Avoid buffer allocations in CodeGenContext.GetCode(). Avoid stream allocations in PTC.PtcInfo.

Refactoring/nits.

ARMeilleure/CodeGen/RegisterAllocators/LinearScanAllocator.cs

@@ -86,8 +86,8 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
         {
             NumberLocals(cfg);
 
-            using (AllocationContext context = new AllocationContext(stackAlloc, regMasks, _intervals.Count))
+            using AllocationContext context = new AllocationContext(stackAlloc, regMasks, _intervals.Count);
-            {
+
             BuildIntervals(cfg, context);
 
             for (int index = 0; index < _intervals.Count; index++)
@@ -131,7 +131,6 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
 
             return new AllocationResult(context.IntUsedRegisters, context.VecUsedRegisters, context.StackAlloc.TotalSize);
         }
-        }
 
         private void AllocateInterval(AllocationContext context, LiveInterval current, int cIndex)
         {

ARMeilleure/CodeGen/X86/CodeGenContext.cs

@@ -302,13 +302,11 @@ namespace ARMeilleure.CodeGen.X86
             {
                 Assembler assembler = new Assembler(codeStream, _ptcInfo);
 
-                Span<byte> buffer;
-
                 for (int index = 0; index < _jumps.Count; index++)
                 {
                     Jump jump = _jumps[index];
 
-                    buffer = new byte[jump.JumpPosition - _stream.Position];
+                    Span<byte> buffer = new byte[jump.JumpPosition - _stream.Position];
 
                     _stream.Read(buffer);
                     _stream.Seek(_ptcDisabled ? ReservedBytesForJump : jump.InstSize, SeekOrigin.Current);
@@ -325,13 +323,7 @@ namespace ARMeilleure.CodeGen.X86
                     }
                 }
 
-                buffer = new byte[_stream.Length - _stream.Position];
+                _stream.CopyTo(codeStream);
-
-                _stream.Read(buffer);
-
-                codeStream.Write(buffer);
-
-                _ptcInfo?.WriteCode(codeStream);
 
                 return codeStream.ToArray();
             }

ARMeilleure/CodeGen/X86/CodeGenerator.cs

@@ -190,6 +190,11 @@ namespace ARMeilleure.CodeGen.X86
 
                 byte[] code = context.GetCode();
 
+                if (ptcInfo != null)
+                {
+                    ptcInfo.Code = code;
+                }
+
                 Logger.EndPass(PassName.CodeGeneration);
 
                 return new CompiledFunction(code, unwindInfo);

ARMeilleure/Translation/PTC/Ptc.cs

@@ -198,11 +198,7 @@ namespace ARMeilleure.Translation.PTC
             using (FileStream compressedStream = new FileStream(fileName, FileMode.Open))
             using (DeflateStream deflateStream = new DeflateStream(compressedStream, CompressionMode.Decompress, true))
             {
-                IntPtr intPtr = IntPtr.Zero;
+                using MD5 md5 = MD5.Create();
-
-                try
-                {
-                    MD5 md5 = MD5.Create();
 
                 int hashSize = md5.HashSize / 8;
 
@@ -223,6 +219,10 @@ namespace ARMeilleure.Translation.PTC
 
                 int size = BitConverter.ToInt32(sizeBytes, 0);
 
+                IntPtr intPtr = IntPtr.Zero;
+
+                try
+                {
                     intPtr = Marshal.AllocHGlobal(size);
 
                     using (UnmanagedMemoryStream stream = new UnmanagedMemoryStream((byte*)intPtr.ToPointer(), size, size, FileAccess.ReadWrite))
@@ -245,8 +245,6 @@ namespace ARMeilleure.Translation.PTC
 
                         byte[] expectedHash = md5.ComputeHash(stream);
 
-                        md5.Dispose();
-
                         if (!CompareHash(currentHash, expectedHash))
                         {
                             InvalidateCompressedStream(compressedStream);
@@ -413,11 +411,7 @@ namespace ARMeilleure.Translation.PTC
         {
             int translatedFuncsCount;
 
-            IntPtr intPtr = IntPtr.Zero;
+            using MD5 md5 = MD5.Create();
-
-            try
-            {
-                MD5 md5 = MD5.Create();
 
             int hashSize = md5.HashSize / 8;
 
@@ -427,6 +421,10 @@ namespace ARMeilleure.Translation.PTC
             Debug.Assert(sizeBytes.Length == sizeof(int));
             byte[] sizeHash = md5.ComputeHash(sizeBytes);
 
+            IntPtr intPtr = IntPtr.Zero;
+
+            try
+            {
                 intPtr = Marshal.AllocHGlobal(size);
 
                 using (UnmanagedMemoryStream stream = new UnmanagedMemoryStream((byte*)intPtr.ToPointer(), size, size, FileAccess.ReadWrite))
@@ -445,8 +443,6 @@ namespace ARMeilleure.Translation.PTC
                     stream.Seek((long)hashSize, SeekOrigin.Begin);
                     byte[] hash = md5.ComputeHash(stream);
 
-                    md5.Dispose();
-
                     stream.Seek(0L, SeekOrigin.Begin);
                     stream.Write(hash, 0, hashSize);
 
@@ -860,11 +856,11 @@ namespace ARMeilleure.Translation.PTC
                 _infosWriter.Write((ulong)guestSize); // InfoEntry.GuestSize
                 _infosWriter.Write((bool)highCq); // InfoEntry.HighCq
                 _infosWriter.Write((bool)false); // InfoEntry.Stubbed
-                _infosWriter.Write((int)ptcInfo.CodeStream.Length); // InfoEntry.CodeLen
+                _infosWriter.Write((int)ptcInfo.Code.Length); // InfoEntry.CodeLen
                 _infosWriter.Write((int)ptcInfo.RelocEntriesCount); // InfoEntry.RelocEntriesCount
 
                 // WriteCode.
-                ptcInfo.CodeStream.WriteTo(_codesStream);
+                _codesStream.Write(ptcInfo.Code, 0, ptcInfo.Code.Length);
 
                 // WriteReloc.
                 ptcInfo.RelocStream.WriteTo(_relocsStream);

ARMeilleure/Translation/PTC/PtcInfo.cs

@@ -9,7 +9,8 @@ namespace ARMeilleure.Translation.PTC
         private readonly BinaryWriter _relocWriter;
         private readonly BinaryWriter _unwindInfoWriter;
 
-        public MemoryStream CodeStream       { get; }
+        public byte[] Code { get; set; }
+
         public MemoryStream RelocStream      { get; }
         public MemoryStream UnwindInfoStream { get; }
 
@@ -17,7 +18,6 @@ namespace ARMeilleure.Translation.PTC
 
         public PtcInfo()
         {
-            CodeStream       = new MemoryStream();
             RelocStream      = new MemoryStream();
             UnwindInfoStream = new MemoryStream();
 
@@ -27,11 +27,6 @@ namespace ARMeilleure.Translation.PTC
             RelocEntriesCount = 0;
         }
 
-        public void WriteCode(MemoryStream codeStream)
-        {
-            codeStream.WriteTo(CodeStream);
-        }
-
         public void WriteRelocEntry(RelocEntry relocEntry)
         {
             _relocWriter.Write((int)relocEntry.Position);
@@ -60,7 +55,6 @@ namespace ARMeilleure.Translation.PTC
             _relocWriter.Dispose();
             _unwindInfoWriter.Dispose();
 
-            CodeStream.Dispose();
             RelocStream.Dispose();
             UnwindInfoStream.Dispose();
         }

ARMeilleure/Translation/Translator.cs

@@ -246,8 +246,10 @@ namespace ARMeilleure.Translation
 
                 ResetPool(highCq ? 1 : 0);
             }
-            else using (PtcInfo ptcInfo = new PtcInfo())
+            else
             {
+                using PtcInfo ptcInfo = new PtcInfo();
+
                 func = Compiler.Compile<GuestFunction>(cfg, argTypes, OperandType.I64, options, ptcInfo);
 
                 ResetPool(highCq ? 1 : 0);