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author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
commit | 57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch) | |
tree | 5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/m68k/fpsp040/sasin.S |
Initial import
Diffstat (limited to 'arch/m68k/fpsp040/sasin.S')
-rw-r--r-- | arch/m68k/fpsp040/sasin.S | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/arch/m68k/fpsp040/sasin.S b/arch/m68k/fpsp040/sasin.S new file mode 100644 index 000000000..2a269a58c --- /dev/null +++ b/arch/m68k/fpsp040/sasin.S @@ -0,0 +1,103 @@ +| +| sasin.sa 3.3 12/19/90 +| +| Description: The entry point sAsin computes the inverse sine of +| an input argument; sAsind does the same except for denormalized +| input. +| +| Input: Double-extended number X in location pointed to +| by address register a0. +| +| Output: The value arcsin(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 sASIN takes approximately 310 cycles. +| +| Algorithm: +| +| ASIN +| 1. If |X| >= 1, go to 3. +| +| 2. (|X| < 1) Calculate asin(X) by +| z := sqrt( [1-X][1+X] ) +| asin(X) = atan( x / z ). +| Exit. +| +| 3. If |X| > 1, go to 5. +| +| 4. (|X| = 1) sgn := sign(X), return asin(X) := sgn * Pi/2. 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. + +|SASIN idnt 2,1 | Motorola 040 Floating Point Software Package + + |section 8 + +PIBY2: .long 0x3FFF0000,0xC90FDAA2,0x2168C235,0x00000000 + + |xref t_operr + |xref t_frcinx + |xref t_extdnrm + |xref satan + + .global sasind +sasind: +|--ASIN(X) = X FOR DENORMALIZED X + + bra t_extdnrm + + .global sasin +sasin: + fmovex (%a0),%fp0 | ...LOAD INPUT + + movel (%a0),%d0 + movew 4(%a0),%d0 + andil #0x7FFFFFFF,%d0 + cmpil #0x3FFF8000,%d0 + bges asinbig + +|--THIS IS THE USUAL CASE, |X| < 1 +|--ASIN(X) = ATAN( X / SQRT( (1-X)(1+X) ) ) + + fmoves #0x3F800000,%fp1 + fsubx %fp0,%fp1 | ...1-X + fmovemx %fp2-%fp2,-(%a7) + fmoves #0x3F800000,%fp2 + faddx %fp0,%fp2 | ...1+X + fmulx %fp2,%fp1 | ...(1+X)(1-X) + fmovemx (%a7)+,%fp2-%fp2 + fsqrtx %fp1 | ...SQRT([1-X][1+X]) + fdivx %fp1,%fp0 | ...X/SQRT([1-X][1+X]) + fmovemx %fp0-%fp0,(%a0) + bsr satan + bra t_frcinx + +asinbig: + fabsx %fp0 | ...|X| + fcmps #0x3F800000,%fp0 + fbgt t_operr |cause an operr exception + +|--|X| = 1, ASIN(X) = +- PI/2. + + fmovex PIBY2,%fp0 + movel (%a0),%d0 + andil #0x80000000,%d0 | ...SIGN BIT OF X + oril #0x3F800000,%d0 | ...+-1 IN SGL FORMAT + movel %d0,-(%sp) | ...push SIGN(X) IN SGL-FMT + fmovel %d1,%FPCR + fmuls (%sp)+,%fp0 + bra t_frcinx + + |end |