1.file "asin.s"
2
3
4// Copyright (c) 2000 - 2003 Intel Corporation
5// All rights reserved.
6//
7//
8// Redistribution and use in source and binary forms, with or without
9// modification, are permitted provided that the following conditions are
10// met:
11//
12// * Redistributions of source code must retain the above copyright
13// notice, this list of conditions and the following disclaimer.
14//
15// * Redistributions in binary form must reproduce the above copyright
16// notice, this list of conditions and the following disclaimer in the
17// documentation and/or other materials provided with the distribution.
18//
19// * The name of Intel Corporation may not be used to endorse or promote
20// products derived from this software without specific prior written
21// permission.
22
23// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL OR ITS
27// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
28// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
29// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
31// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY OR TORT (INCLUDING
32// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34//
35// Intel Corporation is the author of this code, and requests that all
36// problem reports or change requests be submitted to it directly at
37// http://www.intel.com/software/products/opensource/libraries/num.htm.
38
39// History
40//==============================================================
41// 02/02/00 Initial version
42// 08/17/00 New and much faster algorithm.
43// 08/31/00 Avoided bank conflicts on loads, shortened |x|=1 path,
44//          fixed mfb split issue stalls.
45// 12/19/00 Fixed small arg cases to force inexact, or inexact and underflow.
46// 08/02/02 New and much faster algorithm II
47// 02/06/03 Reordered header: .section, .global, .proc, .align
48
49// Description
50//=========================================
51// The asin function computes the principal value of the arc sine of x.
52// asin(0) returns 0, asin(1) returns pi/2, asin(-1) returns -pi/2.
53// A doman error occurs for arguments not in the range [-1,+1].
54//
55// The asin function returns the arc sine in the range [-pi/2, +pi/2] radians.
56//
57// There are 8 paths:
58// 1. x = +/-0.0
59//    Return asin(x) = +/-0.0
60//
61// 2. 0.0 < |x| < 0.625
62//    Return asin(x) = x + x^3 *PolA(x^2)
63//    where PolA(x^2) = A3 + A5*x^2 + A7*x^4 +...+ A35*x^32
64//
65// 3. 0.625 <=|x| < 1.0
66//    Return asin(x) = sign(x) * ( Pi/2 - sqrt(R) * PolB(R))
67//    Where R = 1 - |x|,
68//          PolB(R) = B0 + B1*R + B2*R^2 +...+B12*R^12
69//
70//    sqrt(R) is approximated using the following sequence:
71//        y0 = (1 + eps)/sqrt(R) - initial approximation by frsqrta,
72//             |eps| < 2^(-8)
73//        Then 3 iterations are used to refine the result:
74//        H0 = 0.5*y0
75//        S0 = R*y0
76//
77//        d0 = 0.5 - H0*S0
78//        H1 = H0 + d0*H0
79//        S1 = S0 + d0*S0
80//
81//        d1 = 0.5 - H1*S1
82//        H2 = H1 + d0*H1
83//        S2 = S1 + d0*S1
84//
85//        d2 = 0.5 - H2*S2
86//        S3 = S3 + d2*S3
87//
88//        S3 approximates sqrt(R) with enough accuracy for this algorithm
89//
90//    So, the result should be reconstracted as follows:
91//    asin(x) = sign(x) * (Pi/2 - S3*PolB(R))
92//
93//    But for optimization perposes the reconstruction step is slightly
94//    changed:
95//    asin(x) = sign(x)*(Pi/2 - PolB(R)*S2) + sign(x)*d2*S2*PolB(R)
96//
97// 4. |x| = 1.0
98//    Return asin(x) = sign(x)*Pi/2
99//
100// 5. 1.0 < |x| <= +INF
101//    A doman error occurs for arguments not in the range [-1,+1]
102//
103// 6. x = [S,Q]NaN
104//    Return asin(x) = QNaN
105//
106// 7. x is denormal
107//    Return asin(x) = x + x^3,
108//
109// 8. x is unnormal
110//    Normalize input in f8 and return to the very beginning of the function
111//
112// Registers used
113//==============================================================
114// Floating Point registers used:
115// f8, input, output
116// f6, f7, f9 -> f15, f32 -> f63
117
118// General registers used:
119// r3, r21 -> r31, r32 -> r38
120
121// Predicate registers used:
122// p0, p6 -> p14
123
124//
125// Assembly macros
126//=========================================
127// integer registers used
128// scratch
129rTblAddr                      = r3
130
131rPiBy2Ptr                     = r21
132rTmpPtr3                      = r22
133rDenoBound                    = r23
134rOne                          = r24
135rAbsXBits                     = r25
136rHalf                         = r26
137r0625                         = r27
138rSign                         = r28
139rXBits                        = r29
140rTmpPtr2                      = r30
141rTmpPtr1                      = r31
142
143// stacked
144GR_SAVE_PFS                   = r32
145GR_SAVE_B0                    = r33
146GR_SAVE_GP                    = r34
147GR_Parameter_X                = r35
148GR_Parameter_Y                = r36
149GR_Parameter_RESULT           = r37
150GR_Parameter_TAG              = r38
151
152// floating point registers used
153FR_X                          = f10
154FR_Y                          = f1
155FR_RESULT                     = f8
156
157
158// scratch
159fXSqr                         = f6
160fXCube                        = f7
161fXQuadr                       = f9
162f1pX                          = f10
163f1mX                          = f11
164f1pXRcp                       = f12
165f1mXRcp                       = f13
166fH                            = f14
167fS                            = f15
168// stacked
169fA3                           = f32
170fB1                           = f32
171fA5                           = f33
172fB2                           = f33
173fA7                           = f34
174fPiBy2                        = f34
175fA9                           = f35
176fA11                          = f36
177fB10                          = f35
178fB11                          = f36
179fA13                          = f37
180fA15                          = f38
181fB4                           = f37
182fB5                           = f38
183fA17                          = f39
184fA19                          = f40
185fB6                           = f39
186fB7                           = f40
187fA21                          = f41
188fA23                          = f42
189fB3                           = f41
190fB8                           = f42
191fA25                          = f43
192fA27                          = f44
193fB9                           = f43
194fB12                          = f44
195fA29                          = f45
196fA31                          = f46
197fA33                          = f47
198fA35                          = f48
199fBaseP                        = f49
200fB0                           = f50
201fSignedS                      = f51
202fD                            = f52
203fHalf                         = f53
204fR                            = f54
205fCloseTo1Pol                  = f55
206fSignX                        = f56
207fDenoBound                    = f57
208fNormX                        = f58
209fX8                           = f59
210fRSqr                         = f60
211fRQuadr                       = f61
212fR8                           = f62
213fX16                          = f63
214// Data tables
215//==============================================================
216RODATA
217.align 16
218LOCAL_OBJECT_START(asin_base_range_table)
219// Ai: Polynomial coefficients for the asin(x), |x| < .625000
220// Bi: Polynomial coefficients for the asin(x), |x| > .625000
221data8 0xBFDAAB56C01AE468 //A29
222data8 0x3FE1C470B76A5B2B //A31
223data8 0xBFDC5FF82A0C4205 //A33
224data8 0x3FC71FD88BFE93F0 //A35
225data8 0xB504F333F9DE6487, 0x00003FFF //B0
226data8 0xAAAAAAAAAAAAFC18, 0x00003FFC //A3
227data8 0x3F9F1C71BC4A7823 //A9
228data8 0x3F96E8BBAAB216B2 //A11
229data8 0x3F91C4CA1F9F8A98 //A13
230data8 0x3F8C9DDCEDEBE7A6 //A15
231data8 0x3F877784442B1516 //A17
232data8 0x3F859C0491802BA2 //A19
233data8 0x9999999998C88B8F, 0x00003FFB //A5
234data8 0x3F6BD7A9A660BF5E //A21
235data8 0x3F9FC1659340419D //A23
236data8 0xB6DB6DB798149BDF, 0x00003FFA //A7
237data8 0xBFB3EF18964D3ED3 //A25
238data8 0x3FCD285315542CF2 //A27
239data8 0xF15BEEEFF7D2966A, 0x00003FFB //B1
240data8 0x3EF0DDA376D10FB3 //B10
241data8 0xBEB83CAFE05EBAC9 //B11
242data8 0x3F65FFB67B513644 //B4
243data8 0x3F5032FBB86A4501 //B5
244data8 0x3F392162276C7CBA //B6
245data8 0x3F2435949FD98BDF //B7
246data8 0xD93923D7FA08341C, 0x00003FF9 //B2
247data8 0x3F802995B6D90BDB //B3
248data8 0x3F10DF86B341A63F //B8
249data8 0xC90FDAA22168C235, 0x00003FFF // Pi/2
250data8 0x3EFA3EBD6B0ECB9D //B9
251data8 0x3EDE18BA080E9098 //B12
252LOCAL_OBJECT_END(asin_base_range_table)
253
254
255.section .text
256GLOBAL_LIBM_ENTRY(asin)
257asin_unnormal_back:
258{ .mfi
259      getf.d             rXBits = f8 // grab bits of input value
260      // set p12 = 1 if x is a NaN, denormal, or zero
261      fclass.m           p12, p0 = f8, 0xcf
262      adds               rSign = 1, r0
263}
264{ .mfi
265      addl               rTblAddr = @ltoff(asin_base_range_table),gp
266      // 1 - x = 1 - |x| for positive x
267      fms.s1             f1mX = f1, f1, f8
268      addl               rHalf = 0xFFFE, r0 // exponent of 1/2
269}
270;;
271{ .mfi
272      addl               r0625 = 0x3FE4, r0 // high 16 bits of 0.625
273      // set p8 = 1 if x < 0
274      fcmp.lt.s1         p8, p9 = f8, f0
275      shl                rSign = rSign, 63 // sign bit
276}
277{ .mfi
278      // point to the beginning of the table
279      ld8                rTblAddr = [rTblAddr]
280      // 1 + x = 1 - |x| for negative x
281      fma.s1             f1pX = f1, f1, f8
282      adds               rOne = 0x3FF, r0
283}
284;;
285{ .mfi
286      andcm              rAbsXBits = rXBits, rSign // bits of |x|
287      fmerge.s           fSignX = f8, f1 // signum(x)
288      shl                r0625 = r0625, 48 // bits of DP representation of 0.625
289}
290{ .mfb
291      setf.exp           fHalf = rHalf // load A2 to FP reg
292      fma.s1             fXSqr = f8, f8, f0 // x^2
293      // branch on special path if x is a NaN, denormal, or zero
294(p12) br.cond.spnt       asin_special
295}
296;;
297{ .mfi
298      adds               rPiBy2Ptr = 272, rTblAddr
299      nop.f              0
300      shl                rOne = rOne, 52 // bits of 1.0
301}
302{ .mfi
303      adds               rTmpPtr1 = 16, rTblAddr
304      nop.f              0
305      // set p6 = 1 if |x| < 0.625
306      cmp.lt             p6, p7 = rAbsXBits, r0625
307}
308;;
309{ .mfi
310      ldfpd              fA29, fA31 = [rTblAddr] // A29, fA31
311      // 1 - x = 1 - |x| for positive x
312(p9)  fms.s1             fR = f1, f1, f8
313      // point to coefficient of "near 1" polynomial
314(p7)  adds               rTmpPtr2 = 176, rTblAddr
315}
316{ .mfi
317      ldfpd              fA33, fA35 = [rTmpPtr1], 16 // A33, fA35
318      // 1 + x = 1 - |x| for negative x
319(p8)  fma.s1             fR = f1, f1, f8
320(p6)  adds               rTmpPtr2 = 48, rTblAddr
321}
322;;
323{ .mfi
324      ldfe               fB0 = [rTmpPtr1], 16 // B0
325      nop.f              0
326      nop.i              0
327}
328{ .mib
329      adds               rTmpPtr3 = 16, rTmpPtr2
330      // set p10 = 1 if |x| = 1.0
331      cmp.eq             p10, p0 = rAbsXBits, rOne
332      // branch on special path for |x| = 1.0
333(p10) br.cond.spnt       asin_abs_1
334}
335;;
336{ .mfi
337      ldfe               fA3 = [rTmpPtr2], 48 // A3 or B1
338      nop.f              0
339      adds               rTmpPtr1 = 64, rTmpPtr3
340}
341{ .mib
342      ldfpd              fA9, fA11 = [rTmpPtr3], 16 // A9, A11 or B10, B11
343      // set p11 = 1 if |x| > 1.0
344      cmp.gt             p11, p0 = rAbsXBits, rOne
345      // branch on special path for |x| > 1.0
346(p11) br.cond.spnt       asin_abs_gt_1
347}
348;;
349{ .mfi
350      ldfpd              fA17, fA19 = [rTmpPtr2], 16 // A17, A19 or B6, B7
351      // initial approximation of 1 / sqrt(1 - x)
352      frsqrta.s1         f1mXRcp, p0 = f1mX
353      nop.i              0
354}
355{ .mfi
356      ldfpd              fA13, fA15 = [rTmpPtr3] // A13, A15 or B4, B5
357      fma.s1             fXCube = fXSqr, f8, f0 // x^3
358      nop.i              0
359}
360;;
361{ .mfi
362      ldfe               fA5 = [rTmpPtr2], 48 // A5 or B2
363      // initial approximation of 1 / sqrt(1 + x)
364      frsqrta.s1         f1pXRcp, p0 = f1pX
365      nop.i              0
366}
367{ .mfi
368      ldfpd              fA21, fA23 = [rTmpPtr1], 16 // A21, A23 or B3, B8
369      fma.s1             fXQuadr = fXSqr, fXSqr, f0 // x^4
370      nop.i              0
371}
372;;
373{ .mfi
374      ldfe               fA7 = [rTmpPtr1] // A7 or Pi/2
375      fma.s1             fRSqr = fR, fR, f0 // R^2
376      nop.i              0
377}
378{ .mfb
379      ldfpd              fA25, fA27 = [rTmpPtr2] // A25, A27 or B9, B12
380      nop.f              0
381(p6)  br.cond.spnt       asin_base_range;
382}
383;;
384
385{ .mfi
386      nop.m              0
387(p9)  fma.s1             fH = fHalf, f1mXRcp, f0 // H0 for x > 0
388      nop.i              0
389}
390{ .mfi
391      nop.m              0
392(p9)  fma.s1             fS = f1mX, f1mXRcp, f0  // S0 for x > 0
393      nop.i              0
394}
395;;
396{ .mfi
397      nop.m              0
398(p8)  fma.s1             fH = fHalf, f1pXRcp, f0 // H0 for x < 0
399      nop.i              0
400}
401{ .mfi
402      nop.m              0
403(p8)  fma.s1             fS = f1pX, f1pXRcp, f0  // S0 for x > 0
404      nop.i              0
405}
406;;
407{ .mfi
408      nop.m              0
409      fma.s1             fRQuadr = fRSqr, fRSqr, f0 // R^4
410      nop.i              0
411}
412;;
413{ .mfi
414      nop.m              0
415      fma.s1             fB11 = fB11, fR, fB10
416      nop.i              0
417}
418{ .mfi
419      nop.m              0
420      fma.s1             fB1 = fB1, fR, fB0
421      nop.i              0
422}
423;;
424{ .mfi
425      nop.m              0
426      fma.s1             fB5 = fB5, fR, fB4
427      nop.i              0
428}
429{ .mfi
430      nop.m              0
431      fma.s1             fB7 = fB7, fR, fB6
432      nop.i              0
433}
434;;
435{ .mfi
436      nop.m              0
437      fma.s1             fB3 = fB3, fR, fB2
438      nop.i              0
439}
440;;
441{ .mfi
442      nop.m              0
443      fnma.s1            fD = fH, fS, fHalf // d0 = 1/2 - H0*S0
444      nop.i              0
445}
446;;
447{ .mfi
448      nop.m              0
449      fma.s1             fR8 = fRQuadr, fRQuadr, f0 // R^4
450      nop.i              0
451}
452{ .mfi
453      nop.m              0
454      fma.s1             fB9 = fB9, fR, fB8
455      nop.i              0
456}
457;;
458{.mfi
459      nop.m              0
460      fma.s1             fB12 = fB12, fRSqr, fB11
461      nop.i              0
462}
463{.mfi
464      nop.m              0
465      fma.s1             fB7 = fB7, fRSqr, fB5
466      nop.i              0
467}
468;;
469{.mfi
470      nop.m              0
471      fma.s1             fB3 = fB3, fRSqr, fB1
472      nop.i              0
473}
474;;
475{ .mfi
476      nop.m              0
477      fma.s1             fH = fH, fD, fH // H1 = H0 + H0*d0
478      nop.i              0
479}
480{ .mfi
481      nop.m              0
482      fma.s1             fS = fS, fD, fS // S1 = S0 + S0*d0
483      nop.i              0
484}
485;;
486{.mfi
487      nop.m              0
488      fma.s1             fPiBy2 = fPiBy2, fSignX, f0 // signum(x)*Pi/2
489      nop.i              0
490}
491;;
492{ .mfi
493      nop.m              0
494      fma.s1             fB12 = fB12, fRSqr, fB9
495      nop.i              0
496}
497{ .mfi
498      nop.m              0
499      fma.s1             fB7 = fB7, fRQuadr, fB3
500      nop.i              0
501}
502;;
503{.mfi
504      nop.m              0
505      fnma.s1            fD = fH, fS, fHalf // d1 = 1/2 - H1*S1
506      nop.i              0
507}
508{ .mfi
509      nop.m              0
510      fnma.s1            fSignedS = fSignX, fS, f0 // -signum(x)*S1
511      nop.i              0
512}
513;;
514{ .mfi
515      nop.m              0
516      fma.s1             fCloseTo1Pol = fB12, fR8, fB7
517      nop.i              0
518}
519;;
520{ .mfi
521      nop.m              0
522      fma.s1             fH = fH, fD, fH // H2 = H1 + H1*d1
523      nop.i              0
524}
525{ .mfi
526      nop.m              0
527      fma.s1             fS = fS, fD, fS // S2 = S1 + S1*d1
528      nop.i              0
529}
530;;
531{ .mfi
532      nop.m              0
533      // -signum(x)* S2 = -signum(x)*(S1 + S1*d1)
534      fma.s1             fSignedS = fSignedS, fD, fSignedS
535      nop.i              0
536}
537;;
538{.mfi
539      nop.m              0
540      fnma.s1            fD = fH, fS, fHalf // d2 = 1/2 - H2*S2
541      nop.i              0
542}
543;;
544{ .mfi
545      nop.m              0
546      // signum(x)*(Pi/2 - PolB*S2)
547      fma.s1             fPiBy2 = fSignedS, fCloseTo1Pol, fPiBy2
548      nop.i              0
549}
550{ .mfi
551      nop.m              0
552      // -signum(x)*PolB * S2
553      fma.s1             fCloseTo1Pol = fSignedS, fCloseTo1Pol, f0
554      nop.i              0
555}
556;;
557{ .mfb
558      nop.m              0
559      // final result for 0.625 <= |x| < 1
560      fma.d.s0           f8 = fCloseTo1Pol, fD, fPiBy2
561      // exit here for  0.625 <= |x| < 1
562      br.ret.sptk        b0
563}
564;;
565
566
567// here if |x| < 0.625
568.align 32
569asin_base_range:
570{ .mfi
571      nop.m              0
572      fma.s1             fA33 = fA33, fXSqr, fA31
573      nop.i              0
574}
575{ .mfi
576      nop.m              0
577      fma.s1             fA15 = fA15, fXSqr, fA13
578      nop.i              0
579}
580;;
581{ .mfi
582      nop.m              0
583      fma.s1             fA29 = fA29, fXSqr, fA27
584      nop.i              0
585}
586{ .mfi
587      nop.m              0
588      fma.s1             fA25 = fA25, fXSqr, fA23
589      nop.i              0
590}
591;;
592{ .mfi
593      nop.m              0
594      fma.s1             fA21 = fA21, fXSqr, fA19
595      nop.i              0
596}
597{ .mfi
598      nop.m              0
599      fma.s1             fA9 = fA9, fXSqr, fA7
600      nop.i              0
601}
602;;
603{ .mfi
604      nop.m              0
605      fma.s1             fA5 = fA5, fXSqr, fA3
606      nop.i              0
607}
608;;
609{ .mfi
610      nop.m              0
611      fma.s1             fA35 = fA35, fXQuadr, fA33
612      nop.i              0
613}
614{ .mfi
615      nop.m              0
616      fma.s1             fA17 = fA17, fXQuadr, fA15
617      nop.i              0
618}
619;;
620{ .mfi
621      nop.m              0
622      fma.s1             fX8 = fXQuadr, fXQuadr, f0 // x^8
623      nop.i              0
624}
625{ .mfi
626      nop.m              0
627      fma.s1             fA25 = fA25, fXQuadr, fA21
628      nop.i              0
629}
630;;
631{ .mfi
632      nop.m              0
633      fma.s1             fA9 = fA9, fXQuadr, fA5
634      nop.i              0
635}
636;;
637{ .mfi
638      nop.m              0
639      fma.s1             fA35 = fA35, fXQuadr, fA29
640      nop.i              0
641}
642{ .mfi
643      nop.m              0
644      fma.s1             fA17 = fA17, fXSqr, fA11
645      nop.i              0
646}
647;;
648{ .mfi
649      nop.m              0
650      fma.s1             fX16 = fX8, fX8, f0 // x^16
651      nop.i              0
652}
653;;
654{ .mfi
655      nop.m              0
656      fma.s1             fA35 = fA35, fX8, fA25
657      nop.i              0
658}
659{ .mfi
660      nop.m              0
661      fma.s1             fA17 = fA17, fX8, fA9
662      nop.i              0
663}
664;;
665{ .mfi
666      nop.m              0
667      fma.s1             fBaseP = fA35, fX16, fA17
668      nop.i              0
669}
670;;
671{ .mfb
672      nop.m              0
673      // final result for |x| < 0.625
674      fma.d.s0           f8 = fBaseP, fXCube, f8
675      // exit here for |x| < 0.625 path
676      br.ret.sptk        b0
677}
678;;
679
680// here if |x| = 1
681// asin(x) = sign(x) * Pi/2
682.align 32
683asin_abs_1:
684{ .mfi
685      ldfe               fPiBy2 = [rPiBy2Ptr] // Pi/2
686      nop.f              0
687      nop.i              0
688}
689;;
690{.mfb
691      nop.m              0
692      // result for |x| = 1.0
693      fma.d.s0           f8 = fPiBy2, fSignX, f0
694      // exit here for |x| = 1.0
695      br.ret.sptk        b0
696}
697;;
698
699// here if x is a NaN, denormal, or zero
700.align 32
701asin_special:
702{ .mfi
703      nop.m              0
704      // set p12 = 1 if x is a NaN
705      fclass.m           p12, p0 = f8, 0xc3
706      nop.i              0
707}
708{ .mlx
709      nop.m              0
710      // smallest positive DP normalized number
711      movl               rDenoBound = 0x0010000000000000
712}
713;;
714{ .mfi
715      nop.m              0
716      // set p13 = 1 if x = 0.0
717      fclass.m           p13, p0 = f8, 0x07
718      nop.i              0
719}
720{ .mfi
721      nop.m              0
722      fnorm.s1           fNormX = f8
723      nop.i              0
724}
725;;
726{ .mfb
727      // load smallest normal to FP reg
728      setf.d             fDenoBound = rDenoBound
729      // answer if x is a NaN
730(p12) fma.d.s0           f8 = f8,f1,f0
731      // exit here if x is a NaN
732(p12) br.ret.spnt        b0
733}
734;;
735{ .mfb
736      nop.m              0
737      nop.f              0
738      // exit here if x = 0.0
739(p13) br.ret.spnt        b0
740}
741;;
742// if we still here then x is denormal or unnormal
743{ .mfi
744      nop.m              0
745      // absolute value of normalized x
746      fmerge.s           fNormX = f1, fNormX
747      nop.i              0
748}
749;;
750{ .mfi
751      nop.m              0
752      // set p14 = 1 if normalized x is greater than or
753      // equal to the smallest denormalized value
754      // So, if p14 is set to 1 it means that we deal with
755      // unnormal rather than with "true" denormal
756      fcmp.ge.s1         p14, p0 = fNormX, fDenoBound
757      nop.i              0
758}
759;;
760{ .mfi
761      nop.m              0
762(p14) fcmp.eq.s0         p6, p0 = f8, f0      // Set D flag if x unnormal
763      nop.i              0
764}
765{ .mfb
766      nop.m              0
767      // normalize unnormal input
768(p14) fnorm.s1           f8 = f8
769      // return to the main path
770(p14) br.cond.sptk       asin_unnormal_back
771}
772;;
773// if we still here it means that input is "true" denormal
774{ .mfb
775      nop.m              0
776      // final result if x is denormal
777      fma.d.s0           f8 = f8, fXSqr, f8
778      // exit here if x is denormal
779      br.ret.sptk        b0
780}
781;;
782
783// here if |x| > 1.0
784// error handler should be called
785.align 32
786asin_abs_gt_1:
787{ .mfi
788      alloc              r32 = ar.pfs, 0, 3, 4, 0 // get some registers
789      fmerge.s           FR_X = f8,f8
790      nop.i              0
791}
792{ .mfb
793      mov                GR_Parameter_TAG = 61 // error code
794      frcpa.s0           FR_RESULT, p0 = f0,f0
795      // call error handler routine
796      br.cond.sptk       __libm_error_region
797}
798;;
799GLOBAL_LIBM_END(asin)
800libm_alias_double_other (asin, asin)
801
802
803
804LOCAL_LIBM_ENTRY(__libm_error_region)
805.prologue
806{ .mfi
807        add   GR_Parameter_Y=-32,sp             // Parameter 2 value
808        nop.f 0
809.save   ar.pfs,GR_SAVE_PFS
810        mov  GR_SAVE_PFS=ar.pfs                 // Save ar.pfs
811}
812{ .mfi
813.fframe 64
814        add sp=-64,sp                           // Create new stack
815        nop.f 0
816        mov GR_SAVE_GP=gp                       // Save gp
817};;
818{ .mmi
819        stfd [GR_Parameter_Y] = FR_Y,16         // STORE Parameter 2 on stack
820        add GR_Parameter_X = 16,sp              // Parameter 1 address
821.save   b0, GR_SAVE_B0
822        mov GR_SAVE_B0=b0                       // Save b0
823};;
824.body
825{ .mib
826        stfd [GR_Parameter_X] = FR_X                  // STORE Parameter 1 on stack
827        add   GR_Parameter_RESULT = 0,GR_Parameter_Y  // Parameter 3 address
828        nop.b 0
829}
830{ .mib
831        stfd [GR_Parameter_Y] = FR_RESULT             // STORE Parameter 3 on stack
832        add   GR_Parameter_Y = -16,GR_Parameter_Y
833        br.call.sptk b0=__libm_error_support#         // Call error handling function
834};;
835{ .mmi
836        add   GR_Parameter_RESULT = 48,sp
837        nop.m 0
838        nop.i 0
839};;
840{ .mmi
841        ldfd  f8 = [GR_Parameter_RESULT]       // Get return result off stack
842.restore sp
843        add   sp = 64,sp                       // Restore stack pointer
844        mov   b0 = GR_SAVE_B0                  // Restore return address
845};;
846{ .mib
847        mov   gp = GR_SAVE_GP                  // Restore gp
848        mov   ar.pfs = GR_SAVE_PFS             // Restore ar.pfs
849        br.ret.sptk     b0                     // Return
850};;
851
852LOCAL_LIBM_END(__libm_error_region)
853.type   __libm_error_support#,@function
854.global __libm_error_support#
855