Use BinaryPrimitives more in the ILCompiler

src/coreclr/tools/Common/Pgo/PgoFormat.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
+using System.Buffers.Binary;
 using System.Collections;
 using System.Collections.Generic;
 using System.Diagnostics;
@@ -163,22 +164,12 @@ public bool MoveNext()
                 }
                 else if ((bytes[offset]) == 0xC1) // 8 byte specifier
                 {
-                    signedInt = (((long)bytes[offset + 1]) << 56) |
-                                (((long)bytes[offset + 2]) << 48) |
-                                (((long)bytes[offset + 3]) << 40) |
-                                (((long)bytes[offset + 4]) << 32) |
-                                (((long)bytes[offset + 5]) << 24) |
-                                (((long)bytes[offset + 6]) << 16) |
-                                (((long)bytes[offset + 7]) << 8) |
-                                ((long)bytes[offset + 8]);
+                    signedInt = BinaryPrimitives.ReadInt64BigEndian(bytes.AsSpan(offset + 1, sizeof(long)));
                     offset += 9;
                 }
                 else
                 {
-                    signedInt = (((int)bytes[offset + 1]) << 24) |
-                                (((int)bytes[offset + 2]) << 16) |
-                                (((int)bytes[offset + 3]) << 8) |
-                                ((int)bytes[offset + 4]);
+                    signedInt = BinaryPrimitives.ReadInt32BigEndian(bytes.AsSpan(offset + 1, sizeof(int)));
                     offset += 5;
                 }
 

src/coreclr/tools/Common/TypeSystem/IL/ILDisassembler.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
+using System.Buffers.Binary;
 using System.Text;
 
 using Internal.TypeSystem;
@@ -191,15 +192,15 @@ private byte ReadILByte()
 
         private ushort ReadILUInt16()
         {
-            ushort val = (ushort)(_ilBytes[_currentOffset] + (_ilBytes[_currentOffset + 1] << 8));
-            _currentOffset += 2;
+            ushort val = BinaryPrimitives.ReadUInt16LittleEndian(_ilBytes.AsSpan(_currentOffset, sizeof(ushort)));
+            _currentOffset += sizeof(ushort);
             return val;
         }
 
         private uint ReadILUInt32()
         {
-            uint val = (uint)(_ilBytes[_currentOffset] + (_ilBytes[_currentOffset + 1] << 8) + (_ilBytes[_currentOffset + 2] << 16) + (_ilBytes[_currentOffset + 3] << 24));
-            _currentOffset += 4;
+            uint val = BinaryPrimitives.ReadUInt32LittleEndian(_ilBytes.AsSpan(_currentOffset, sizeof(uint)));
+            _currentOffset += sizeof(uint);
             return val;
         }
 
@@ -211,8 +212,8 @@ private int ReadILToken()
 
         private ulong ReadILUInt64()
         {
-            ulong value = ReadILUInt32();
-            value |= (((ulong)ReadILUInt32()) << 32);
+            ulong value = BinaryPrimitives.ReadUInt64LittleEndian(_ilBytes.AsSpan(_currentOffset, sizeof(ulong)));
+            _currentOffset += sizeof(ulong);
             return value;
         }
 

src/coreclr/tools/Common/TypeSystem/IL/ILImporter.cs

@@ -1,6 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System;
+using System.Buffers.Binary;
 using Internal.TypeSystem;
 
 namespace Internal.IL
@@ -20,30 +22,28 @@ internal sealed partial class ILImporter
 
         private byte ReadILByte()
         {
-            if (_currentOffset >= _ilBytes.Length)
+            if (_currentOffset + 1 > _ilBytes.Length)
                 ReportMethodEndInsideInstruction();
 
             return _ilBytes[_currentOffset++];
         }
 
         private ushort ReadILUInt16()
         {
-            if (_currentOffset + 1 >= _ilBytes.Length)
+            if (!BinaryPrimitives.TryReadUInt16LittleEndian(_ilBytes.AsSpan(_currentOffset), out ushort value))
                 ReportMethodEndInsideInstruction();
 
-            ushort val = (ushort)(_ilBytes[_currentOffset] + (_ilBytes[_currentOffset + 1] << 8));
-            _currentOffset += 2;
-            return val;
+            _currentOffset += sizeof(ushort);
+            return value;
         }
 
         private uint ReadILUInt32()
         {
-            if (_currentOffset + 3 >= _ilBytes.Length)
+            if (!BinaryPrimitives.TryReadUInt32LittleEndian(_ilBytes.AsSpan(_currentOffset), out uint value))
                 ReportMethodEndInsideInstruction();
 
-            uint val = (uint)(_ilBytes[_currentOffset] + (_ilBytes[_currentOffset + 1] << 8) + (_ilBytes[_currentOffset + 2] << 16) + (_ilBytes[_currentOffset + 3] << 24));
-            _currentOffset += 4;
-            return val;
+            _currentOffset += sizeof(uint);
+            return value;
         }
 
         private int ReadILToken()
@@ -53,8 +53,10 @@ private int ReadILToken()
 
         private ulong ReadILUInt64()
         {
-            ulong value = ReadILUInt32();
-            value |= (((ulong)ReadILUInt32()) << 32);
+            if (!BinaryPrimitives.TryReadUInt64LittleEndian(_ilBytes.AsSpan(_currentOffset), out ulong value))
+                ReportMethodEndInsideInstruction();
+
+            _currentOffset += sizeof(ulong);
             return value;
         }
 

src/coreclr/tools/Common/TypeSystem/IL/Stubs/ILEmitter.cs

@@ -2,8 +2,9 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
+using System.Buffers.Binary;
 using System.Collections.Generic;
-
+using System.Runtime.CompilerServices;
 using Internal.TypeSystem;
 
 using Debug = System.Diagnostics.Debug;
@@ -49,23 +50,33 @@ internal int RelativeToAbsoluteOffset(int relativeOffset)
 
         private void EmitByte(byte b)
         {
-            if (_instructions.Length == _length)
-                Array.Resize<byte>(ref _instructions, 2 * _instructions.Length + 10);
+            if (_length == _instructions.Length)
+                Grow();
             _instructions[_length++] = b;
         }
 
         private void EmitUInt16(ushort value)
         {
-            EmitByte((byte)value);
-            EmitByte((byte)(value >> 8));
+            if (_length + sizeof(ushort) > _instructions.Length)
+                Grow();
+
+            BinaryPrimitives.WriteUInt16LittleEndian(_instructions.AsSpan(_length, sizeof(ushort)), value);
+            _length += sizeof(ushort);
         }
 
         private void EmitUInt32(int value)
         {
-            EmitByte((byte)value);
-            EmitByte((byte)(value >> 8));
-            EmitByte((byte)(value >> 16));
-            EmitByte((byte)(value >> 24));
+            if (_length + sizeof(int) > _instructions.Length)
+                Grow();
+
+            BinaryPrimitives.WriteInt32LittleEndian(_instructions.AsSpan(_length, sizeof(int)), value);
+            _length += sizeof(int);
+        }
+
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        private void Grow()
+        {
+            Array.Resize(ref _instructions, 2 * _instructions.Length + 10);
         }
 
         public void Emit(ILOpcode opcode)
@@ -468,19 +479,13 @@ internal void PatchLabels()
                 Debug.Assert(patch.Label.IsPlaced);
                 Debug.Assert(_startOffsetForLinking != StartOffsetNotSet);
 
-                int offset = patch.Offset;
+                Span<byte> offsetSpan = _instructions.AsSpan(patch.Offset, sizeof(int));
 
-                int delta = _instructions[offset + 3] << 24 |
-                    _instructions[offset + 2] << 16 |
-                    _instructions[offset + 1] << 8 |
-                    _instructions[offset];
+                int delta = BinaryPrimitives.ReadInt32LittleEndian(offsetSpan);
 
                 int value = patch.Label.AbsoluteOffset - _startOffsetForLinking - patch.Offset - delta;
 
-                _instructions[offset] = (byte)value;
-                _instructions[offset + 1] = (byte)(value >> 8);
-                _instructions[offset + 2] = (byte)(value >> 16);
-                _instructions[offset + 3] = (byte)(value >> 24);
+                BinaryPrimitives.WriteInt32LittleEndian(offsetSpan, value);
             }
         }