locations 60400-607FF of the first oper
and would have been filled with1,024 copies of the padding byte X'FO', as
specified by the leftmost byte of regis
ter3. Bits 8-31 of registers 2 and 8
would have been incremented by400{16}, and bits 0-7 of registers 2 and 8 set to
zeros. Bits 8-31 of registers3 and 9
would still have been decremented to
zero.Condition code 2 would have been
set to indicate that the first operand
was longer than the second.
The technique for setting a field to
zeros that is illustrated in the second
example ofMVC cannot be used with MVCl. If the registers were set up to attempt
such an operation withMVCl, no data
movement would take place and condition
code3 would indicate destructive over
lap.
Instead,MVCl may be used to clear a
storage area to zeros as follows.
Assume register 8 and 9 are set up as
before. Register3 contains only zeros,
specifying zero length for the second
operand and a zero padding byte. Regis
ter 2 is not used to access storage, and
its contents are not significant.
Executing the instructionMVCl 8,2 caus
es locations60000-607FF to be filled
with zeros. Bits 8-31 of register 8 are
incremented by800{16}, and bits 0-7 of
registers 2 and 8 are set to zeros.
Bits 8-31 of register 9 are decremented
to zero, and condition code 2 is set to
indicate that the first operand is long
er than the second.MOVE NUMERICS (MVN) Two related instructions, MOVE NUMERICS and MOVE ZONES, may be used with decimal
data in the zoned format to operate
separately on the rightmost four bits
(the numeric bits) and the leftmost four
bits (the zone bits) of each byte. Both
are similar toMOVE (MVC), except that MOVE NUMERICS moves only the numeric
bits andMOVE ZONES moves only the zone
bits.
To illustrate the operation of theMOVE NUMERICS instruction, assume that the
following two fields are in storage:7090 7093 Field A IC61C71C81C91 7041 7046 Field B IFO/F1IF2IF3IF4IF51 Also assume:
Register 14 contains00 00 70 90. Register 15 contains 00 00 70 40. After the instruction:
Machine FormatOp Code l 01 03 F E 0001 Assembler Format MVN 1(4,15),0(14) is executed, field B becomes: 7041 7046 IF61F71F81F91F41F51 The numeric bits of the bytes at
locations7090-7093 have been stored in
the numeric bits of the bytes at
locations7041-7044. The contents of
locations7090-7093 and 7045-7046 are
unchanged.MOVE WITH OFFSET (MVO) MOVE WITH OFFSET may be used to shift a
packed-decimal number an odd number of
digit positions or to concatenate a sign
to an unsigned packed-decimal number.
Assume that the three-byte
packed-decimal number in
locations4500-4502 is to be
locations5600-5603 and given
of the packed-decimal number
location5603. Also assume:
unsigned
storage
moved to
the sign
ending at
Register 12 contains00 00 56 00. Register 15 contains 00 00 45 00. Storage locations 5600-5603 contain 77
88 99OC. Storage locations 4500-4502 contain 12 34 56.
After the instruction:
Machine FormatOp Code F1 3 2 C 000 I F 0001 Assembler Format MVO 0(4,12),0(3,15) Appendix A. Number Representation and Instruction-Use Examples A-23
and would have been filled with
specified by the leftmost byte of regis
ter
would have been incremented by
zeros. Bits 8-31 of registers
would still have been decremented to
zero.
set to indicate that the first operand
was longer than the second.
The technique for setting a field to
zeros that is illustrated in the second
example of
such an operation with
movement would take place and condition
code
lap.
Instead,
storage area to zeros as follows.
Assume register 8 and 9 are set up as
before. Register
specifying zero length for the second
operand and a zero padding byte. Regis
ter 2 is not used to access storage, and
its contents are not significant.
Executing the instruction
es locations
with zeros. Bits 8-31 of register 8 are
incremented by
registers 2 and 8 are set to zeros.
Bits 8-31 of register 9 are decremented
to zero, and condition code 2 is set to
indicate that the first operand is long
er than the second.
data in the zoned format to operate
separately on the rightmost four bits
(the numeric bits) and the leftmost four
bits (the zone bits) of each byte. Both
are similar to
bits and
bits.
To illustrate the operation of the
following two fields are in storage:
Register 14 contains
Machine Format
locations
the numeric bits of the bytes at
locations
locations
unchanged.
packed-decimal number an odd number of
digit positions or to concatenate a sign
to an unsigned packed-decimal number.
Assume that the three-byte
packed-decimal number in
locations
locations
of the packed-decimal number
location
unsigned
storage
moved to
the sign
ending at
Register 12 contains
88 99
After the instruction:
Machine Format