RDFFR (unpredicated)

Read the first-fault register

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

This instruction is illegal when executed in Streaming SVE mode, unless FEAT_SME_FA64 is implemented and enabled at the current Exception level.

313029282726252423222120191817161514131211109876543210
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

CheckNonStreamingSVEEnabled(); constant integer VL = CurrentVL; constant integer PL = VL DIV 8; bits(PL) ffr = FFR[PL]; P[d, PL] = ffr;

Operational information

If FEAT_SVE2 is implemented or FEAT_SME is implemented, then when PSTATE.DIT is 1:


Internal version only: isa v33.53, AdvSIMD v29.11, pseudocode v2022-09_rel, sve v2022-09_rel ; Build timestamp: 2022-09-30T16:37

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