LRDR Rl,R2
[RR, Extended Operand 2, Long Operand 1]
25
o 8 12 15
The second operand is rounded to the next smaller
format, and the result is placed in the first-operand
location.
Rounding consists in adding a one in bit position
32 or 72 of the long or extended second operand,
respectively, and propagating the carry, if any, to the
left. For both cases, the sign of the fraction is ig
nored, and addition is performed as if the fractions
were positive.
If rounding causes a carry out of the high-order
digit position of the fraction, the fraction is shifted
right one digit position, and the characteristic is in
creased by one.
The sign of the result is the same as the sign of
the second operand. No normalization takes place.
An exponent-overflow exception is recognized
when shifting the fraction right causes the character
istic to exceed 127. The operation is completed by
loading a number whose characteristic is 128 less
than the correct value, and a program interruption
for exponent overflow occurs. The result is normal
ized, and the sign and fraction remain correct.
Exponent-underflow and significance exceptions
cannot occur.
The Rl field must designate register0, 2, 4, or 6;
the R2 field of LRER must designate register0, 2, 4,
or 6; and the R2 field of LRDR must designate reg
ister° or 4. Otherwise, a specification exception is
recognized.
Condition Code:
The code remains unchanged.
Program Exceptions:
Operation (if the extended-precision floating
point feature is not installed)
Specification
Exponent Overflow
Multiply
MER Rl,R2
[RR, Short Multiplier and Multiplicand,
Long Product]
3C
o 8 12 15
ME Rl,D2(X2,B2)
[RX, Short Multiplier and Multiplicand,
Long Product]
o 8 12 16
MDR
[RR, Long Operands]
o 8 12 15
MD Rl,D2(X2,B2)
[RX, Long Operands]
6C20 o 8 12 16 20 MXDR Rl,R2
[RR, Long Multiplier and Multiplicand,
Extended Product 1
o 8 12 15
MXD Rl,D2(X2,B2)
[RX, Long Multiplier and Multiplicand,
Extended Product 1
67
o 8 12 1620 MXR Rl,R2
[RR, Extended Operands]
o 8 12 15
31
31
31
The normalized product of the second operand (the
multiplier) and the first operand (the multiplicand) is
placed in the first-operand location.
Floating-Point Instructions 167
[RR, Extended Operand 2, Long Operand 1]
25
o 8 12 15
The second operand is rounded to the next smaller
format, and the result is placed in the first-operand
location.
Rounding consists in adding a one in bit position
32 or 72 of the long or extended second operand,
respectively, and propagating the carry, if any, to the
left. For both cases, the sign of the fraction is ig
nored, and addition is performed as if the fractions
were positive.
If rounding causes a carry out of the high-order
digit position of the fraction, the fraction is shifted
right one digit position, and the characteristic is in
creased by one.
The sign of the result is the same as the sign of
the second operand. No normalization takes place.
An exponent-overflow exception is recognized
when shifting the fraction right causes the character
istic to exceed 127. The operation is completed by
loading a number whose characteristic is 128 less
than the correct value, and a program interruption
for exponent overflow occurs. The result is normal
ized, and the sign and fraction remain correct.
Exponent-underflow and significance exceptions
cannot occur.
The Rl field must designate register
the R2 field of LRER must designate register
or 6; and the R2 field of LRDR must designate reg
ister
recognized.
Condition Code:
The code remains unchanged.
Program Exceptions:
Operation (if the extended-precision floating
point feature is not installed)
Specification
Exponent Overflow
Multiply
MER Rl,R2
[RR, Short Multiplier and Multiplicand,
Long Product]
3C
o 8 12 15
ME Rl,D2(X2,B2)
[RX, Short Multiplier and Multiplicand,
Long Product]
o 8 12 16
MDR
[RR, Long Operands]
o 8 12 15
MD Rl,D2(X2,B2)
[RX, Long Operands]
6C
[RR, Long Multiplier and Multiplicand,
Extended Product 1
o 8 12 15
MXD Rl,D2(X2,B2)
[RX, Long Multiplier and Multiplicand,
Extended Product 1
67
o 8 12 16
[RR, Extended Operands]
o 8 12 15
31
31
31
The normalized product of the second operand (the
multiplier) and the first operand (the multiplicand) is
placed in the first-operand location.
Floating-Point Instructions 167