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This commit bulk-updates the libclc license headers to the current Apache-2.0 WITH LLVM-exception license in situations where they were previously attributed to AMD - and occasionally under an additional single individual contributor - under an MIT license. AMD signed the LLVM relicensing agreement and so agreed for their past contributions under the new LLVM license. The LLVM project also has had a long-standing, unwritten, policy of not adding copyright notices to source code. This policy was recently written up [1]. This commit therefore also removes these copyright notices at the same time. Note that there are outstanding copyright notices attributed to others - and many files missing copyright headers - which will be dealt with in future work. [1] https://llvm.org/docs/DeveloperPolicy.html#embedded-copyright-or-contributed-by-statements
47 lines
1.8 KiB
C
47 lines
1.8 KiB
C
//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include <clc/math/clc_mad.h>
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// Evaluate single precisions in and cos of value in interval [-pi/4, pi/4]
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_CLC_INLINE float2 __libclc__sincosf_piby4(float x) {
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// Taylor series for sin(x) is x - x^3/3! + x^5/5! - x^7/7! ...
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// = x * (1 - x^2/3! + x^4/5! - x^6/7! ...
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// = x * f(w)
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// where w = x*x and f(w) = (1 - w/3! + w^2/5! - w^3/7! ...
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// We use a minimax approximation of (f(w) - 1) / w
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// because this produces an expansion in even powers of x.
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// Taylor series for cos(x) is 1 - x^2/2! + x^4/4! - x^6/6! ...
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// = f(w)
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// where w = x*x and f(w) = (1 - w/2! + w^2/4! - w^3/6! ...
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// We use a minimax approximation of (f(w) - 1 + w/2) / (w*w)
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// because this produces an expansion in even powers of x.
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const float sc1 = -0.166666666638608441788607926e0F;
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const float sc2 = 0.833333187633086262120839299e-2F;
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const float sc3 = -0.198400874359527693921333720e-3F;
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const float sc4 = 0.272500015145584081596826911e-5F;
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const float cc1 = 0.41666666664325175238031e-1F;
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const float cc2 = -0.13888887673175665567647e-2F;
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const float cc3 = 0.24800600878112441958053e-4F;
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const float cc4 = -0.27301013343179832472841e-6F;
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float x2 = x * x;
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float2 ret;
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ret.x = __clc_mad(
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x * x2, __clc_mad(x2, __clc_mad(x2, __clc_mad(x2, sc4, sc3), sc2), sc1),
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x);
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ret.y = __clc_mad(
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x2 * x2, __clc_mad(x2, __clc_mad(x2, __clc_mad(x2, cc4, cc3), cc2), cc1),
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__clc_mad(x2, -0.5f, 1.0f));
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return ret;
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}
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