1 files changed, 57 insertions, 0 deletions
diff --git a/math/aarch64/advsimd/v_sincospif_common.h b/math/aarch64/advsimd/v_sincospif_common.h
new file mode 100644
index 000000000000..8d4177dd871e
--- /dev/null
+++ b/math/aarch64/advsimd/v_sincospif_common.h
@@ -0,0 +1,57 @@
+/*
+ * Helper for Single-precision vector sincospi function.
+ *
+ * Copyright (c) 2024, Arm Limited.
+ * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
+ */
+#include "mathlib.h"
+#include "v_math.h"
+#include "v_poly_f32.h"
+
+const static struct v_sincospif_data
+{
+  float32x4_t poly[6], range_val;
+} v_sincospif_data = {
+  /* Taylor series coefficents for sin(pi * x).  */
+  .poly = { V4 (0x1.921fb6p1f), V4 (-0x1.4abbcep2f), V4 (0x1.466bc6p1f),
+	    V4 (-0x1.32d2ccp-1f), V4 (0x1.50783p-4f), V4 (-0x1.e30750p-8f) },
+  .range_val = V4 (0x1p31f),
+};
+
+/* Single-precision vector function allowing calculation of both sinpi and
+   cospi in one function call, using shared argument reduction and polynomials.
+   Worst-case error for sin is 3.04 ULP:
+   _ZGVnN4v_sincospif_sin(0x1.1d341ap-1) got 0x1.f7cd56p-1 want 0x1.f7cd5p-1.
+   Worst-case error for cos is 3.18 ULP:
+   _ZGVnN4v_sincospif_cos(0x1.d341a8p-5) got 0x1.f7cd56p-1 want 0x1.f7cd5p-1.
+ */
+static inline float32x4x2_t
+v_sincospif_inline (float32x4_t x, const struct v_sincospif_data *d)
+{
+  /* If r is odd, the sign of the result should be inverted for sinpi and
+     reintroduced for cospi.  */
+  uint32x4_t cmp = vcgeq_f32 (x, d->range_val);
+  uint32x4_t odd = vshlq_n_u32 (
+      vbicq_u32 (vreinterpretq_u32_s32 (vcvtaq_s32_f32 (x)), cmp), 31);
+
+  /* r = x - rint(x).  */
+  float32x4_t sr = vsubq_f32 (x, vrndaq_f32 (x));
+  /* cospi(x) = sinpi(0.5 - abs(x)) for values -1/2 .. 1/2.  */
+  float32x4_t cr = vsubq_f32 (v_f32 (0.5f), vabsq_f32 (sr));
+
+  /* Pairwise Horner approximation for y = sin(r * pi).  */
+  float32x4_t sr2 = vmulq_f32 (sr, sr);
+  float32x4_t sr4 = vmulq_f32 (sr2, sr2);
+  float32x4_t cr2 = vmulq_f32 (cr, cr);
+  float32x4_t cr4 = vmulq_f32 (cr2, cr2);
+
+  float32x4_t ss = vmulq_f32 (v_pw_horner_5_f32 (sr2, sr4, d->poly), sr);
+  float32x4_t cc = vmulq_f32 (v_pw_horner_5_f32 (cr2, cr4, d->poly), cr);
+
+  float32x4_t sinpix
+      = vreinterpretq_f32_u32 (veorq_u32 (vreinterpretq_u32_f32 (ss), odd));
+  float32x4_t cospix
+      = vreinterpretq_f32_u32 (veorq_u32 (vreinterpretq_u32_f32 (cc), odd));
+
+  return (float32x4x2_t){ sinpix, cospix };
+}