private static void WriteAssign(LanguageWriter w, IAssignExpression exp)
{
#if EXTRA_TEMP
// 無駄な変数の除去
// 之はその内に StatementAnalyze に引っ越した方が分かりやすいかも知れない
// 但し、その場合には式内で代入を行う場合には対応出来ない (例: (i=j)==0 等)
IVariableDeclarationExpression target = exp.Target as IVariableDeclarationExpression;
IVariableReferenceExpression target2 = exp.Target as IVariableReferenceExpression;
IVariableReferenceExpression right = exp.Expression as IVariableReferenceExpression;
if (w.ExtraTemporaries != null)
{
// 無駄変数の宣言
if (target != null)
{
for (int i = 0; i < w.ExtraTemporaries.Length; i++)
{
if (!w.EssentialTemporaries[i] && target.Variable.Name == w.ExtraTemporaries[i])
{
return;
}
}
}
// 無駄変数から無駄変数への受け渡し
if (target2 != null && right != null)
{
int iTarget = -1;
int iRight = -1;
for (int j = 0; j < w.ExtraTemporaries.Length; j++)
{
if (target2.Variable.ToString() == w.ExtraTemporaries[j])
{
iTarget = j;
w.VerifyCorrectBlock(j);
}
if (right.Variable.ToString() == w.ExtraTemporaries[j])
{
iRight = j;
w.VerifyCorrectBlock(j);
}
}
if (iTarget >= 0 && !w.EssentialTemporaries[iTarget])
{
string str;
if (iRight >= 0 && !w.EssentialTemporaries[iRight])
{
if (w.ExtraMappings[iRight] == null)
{
w.EssentialTemporaries[iRight] = true;
str = null;
}
else
{
str = w.ExtraMappings[iRight];
}
}
else
{
str = right.Variable.ToString();
}
if (str != null && target2.Variable.ToString()[0] == str[0])
{
w.ExtraMappings[iTarget] = str;
return;
}
}
}
}
#endif
WriteExpression(w, exp.Target, false);
w.Write(" = ");
WriteExpression(w, exp.Expression, false);
}