=head1 NAME

cmp.ops - Comparison Opcodes


=cut

=head1 DESCRIPTION

Operations that compare two registers against each other.
Some of these operations affect control flow directly; others
do not.


=cut

=head2 Flow control comparison operators

These operators branch based on the relationship between
their operands.

=over 4


=cut

=item B<eq>(in INT, in INT, inconst LABEL)

=item B<eq>(in NUM, in NUM, inconst LABEL)

=item B<eq>(in STR, in STR, inconst LABEL)

=item B<eq>(invar PMC, invar PMC, inconst LABEL)

=item B<eq>(invar PMC, in INT, inconst LABEL)

=item B<eq>(invar PMC, in NUM, inconst LABEL)

=item B<eq>(invar PMC, in STR, inconst LABEL)

=item B<eq_str>(invar PMC, invar PMC, inconst LABEL)

=item B<eq_num>(invar PMC, invar PMC, inconst LABEL)

=item B<eq_addr>(in STR, in STR, inconst LABEL)

=item B<eq_addr>(invar PMC, invar PMC, inconst LABEL)

Branch if $1 is equal to $2. For PMCs this does a generic comparison,
whatever that is for the involved PMCs. Mixed PMC number/string
operands do a numeric or string comparison respectively.

B<eq_str> and B<eq_num> enforce string or number comparisons.

B<eq_addr> compares the address of the objects or strings.


=cut

=item B<ne>(in INT, in INT, inconst LABEL)

=item B<ne>(in NUM, in NUM, inconst LABEL)

=item B<ne>(in STR, in STR, inconst LABEL)

=item B<ne>(invar PMC, invar PMC, inconst LABEL)

=item B<ne>(invar PMC, in INT, inconst LABEL)

=item B<ne>(invar PMC, in NUM, inconst LABEL)

=item B<ne>(invar PMC, in STR, inconst LABEL)

=item B<ne_str>(invar PMC, invar PMC, inconst LABEL)

=item B<ne_num>(invar PMC, invar PMC, inconst LABEL)

=item B<ne_addr>(in STR, in STR, inconst LABEL)

=item B<ne_addr>(invar PMC, invar PMC, inconst LABEL)

Branch if $1 is not equal to $2.


=cut

=item B<lt>(in INT, in INT, inconst LABEL)

=item B<lt>(in NUM, in NUM, inconst LABEL)

=item B<lt>(in STR, in STR, inconst LABEL)

=item B<lt>(invar PMC, invar PMC, inconst LABEL)

=item B<lt>(invar PMC, in INT, inconst LABEL)

=item B<lt>(invar PMC, in NUM, inconst LABEL)

=item B<lt>(invar PMC, in STR, inconst LABEL)

=item B<lt_str>(invar PMC, invar PMC, inconst LABEL)

=item B<lt_num>(invar PMC, invar PMC, inconst LABEL)

Branch if $1 is less than $2.


=cut

=item B<le>(in INT, in INT, inconst LABEL)

=item B<le>(in NUM, in NUM, inconst LABEL)

=item B<le>(in STR, in STR, inconst LABEL)

=item B<le>(invar PMC, invar PMC, inconst LABEL)

=item B<le>(invar PMC, in INT, inconst LABEL)

=item B<le>(invar PMC, in NUM, inconst LABEL)

=item B<le>(invar PMC, in STR, inconst LABEL)

=item B<le_str>(invar PMC, invar PMC, inconst LABEL)

=item B<le_num>(invar PMC, invar PMC, inconst LABEL)

Branch if $1 is less than or equal to $2.


=cut

=item B<gt>(invar PMC, invar PMC, inconst LABEL)

=item B<gt>(invar PMC, in INT, inconst LABEL)

=item B<gt>(invar PMC, in NUM, inconst LABEL)

=item B<gt>(invar PMC, in STR, inconst LABEL)

=item B<gt_str>(invar PMC, invar PMC, inconst LABEL)

=item B<gt_num>(invar PMC, invar PMC, inconst LABEL)

Branch if $1 is greater than $2.


=cut

=item B<ge>(invar PMC, invar PMC, inconst LABEL)

=item B<ge>(invar PMC, in INT, inconst LABEL)

=item B<ge>(invar PMC, in NUM, inconst LABEL)

=item B<ge>(invar PMC, in STR, inconst LABEL)

=item B<ge_str>(invar PMC, invar PMC, inconst LABEL)

=item B<ge_num>(invar PMC, invar PMC, inconst LABEL)

Branch if $1 is greater than or equal to $2.


=cut

=item B<if_null>(invar PMC, inconst LABEL)

Branch to $2 if $1 is a NULL PMC.

=item B<if_null>(invar STR, inconst LABEL)

Branch to $2 if $1 is a NULL STRING.


=cut

=item B<unless_null>(invar PMC, inconst LABEL)

Branch to $2 if $1 is I<not> a NULL PMC.

=item B<unless_null>(invar STR, inconst LABEL)

Branch to $2 if $1 is I<not> a NULL STRING.


=cut

=back


=cut

=head2 Non-flow control comparison ops

These ops do comparisons and truth testing without doing flow control.

=over 4

=item B<cmp>(out INT, in INT, in INT)

=item B<cmp>(out INT, in NUM, in NUM)

=item B<cmp>(out INT, in STR, in STR)

=item B<cmp>(out INT, invar PMC, invar PMC)

=item B<cmp>(out INT, invar PMC, in INT)

=item B<cmp>(out INT, invar PMC, in NUM)

=item B<cmp>(out INT, invar PMC, in STR)

=item B<cmp_str>(out INT, invar PMC, invar PMC)

=item B<cmp_num>(out INT, invar PMC, invar PMC)

Sets $1 to -1 if $2 < $3, +1 if $2 > $3, and 0 otherwise.


=cut

=item B<cmp_pmc>(out PMC, invar PMC, invar PMC)

Does the same thing as the other cmp_* variants, but puts a PMC in $1.  This is
useful for avoiding the semipredicate problem in HLLs where two aggregate PMCs
are not always comparable.


=cut

=item B<issame>(out INT, invar PMC, invar PMC)

=item B<issame>(out INT, in STR, in STR)

Sets $1 to 1 or 0, depending on the identity of the 2 objects.
The identity is the PMCs memory address.

=item B<isntsame>(out INT, invar PMC, invar PMC)

=item B<isntsame>(out INT, in STR, in STR)

Sets $1 to 0 or 1, depending on the identity of the 2 objects.

=item B<istrue>(out INT, invar PMC)

Sets $1 to 1 or 0, depending on whether $2 is true or not.

=item B<isfalse>(out INT, invar PMC)

Sets $1 to 1 or 0, depending on whether $2 is false or not.

=item B<isnull>(out INT, in PMC)

Sets $1 to 1 if the object is null, 0 otherwise.

=item B<isnull>(out INT, in STR)

Sets $1 to 1 if the string is null, 0 otherwise.


=cut

=item B<isgt>(out INT, in INT, in INT)

=item B<isgt>(out INT, in NUM, in NUM)

=item B<isgt>(out INT, in STR, in STR)

These 3 opcodes are valid, but create as their reverse.

=item B<isgt>(out INT, invar PMC, invar PMC)

Sets $1 to 1 if $2 is greater than $3.


=cut

=item B<isge>(out INT, in INT, in INT)

=item B<isge>(out INT, in NUM, in NUM)

=item B<isge>(out INT, in STR, in STR)

These 3 opcodes are valid, but create as their reverse.

=item B<isge>(out INT, invar PMC, invar PMC)

Sets $1 to 1 if $2 is greater than or equal to $3.


=cut

=item B<isle>(out INT, in INT, in INT)

=item B<isle>(out INT, in NUM, in NUM)

=item B<isle>(out INT, in STR, in STR)

=item B<isle>(out INT, invar PMC, invar PMC)

Sets $1 to 1 if $2 is less than or equal to $3.


=cut

=item B<islt>(out INT, in INT, in INT)

=item B<islt>(out INT, in NUM, in NUM)

=item B<islt>(out INT, in STR, in STR)

=item B<islt>(out INT, invar PMC, invar PMC)

Sets $1 to 1 if $2 is less than $3.


=cut

=item B<iseq>(out INT, in INT, in INT)

=item B<iseq>(out INT, in NUM, in NUM)

=item B<iseq>(out INT, in STR, in STR)

=item B<iseq>(out INT, invar PMC, invar PMC)

Sets $1 to 1 if $2 is equal to $3.


=cut

=item B<isne>(out INT, in INT, in INT)

=item B<isne>(out INT, in NUM, in NUM)

=item B<isne>(out INT, in STR, in STR)

=item B<isne>(out INT, invar PMC, invar PMC)

Sets $1 to 1 if $2 is not equal to $3.


=cut

=back


=cut

=head2 Logical operations

These operations apply logical functions to their arguments.

=over 4


=cut

=item B<and>(out INT, in INT, in INT)

=item B<and>(invar PMC, invar PMC, invar PMC)

Short-circuiting logical and.  Returns $2 if it's false, else returns $3.


=cut

=item B<not>(inout INT)

=item B<not>(invar PMC)

Set the boolean state of $1 to the opposite of the boolean state from $1.

=item B<not>(out INT, in INT)

=item B<not>(out PMC, invar PMC)


=cut

=item B<or>(out INT, in INT, in INT)

=item B<or>(invar PMC, invar PMC, invar PMC)

Short-circuiting logical or.  Returns $2 if it's true, else returns $3.


=cut

=item B<xor>(out INT, in INT, in INT)

=item B<xor>(invar PMC, invar PMC, invar PMC)

Logical xor.  Returns $2 if it's true and $3 isn't,
returns $3 if it's true and $2 isn't, else returns false.


=cut

=back


=cut

=head1 COPYRIGHT

Copyright (C) 2001-2009, Parrot Foundation.

=head1 LICENSE

This program is free software. It is subject to the same license
as the Parrot interpreter itself.


=cut