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-rw-r--r--math/aarch64/advsimd/coshf.c92
1 files changed, 92 insertions, 0 deletions
diff --git a/math/aarch64/advsimd/coshf.c b/math/aarch64/advsimd/coshf.c
new file mode 100644
index 000000000000..f1ed3e5161fd
--- /dev/null
+++ b/math/aarch64/advsimd/coshf.c
@@ -0,0 +1,92 @@
+/*
+ * Single-precision vector cosh(x) function.
+ *
+ * Copyright (c) 2022-2024, Arm Limited.
+ * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
+ */
+
+#include "v_expf_inline.h"
+#include "v_math.h"
+#include "test_sig.h"
+#include "test_defs.h"
+
+static const struct data
+{
+ struct v_expf_data expf_consts;
+ uint32x4_t tiny_bound;
+ float32x4_t bound;
+#if WANT_SIMD_EXCEPT
+ uint32x4_t special_bound;
+#endif
+} data = {
+ .expf_consts = V_EXPF_DATA,
+ .tiny_bound = V4 (0x20000000), /* 0x1p-63: Round to 1 below this. */
+ /* 0x1.5a92d8p+6: expf overflows above this, so have to use special case. */
+ .bound = V4 (0x1.5a92d8p+6),
+#if WANT_SIMD_EXCEPT
+ .special_bound = V4 (0x42ad496c),
+#endif
+};
+
+#if !WANT_SIMD_EXCEPT
+static float32x4_t NOINLINE VPCS_ATTR
+special_case (float32x4_t x, float32x4_t half_t, float32x4_t half_over_t,
+ uint32x4_t special)
+{
+ return v_call_f32 (coshf, x, vaddq_f32 (half_t, half_over_t), special);
+}
+#endif
+
+/* Single-precision vector cosh, using vector expf.
+ Maximum error is 2.38 ULP:
+ _ZGVnN4v_coshf (0x1.e8001ep+1) got 0x1.6a491ep+4
+ want 0x1.6a4922p+4. */
+float32x4_t VPCS_ATTR NOINLINE V_NAME_F1 (cosh) (float32x4_t x)
+{
+ const struct data *d = ptr_barrier (&data);
+
+#if WANT_SIMD_EXCEPT
+ /* If fp exceptions are to be triggered correctly, fall back to the scalar
+ variant for all inputs if any input is a special value or above the bound
+ at which expf overflows. */
+ float32x4_t ax = vabsq_f32 (x);
+ uint32x4_t iax = vreinterpretq_u32_f32 (ax);
+ uint32x4_t special = vcgeq_u32 (iax, d->special_bound);
+ if (unlikely (v_any_u32 (special)))
+ return v_call_f32 (coshf, x, x, v_u32 (-1));
+
+ uint32x4_t tiny = vcleq_u32 (iax, d->tiny_bound);
+ /* If any input is tiny, avoid underflow exception by fixing tiny lanes of
+ input to 0, which will generate no exceptions. */
+ if (unlikely (v_any_u32 (tiny)))
+ ax = v_zerofy_f32 (ax, tiny);
+ float32x4_t t = v_expf_inline (ax, &d->expf_consts);
+#else
+ uint32x4_t special = vcageq_f32 (x, d->bound);
+ float32x4_t t = v_expf_inline (x, &d->expf_consts);
+#endif
+
+ /* Calculate cosh by exp(x) / 2 + exp(-x) / 2. */
+ float32x4_t half_t = vmulq_n_f32 (t, 0.5);
+ float32x4_t half_over_t = vdivq_f32 (v_f32 (0.5), t);
+
+#if WANT_SIMD_EXCEPT
+ if (unlikely (v_any_u32 (tiny)))
+ return vbslq_f32 (tiny, v_f32 (1), vaddq_f32 (half_t, half_over_t));
+#else
+ if (unlikely (v_any_u32 (special)))
+ return special_case (x, half_t, half_over_t, special);
+#endif
+
+ return vaddq_f32 (half_t, half_over_t);
+}
+
+HALF_WIDTH_ALIAS_F1 (cosh)
+
+TEST_SIG (V, F, 1, cosh, -10.0, 10.0)
+TEST_ULP (V_NAME_F1 (cosh), 1.89)
+TEST_DISABLE_FENV_IF_NOT (V_NAME_F1 (cosh), WANT_SIMD_EXCEPT)
+TEST_SYM_INTERVAL (V_NAME_F1 (cosh), 0, 0x1p-63, 100)
+TEST_SYM_INTERVAL (V_NAME_F1 (cosh), 0x1p-63, 1, 1000)
+TEST_SYM_INTERVAL (V_NAME_F1 (cosh), 1, 0x1.5a92d8p+6, 80000)
+TEST_SYM_INTERVAL (V_NAME_F1 (cosh), 0x1.5a92d8p+6, inf, 2000)