dsqrt - 2024.2 English

Description

Performs a double precision floating-point square root on the value in rA_L and puts the result in register rD_L.

Pseudocode

if isDnz(rAL) then
   (rDL) ← 0xFFF8000000000000
   FSR[DO] ← 1
   ESR[EC] ← 00110
else if isSigNaN(rAL) then
   (rDL) ← 0xFFF8000000000000
   FSR[IO] ← 1
   ESR[EC] ← 00110
else if isQuietNaN(rAL) then
   (rDL) ← 0xFFF8000000000000
else if (rAL) < 0 then
   (rDL) ← 0xFFF8000000000000
   FSR[IO] ← 1
   ESR[EC] ← 00110
else if (rAL) = -0 then
   (rDL) ← -0
else
   (rDL) ← sqrt ((rAL))

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

• 27 cycles with C_AREA_OPTIMIZED=0
• 29 cycles with C_AREA_OPTIMIZED=1
• 23 cycles with C_AREA_OPTIMIZED=2

Notes

• This instruction is only available when the MicroBlaze parameter C_USE_FPU is set to 2 (Extended).