4
FLOG N P1 ,x÷ FLOG N P1
Operation:
Loge of {Source + 1) I~ FPn
Assembler
FLOGNPI.<fmt> <ea>,FPn
Syntax:
FLOGNPI.X FPm,FPn
FLOGNPI.X FPn
Attributes: Format= (Byte, Word, Long, Single, Double, Extended, Packed)
Description:
Converts the source operand to extended precision (if necessary), adds
one to that value, and calculates the natural logarithm of that intermediate result.
Stores the result in the destination floating-point data register. This function is not
defined for input values less than - 1.
Operation Table:
Source In
Range Zero
i Infinity
Destination
~ + - + - + -
Result In(x+1) In(x+1) 1 +0.0 -0.0 I --inf NAN 2
NOTES:
1. If the source is - 1, sets the DZ bit in the FPSR exception byte and returns a NAN. If the source
is < - 1, sets the OPERR bit in the FPSR exception byte and returns a NAN.
2. Sets the OPERR bit in the FPSR exception byte.
3. If the source operand is a NAN, refer to 4.5.4 NANs for more information.
Status Register:
Condition Codes:
Quotient Byte:
Exception Byte:
Accrued Exception Byte:
Affected as described in 4.5.5.1 SE'I-FING FLOATING-POINT
CONDITION
CODES
Not affected
BSUN
SNAN
OPERR
OVFL
UNFL
DZ
INEX2
INEX1
Cleared
Refer to 4.5.4
NANs.
Set if the source operand is < -1; cleared
otherwise
Cleared
Refer to 6.1.5 Underflow.
Set if the source operand is - 1; cleared oth-
erwise
Refer to 6.1.7 Inexact Result.
If <fmt> is Packed, refer to 6.1.8 Inexact Result
on
Decimal Input; cleared otherwise.
Affected as described in 6.1.10 IEEE Exception and Trap Com-
patibility
FREESCALE
4-60
MC68881/MC68882 USER'S MANUAL
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