1 files changed, 76 insertions, 0 deletions
diff --git a/math/v_cosf.c b/math/v_cosf.c
new file mode 100644
index 0000000..150294b
--- /dev/null
+++ b/math/v_cosf.c
@@ -0,0 +1,76 @@
+/*
+ * Single-precision vector cos function.
+ *
+ * Copyright (c) 2019, Arm Limited.
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "mathlib.h"
+#include "v_math.h"
+#if V_SUPPORTED
+
+static const float Poly[] = {
+  /* 1.886 ulp error */
+  0x1.5b2e76p-19f,
+  -0x1.9f42eap-13f,
+  0x1.110df4p-7f,
+  -0x1.555548p-3f,
+};
+#define Pi1 v_f32 (0x1.921fb6p+1f)
+#define Pi2 v_f32 (-0x1.777a5cp-24f)
+#define Pi3 v_f32 (-0x1.ee59dap-49f)
+#define A3 v_f32 (Poly[3])
+#define A5 v_f32 (Poly[2])
+#define A7 v_f32 (Poly[1])
+#define A9 v_f32 (Poly[0])
+#define RangeVal v_f32 (0x1p20f)
+#define InvPi v_f32 (0x1.45f306p-2f)
+#define Shift v_f32 (0x1.8p+23f)
+#define AbsMask v_u32 (0x7fffffff)
+#define HalfPi v_f32 (0x1.921fb6p0f)
+
+VPCS_ATTR
+static v_f32_t
+specialcase (v_f32_t x, v_f32_t y, v_u32_t cmp)
+{
+  /* Fall back to scalar code.  */
+  return v_call_f32 (cosf, x, y, cmp);
+}
+
+VPCS_ATTR
+v_f32_t
+V_NAME(cosf) (v_f32_t x)
+{
+  v_f32_t n, r, r2, y;
+  v_u32_t odd, cmp;
+
+  r = v_as_f32_u32 (v_as_u32_f32 (x) & AbsMask);
+  cmp = v_cond_u32 (v_as_u32_f32 (r) >= v_as_u32_f32 (RangeVal));
+
+  /* n = rint((|x|+pi/2)/pi) - 0.5 */
+  n = v_fma_f32 (InvPi, r + HalfPi, Shift);
+  odd = v_as_u32_f32 (n) << 31;
+  n -= Shift;
+  n -= v_f32 (0.5f);
+
+  /* r = |x| - n*pi  (range reduction into -pi/2 .. pi/2) */
+  r = v_fma_f32 (-Pi1, n, r);
+  r = v_fma_f32 (-Pi2, n, r);
+  r = v_fma_f32 (-Pi3, n, r);
+
+  /* y = sin(r) */
+  r2 = r * r;
+  y = v_fma_f32 (A9, r2, A7);
+  y = v_fma_f32 (y, r2, A5);
+  y = v_fma_f32 (y, r2, A3);
+  y = v_fma_f32 (y * r2, r, r);
+
+  /* sign fix */
+  y = v_as_f32_u32 (v_as_u32_f32 (y) ^ odd);
+
+  if (unlikely (v_any_u32 (cmp)))
+    return specialcase (x, y, cmp);
+  return y;
+}
+VPCS_ALIAS
+#endif