Fp0 and Fp1 for SINCOS.
 17 |
 18 |       Accuracy and Monotonicity: The returned result is within 1 ulp in
 19 |               64 significant bit, i.e. within 0.5001 ulp to 53 bits if the
 20 |               result is subsequently rounded to double precision. The
 21 |               result is provably monotonic in double precision.
 22 |
 23 |       Speed: The programs sSIN and sCOS take approximately 150 cycles for
 24 |               input argument X such that |X| < 15Pi, which is the usual
 25 |               situation. The speed for sSINCOS is approximately 190 cycles.
 26 |
 27 |       Algorithm:
 28 |
 29 |       SIN and COS:
 30 |       1. If SIN is invoked, set AdjN := 0; otherwise, set AdjN := 1.
 31 |
 32 |       2. If |X| >= 15Pi or |X| < 2**(-40), go to 7.
 33 |
 34 |       3. Decompose X as X = N(Pi/2) + r where |r| <= Pi/4. Let
 35 |               k = N mod 4, so in particular, k = 0,1,2,or 3. Overwrite
 36 |               k by k := k + AdjN.
 37 |
 38 |       4. If k is even, go to 6.
 39 |
 40 |       5. (k is odd) Set j := (k-1)/2, sgn := (-1)**j. Return sgn*cos(r)
 41 |               where cos(r) is approximated by an even polynomial in r,
 42 |               1 + r*r*(B1+s*(B2+ ... + s*B8)),        s = r*r.
 43 |               Exit.
 44 |
 45 |       6. (k is even) Set j := k/2, sgn := (-1)**j. Return sgn*sin(r)
 46 |               where sin(r) is approximated by an odd polynomial in r
 47 |               r + r*s*(A1+s*(A2+ ... + s*A7)),        s = r*r.
 48 |               Exit.
 49 |
 50 |       7. If |X| > 1, go to 9.
 51 |
 52 |       8. (|X|<2**(-40)) If SIN is invoked, return X; otherwise return 1.
 53 |
 54 |       9. Overwrite X by X := X rem 2Pi. Now that |X| <= Pi, go back to 3.
 55 |
 56 |       SINCOS:
 57 |       1. If |X| >= 15Pi or |X| < 2**(-40), go to 6.
 58 |
 59 |       2. Decompose X as X = N(Pi/2) + r where |r| <= Pi/4. Let
 60 |               k = N mod 4, so in particular, k = 0,1,2,or 3.
 61 |
 62 |       3. If k is even, go to 5.
 63 |
 64 |       4. (k is odd) Set j1 := (k-1)/2, j2 := j1 (EOR) (k mod 2), i.e.
 65 |               j1 exclusive or with the l.s.b. of k.
 66 |               sgn1 := (-1)**j1, sgn2 := (-1)**j2.
 67 |               SIN(X) = sgn1 * cos(r) and COS(X) = sgn2*sin(r) where
 68 |               sin(r) and cos(r) are computed as odd and even polynomials
 69 |               in r, respectively. Exit
 70 |
 71 |       5. (k is even) Set j1 := k/2, sgn1 := (-1)**j1.
 72 |               SIN(X) = sgn1 * sin(r) and COS(X) = sgn1*cos(r) where
 73 |               sin(r) and cos(r) are computed as odd and even polynomials
 74 |               in r, respectively. Exit
 75 |
 76 |       6. If |X| > 1, go to 8.
 77 |
 78 |       7. (|X|<2**(-40)) SIN(X) = X and COS(X) = 1. Exit.
 79 |
 80 |       8. Overwrite X by X := X rem 2Pi. Now that |X| <= Pi, go back to 2.
 81 |
 82 
 83 |               Copyright (C) Motorola, Inc. 1990
 84 |                       All Rights Reserved
 85 |
 86 |       For details on the license for this file, please see the
 87 |       file, README, in this same directory.
 88 
 89 |SSIN   idnt    2,1 | Motorola 040 Floating Point Software Package
 90 
 91         |section        8
 92 
 93 #include "fpsp.h"
 94 
 95 BOUNDS1:        .long 0x3FD78000,0x4004BC7E
 96 TWOBYPI:        .long 0x3FE45F30,0x6DC9C883
 97 
 98 SINA7:  .long 0xBD6AAA77,0xCCC994F5
 99 SINA6:  .long 0x3DE61209,0x7AAE8DA1
100 
101 SINA5:  .long 0xBE5AE645,0x2A118AE4
102 SINA4:  .long 0x3EC71DE3,0xA5341531
103 
104 SINA3:  .long 0xBF2A01A0,0x1A018B59,0x00000000,0x00000000
105 
106 SINA2:  .long 0x3FF80000,0x88888888,0x888859AF,0x00000000
107 
108 SINA1:  .long 0xBFFC0000,0xAAAAAAAA,0xAAAAAA99,0x00000000
109 
110 COSB8:  .long 0x3D2AC4D0,0xD6011EE3
111 COSB7:  .long 0xBDA9396F,0x9F45AC19
112 
113 COSB6:  .long 0x3E21EED9,0x0612C972
114 COSB5:  .long 0xBE927E4F,0xB79D9FCF
115 
116 COSB4:  .long 0x3EFA01A0,0x1A01D423,0x00000000,0x00000000
117 
118 COSB3:  .long 0xBFF50000,0xB60B60B6,0x0B61D438,0x00000000
119 
120 COSB2:  .long 0x3FFA0000,0xAAAAAAAA,0xAAAAAB5E
121 COSB1:  .long 0xBF000000
122 
123 INVTWOPI: .long 0x3FFC0000,0xA2F9836E,0x4E44152A
124 
125 TWOPI1: .long 0x40010000,0xC90FDAA2,0x00000000,0x00000000
126 TWOPI2: .long 0x3FDF0000,0x85A308D4,0x00000000,0x00000000
127 
128         |xref   PITBL
129 
130         .set    INARG,FP_SCR4
131 
132         .set    X,FP_SCR5
133         .set    XDCARE,X+2
134         .set    XFRAC,X+4
135 
136         .set    RPRIME,FP_SCR1
137         .set    SPRIME,FP_SCR2
138 
139         .set    POSNEG1,L_SCR1
140         .set    TWOTO63,L_SCR1
141 
142         .set    ENDFLAG,L_SCR2
143         .set    N,L_SCR2
144 
145         .set    ADJN,L_SCR3
146 
147         | xref  t_frcinx
148         |xref   t_extdnrm
149         |xref   sto_cos
150 
151         .global ssind
152 ssind:
153 |--SIN(X) = X FOR DENORMALIZED X
154         bra             t_extdnrm
155 
156         .global scosd
157 scosd:
158 |--COS(X) = 1 FOR DENORMALIZED X
159 
160         fmoves          #0x3F800000,%fp0
161 |
162 |       9D25B Fix: Sometimes the previous fmove.s sets fpsr bits
163 |
164         fmovel          #0,%fpsr
165 |
166         bra             t_frcinx
167 
168         .global ssin
169 ssin:
170 |--SET ADJN TO 0
171         movel           #0,ADJN(%a6)
172         bras            SINBGN
173 
174         .global scos
175 scos:
176 |--SET ADJN TO 1
177         movel           #1,ADJN(%a6)
178 
179 SINBGN:
180 |--SAVE FPCR, FP1. CHECK IF |X| IS TOO SMALL OR LARGE
181 
182         fmovex          (%a0),%fp0      | ...LOAD INPUT
183 
184         movel           (%a0),%d0
185         movew           4(%a0),%d0
186         fmovex          %fp0,X(%a6)
187         andil           #0x7FFFFFFF,%d0         | ...COMPACTIFY X
188 
189         cmpil           #0x3FD78000,%d0         | ...|X| >= 2**(-40)?
190         bges            SOK1
191         bra             SINSM
192 
193 SOK1:
194         cmpil           #0x4004BC7E,%d0         | ...|X| < 15 PI?
195         blts            SINMAIN
196         bra             REDUCEX
197 
198 SINMAIN:
199 |--THIS IS THE USUAL CASE, |X| <= 15 PI.
200 |--THE ARGUMENT REDUCTION IS DONE BY TABLE LOOK UP.
201         fmovex          %fp0,%fp1
202         fmuld           TWOBYPI,%fp1    | ...X*2/PI
203 
204 |--HIDE THE NEXT THREE INSTRUCTIONS
205         lea             PITBL+0x200,%a1 | ...TABLE OF N*PI/2, N = -32,...,32
206 
207 
208 |--FP1 IS NOW READY
209         fmovel          %fp1,N(%a6)             | ...CONVERT TO INTEGER
210 
211         movel           N(%a6),%d0
212         asll            #4,%d0
213         addal           %d0,%a1 | ...A1 IS THE ADDRESS OF N*PIBY2
214 |                               ...WHICH IS IN TWO PIECES Y1 & Y2
215 
216         fsubx           (%a1)+,%fp0     | ...X-Y1
217 |--HIDE THE NEXT ONE
218         fsubs           (%a1),%fp0      | ...FP0 IS R = (X-Y1)-Y2
219 
220 SINCONT:
221 |--continuation from REDUCEX
222 
223 |--GET N+ADJN AND SEE IF SIN(R) OR COS(R) IS NEEDED
224         movel           N(%a6),%d0
225         addl            ADJN(%a6),%d0   | ...SEE IF D0 IS ODD OR EVEN
226         rorl            #1,%d0  | ...D0 WAS ODD IFF D0 IS NEGATIVE
227         cmpil           #0,%d0
228         blt             COSPOLY
229 
230 SINPOLY:
231 |--LET J BE THE LEAST SIG. BIT OF D0, LET SGN := (-1)**J.
232 |--THEN WE RETURN       SGN*SIN(R). SGN*SIN(R) IS COMPUTED BY
233 |--R' + R'*S*(A1 + S(A2 + S(A3 + S(A4 + ... + SA7)))), WHERE
234 |--R' = SGN*R, S=R*R. THIS CAN BE REWRITTEN AS
235 |--R' + R'*S*( [A1+T(A3+T(A5+TA7))] + [S(A2+T(A4+TA6))])
236 |--WHERE T=S*S.
237 |--NOTE THAT A3 THROUGH A7 ARE STORED IN DOUBLE PRECISION
238 |--WHILE A1 AND A2 ARE IN DOUBLE-EXTENDED FORMAT.
239         fmovex          %fp0,X(%a6)     | ...X IS R
240         fmulx           %fp0,%fp0       | ...FP0 IS S
241 |---HIDE THE NEXT TWO WHILE WAITING FOR FP0
242         fmoved          SINA7,%fp3
243         fmoved          SINA6,%fp2
244 |--FP0 IS NOW READY
245         fmovex          %fp0,%fp1
246         fmulx           %fp1,%fp1       | ...FP1 IS T
247 |--HIDE THE NEXT TWO WHILE WAITING FOR FP1
248 
249         rorl            #1,%d0
250         andil           #0x80000000,%d0
251 |                               ...LEAST SIG. BIT OF D0 IN SIGN POSITION
252         eorl            %d0,X(%a6)      | ...X IS NOW R'= SGN*R
253 
254         fmulx           %fp1,%fp3       | ...TA7
255         fmulx           %fp1,%fp2       | ...TA6
256 
257         faddd           SINA5,%fp3 | ...A5+TA7
258         faddd           SINA4,%fp2 | ...A4+TA6
259 
260         fmulx           %fp1,%fp3       | ...T(A5+TA7)
261         fmulx           %fp1,%fp2       | ...T(A4+TA6)
262 
263         faddd           SINA3,%fp3 | ...A3+T(A5+TA7)
264         faddx           SINA2,%fp2 | ...A2+T(A4+TA6)
265 
266         fmulx           %fp3,%fp1       | ...T(A3+T(A5+TA7))
267 
268         fmulx           %fp0,%fp2       | ...S(A2+T(A4+TA6))
269         faddx           SINA1,%fp1 | ...A1+T(A3+T(A5+TA7))
270         fmulx           X(%a6),%fp0     | ...R'*S
271 
272         faddx           %fp2,%fp1       | ...[A1+T(A3+T(A5+TA7))]+[S(A2+T(A4+TA6))]
273 |--FP3 RELEASED, RESTORE NOW AND TAKE SOME ADVANTAGE OF HIDING
274 |--FP2 RELEASED, RESTORE NOW AND TAKE FULL ADVANTAGE OF HIDING
275 
276 
277         fmulx           %fp1,%fp0               | ...SIN(R')-R'
278 |--FP1 RELEASED.
279 
280         fmovel          %d1,%FPCR               |restore users exceptions
281         faddx           X(%a6),%fp0             |last inst - possible exception set
282         bra             t_frcinx
283 
284 
285 COSPOLY:
286 |--LET J BE THE LEAST SIG. BIT OF D0, LET SGN := (-1)**J.
287 |--THEN WE RETURN       SGN*COS(R). SGN*COS(R) IS COMPUTED BY
288 |--SGN + S'*(B1 + S(B2 + S(B3 + S(B4 + ... + SB8)))), WHERE
289 |--S=R*R AND S'=SGN*S. THIS CAN BE REWRITTEN AS
290 |--SGN + S'*([B1+T(B3+T(B5+TB7))] + [S(B2+T(B4+T(B6+TB8)))])
291 |--WHERE T=S*S.
292 |--NOTE THAT B4 THROUGH B8 ARE STORED IN DOUBLE PRECISION
293 |--WHILE B2 AND B3 ARE IN DOUBLE-EXTENDED FORMAT, B1 IS -1/2
294 |--AND IS THEREFORE STORED AS SINGLE PRECISION.
295 
296         fmulx           %fp0,%fp0       | ...FP0 IS S
297 |---HIDE THE NEXT TWO WHILE WAITING FOR FP0
298         fmoved          COSB8,%fp2
299         fmoved          COSB7,%fp3
300 |--FP0 IS NOW READY
301         fmovex          %fp0,%fp1
302         fmulx           %fp1,%fp1       | ...FP1 IS T
303 |--HIDE THE NEXT TWO WHILE WAITING FOR FP1
304         fmovex          %fp0,X(%a6)     | ...X IS S
305         rorl            #1,%d0
306         andil           #0x80000000,%d0
307 |                       ...LEAST SIG. BIT OF D0 IN SIGN POSITION
308 
309         fmulx           %fp1,%fp2       | ...TB8
310 |--HIDE THE NEXT TWO WHILE WAITING FOR THE XU
311         eorl            %d0,X(%a6)      | ...X IS NOW S'= SGN*S
312         andil           #0x80000000,%d0
313 
314         fmulx           %fp1,%fp3       | ...TB7
315 |--HIDE THE NEXT TWO WHILE WAITING FOR THE XU
316         oril            #0x3F800000,%d0 | ...D0 IS SGN IN SINGLE
317         movel           %d0,POSNEG1(%a6)
318 
319         faddd           COSB6,%fp2 | ...B6+TB8
320         faddd           COSB5,%fp3 | ...B5+TB7
321 
322         fmulx           %fp1,%fp2       | ...T(B6+TB8)
323         fmulx           %fp1,%fp3       | ...T(B5+TB7)
324 
325         faddd           COSB4,%fp2 | ...B4+T(B6+TB8)
326         faddx           COSB3,%fp3 | ...B3+T(B5+TB7)
327 
328         fmulx           %fp1,%fp2       | ...T(B4+T(B6+TB8))
329         fmulx           %fp3,%fp1       | ...T(B3+T(B5+TB7))
330 
331         faddx           COSB2,%fp2 | ...B2+T(B4+T(B6+TB8))
332         fadds           COSB1,%fp1 | ...B1+T(B3+T(B5+TB7))
333 
334         fmulx           %fp2,%fp0       | ...S(B2+T(B4+T(B6+TB8)))
335 |--FP3 RELEASED, RESTORE NOW AND TAKE SOME ADVANTAGE OF HIDING
336 |--FP2 RELEASED.
337 
338 
339         faddx           %fp1,%fp0
340 |--FP1 RELEASED
341 
342         fmulx           X(%a6),%fp0
343 
344         fmovel          %d1,%FPCR               |restore users exceptions
345         fadds           POSNEG1(%a6),%fp0       |last inst - possible exception set
346         bra             t_frcinx
347 
348 
349 SINBORS:
350 |--IF |X| > 15PI, WE USE THE GENERAL ARGUMENT REDUCTION.
351 |--IF |X| < 2**(-40), RETURN X OR 1.
352         cmpil           #0x3FFF8000,%d0
353         bgts            REDUCEX
354 
355 
356 SINSM:
357         movel           ADJN(%a6),%d0
358         cmpil           #0,%d0
359         bgts            COSTINY
360 
361 SINTINY:
362         movew           #0x0000,XDCARE(%a6)     | ...JUST IN CASE
363         fmovel          %d1,%FPCR               |restore users exceptions
364         fmovex          X(%a6),%fp0             |last inst - possible exception set
365         bra             t_frcinx
366 
367 
368 COSTINY:
369         fmoves          #0x3F800000,%fp0
370 
371         fmovel          %d1,%FPCR               |restore users exceptions
372         fsubs           #0x00800000,%fp0        |last inst - possible exception set
373         bra             t_frcinx
374 
375 
376 REDUCEX:
377 |--WHEN REDUCEX IS USED, THE CODE WILL INEVITABLY BE SLOW.
378 |--THIS REDUCTION METHOD, HOWEVER, IS MUCH FASTER THAN USING
379 |--THE REMAINDER INSTRUCTION WHICH IS NOW IN SOFTWARE.
380 
381         fmovemx %fp2-%fp5,-(%a7)        | ...save FP2 through FP5
382         movel           %d2,-(%a7)
383         fmoves         #0x00000000,%fp1
384 |--If compact form of abs(arg) in d0=$7ffeffff, argument is so large that
385 |--there is a danger of unwanted overflow in first LOOP iteration.  In this
386 |--case, reduce argument by one remainder step to make subsequent reduction
387 |--safe.
388         cmpil   #0x7ffeffff,%d0         |is argument dangerously large?
389         bnes    LOOP
390         movel   #0x7ffe0000,FP_SCR2(%a6)        |yes
391 |                                       ;create 2**16383*PI/2
392         movel   #0xc90fdaa2,FP_SCR2+4(%a6)
393         clrl    FP_SCR2+8(%a6)
394         ftstx   %fp0                    |test sign of argument
395         movel   #0x7fdc0000,FP_SCR3(%a6)        |create low half of 2**16383*
396 |                                       ;PI/2 at FP_SCR3
397         movel   #0x85a308d3,FP_SCR3+4(%a6)
398         clrl   FP_SCR3+8(%a6)
399         fblt    red_neg
400         orw     #0x8000,FP_SCR2(%a6)    |positive arg
401         orw     #0x8000,FP_SCR3(%a6)
402 red_neg:
403         faddx  FP_SCR2(%a6),%fp0                |high part of reduction is exact
404         fmovex  %fp0,%fp1               |save high result in fp1
405         faddx  FP_SCR3(%a6),%fp0                |low part of reduction
406         fsubx  %fp0,%fp1                        |determine low component of result
407         faddx  FP_SCR3(%a6),%fp1                |fp0/fp1 are reduced argument.
408 
409 |--ON ENTRY, FP0 IS X, ON RETURN, FP0 IS X REM PI/2, |X| <= PI/4.
410 |--integer quotient will be stored in N
411 |--Intermediate remainder is 66-bit long; (R,r) in (FP0,FP1)
412 
413 LOOP:
414         fmovex          %fp0,INARG(%a6) | ...+-2**K * F, 1 <= F < 2
415         movew           INARG(%a6),%d0
416         movel          %d0,%a1          | ...save a copy of D0
417         andil           #0x00007FFF,%d0
418         subil           #0x00003FFF,%d0 | ...D0 IS K
419         cmpil           #28,%d0
420         bles            LASTLOOP
421 CONTLOOP:
422         subil           #27,%d0  | ...D0 IS L := K-27
423         movel           #0,ENDFLAG(%a6)
424         bras            WORK
425 LASTLOOP:
426         clrl            %d0             | ...D0 IS L := 0
427         movel           #1,ENDFLAG(%a6)
428 
429 WORK:
430 |--FIND THE REMAINDER OF (R,r) W.R.T.   2**L * (PI/2). L IS SO CHOSEN
431 |--THAT INT( X * (2/PI) / 2**(L) ) < 2**29.
432 
433 |--CREATE 2**(-L) * (2/PI), SIGN(INARG)*2**(63),
434 |--2**L * (PIby2_1), 2**L * (PIby2_2)
435 
436         movel           #0x00003FFE,%d2 | ...BIASED EXPO OF 2/PI
437         subl            %d0,%d2         | ...BIASED EXPO OF 2**(-L)*(2/PI)
438 
439         movel           #0xA2F9836E,FP_SCR1+4(%a6)
440         movel           #0x4E44152A,FP_SCR1+8(%a6)
441         movew           %d2,FP_SCR1(%a6)        | ...FP_SCR1 is 2**(-L)*(2/PI)
442 
443         fmovex          %fp0,%fp2
444         fmulx           FP_SCR1(%a6),%fp2
445 |--WE MUST NOW FIND INT(FP2). SINCE WE NEED THIS VALUE IN
446 |--FLOATING POINT FORMAT, THE TWO FMOVE'S       FMOVE.L FP <--> N
447 |--WILL BE TOO INEFFICIENT. THE WAY AROUND IT IS THAT
448 |--(SIGN(INARG)*2**63   +       FP2) - SIGN(INARG)*2**63 WILL GIVE
449 |--US THE DESIRED VALUE IN FLOATING POINT.
450 
451 |--HIDE SIX CYCLES OF INSTRUCTION
452         movel           %a1,%d2
453         swap            %d2
454         andil           #0x80000000,%d2
455         oril            #0x5F000000,%d2 | ...D2 IS SIGN(INARG)*2**63 IN SGL
456         movel           %d2,TWOTO63(%a6)
457 
458         movel           %d0,%d2
459         addil           #0x00003FFF,%d2 | ...BIASED EXPO OF 2**L * (PI/2)
460 
461 |--FP2 IS READY
462         fadds           TWOTO63(%a6),%fp2       | ...THE FRACTIONAL PART OF FP1 IS ROUNDED
463 
464 |--HIDE 4 CYCLES OF INSTRUCTION; creating 2**(L)*Piby2_1  and  2**(L)*Piby2_2
465         movew           %d2,FP_SCR2(%a6)
466         clrw           FP_SCR2+2(%a6)
467         movel           #0xC90FDAA2,FP_SCR2+4(%a6)
468         clrl            FP_SCR2+8(%a6)          | ...FP_SCR2 is  2**(L) * Piby2_1
469 
470 |--FP2 IS READY
471         fsubs           TWOTO63(%a6),%fp2               | ...FP2 is N
472 
473         addil           #0x00003FDD,%d0
474         movew           %d0,FP_SCR3(%a6)
475         clrw           FP_SCR3+2(%a6)
476         movel           #0x85A308D3,FP_SCR3+4(%a6)
477         clrl            FP_SCR3+8(%a6)          | ...FP_SCR3 is 2**(L) * Piby2_2
478 
479         movel           ENDFLAG(%a6),%d0
480 
481 |--We are now ready to perform (R+r) - N*P1 - N*P2, P1 = 2**(L) * Piby2_1 and
482 |--P2 = 2**(L) * Piby2_2
483         fmovex          %fp2,%fp4
484         fmulx           FP_SCR2(%a6),%fp4               | ...W = N*P1
485         fmovex          %fp2,%fp5
486         fmulx           FP_SCR3(%a6),%fp5               | ...w = N*P2
487         fmovex          %fp4,%fp3
488 |--we want P+p = W+w  but  |p| <= half ulp of P
489 |--Then, we need to compute  A := R-P   and  a := r-p
490         faddx           %fp5,%fp3                       | ...FP3 is P
491         fsubx           %fp3,%fp4                       | ...W-P
492 
493         fsubx           %fp3,%fp0                       | ...FP0 is A := R - P
494         faddx           %fp5,%fp4                       | ...FP4 is p = (W-P)+w
495 
496         fmovex          %fp0,%fp3                       | ...FP3 A
497         fsubx           %fp4,%fp1                       | ...FP1 is a := r - p
498 
499 |--Now we need to normalize (A,a) to  "new (R,r)" where R+r = A+a but
500 |--|r| <= half ulp of R.
501         faddx           %fp1,%fp0                       | ...FP0 is R := A+a
502 |--No need to calculate r if this is the last loop
503         cmpil           #0,%d0
504         bgt             RESTORE
505 
506 |--Need to calculate r
507         fsubx           %fp0,%fp3                       | ...A-R
508         faddx           %fp3,%fp1                       | ...FP1 is r := (A-R)+a
509         bra             LOOP
510 
511 RESTORE:
512         fmovel          %fp2,N(%a6)
513         movel           (%a7)+,%d2
514         fmovemx (%a7)+,%fp2-%fp5
515 
516 
517         movel           ADJN(%a6),%d0
518         cmpil           #4,%d0
519 
520         blt             SINCONT
521         bras            SCCONT
522 
523         .global ssincosd
524 ssincosd:
525 |--SIN AND COS OF X FOR DENORMALIZED X
526 
527         fmoves          #0x3F800000,%fp1
528         bsr             sto_cos         |store cosine result
529         bra             t_extdnrm
530 
531         .global ssincos
532 ssincos:
533 |--SET ADJN TO 4
534         movel           #4,ADJN(%a6)
535 
536         fmovex          (%a0),%fp0      | ...LOAD INPUT
537 
538         movel           (%a0),%d0
539         movew           4(%a0),%d0
540         fmovex          %fp0,X(%a6)
541         andil           #0x7FFFFFFF,%d0         | ...COMPACTIFY X
542 
543         cmpil           #0x3FD78000,%d0         | ...|X| >= 2**(-40)?
544         bges            SCOK1
545         bra             SCSM
546 
547 SCOK1:
548         cmpil           #0x4004BC7E,%d0         | ...|X| < 15 PI?
549         blts            SCMAIN
550         bra             REDUCEX
551 
552 
553 SCMAIN:
554 |--THIS IS THE USUAL CASE, |X| <= 15 PI.
555 |--THE ARGUMENT REDUCTION IS DONE BY TABLE LOOK UP.
556         fmovex          %fp0,%fp1
557         fmuld           TWOBYPI,%fp1    | ...X*2/PI
558 
559 |--HIDE THE NEXT THREE INSTRUCTIONS
560         lea             PITBL+0x200,%a1 | ...TABLE OF N*PI/2, N = -32,...,32
561 
562 
563 |--FP1 IS NOW READY
564         fmovel          %fp1,N(%a6)             | ...CONVERT TO INTEGER
565 
566         movel           N(%a6),%d0
567         asll            #4,%d0
568         addal           %d0,%a1         | ...ADDRESS OF N*PIBY2, IN Y1, Y2
569 
570         fsubx           (%a1)+,%fp0     | ...X-Y1
571         fsubs           (%a1),%fp0      | ...FP0 IS R = (X-Y1)-Y2
572 
573 SCCONT:
574 |--continuation point from REDUCEX
575 
576 |--HIDE THE NEXT TWO
577         movel           N(%a6),%d0
578         rorl            #1,%d0
579 
580         cmpil           #0,%d0          | ...D0 < 0 IFF N IS ODD
581         bge             NEVEN
582 
583 NODD:
584 |--REGISTERS SAVED SO FAR: D0, A0, FP2.
585 
586         fmovex          %fp0,RPRIME(%a6)
587         fmulx           %fp0,%fp0        | ...FP0 IS S = R*R
588         fmoved          SINA7,%fp1      | ...A7
589         fmoved          COSB8,%fp2      | ...B8
590         fmulx           %fp0,%fp1        | ...SA7
591         movel           %d2,-(%a7)
592         movel           %d0,%d2
593         fmulx           %fp0,%fp2        | ...SB8
594         rorl            #1,%d2
595         andil           #0x80000000,%d2
596 
597         faddd           SINA6,%fp1      | ...A6+SA7
598         eorl            %d0,%d2
599         andil           #0x80000000,%d2
600         faddd           COSB7,%fp2      | ...B7+SB8
601 
602         fmulx           %fp0,%fp1        | ...S(A6+SA7)
603         eorl            %d2,RPRIME(%a6)
604         movel           (%a7)+,%d2
605         fmulx           %fp0,%fp2        | ...S(B7+SB8)
606         rorl            #1,%d0
607         andil           #0x80000000,%d0
608 
609         faddd           SINA5,%fp1      | ...A5+S(A6+SA7)
610         movel           #0x3F800000,POSNEG1(%a6)
611         eorl            %d0,POSNEG1(%a6)
612         faddd           COSB6,%fp2      | ...B6+S(B7+SB8)
613 
614         fmulx           %fp0,%fp1        | ...S(A5+S(A6+SA7))
615         fmulx           %fp0,%fp2        | ...S(B6+S(B7+SB8))
616         fmovex          %fp0,SPRIME(%a6)
617 
618         faddd           SINA4,%fp1      | ...A4+S(A5+S(A6+SA7))
619         eorl            %d0,SPRIME(%a6)
620         faddd           COSB5,%fp2      | ...B5+S(B6+S(B7+SB8))
621 
622         fmulx           %fp0,%fp1        | ...S(A4+...)
623         fmulx           %fp0,%fp2        | ...S(B5+...)
624 
625         faddd           SINA3,%fp1      | ...A3+S(A4+...)
626         faddd           COSB4,%fp2      | ...B4+S(B5+...)
627 
628         fmulx           %fp0,%fp1        | ...S(A3+...)
629         fmulx           %fp0,%fp2        | ...S(B4+...)
630 
631         faddx           SINA2,%fp1      | ...A2+S(A3+...)
632         faddx           COSB3,%fp2      | ...B3+S(B4+...)
633 
634         fmulx           %fp0,%fp1        | ...S(A2+...)
635         fmulx           %fp0,%fp2        | ...S(B3+...)
636 
637         faddx           SINA1,%fp1      | ...A1+S(A2+...)
638         faddx           COSB2,%fp2      | ...B2+S(B3+...)
639 
640         fmulx           %fp0,%fp1        | ...S(A1+...)
641         fmulx           %fp2,%fp0        | ...S(B2+...)
642 
643 
644 
645         fmulx           RPRIME(%a6),%fp1        | ...R'S(A1+...)
646         fadds           COSB1,%fp0      | ...B1+S(B2...)
647         fmulx           SPRIME(%a6),%fp0        | ...S'(B1+S(B2+...))
648 
649         movel           %d1,-(%sp)      |restore users mode & precision
650         andil           #0xff,%d1               |mask off all exceptions
651         fmovel          %d1,%FPCR
652         faddx           RPRIME(%a6),%fp1        | ...COS(X)
653         bsr             sto_cos         |store cosine result
654         fmovel          (%sp)+,%FPCR    |restore users exceptions
655         fadds           POSNEG1(%a6),%fp0       | ...SIN(X)
656 
657         bra             t_frcinx
658 
659 
660 NEVEN:
661 |--REGISTERS SAVED SO FAR: FP2.
662 
663         fmovex          %fp0,RPRIME(%a6)
664         fmulx           %fp0,%fp0        | ...FP0 IS S = R*R
665         fmoved          COSB8,%fp1                      | ...B8
666         fmoved          SINA7,%fp2                      | ...A7
667         fmulx           %fp0,%fp1        | ...SB8
668         fmovex          %fp0,SPRIME(%a6)
669         fmulx           %fp0,%fp2        | ...SA7
670         rorl            #1,%d0
671         andil           #0x80000000,%d0
672         faddd           COSB7,%fp1      | ...B7+SB8
673         faddd           SINA6,%fp2      | ...A6+SA7
674         eorl            %d0,RPRIME(%a6)
675         eorl            %d0,SPRIME(%a6)
676         fmulx           %fp0,%fp1        | ...S(B7+SB8)
677         oril            #0x3F800000,%d0
678         movel           %d0,POSNEG1(%a6)
679         fmulx           %fp0,%fp2        | ...S(A6+SA7)
680 
681         faddd           COSB6,%fp1      | ...B6+S(B7+SB8)
682         faddd           SINA5,%fp2      | ...A5+S(A6+SA7)
683 
684         fmulx           %fp0,%fp1        | ...S(B6+S(B7+SB8))
685         fmulx           %fp0,%fp2        | ...S(A5+S(A6+SA7))
686 
687         faddd           COSB5,%fp1      | ...B5+S(B6+S(B7+SB8))
688         faddd           SINA4,%fp2      | ...A4+S(A5+S(A6+SA7))
689 
690         fmulx           %fp0,%fp1        | ...S(B5+...)
691         fmulx           %fp0,%fp2        | ...S(A4+...)
692 
693         faddd           COSB4,%fp1      | ...B4+S(B5+...)
694         faddd           SINA3,%fp2      | ...A3+S(A4+...)
695 
696         fmulx           %fp0,%fp1        | ...S(B4+...)
697         fmulx           %fp0,%fp2        | ...S(A3+...)
698 
699         faddx           COSB3,%fp1      | ...B3+S(B4+...)
700         faddx           SINA2,%fp2      | ...A2+S(A3+...)
701 
702         fmulx           %fp0,%fp1        | ...S(B3+...)
703         fmulx           %fp0,%fp2        | ...S(A2+...)
704 
705         faddx           COSB2,%fp1      | ...B2+S(B3+...)
706         faddx           SINA1,%fp2      | ...A1+S(A2+...)
707 
708         fmulx           %fp0,%fp1        | ...S(B2+...)
709         fmulx           %fp2,%fp0        | ...s(a1+...)
710 
711 
712 
713         fadds           COSB1,%fp1      | ...B1+S(B2...)
714         fmulx           RPRIME(%a6),%fp0        | ...R'S(A1+...)
715         fmulx           SPRIME(%a6),%fp1        | ...S'(B1+S(B2+...))
716 
717         movel           %d1,-(%sp)      |save users mode & precision
718         andil           #0xff,%d1               |mask off all exceptions
719         fmovel          %d1,%FPCR
720         fadds           POSNEG1(%a6),%fp1       | ...COS(X)
721         bsr             sto_cos         |store cosine result
722         fmovel          (%sp)+,%FPCR    |restore users exceptions
723         faddx           RPRIME(%a6),%fp0        | ...SIN(X)
724 
725         bra             t_frcinx
726 
727 SCBORS:
728         cmpil           #0x3FFF8000,%d0
729         bgt             REDUCEX
730 
731 
732 SCSM:
733         movew           #0x0000,XDCARE(%a6)
734         fmoves          #0x3F800000,%fp1
735 
736         movel           %d1,-(%sp)      |save users mode & precision
737         andil           #0xff,%d1               |mask off all exceptions
738         fmovel          %d1,%FPCR
739         fsubs           #0x00800000,%fp1
740         bsr             sto_cos         |store cosine result
741         fmovel          (%sp)+,%FPCR    |restore users exceptions
742         fmovex          X(%a6),%fp0
743         bra             t_frcinx
744 
745         |end

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