Cray CRAY-1 - 062 Ijk Floating Sum of (Sj) and (Sk) to si; 063 Ijk Floating Difference of (Sj) and (Sk) to si

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062ijk Floating sum of (Sj) and (Sk) to Si :
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063ijk Floating difference of (Sj) and (Sk) to Si :
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These instructions are performed by the floati~q point add unit.
Operands are assumed to be in floating point format. The result is
normalized even if the operands are unnormalized. Underflow and
overflow conditions are described in Section 3.
The 062 instruction forms the sum of the floating point quantities
in
Sj and Sk and enters the normalized result into Si.
The 063 instruction forms the difference of the floating point
quantities in
Sj and Sk and enters the normalized result into Si.
Hold issue conditions
034 - 037 in process
Exchange in process
Si register access conflict
Si, Sj, or Sk reserved
170 - 173 in process; unit busy (VL) + 4 CPs
Execution time
Si ready 6 CPs
Instruction issue 1 CP
Special cases
For 062:
(Si) = (Sk) normalized if j = 0 and k ~ 0
(Si)
= (Sj) normalized if (Sj) exponent is valid, j f 0 and k = 0
For 063:
(Si) = -(Sk) normalized if j = 0 and k ~ 0
(Si)
= (Sj) normalized if (Sj) exponent is valid, j f 0 and k = 0
Arithmetic error allows 0 to 9 CPs + 2 parcels to issue before
interrupt occurs if f.p. error flag is set.
2240004
4-41
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