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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/m68k/fpsp040/sacos.S | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/m68k/fpsp040/sacos.S')
-rw-r--r-- | arch/m68k/fpsp040/sacos.S | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/arch/m68k/fpsp040/sacos.S b/arch/m68k/fpsp040/sacos.S new file mode 100644 index 000000000..513c7cca7 --- /dev/null +++ b/arch/m68k/fpsp040/sacos.S @@ -0,0 +1,114 @@ +| +| sacos.sa 3.3 12/19/90 +| +| Description: The entry point sAcos computes the inverse cosine of +| an input argument; sAcosd does the same except for denormalized +| input. +| +| Input: Double-extended number X in location pointed to +| by address register a0. +| +| Output: The value arccos(X) returned in floating-point register Fp0. +| +| Accuracy and Monotonicity: The returned result is within 3 ulps in +| 64 significant bit, i.e. within 0.5001 ulp to 53 bits if the +| result is subsequently rounded to double precision. The +| result is provably monotonic in double precision. +| +| Speed: The program sCOS takes approximately 310 cycles. +| +| Algorithm: +| +| ACOS +| 1. If |X| >= 1, go to 3. +| +| 2. (|X| < 1) Calculate acos(X) by +| z := (1-X) / (1+X) +| acos(X) = 2 * atan( sqrt(z) ). +| Exit. +| +| 3. If |X| > 1, go to 5. +| +| 4. (|X| = 1) If X > 0, return 0. Otherwise, return Pi. Exit. +| +| 5. (|X| > 1) Generate an invalid operation by 0 * infinity. +| Exit. +| + +| Copyright (C) Motorola, Inc. 1990 +| All Rights Reserved +| +| For details on the license for this file, please see the +| file, README, in this same directory. + +|SACOS idnt 2,1 | Motorola 040 Floating Point Software Package + + |section 8 + +PI: .long 0x40000000,0xC90FDAA2,0x2168C235,0x00000000 +PIBY2: .long 0x3FFF0000,0xC90FDAA2,0x2168C235,0x00000000 + + |xref t_operr + |xref t_frcinx + |xref satan + + .global sacosd +sacosd: +|--ACOS(X) = PI/2 FOR DENORMALIZED X + fmovel %d1,%fpcr | ...load user's rounding mode/precision + fmovex PIBY2,%fp0 + bra t_frcinx + + .global sacos +sacos: + fmovex (%a0),%fp0 | ...LOAD INPUT + + movel (%a0),%d0 | ...pack exponent with upper 16 fraction + movew 4(%a0),%d0 + andil #0x7FFFFFFF,%d0 + cmpil #0x3FFF8000,%d0 + bges ACOSBIG + +|--THIS IS THE USUAL CASE, |X| < 1 +|--ACOS(X) = 2 * ATAN( SQRT( (1-X)/(1+X) ) ) + + fmoves #0x3F800000,%fp1 + faddx %fp0,%fp1 | ...1+X + fnegx %fp0 | ... -X + fadds #0x3F800000,%fp0 | ...1-X + fdivx %fp1,%fp0 | ...(1-X)/(1+X) + fsqrtx %fp0 | ...SQRT((1-X)/(1+X)) + fmovemx %fp0-%fp0,(%a0) | ...overwrite input + movel %d1,-(%sp) |save original users fpcr + clrl %d1 + bsr satan | ...ATAN(SQRT([1-X]/[1+X])) + fmovel (%sp)+,%fpcr |restore users exceptions + faddx %fp0,%fp0 | ...2 * ATAN( STUFF ) + bra t_frcinx + +ACOSBIG: + fabsx %fp0 + fcmps #0x3F800000,%fp0 + fbgt t_operr |cause an operr exception + +|--|X| = 1, ACOS(X) = 0 OR PI + movel (%a0),%d0 | ...pack exponent with upper 16 fraction + movew 4(%a0),%d0 + cmpl #0,%d0 |D0 has original exponent+fraction + bgts ACOSP1 + +|--X = -1 +|Returns PI and inexact exception + fmovex PI,%fp0 + fmovel %d1,%FPCR + fadds #0x00800000,%fp0 |cause an inexact exception to be put +| ;into the 040 - will not trap until next +| ;fp inst. + bra t_frcinx + +ACOSP1: + fmovel %d1,%FPCR + fmoves #0x00000000,%fp0 + rts |Facos ; of +1 is exact + + |end |