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


Internal version only: isa v33.64, AdvSIMD v29.12, pseudocode v2023-06_rel, sve v2023-06_rel ; Build timestamp: 2023-07-04T19:42

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