/*
 * Renjin : JVM-based interpreter for the R language for the statistical analysis
 * Copyright Â© 2010-2019 BeDataDriven Groep B.V. and contributors
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, a copy is available at
 * https://www.gnu.org/licenses/gpl-2.0.txt
 */
package org.renjin.gcc.codegen.call;

import org.renjin.gcc.InternalCompilerException;
import org.renjin.gcc.codegen.MethodGenerator;
import org.renjin.gcc.codegen.expr.ExprFactory;
import org.renjin.gcc.codegen.expr.GExpr;
import org.renjin.gcc.codegen.expr.JExpr;
import org.renjin.gcc.codegen.expr.PtrExpr;
import org.renjin.gcc.gimple.expr.GimpleExpr;
import org.renjin.gcc.gimple.statement.GimpleCall;


/**
 * Generates calls to memcpy() depending on the type of its arguments
 */
public class MemCopyCallGenerator implements CallGenerator {
  
  public static final String BUILTIN_MEMCPY = "__builtin_memcpy";
  public static final String MEMMOVE = "memmove";

  private final boolean buffer;

  public MemCopyCallGenerator(boolean buffer) {
    this.buffer = buffer;
  }

  @Override
  public void emitCall(MethodGenerator mv, ExprFactory exprFactory, GimpleCall call) {
    
    if(call.getOperands().size() != 3) {
      throw new InternalCompilerException("memcpy() expects 3 args.");
    }

    GimpleExpr destination = call.getOperand(0);
    GimpleExpr source = call.getOperand(1);

    PtrExpr sourcePtr = (PtrExpr) exprFactory.findGenerator(source);
    PtrExpr destinationPtr = (PtrExpr) exprFactory.findGenerator(destination);
    JExpr length = exprFactory.findPrimitiveGenerator(call.getOperand(2));

    destinationPtr.memoryCopy(mv, sourcePtr, length, buffer);

    if(call.getLhs() != null) {
      // memcpy() returns the destination pointer
      GExpr lhs = exprFactory.findGenerator(call.getLhs());

      lhs.store(mv, destinationPtr);
    }
  }
}
