VBIF

Vector Bitwise Insert if False inserts each bit from the first source register into the destination register if the corresponding bit of the second source register is 0, otherwise leaves the bit in the destination register unchanged.

Depending on settings in the CPACR, NSACR, and HCPTR registers, and the Security state and PE mode in which the instruction is executed, an attempt to execute the instruction might be undefined, or trapped to Hyp mode. For more information see Enabling Advanced SIMD and floating-point support.

It has encodings from the following instruction sets: A32 ( A1 ) and T32 ( T1 ) .

A1

313029282726252423222120191817161514131211109876543210
111100110D11VnVd0001NQM1Vm
op

64-bit SIMD vector (Q == 0)

VBIF{<c>}{<q>}{.<dt>} {<Dd>,} <Dn>, <Dm>

128-bit SIMD vector (Q == 1)

VBIF{<c>}{<q>}{.<dt>} {<Qd>,} <Qn>, <Qm>

if Q == '1' && (Vd<0> == '1' || Vn<0> == '1' || Vm<0> == '1') then UNDEFINED; if op == '00' then SEE "VEOR"; if op == '01' then operation = VBitOps_VBSL; if op == '10' then operation = VBitOps_VBIT; if op == '11' then operation = VBitOps_VBIF; constant d = UInt(D:Vd); constant n = UInt(N:Vn); constant m = UInt(M:Vm); constant regs = if Q == '0' then 1 else 2;

T1

15141312111098765432101514131211109876543210
111111110D11VnVd0001NQM1Vm
op

64-bit SIMD vector (Q == 0)

VBIF{<c>}{<q>}{.<dt>} {<Dd>,} <Dn>, <Dm>

128-bit SIMD vector (Q == 1)

VBIF{<c>}{<q>}{.<dt>} {<Qd>,} <Qn>, <Qm>

if Q == '1' && (Vd<0> == '1' || Vn<0> == '1' || Vm<0> == '1') then UNDEFINED; if op == '00' then SEE "VEOR"; if op == '01' then operation = VBitOps_VBSL; if op == '10' then operation = VBitOps_VBIT; if op == '11' then operation = VBitOps_VBIF; constant d = UInt(D:Vd); constant n = UInt(N:Vn); constant m = UInt(M:Vm); constant regs = if Q == '0' then 1 else 2;

Assembler Symbols

<c>

For encoding A1: see Standard assembler syntax fields. This encoding must be unconditional.

For encoding T1: see Standard assembler syntax fields.

<q>

See Standard assembler syntax fields.

<dt>

An optional data type. It is ignored by assemblers, and does not affect the encoding.

<Qd>

Is the 128-bit name of the SIMD&FP destination register, encoded in the "D:Vd" field as <Qd>*2.

<Qn>

Is the 128-bit name of the first SIMD&FP source register, encoded in the "N:Vn" field as <Qn>*2.

<Qm>

Is the 128-bit name of the second SIMD&FP source register, encoded in the "M:Vm" field as <Qm>*2.

<Dd>

Is the 64-bit name of the SIMD&FP destination register, encoded in the "D:Vd" field.

<Dn>

Is the 64-bit name of the first SIMD&FP source register, encoded in the "N:Vn" field.

<Dm>

Is the 64-bit name of the second SIMD&FP source register, encoded in the "M:Vm" field.

Operation

if ConditionPassed() then EncodingSpecificOperations(); CheckAdvSIMDEnabled(); for r = 0 to regs-1 case operation of when VBitOps_VBIF D[d+r] = (D[d+r] AND D[m+r]) OR (D[n+r] AND NOT(D[m+r])); when VBitOps_VBIT D[d+r] = (D[n+r] AND D[m+r]) OR (D[d+r] AND NOT(D[m+r])); when VBitOps_VBSL D[d+r] = (D[n+r] AND D[d+r]) OR (D[m+r] AND NOT(D[d+r]));

Operational information

If CPSR.DIT is 1 and this instruction passes its condition execution check:


Internal version only: isa v01_31, pseudocode v2024-03_rel ; Build timestamp: 2024-03-25T10:05

Copyright © 2010-2024 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.