fcmp - 2024.2 English

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

if isDnz(rA) or isDnz(rB) then
   (rD) ← 0
   FSR[DO] ← 1
   ESR[EC] ← 00110
else
   {read out behavior from Table 1}

Registers Altered

• 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]

Latency

• 1 cycle with C_AREA_OPTIMIZED=0 or 2
• 3 cycles with C_AREA_OPTIMIZED=1

Note

These instructions are only available when the MicroBlaze parameter C_USE_FPU is greater than 0.

The following table lists the floating-point comparison operations.