dlong - 2024.2 English

Description

Converts the double precision floating-point number in register rA_L to a signed long value and puts the result in register rD_L. This is a 64-bit truncating signed conversion that will produce a 64-bit long result.

Pseudocode

if isDnz(rAL) then
   (rDL) ← 0xFFF8000000000000
   FSR[DO] ← 1
   ESR[EC] ← 00110
else if isNaN(rAL) then
   (rDL) ← 0xFFF8000000000000
   FSR[IO] ← 1
   ESR[EC] ← 00110
else if isInf(rAL) or (rAL) < -263 or (rAL) > 263 - 1 then
   (rDL) ← 0xFFF8000000000000
   FSR[IO] ← 1
   ESR[EC] ← 00110
else
   (rDL) ← long ((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

• 4 cycles with C_AREA_OPTIMIZED=0
• 6 cycles with C_AREA_OPTIMIZED=1
• 1 cycle with C_AREA_OPTIMIZED=2

Notes

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