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Diffstat (limited to 'contrib/arm-optimized-routines/pl/math/tools/sincosf.sollya')
-rw-r--r-- | contrib/arm-optimized-routines/pl/math/tools/sincosf.sollya | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/contrib/arm-optimized-routines/pl/math/tools/sincosf.sollya b/contrib/arm-optimized-routines/pl/math/tools/sincosf.sollya new file mode 100644 index 000000000000..178ee83ac196 --- /dev/null +++ b/contrib/arm-optimized-routines/pl/math/tools/sincosf.sollya @@ -0,0 +1,33 @@ +// polynomial for approximating cos(x) +// +// Copyright (c) 2023, Arm Limited. +// SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception + +// This script only finds the coeffs for cos - see math/tools/sin.sollya for sin coeffs. + +deg = 8; // polynomial degree +a = -pi/4; // interval +b = pi/4; + +// find even polynomial with minimal abs error compared to cos(x) + +f = cos(x); + +// return p that minimizes |f(x) - poly(x) - x^d*p(x)| +approx = proc(poly,d) { + return remez(f(x)-poly(x), deg-d, [a;b], x^d, 1e-10); +}; + +// first coeff is fixed, iteratively find optimal double prec coeffs +poly = 1; +for i from 1 to deg/2 do { + p = roundcoefficients(approx(poly,2*i), [|single ...|]); + poly = poly + x^(2*i)*coeff(p,0); +}; + +display = hexadecimal; +//print("rel error:", accurateinfnorm(1-poly(x)/f(x), [a;b], 30)); +//print("abs error:", accurateinfnorm(f(x)-poly(x), [a;b], 30)); +print("in [",a,b,"]"); +print("coeffs:"); +for i from 0 to deg do coeff(poly,i); |