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# BPIALL, Branch Predictor Invalidate All

The BPIALL characteristics are:

## Purpose

Invalidate all entries from branch predictors.

## Configuration

In an implementation where the branch predictors are architecturally invisible, this instruction can execute as a NOP.

## Attributes

BPIALL is a 32-bit System instruction.

## Field descriptions

BPIALL ignores the value in the register specified by the instruction encoding. Software does not have to write a value to the register before issuing this instruction.

## Executing the BPIALL instruction

The PE ignores the value of <Rt>. Software does not have to write a value to this register before issuing this instruction.

When HCR.FB is 1, at Non-secure EL1 this instruction executes as a BPIALLIS.

Accesses to this instruction use the following encodings:

#### MCR{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>}

coproc | opc1 | CRn | CRm | opc2
--- | --- | --- | --- | ---
0b1111 | 0b000 | 0b0111 | 0b0101 | 0b110

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T7 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T7 == '1' then AArch32.TakeHypTrapException(0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HCR.FB == '1' then BPIALLIS(); else BPIALL(); elsif PSTATE.EL == EL2 then BPIALL(); elsif PSTATE.EL == EL3 then BPIALL();

AArch32 Registers | AArch64 Registers | AArch32 Instructions | AArch64 Instructions | Index by Encoding | External Registers | External Registers by Offset | Registers by Functional Group | Proprietary Notice

27/03/2019 21:59; e5e4db499bf9867a4b93324c4dbac985d3da9376

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