setffr

SETFFR

Set First-Fault Register.

Pseudocode Operation

No pseudocode available.

Encoding

Binary Layout
00
31:30
100101
29:24
0
23
0
22
10
21:20
1100100100
19:10
000000
9:4
0
3
0
2
00
1:0
 
Format SVE
Opcode 0x252C9000
Extension SVE

Related

More in SVE

Reference

View in Arm A64 ISA Reference ↗ Arm A64 ISA

Instruction Forms

Encoding Instruction ISA Bit pattern
0x252C9000 SETFFR A64 00 | 100101 | 0 | 0 | 10 | 1100100100 | 000000 | 0 | 0 | 00

Description

Initialise 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.

Operation

CheckNonStreamingSVEEnabled();
constant integer VL = CurrentVL;
constant integer PL = VL DIV 8;
FFR[PL] = Ones(PL);