/// <summary>
/// Inserts an unconditional jump to the location described by the jump token.
/// This may be a forward or backward jump, but should be local to the Assembler.
/// </summary>
public override void Jump(Compiler.JumpToken token)
{
JumpToken t = (JumpToken)token;
t.SetKind(JumpTokenKind.Relative);
region.WriteByte(0xe9); // relative offset next instruction
t.SetJumpSite(region.InsertIntToken());
}
/// <summary>
/// Conditional version of Jump().
/// Takes the jump if the type part of the accumulator is empty
/// </summary>
public override void JumpIfUnassigned(JumpToken token)
{
token.SetKind(JumpTokenKind.Relative);
region.Write(new byte[] {
0x48, 0x21, 0xd2, // and rdx, rdx
0x0f, 0x84 // jz
});
token.SetJumpSite(region.InsertIntToken());
}
/// <summary>
/// Conditional version of Jump().
/// Reads a boolean value from the accumulator
/// </summary>
public override void JumpIfFalse(JumpToken token)
{
token.SetKind(JumpTokenKind.Relative);
region.Write(new byte[] {
0x48, 0x21, 0xc0, // and rax, rax
0x0f, 0x84 // jz
});
token.SetJumpSite(region.InsertIntToken());
}
public override void JumpIfUnassigned(Compiler.JumpToken token)
{
JumpToken t = (JumpToken)token;
t.SetKind(JumpTokenKind.Relative);
region.Write(new byte[] {
0x21, 0xd2, // and edx, edx
0x0f, 0x84 // jz
});
t.SetJumpSite(region.InsertIntToken());
}
public override void JumpIfTrue(Compiler.JumpToken token)
{
JumpToken t = (JumpToken)token;
t.SetKind(JumpTokenKind.Relative);
region.Write(new byte[] {
0x21, 0xc0, // and eax, eax
0x0f, 0x85 // jnz
});
t.SetJumpSite(region.InsertIntToken());
}
public override void JumpIfNotMarked(Compiler.JumpToken token)
{
region.Write(new byte[] {
0x48, 0xF7, 0xC2, 0x01, 0x00, 0x00, 0x00 // test rdx, 1
});
JumpToken t = (JumpToken)token;
t.SetKind(JumpTokenKind.Relative);
region.Write(new byte[] {
0x0f, 0x84 // jz
});
t.SetJumpSite(region.InsertIntToken());
}
/// <summary>
/// Tests the content of the accumulator for nullness and puts the result as a boolean in the accumulator.
/// Note: the type part of the boolean is missing.
/// </summary>
public override void IsNotNull()
{
JumpToken zeroJump = new JumpToken();
zeroJump.SetKind(JumpTokenKind.Relative);
region.Write(new byte[] {
0x48, 0x31, 0xC0, // xor rax, rax
0x48, 0x21, 0xd2, // and rdx, rdx
0x0f, 0x84 // jz
});
zeroJump.SetJumpSite(region.InsertIntToken());
region.Write(new byte[] {
0x48, 0x83, 0xf0, 0x01 // xor rax, 1
});
zeroJump.SetDestination(region.CurrentLocation);
}
