Xilinx MicroBlaze Reference Manual page 194

Chapter 5: MicroBlaze Instruction Set Architecture
fcmp
Floating Point Number Comparison
fcmp.un
fcmp.lt
fcmp.eq
fcmp.le
fcmp.gt
fcmp.ne
fcmp.ge
0 1 0 1 1 0
0 6
Description
The floating point value in rB is compared with the floating point value in rA and the comparison
result is placed into register rD. The OpSel field in the instruction code determines the type of
comparison performed.
Pseudocode
Registers Altered
•
•
•
Latency
•
•
Note
These instructions are only available when the MicroBlaze parameter C_USE_FPU is greater than
0.
Table 5-2, page 195
194
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rD, rA, rB
rD, rA, rB
rD, rA, rB
rD, rA, rB
rD, rA, rB
rD, rA, rB
rD, rA, rB
rD rA
11
if isDnz(rA) or isDnz(rB) then
←
(rD) 0
←
FSR[DO] 1
←
ESR[EC] 00110
else
{read out behavior from
rD, unless an FP exception is generated, in which case the register is unchanged
ESR[EC], if an FP exception is generated
FSR[IO,DO]
1 cycle with C_AREA_OPTIMIZED=0
3 cycles with C_AREA_OPTIMIZED=1
lists the floating point comparison operations.
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Unordered floating point comparison
Less-than floating point comparison
Equal floating point comparison
Less-or-Equal floating point comparison
Greater-than floating point comparison
Not-Equal floating point comparison
Greater-or-Equal floating point comparison
rB 0 1 0 0
16 21
Table 5-2}
MicroBlaze Processor Reference Guide
OpSel 0 0 0 0
25 28 31
UG081 (v14.7)