Use nint

src/ImageSharp/Common/Helpers/Numerics.cs

@@ -75,6 +75,12 @@ namespace SixLabors.ImageSharp
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static int Modulo8(int x) => x & 7;
 
+        /// <summary>
+        /// Calculates <paramref name="x"/> % 8
+        /// </summary>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static nint Modulo8(nint x) => x & 7;
+
         /// <summary>
         /// Fast (x mod m) calculator, with the restriction that
         /// <paramref name="m"/> should be power of 2.

src/ImageSharp/Formats/Tiff/Compression/BitWriterUtils.cs

@@ -9,16 +9,16 @@ namespace SixLabors.ImageSharp.Formats.Tiff.Compression
 {
     internal static class BitWriterUtils
     {
-        public static void WriteBits(Span<byte> buffer, int pos, int count, byte value)
+        public static void WriteBits(Span<byte> buffer, nint pos, nint count, byte value)
         {
-            int bitPos = Numerics.Modulo8(pos);
+            nint bitPos = Numerics.Modulo8(pos);
-            int bufferPos = pos / 8;
+            nint bufferPos = pos / 8;
-            int startIdx = bufferPos + bitPos;
+            nint startIdx = bufferPos + bitPos;
-            int endIdx = startIdx + count;
+            nint endIdx = startIdx + count;
 
             if (value == 1)
             {
-                for (int i = startIdx; i < endIdx; i++)
+                for (nint i = startIdx; i < endIdx; i++)
                 {
                     WriteBit(buffer, bufferPos, bitPos);
 
@@ -32,7 +32,7 @@ namespace SixLabors.ImageSharp.Formats.Tiff.Compression
             }
             else
             {
-                for (int i = startIdx; i < endIdx; i++)
+                for (nint i = startIdx; i < endIdx; i++)
                 {
                     WriteZeroBit(buffer, bufferPos, bitPos);
 
@@ -47,17 +47,17 @@ namespace SixLabors.ImageSharp.Formats.Tiff.Compression
         }
 
         [MethodImpl(InliningOptions.ShortMethod)]
-        public static void WriteBit(Span<byte> buffer, int bufferPos, int bitPos)
+        public static void WriteBit(Span<byte> buffer, nint bufferPos, nint bitPos)
         {
             ref byte b = ref Unsafe.Add(ref MemoryMarshal.GetReference(buffer), bufferPos);
-            b |= (byte)(1 << (7 - bitPos));
+            b |= (byte)(1 << (int)(7 - bitPos));
         }
 
         [MethodImpl(InliningOptions.ShortMethod)]
-        public static void WriteZeroBit(Span<byte> buffer, int bufferPos, int bitPos)
+        public static void WriteZeroBit(Span<byte> buffer, nint bufferPos, nint bitPos)
         {
             ref byte b = ref Unsafe.Add(ref MemoryMarshal.GetReference(buffer), bufferPos);
-            b = (byte)(b & ~(1 << (7 - bitPos)));
+            b = (byte)(b & ~(1 << (int)(7 - bitPos)));
         }
     }
 }

src/ImageSharp/Formats/Tiff/Compression/Decompressors/ModifiedHuffmanTiffCompression.cs

@@ -45,8 +45,8 @@ namespace SixLabors.ImageSharp.Formats.Tiff.Compression.Decompressors
             var bitReader = new ModifiedHuffmanBitReader(stream, this.FillOrder, byteCount);
 
             buffer.Clear();
-            int bitsWritten = 0;
+            nint bitsWritten = 0;
-            uint pixelsWritten = 0;
+            nuint pixelsWritten = 0;
             nint rowsWritten = 0;
             while (bitReader.HasMoreData)
             {
@@ -67,13 +67,13 @@ namespace SixLabors.ImageSharp.Formats.Tiff.Compression.Decompressors
                     pixelsWritten += bitReader.RunLength;
                 }
 
-                if (pixelsWritten == this.Width)
+                if (pixelsWritten == (ulong)this.Width)
                 {
                     rowsWritten++;
                     pixelsWritten = 0;
 
                     // Write padding bits, if necessary.
-                    int pad = 8 - Numerics.Modulo8(bitsWritten);
+                    nint pad = 8 - Numerics.Modulo8(bitsWritten);
                     if (pad != 8)
                     {
                         BitWriterUtils.WriteBits(buffer, bitsWritten, pad, 0);
@@ -88,7 +88,7 @@ namespace SixLabors.ImageSharp.Formats.Tiff.Compression.Decompressors
                     bitReader.StartNewRow();
                 }
 
-                if (pixelsWritten > this.Width)
+                if (pixelsWritten > (ulong)this.Width)
                 {
                     TiffThrowHelper.ThrowImageFormatException("ccitt compression parsing error, decoded more pixels then image width");
                 }

src/ImageSharp/Formats/Tiff/Compression/Decompressors/T4TiffCompression.cs

@@ -64,8 +64,8 @@ namespace SixLabors.ImageSharp.Formats.Tiff.Compression.Decompressors
             var bitReader = new T4BitReader(stream, this.FillOrder, byteCount, eolPadding);
 
             buffer.Clear();
-            int bitsWritten = 0;
+            nint bitsWritten = 0;
-            uint pixelsWritten = 0;
+            nuint pixelsWritten = 0;
             nint rowsWritten = 0;
             while (bitReader.HasMoreData)
             {
@@ -82,7 +82,7 @@ namespace SixLabors.ImageSharp.Formats.Tiff.Compression.Decompressors
                 if (bitReader.IsEndOfScanLine)
                 {
                     // Write padding bytes, if necessary.
-                    int pad = 8 - Numerics.Modulo8(bitsWritten);
+                    nint pad = 8 - Numerics.Modulo8(bitsWritten);
                     if (pad != 8)
                     {
                         BitWriterUtils.WriteBits(buffer, bitsWritten, pad, 0);
@@ -100,14 +100,14 @@ namespace SixLabors.ImageSharp.Formats.Tiff.Compression.Decompressors
             }
 
             // Edge case for when we are at the last byte, but there are still some unwritten pixels left.
-            if (pixelsWritten > 0 && pixelsWritten < this.width)
+            if (pixelsWritten > 0 && pixelsWritten < (ulong)this.width)
             {
                 bitReader.ReadNextRun();
                 this.WritePixelRun(buffer, bitReader, bitsWritten);
             }
         }
 
-        private void WritePixelRun(Span<byte> buffer, T4BitReader bitReader, int bitsWritten)
+        private void WritePixelRun(Span<byte> buffer, T4BitReader bitReader, nint bitsWritten)
         {
             if (bitReader.IsWhiteRun)
             {

src/ImageSharp/Formats/Tiff/Compression/Decompressors/T6TiffCompression.cs

@@ -60,7 +60,7 @@ namespace SixLabors.ImageSharp.Formats.Tiff.Compression.Decompressors
             var bitReader = new T6BitReader(stream, this.FillOrder, byteCount);
 
             var referenceScanLine = new CcittReferenceScanline(this.isWhiteZero, this.width);
-            int bitsWritten = 0;
+            nint bitsWritten = 0;
             for (int y = 0; y < height; y++)
             {
                 scanLine.Clear();
@@ -73,10 +73,10 @@ namespace SixLabors.ImageSharp.Formats.Tiff.Compression.Decompressors
             }
         }
 
-        private int WriteScanLine(Span<byte> buffer, Span<byte> scanLine, int bitsWritten)
+        private nint WriteScanLine(Span<byte> buffer, Span<byte> scanLine, nint bitsWritten)
         {
-            int bitPos = Numerics.Modulo8(bitsWritten);
+            nint bitPos = Numerics.Modulo8(bitsWritten);
-            int bufferPos = bitsWritten / 8;
+            nint bufferPos = bitsWritten / 8;
             for (nint i = 0; i < scanLine.Length; i++)
             {
                 if (Unsafe.Add(ref MemoryMarshal.GetReference(scanLine), i) != this.white)
@@ -95,10 +95,10 @@ namespace SixLabors.ImageSharp.Formats.Tiff.Compression.Decompressors
             }
 
             // Write padding bytes, if necessary.
-            int remainder = bitsWritten % 8;
+            nint remainder = Numerics.Modulo8(bitsWritten);
             if (remainder != 0)
             {
-                int padding = 8 - remainder;
+                nint padding = 8 - remainder;
                 BitWriterUtils.WriteBits(buffer, bitsWritten, padding, 0);
                 bitsWritten += padding;
             }