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.
Green
False
True
SM_0_only
0
0
1
0
0
1
0
1
0
0
0
1
1
0
0
1
1
1
1
1
0
0
0
0
0
0
0
0
RDFFR <Pd>.B
if !IsFeatureImplemented(FEAT_SVE) then UNDEFINED;
constant integer d = UInt(Pd);
<Pd>
Is the name of the destination scalable predicate register, encoded in the "Pd" field.
CheckNonStreamingSVEEnabled();
constant integer VL = CurrentVL;
constant integer PL = VL DIV 8;
constant bits(PL) ffr = FFR[PL];
P[d, PL] = ffr;