1 files changed, 82 insertions, 0 deletions
diff --git a/contrib/arm-optimized-routines/math/aarch64/advsimd/expm1f.c b/contrib/arm-optimized-routines/math/aarch64/advsimd/expm1f.c
new file mode 100644
index 000000000000..6d4431dcd8a5
--- /dev/null
+++ b/contrib/arm-optimized-routines/math/aarch64/advsimd/expm1f.c
@@ -0,0 +1,82 @@
+/*
+ * Single-precision vector exp(x) - 1 function.
+ *
+ * Copyright (c) 2022-2024, Arm Limited.
+ * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
+ */
+
+#include "v_math.h"
+#include "test_sig.h"
+#include "test_defs.h"
+#include "v_expm1f_inline.h"
+
+static const struct data
+{
+  struct v_expm1f_data d;
+#if WANT_SIMD_EXCEPT
+  uint32x4_t thresh;
+#else
+  float32x4_t oflow_bound;
+#endif
+} data = {
+  .d = V_EXPM1F_DATA,
+#if !WANT_SIMD_EXCEPT
+  /* Value above which expm1f(x) should overflow. Absolute value of the
+     underflow bound is greater than this, so it catches both cases - there is
+     a small window where fallbacks are triggered unnecessarily.  */
+  .oflow_bound = V4 (0x1.5ebc4p+6),
+#else
+  /* asuint(oflow_bound) - asuint(0x1p-23), shifted left by 1 for absolute
+     compare.  */
+  .thresh = V4 (0x1d5ebc40),
+#endif
+};
+
+/* asuint(0x1p-23), shifted by 1 for abs compare.  */
+#define TinyBound v_u32 (0x34000000 << 1)
+
+static float32x4_t VPCS_ATTR NOINLINE
+special_case (float32x4_t x, uint32x4_t special, const struct data *d)
+{
+  return v_call_f32 (
+      expm1f, x, expm1f_inline (v_zerofy_f32 (x, special), &d->d), special);
+}
+
+/* Single-precision vector exp(x) - 1 function.
+   The maximum error is 1.62 ULP:
+   _ZGVnN4v_expm1f(0x1.85f83p-2) got 0x1.da9f4p-2
+				want 0x1.da9f44p-2.  */
+float32x4_t VPCS_ATTR NOINLINE V_NAME_F1 (expm1) (float32x4_t x)
+{
+  const struct data *d = ptr_barrier (&data);
+
+#if WANT_SIMD_EXCEPT
+  uint32x4_t ix = vreinterpretq_u32_f32 (x);
+  /* If fp exceptions are to be triggered correctly, fall back to scalar for
+     |x| < 2^-23, |x| > oflow_bound, Inf & NaN. Add ix to itself for
+     shift-left by 1, and compare with thresh which was left-shifted offline -
+     this is effectively an absolute compare.  */
+  uint32x4_t special
+      = vcgeq_u32 (vsubq_u32 (vaddq_u32 (ix, ix), TinyBound), d->thresh);
+#else
+  /* Handles very large values (+ve and -ve), +/-NaN, +/-Inf.  */
+  uint32x4_t special = vcagtq_f32 (x, d->oflow_bound);
+#endif
+
+  if (unlikely (v_any_u32 (special)))
+    return special_case (x, special, d);
+
+  /* expm1(x) ~= p * t + (t - 1).  */
+  return expm1f_inline (x, &d->d);
+}
+
+HALF_WIDTH_ALIAS_F1 (expm1)
+
+TEST_SIG (V, F, 1, expm1, -9.9, 9.9)
+TEST_ULP (V_NAME_F1 (expm1), 1.13)
+TEST_DISABLE_FENV_IF_NOT (V_NAME_F1 (expm1), WANT_SIMD_EXCEPT)
+TEST_SYM_INTERVAL (V_NAME_F1 (expm1), 0, 0x1p-23, 1000)
+TEST_INTERVAL (V_NAME_F1 (expm1), -0x1p-23, 0x1.5ebc4p+6, 1000000)
+TEST_INTERVAL (V_NAME_F1 (expm1), -0x1p-23, -0x1.9bbabcp+6, 1000000)
+TEST_INTERVAL (V_NAME_F1 (expm1), 0x1.5ebc4p+6, inf, 1000)
+TEST_INTERVAL (V_NAME_F1 (expm1), -0x1.9bbabcp+6, -inf, 1000)