1 files changed, 82 insertions, 0 deletions
diff --git a/pl/math/sv_cosf_2u1.c b/pl/math/sv_cosf_2u1.c
new file mode 100644
index 0000000..8f138bc
--- /dev/null
+++ b/pl/math/sv_cosf_2u1.c
@@ -0,0 +1,82 @@
+/*
+ * Single-precision SVE cos(x) function.
+ *
+ * Copyright (c) 2019-2023, Arm Limited.
+ * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
+ */
+
+#include "sv_math.h"
+#include "pl_sig.h"
+#include "pl_test.h"
+
+#if SV_SUPPORTED
+
+#define NegPio2_1 (sv_f32 (-0x1.921fb6p+0f))
+#define NegPio2_2 (sv_f32 (0x1.777a5cp-25f))
+#define NegPio2_3 (sv_f32 (0x1.ee59dap-50f))
+#define RangeVal (sv_f32 (0x1p20f))
+#define InvPio2 (sv_f32 (0x1.45f306p-1f))
+/* Original shift used in Neon cosf,
+   plus a contribution to set the bit #0 of q
+   as expected by trigonometric instructions.  */
+#define Shift (sv_f32 (0x1.800002p+23f))
+#define AbsMask (0x7fffffff)
+
+static NOINLINE sv_f32_t
+__sv_cosf_specialcase (sv_f32_t x, sv_f32_t y, svbool_t cmp)
+{
+  return sv_call_f32 (cosf, x, y, cmp);
+}
+
+/* A fast SVE implementation of cosf based on trigonometric
+   instructions (FTMAD, FTSSEL, FTSMUL).
+   Maximum measured error: 2.06 ULPs.
+   __sv_cosf(0x1.dea2f2p+19) got 0x1.fffe7ap-6
+			    want 0x1.fffe76p-6.  */
+sv_f32_t
+__sv_cosf_x (sv_f32_t x, const svbool_t pg)
+{
+  sv_f32_t n, r, r2, y;
+  svbool_t cmp;
+
+  r = sv_as_f32_u32 (svand_n_u32_x (pg, sv_as_u32_f32 (x), AbsMask));
+  cmp = svcmpge_u32 (pg, sv_as_u32_f32 (r), sv_as_u32_f32 (RangeVal));
+
+  /* n = rint(|x|/(pi/2)).  */
+  sv_f32_t q = sv_fma_f32_x (pg, InvPio2, r, Shift);
+  n = svsub_f32_x (pg, q, Shift);
+
+  /* r = |x| - n*(pi/2)  (range reduction into -pi/4 .. pi/4).  */
+  r = sv_fma_f32_x (pg, NegPio2_1, n, r);
+  r = sv_fma_f32_x (pg, NegPio2_2, n, r);
+  r = sv_fma_f32_x (pg, NegPio2_3, n, r);
+
+  /* Final multiplicative factor: 1.0 or x depending on bit #0 of q.  */
+  sv_f32_t f = svtssel_f32 (r, sv_as_u32_f32 (q));
+
+  /* cos(r) poly approx.  */
+  r2 = svtsmul_f32 (r, sv_as_u32_f32 (q));
+  y = sv_f32 (0.0f);
+  y = svtmad_f32 (y, r2, 4);
+  y = svtmad_f32 (y, r2, 3);
+  y = svtmad_f32 (y, r2, 2);
+  y = svtmad_f32 (y, r2, 1);
+  y = svtmad_f32 (y, r2, 0);
+
+  /* Apply factor.  */
+  y = svmul_f32_x (pg, f, y);
+
+  /* No need to pass pg to specialcase here since cmp is a strict subset,
+     guaranteed by the cmpge above.  */
+  if (unlikely (svptest_any (pg, cmp)))
+    return __sv_cosf_specialcase (x, y, cmp);
+  return y;
+}
+
+PL_ALIAS (__sv_cosf_x, _ZGVsMxv_cosf)
+
+PL_SIG (SV, F, 1, cos, -3.1, 3.1)
+PL_TEST_ULP (__sv_cosf, 1.57)
+PL_TEST_INTERVAL (__sv_cosf, 0, 0xffff0000, 10000)
+PL_TEST_INTERVAL (__sv_cosf, 0x1p-4, 0x1p4, 500000)
+#endif