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ColdFire CF4e Core User’s Manual
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FPU Programmer’s Model
When using the IEEE nonaware tests, the user receives a BSUN exception if a branch is
attempted and FPCC[NAN] is set, unless the branch is an FBEQ or an FBNE. If the
BSUN exception is enabled in FPCR, the exception takes a BSUN trap. Therefore, the
IEEE nonaware program is interrupted if an unexpected condition occurs. Users
knowledgeable of the IEEE-754 standard should use IEEE-aware tests in programs that
contain ordered and unordered conditions. Because the ordered or unordered attribute is
explicitly included in the conditional test, EXC[BSUN] is not set when the unordered
condition occurs. Table 4-9 summarizes conditional mnemonics, definitions, equations,
predicates, and whether EXC[BSUN] is set for the 32 floating-point conditional tests. The
equation column lists FPCC bit combinations for each test in the form of an equation.
Condition codes with an overbar indicate cleared bits; all other bits are set.
Table 4-9. Floating-Point Conditional Tests
Mnemonic
Definition
Equation
Predicate
1
EXC[BSUN] Set
IEEE Nonaware Tests
EQ
Equal
Z
000001
No
NE
Not equal
Z
001110
No
GT
Greater than
NAN | Z | N
010010
Yes
NGT
Not greater than
NAN | Z | N
011101
Yes
GE
Greater than or equal
Z | (NAN | N)
010011
Yes
NGE
Not greater than or equal
NAN | (N & Z)
011100
Yes
LT
Less than
N & (NAN | Z)
010100
Yes
NLT
Not less than
NAN | (Z | N)
011011
Yes
LE
Less than or equal
Z | (N & NAN)
010101
Yes
NLE
Not less than or equal
NAN | (N | Z)
011010
Yes
GL
Greater or less than
NAN | Z
010110
Yes
NGL
Not greater or less than
NAN | Z
011001
Yes
GLE
Greater, less or equal
NAN
010111
Yes
NGLE
Not greater, less or equal
NAN
011000
Yes
IEEE-Aware Tests
EQ
Equal
Z
000001
No
NE
Not equal
Z
001110
No
OGT
Ordered greater than
NAN | Z | N
000010
No
ULE
Unordered or less or equal
NAN | Z | N
001101
No
OGE
Ordered greater than or equal
Z | (NAN | N)
000011
No
ULT
Unordered or less than
NAN | (N & Z)
001100
No
OLT
Ordered less than
N & (NAN | Z)
000100
No
UGE
Unordered or greater or equal
NAN | (Z | N)
001011
No
OLE
Ordered less than or equal
Z | (N & NAN)
000101
No
F
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