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RDFFR (unpredicated)

Read the first-fault register.

Read the first-fault register (FFR) and place in the destination predicate without predication.

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0010010100011001111100000000Pd
S

RDFFR <Pd>.B

if !HaveSVE() then UNDEFINED;
integer d = UInt(Pd);

Assembler Symbols

<Pd>

Is the name of the destination scalable predicate register, encoded in the "Pd" field.

Operation

CheckSVEEnabled();
bits(PL) ffr = FFR[];
P[d] = ffr;

Operational information

If PSTATE.DIT is 1:

  • The execution time of this instruction is independent of:
    • The values of the data supplied in any of its registers.
    • The values of the NZCV flags.
  • The response of this instruction to asynchronous exceptions does not vary based on:
    • The values of the data supplied in any of its registers.
    • The values of the NZCV flags.