LDR (literal)

Load Register (literal) calculates an address from the PC value and an immediate offset, loads a word from memory, and writes it to a register. For information about memory accesses, see Load/Store addressing modes.

313029282726252423222120191817161514131211109876543210
0x011000imm19Rt
opcVR

32-bit (opc == 00)

LDR <Wt>, <label>

64-bit (opc == 01)

LDR <Xt>, <label>

integer t = UInt(Rt); MemOp memop = if opc == '11' then MemOp_PREFETCH else MemOp_LOAD; constant integer size = 4 << UInt(opc<0>); boolean signed = opc == '10'; bits(64) offset = SignExtend(imm19:'00', 64);

Assembler Symbols

<Wt>

Is the 32-bit name of the general-purpose register to be loaded, encoded in the "Rt" field.

<label>

Is the program label from which the data is to be loaded. Its offset from the address of this instruction, in the range +/-1MB, is encoded as "imm19" times 4.

<Xt>

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

Operation

bits(64) address = PC64 + offset; bits(size*8) data; boolean privileged = PSTATE.EL != EL0; AccessDescriptor accdesc = CreateAccDescGPR(memop, FALSE, privileged, FALSE); case memop of when MemOp_LOAD data = Mem[address, size, accdesc]; if signed then X[t, 64] = SignExtend(data, 64); else X[t, size*8] = data; when MemOp_PREFETCH Prefetch(address, t<4:0>);

Operational information

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 v2023-12_rel, pseudocode v2023-12_rel, sve v2023-12_rel ; Build timestamp: 2023-12-15T16:46

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