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FASINA

Operation

Approximates arcsine in radians for finite source magnitudes at most one.

Assembler Syntax

FASINA.{S|D}(z) Fn(s), Fn(d)

Privilege

Unprivileged

Required CPUID flags

FP

FPTRANSA

Repeat eligibility

REP eligible

Computes the \(\operatorname{asin}(x)\) reference in radians over finite \(x\) with \(|x| \le 1\) after DAZ and writes an implementation-bounded S- or D-format approximation under the selected FPTRANSA accuracy contract.

The required FPTRANSA_ACCURACY contract is 0x0011.

Special values

  • Zero source: the result is the source.

  • A finite source with magnitude greater than one, or either infinity, generates NV and produces the architectural default quiet NaN.

Exact anchors

  • \(\operatorname{asin}(+0) = +0\)

  • \(\operatorname{asin}(-0) = -0\)

Required properties

  • odd

  • monotonically increasing on \([-1, 1]\)

  • result is in \([-\pi/2, \pi/2]\)

2.75in

Encodings

FASINA.{S|D}(z) Fn(s), Fn(d)

Format: Instruction format for FASINA.{S|D}(z) Fn(s), Fn(d)

Format: Instruction format for FASINA.{S|D}(z) Fn(s), Fn(d)