Clm - Xerox 550 Reference Manual

Instruction Name Mnemonic
Compare Halfword CH
Compare Word
CW
Compare Doub I eword
CD
Compare Selective
CS
Compare With Limits in Register
CLR
Compare With Limits in Memory CLM
All comparison instructions produce a condition code
setting which is indicative of the results of the com-
parison, without affecting the effective operand in mem-
ory and wi thout affecti ng the contents of the desi gnated
register.
CI
o
I
COMPARE IMMEDIATE
(Immediate operand)
COMPARE IMMEDIATE extends the sign of the value field
(bi t posi tion 12) of the instruction word 12 bi t posi ti ons to
the left, compares the 32-bit result with the contents of
register R (with both operands treated as signed fixed-point
quantities), and then sets the condition code according to
the results of the comparison.
Affected: CC2, CC3, CC4
(R) : (I)12-31SE
Condition code settings:
Trap: Nonexistent instruc-
tion if bit 0 is a 1.
2 3 4
Resu
it
of Com pari son
o
0
Equal.
- 0 Register value less than immediate value.
o
Register value greater than immediate value.
- 0
No 1-bits compare, (R) n
(I)
12-325 E =
O.
One or more 1-bi ts compare,
(R) n (I) 12-32SE
10.
If
CI is indirectly addressed, it is treated as a nonexistent
instruction, in which case the basic processor uncondi-
tionally aborts execution of the instruction (at the time of
operation code decoding) and then traps to location X'40'
with the condition code unchanged.
66 Comparison Instructions
CB COMPARE BYTE
(Byte index alignment)
COMPARE BYTE compares the contents of bit positions 24-31
of register R with the effective byte (with both bytes treated
as positive integer magnitudes) and sets the condition code
accordi ng to the resu
I
ts of the compari son.
Affected: CC2, CC3, CC4
(R)24-3I : EB
Condition code settings:
2 3 4 Result of Comparison
- 0 0
Equal.
o
Register byte less than effective byte.
- 0
CH
H
o
I 2
o
Register byte greater than effective byte.
No 1-bits compare, (R)24-3I n EB
=
O.
One or more I-bits compare,
(R)24-31 n EB
10.
COMPARE HALFWORD
(Halfword index alignment)
COMPARE HALFWORD extends the sign of the effective
halfword 16 bit positions to the left, then compares the
resultant 32-bit word with the contents of register R (with
both words treated as signed, fixed-point quantities) and
sets the condition code according to the results of thp.
comparison.
Affected: CC2, CC3, CC4
(R) : EHSE
Condition code settings:
2
3 4 Result of Comparison
0 0
t:_ .. ~1
... '-I
v .......
0
Register word less than effective halfword
with sign extended.
0 Register word greater than effective halfword
with sign extended.