public int optimizeLocals()
{
if (locals.Count == 0)
{
return(0);
}
var usedLocals = new Dictionary <Local, List <LocalVariableInfo> >();
foreach (var block in methodBlocks.getAllBlocks())
{
for (int i = 0; i < block.Instructions.Count; i++)
{
var instr = block.Instructions[i];
Local local;
switch (instr.OpCode.Code)
{
case Code.Ldloc:
case Code.Ldloc_S:
case Code.Ldloc_0:
case Code.Ldloc_1:
case Code.Ldloc_2:
case Code.Ldloc_3:
case Code.Stloc:
case Code.Stloc_S:
case Code.Stloc_0:
case Code.Stloc_1:
case Code.Stloc_2:
case Code.Stloc_3:
local = Instr.getLocalVar(locals, instr);
break;
case Code.Ldloca_S:
case Code.Ldloca:
local = (Local)instr.Operand;
break;
default:
local = null;
break;
}
if (local == null)
{
continue;
}
List <LocalVariableInfo> list;
if (!usedLocals.TryGetValue(local, out list))
{
usedLocals[local] = list = new List <LocalVariableInfo>();
}
list.Add(new LocalVariableInfo(block, i));
if (usedLocals.Count == locals.Count)
{
return(0);
}
}
}
int newIndex = -1;
var newLocals = new List <Local>(usedLocals.Count);
var newLocalsDict = new Dictionary <Local, bool>(usedLocals.Count);
foreach (var local in usedLocals.Keys)
{
newIndex++;
newLocals.Add(local);
newLocalsDict[local] = true;
foreach (var info in usedLocals[local])
{
info.block.Instructions[info.index] = new Instr(optimizeLocalInstr(info.block.Instructions[info.index], local, (uint)newIndex));
}
}
// We can't remove all locals. Locals that reference another assembly will
// cause the CLR to load that assembly before the method is executed if it
// hasn't been loaded yet. This is a side effect the program may depend on.
// At least one program has this dependency and will crash if we remove the
// unused local. This took a while to figure out...
var keptAssemblies = new Dictionary <string, bool>(StringComparer.Ordinal);
foreach (var local in locals)
{
if (newLocalsDict.ContainsKey(local))
{
continue;
}
var defAsm = local.Type.DefinitionAssembly;
if (defAsm == null)
{
continue; // eg. fnptr
}
if (defAsm == method.DeclaringType.Module.Assembly)
{
continue; // this assembly is always loaded
}
if (defAsm.IsCorLib())
{
continue; // mscorlib is always loaded
}
var asmName = defAsm.FullName;
if (keptAssemblies.ContainsKey(asmName))
{
continue;
}
keptAssemblies[asmName] = true;
newLocals.Add(local);
}
int numRemoved = locals.Count - newLocals.Count;
locals.Clear();
foreach (var local in newLocals)
{
locals.Add(local);
}
return(numRemoved);
}
public int optimizeLocals()
{
if (locals.Count == 0)
{
return(0);
}
var usedLocals = new Dictionary <VariableDefinition, List <LocalVariableInfo> >();
foreach (var block in methodBlocks.getAllBlocks())
{
for (int i = 0; i < block.Instructions.Count; i++)
{
var instr = block.Instructions[i];
VariableDefinition local;
switch (instr.OpCode.Code)
{
case Code.Ldloc:
case Code.Ldloc_S:
case Code.Ldloc_0:
case Code.Ldloc_1:
case Code.Ldloc_2:
case Code.Ldloc_3:
case Code.Stloc:
case Code.Stloc_S:
case Code.Stloc_0:
case Code.Stloc_1:
case Code.Stloc_2:
case Code.Stloc_3:
local = Instr.getLocalVar(locals, instr);
break;
case Code.Ldloca_S:
case Code.Ldloca:
local = (VariableDefinition)instr.Operand;
break;
default:
local = null;
break;
}
if (local == null)
{
continue;
}
List <LocalVariableInfo> list;
if (!usedLocals.TryGetValue(local, out list))
{
usedLocals[local] = list = new List <LocalVariableInfo>();
}
list.Add(new LocalVariableInfo(block, i));
if (usedLocals.Count == locals.Count)
{
return(0);
}
}
}
int newIndex = -1;
var newLocals = new List <VariableDefinition>(usedLocals.Count);
foreach (var local in usedLocals.Keys)
{
newIndex++;
newLocals.Add(local);
foreach (var info in usedLocals[local])
{
info.block.Instructions[info.index] = new Instr(optimizeLocalInstr(info.block.Instructions[info.index], local, (uint)newIndex));
}
}
int numRemoved = locals.Count - newLocals.Count;
locals.Clear();
foreach (var local in newLocals)
{
locals.Add(local);
}
return(numRemoved);
}
