1 files changed, 51 insertions, 0 deletions
diff --git a/sysdeps/aarch64/fpu/acosh_sve.c b/sysdeps/aarch64/fpu/acosh_sve.c
new file mode 100644
index 0000000000..3e4faaa5ca
--- /dev/null
+++ b/sysdeps/aarch64/fpu/acosh_sve.c
@@ -0,0 +1,51 @@
+/* Double-precision vector (SVE) acosh function
+
+   Copyright (C) 2024 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#define WANT_SV_LOG1P_K0_SHORTCUT 1
+#include "sv_log1p_inline.h"
+
+#define One (0x3ff0000000000000)
+#define Thres (0x1ff0000000000000) /* asuint64 (0x1p511) - One.  */
+
+static svfloat64_t NOINLINE
+special_case (svfloat64_t x, svfloat64_t y, svbool_t special)
+{
+  return sv_call_f64 (acosh, x, y, special);
+}
+
+/* SVE approximation for double-precision acosh, based on log1p.
+   The largest observed error is 3.19 ULP in the region where the
+   argument to log1p falls in the k=0 interval, i.e. x close to 1:
+   SV_NAME_D1 (acosh)(0x1.1e4388d4ca821p+0) got 0x1.ed23399f5137p-2
+					   want 0x1.ed23399f51373p-2.  */
+svfloat64_t SV_NAME_D1 (acosh) (svfloat64_t x, const svbool_t pg)
+{
+  /* (ix - One) >= (BigBound - One).  */
+  svuint64_t ix = svreinterpret_u64 (x);
+  svbool_t special = svcmpge (pg, svsub_x (pg, ix, One), Thres);
+
+  svfloat64_t xm1 = svsub_x (pg, x, 1.0);
+  svfloat64_t u = svmul_x (pg, xm1, svadd_x (pg, x, 1.0));
+  svfloat64_t y = svadd_x (pg, xm1, svsqrt_x (pg, u));
+
+  /* Fall back to scalar routine for special lanes.  */
+  if (__glibc_unlikely (svptest_any (pg, special)))
+    return special_case (x, sv_log1p_inline (y, pg), special);
+  return sv_log1p_inline (y, pg);
+}