LastIndexOf() [3/3]

static unsafe int System.SpanHelpers.LastIndexOf ( ref char searchSpace, char value, int length )

inlinestatic

Definition at line 2595 of file SpanHelpers.cs.

    {
        fixed (char* ptr = &searchSpace)
        {
            char* ptr2 = ptr + length;
            char* ptr3 = ptr;
            if (Vector.IsHardwareAccelerated && length >= Vector<ushort>.Count * 2)
            {
                length = ((int)ptr2 & (Unsafe.SizeOf<Vector<ushort>>() - 1)) / 2;
            }
            while (true)
            {
                if (length >= 4)
                {
                    length -= 4;
                    ptr2 -= 4;
                    if (ptr2[3] == value)
                    {
                        break;
                    }
                    if (ptr2[2] != value)
                    {
                        if (ptr2[1] != value)
                        {
                            if (*ptr2 != value)
                            {
                                continue;
                            }
                            goto IL_011d;
                        }
                        return (int)(ptr2 - ptr3) + 1;
                    }
                    return (int)(ptr2 - ptr3) + 2;
                }
                while (length > 0)
                {
                    length--;
                    ptr2--;
                    if (*ptr2 != value)
                    {
                        continue;
                    }
                    goto IL_011d;
                }
                if (Vector.IsHardwareAccelerated && ptr2 > ptr3)
                {
                    length = (int)((ptr2 - ptr3) & ~(Vector<ushort>.Count - 1));
                    Vector<ushort> left = new Vector<ushort>(value);
                    while (length > 0)
                    {
                        char* ptr4 = ptr2 - Vector<ushort>.Count;
                        Vector<ushort> vector = Vector.Equals(left, Unsafe.Read<Vector<ushort>>(ptr4));
                        if (Vector<ushort>.Zero.Equals(vector))
                        {
                            ptr2 -= Vector<ushort>.Count;
                            length -= Vector<ushort>.Count;
                            continue;
                        }
                        return (int)(ptr4 - ptr3) + LocateLastFoundChar(vector);
                    }
                    if (ptr2 > ptr3)
                    {
                        length = (int)(ptr2 - ptr3);
                        continue;
                    }
                }
                return -1;
                IL_011d:
                return (int)(ptr2 - ptr3);
            }
            return (int)(ptr2 - ptr3) + 3;
        }
    }

References System.Collections.Generic.Dictionary< TKey, TValue >.Count, System.Numerics.Vector< T >.Equals(), System.Numerics.Vector< T >.IsHardwareAccelerated, System.length, System.SpanHelpers.LocateLastFoundChar(), and System.value.