ST64BV0

Single-copy Atomic 64-byte EL0 Store with Return stores eight 64-bit doublewords from consecutive registers, Xt to X(t+7), to a memory location, with the bottom 32 bits taken from ACCDATA_EL1, and writes the status result of the store to a register. The data that is stored is atomic and is required to be 64-byte aligned.

Integer
(FEAT_LS64_V)

313029282726252423222120191817161514131211109876543210
11111000001Rs101000RnRt

ST64BV0 <Xs>, <Xt>, [<Xn|SP>]

if !HaveFeatLS64() then UNDEFINED; if Rt<4:3> == '11' || Rt<0> == '1' then UNDEFINED; integer n = UInt(Rn); integer t = UInt(Rt); integer s = UInt(Rs); boolean tag_checked = n != 31;

Assembler Symbols

<Xs>

Is the 64-bit name of the general-purpose register into which the status result of this instruction is written, encoded in the "Rs" field.

The value returned is:

0xFFFFFFFF_FFFFFFFF
If the memory location accessed does not support this instruction. In this case, the value at the memory location is UNKNOWN.
!= 0xFFFFFFFF_FFFFFFFF
If the memory location accessed does support this instruction. In this case, the peripheral that provides the response defines the returned value and provides information on the state of the memory update at the memory location.

If XZR is used, then the return value is ignored.

<Xt>

Is the 64-bit name of the first general-purpose register to be transferred, encoded in the "Rt" field.

<Xn|SP>

Is the 64-bit name of the general-purpose base register or stack pointer, encoded in the "Rn" field.

Operation

CheckST64BV0Enabled(); bits(512) data; bits(64) address; bits(64) value; bits(64) status; acctype = AccType_ATOMICLS64; if HaveMTE2Ext() then SetTagCheckedInstruction(tag_checked); bits(64) Xt = X[t]; value<31:0> = ACCDATA_EL1<31:0>; value<63:32> = Xt<63:32>; if BigEndian(acctype) then value = BigEndianReverse(value); data<63:0> = value; for i = 1 to 7 value = X[t+i]; if BigEndian(acctype) then value = BigEndianReverse(value); data<63+64*i : 64*i> = value; if n == 31 then CheckSPAlignment(); address = SP[]; else address = X[n]; status = MemStore64BWithRet(address, data, acctype); if s != 31 then X[s] = status;


Internal version only: isa v33.11seprel, AdvSIMD v29.05, pseudocode v2021-09_rel, sve v2021-09_rc3d ; Build timestamp: 2021-10-06T11:41

Copyright © 2010-2021 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.