dcmp - 2024.2 English

Description

The double precision floating-point value in rB_L is compared with the double precision floating-point value in rA_L 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(rAL) or isDnz(rBL) then
   (rD) ← 0
   FSR[DO] ← 1
   ESR[EC] ← 00110
else
   {read out behavior from Table: Table 1}    

Registers Altered

• rD_L, 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

Notes

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