Store register (immediate)
This instruction stores a word or a doubleword from a register to memory. The address that is used for the store is calculated from a base register and an immediate offset. For information about addressing modes, see Load/Store addressing modes.
It has encodings from 3 classes: Post-index , Pre-index and Unsigned offset
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| 1 | x | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | imm9 | 0 | 1 | Rn | Rt | ||||||||||||||||
| size | VR | opc | |||||||||||||||||||||||||||||
constant boolean wback = TRUE; constant boolean postindex = TRUE; constant integer scale = UInt(size); constant bits(64) offset = SignExtend(imm9, 64);
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| 1 | x | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | imm9 | 1 | 1 | Rn | Rt | ||||||||||||||||
| size | VR | opc | |||||||||||||||||||||||||||||
constant boolean wback = TRUE; constant boolean postindex = FALSE; constant integer scale = UInt(size); constant bits(64) offset = SignExtend(imm9, 64);
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| 1 | x | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | imm12 | Rn | Rt | |||||||||||||||||||
| size | VR | opc | |||||||||||||||||||||||||||||
constant boolean wback = FALSE; constant boolean postindex = FALSE; constant integer scale = UInt(size); constant bits(64) offset = LSL(ZeroExtend(imm12, 64), scale);
| <Wt> |
Is the 32-bit name of the 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. |
| <simm> |
Is the signed immediate byte offset, in the range -256 to 255, encoded in the "imm9" field. |
| <Xt> |
Is the 64-bit name of the general-purpose register to be transferred, encoded in the "Rt" field. |
constant integer t = UInt(Rt); constant integer n = UInt(Rn); constant integer datasize = 8 << scale; constant boolean nontemporal = FALSE; constant boolean tagchecked = wback || n != 31; Constraint c; boolean rt_unknown = FALSE; if wback && n == t && n != 31 then c = ConstrainUnpredictable(Unpredictable_WBOVERLAPST); assert c IN {Constraint_NONE, Constraint_UNKNOWN, Constraint_UNDEF, Constraint_NOP}; case c of when Constraint_NONE rt_unknown = FALSE; // Value stored is original value when Constraint_UNKNOWN rt_unknown = TRUE; // Value stored is UNKNOWN when Constraint_UNDEF EndOfDecode(Decode_UNDEF); when Constraint_NOP EndOfDecode(Decode_NOP);
bits(64) address; constant boolean privileged = PSTATE.EL != EL0; constant AccessDescriptor accdesc = CreateAccDescGPR(MemOp_STORE, nontemporal, privileged, tagchecked); if n == 31 then CheckSPAlignment(); address = SP[64]; else address = X[n, 64]; if !postindex then address = AddressAdd(address, offset, accdesc); bits(datasize) data; if rt_unknown then data = bits(datasize) UNKNOWN; else data = X[t, datasize]; Mem[address, datasize DIV 8, accdesc] = data; if wback then if postindex then address = AddressAdd(address, offset, accdesc); if n == 31 then SP[64] = address; else X[n, 64] = address;
If PSTATE.DIT is 1, the timing of this instruction is insensitive to the value of the data being loaded or stored.
Internal version only: aarchmrs v2024-12_rel, pseudocode v2024-12_rel ; Build timestamp: 2024-12-15T22:18
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