RCA 70/46 - Compare (CER) (CE) (CDR) (CD)

Compare
(CER) (CE) (CDR) (CD)
General Description
Format
(RR Short)
(RX Short)
(RR Long)
(RX Long)
Condition Code
Interrupt Action
Notes
Floating-Point Instructions
• The operand in the floating-point register specified by the first address
(R
1
)
is algebraically compared to the operand specified by the second
address (R
2
or XdBdD2). The result determines the condition code.
o
7 8 11 12 15
o 7 8 11 12 15 16 19 20
31
o
7 8 11 12 15
o
7 8 11 12 15 16 19 20
31
• 0 - operands are equal.
1 - operand specified by
the first address is less than the one specified
by
the second address.
2 - operand specified by
the first address is greater than the one
specified by
the second address.
3
-not used.
• Address error:
Addressing (RX f.ormat).
Specification.
• 1. Comparison takes into account the sign, exponent, and mantissa of
each number. Exponent inequality is not decisive for magnitude
determination since the mantissas may have different numbers of
leading zeros. The operands are scaled, as in Subtract Normalized,
and if the mantissa of each operand is zero, the numbers are con-
sidered equal
regardless of the sign and exponent.
2.
Both operands are unaltered.
215