[libc-commits] [libc] [libc][math][c23] Add acoshf16 C23 math function. (PR #130588)

[Harrison Hao via libc-commits]

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@@ -0,0 +1,120 @@
+//===-- Half-precision acoshf16 function ----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/math/acoshf16.h"
+#include "hdr/errno_macros.h"
+#include "hdr/fenv_macros.h"
+#include "src/__support/FPUtil/FEnvImpl.h"
+#include "src/__support/FPUtil/FPBits.h"
+#include "src/__support/FPUtil/cast.h"
+#include "src/__support/FPUtil/except_value_utils.h"
+#include "src/__support/FPUtil/multiply_add.h"
+#include "src/__support/FPUtil/sqrt.h"
+#include "src/__support/macros/optimization.h"
+#include "src/math/generic/explogxf.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+static constexpr size_t N_EXCEPTS = 2;
+static constexpr fputil::ExceptValues<float16, N_EXCEPTS> ACOSHF16_EXCEPTS{{
+    // (input, RZ output, RU offset, RD offset, RN offset)
+    // x = 0x1.6ep+1, acoshf16(x) = 0x1.dbp+0 (RZ)
+    {0x41B7, 0x3ED8, 1, 0, 0},
+    // x = 0x1.c8p+0, acoshf16(x) = 0x1.27cp-1 (RZ)
+    {0x3CE4, 0x393E, 1, 0, 1},
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harrisonGPU wrote:

How can you calculate it? I really want to know?

https://github.com/llvm/llvm-project/pull/130588