SETFFR

Initialize the first-fault register to all true

This instruction initializes the first-fault register (FFR) to all true prior to a sequence of first-fault or non-fault loads. This instruction is unpredicated.

This instruction is illegal when executed in Streaming SVE mode, unless FEAT_SME_FA64 is implemented and enabled.

SVE
(FEAT_SVE)

313029282726252423222120191817161514131211109876543210
00100101001011001001000000000000
opc

Encoding

SETFFR

Decode for this encoding

if !IsFeatureImplemented(FEAT_SVE) then EndOfDecode(Decode_UNDEF); end;

Operation

CheckNonStreamingSVEEnabled(); let VL : integer{} = CurrentVL(); let PL : integer{} = VL DIV 8; FFR{PL}() = Ones{PL};


2026-03_rel 2026-03-26 20:48:11

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