STZGM

Store Tag and Zero Multiple writes a naturally aligned block of N Allocation Tags and stores zero to the associated data locations, where the size of N is identified in DCZID_EL0.BS, and the Allocation Tag written to address A is taken from the source register bits<3:0>.

This instruction is undefined at EL0.

This instruction generates an Unchecked access.

Integer
(FEAT_MTE2)

313029282726252423222120191817161514131211109876543210
1101100100100000000000XnXt

STZGM <Xt>, [<Xn|SP>]

if !HaveMTE2Ext() then UNDEFINED; integer t = UInt(Xt); integer n = UInt(Xn);

Assembler Symbols

<Xt>

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

<Xn|SP>

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

Operation

if PSTATE.EL == EL0 then UNDEFINED; bits(64) data = X[t]; bits(4) tag = data<3:0>; bits(64) address; if n == 31 then CheckSPAlignment(); address = SP[]; else address = X[n]; integer size = 4*(2^(UInt(DCZID_EL0.BS))); address = Align(address,size); integer count = size >> LOG2_TAG_GRANULE; for i = 0 to count-1 AArch64.MemTag[address, AccType_NORMAL] = tag; Mem[address, TAG_GRANULE, AccType_NORMAL] = Zeros(8*TAG_GRANULE); address = address + TAG_GRANULE;


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

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