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BPIALL: Branch Predictor Invalidate All

Purpose

Invalidate all entries from branch predictors.

Configuration

This instruction is present only when FEAT_AA32EL1 is implemented. Otherwise, direct accesses to BPIALL are UNDEFINED.

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

This instruction has no applicable fields.

The value in the register specified by <Rt> is ignored.

Executing BPIALL

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 in the System instruction encoding space:

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

coprocopc1CRnCRmopc2
0b11110b0000b01110b01010b110

if !IsFeatureImplemented(FEAT_AA32EL1) then UNDEFINED; elsif PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && HSTR_EL2.T7 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2) && HSTR.T7 == '1' then AArch32.TakeHypTrapException(0x03); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2) && HCR.FB == '1' then BPIALLIS(); else BPIALL(); elsif PSTATE.EL == EL2 then BPIALL(); elsif PSTATE.EL == EL3 then BPIALL();