Single-copy atomic 64-byte EL0 store with status result
This instruction stores eight 64-bit doublewords from consecutive registers 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 store starts at register Xt, with the data being formed as Data[511:0] = X(t+7)::X(t+6)::X(t+5)::X(t+4)::X(t+3)::X(t+2)::X(t+1)::Xt[63:32]::ACCDATA_EL1()[31:0]. The data is stored atomically and is required to be 64-byte aligned.
It is IMPLEMENTATION DEFINED which memory locations support this instruction. A memory location that supports ST64BV0 also supports ST64BV.
For more information, including about the memory types accessible and how the accesses are performed, see Single-copy atomic 64-byte load/store.
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | Rs | 1 | 0 | 1 | 0 | 0 | 0 | Rn | Rt | ||||||||||||
| size | VR | A | R | o3 | opc | ||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_LS64_ACCDATA) then EndOfDecode(Decode_UNDEF); end; if Rt[4:3] == '11' || Rt[0] == '1' then EndOfDecode(Decode_UNDEF); end; let withstatus : boolean = TRUE; let s : integer{} = UInt(Rs); let t : integer{} = UInt(Rt); let n : integer{} = UInt(Rn); let tagchecked : boolean = n != 31;
| <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. |
CheckST64BV0Enabled(); var data : bits(512); var address : bits(64); var value : bits(64); let accdesc : AccessDescriptor = CreateAccDescLS64(MemOp_STORE, withstatus, tagchecked); let Xt : bits(64) = X{}(t); value[31:0] = ACCDATA_EL1()[31:0]; value[63:32] = Xt[63:32]; if BigEndian(accdesc.acctype) then value = BigEndianReverse{64}(value); end; data[63:0] = value; for i = 1 to 7 do value = X{64}(t+i); if BigEndian(accdesc.acctype) then value = BigEndianReverse{64}(value); end; data[63+64*i : 64*i] = value; end; if n == 31 then CheckSPAlignment(); address = SP{64}(); else address = X{64}(n); end; let status : bits(64) = MemStore64BWithRet(address, data, accdesc); if s != 31 then X{64}(s) = status; end;
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