add values.dtype.kind==f branch to array_with_unit_datetime

Author: arw2019

pandas/_libs/tslib.pyx

@@ -227,7 +227,6 @@ def array_with_unit_to_datetime(
     m = cast_from_unit(None, unit)
 
     if is_raise:
-
         # try a quick conversion to i8
         # if we have nulls that are not type-compat
         # then need to iterate
@@ -240,9 +239,17 @@ def array_with_unit_to_datetime(
             fvalues = iresult.astype('f8') * m
             need_to_iterate = False
 
+        # GH20445
+        if values.dtype.kind == "f":
+            fresult = values.astype('f8', casting='same_kind', copy=False)
+            # fill by comparing to NPY_NAT constant
+            mask = fresult == NPY_NAT
+            fresult[mask] = 0.0
+            fvalues = fvalues.astype('f8') * m  # FIXME: this line segfaults rn
+            need_to_iterate = False
+
         # check the bounds
         if not need_to_iterate:
-
             if ((fvalues < Timestamp.min.value).any()
                     or (fvalues > Timestamp.max.value).any()):
                 raise OutOfBoundsDatetime(f"cannot convert input with unit '{unit}'")
@@ -410,7 +417,6 @@ cpdef array_to_datetime(
         float offset_seconds, tz_offset
         set out_tzoffset_vals = set()
         bint string_to_dts_failed
-
     # specify error conditions
     assert is_raise or is_ignore or is_coerce