20 lines
496 B
Plaintext
20 lines
496 B
Plaintext
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// polynomial for approximating erf(x).
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// To generate coefficients for interval i (0 to 47) do:
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// $ sollya v_erf.sollya $i
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//
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// Copyright (c) 2022-2023, Arm Limited.
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// SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
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scale = 1/8;
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deg = 9;
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itv = parse(__argv[0]);
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if (itv == 0) then { a = 0x1p-1022; }
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else { a = itv * scale; };
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prec=256;
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poly = fpminimax(erf(scale*x+a), deg, [|D ...|], [0; 1]);
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display = hexadecimal;
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for i from 0 to deg do coeff(poly, i);
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