All instructionsArm64 · AArch64Memory

LDRSH

Load with sign extension

Load values through a 64-bit base address, with the selected byte offset and writeback behavior.

Armv8-A

Instruction forms

2 in this sample
FormBitsRequiresEncoding
LDRSH Wt, [Xn|SP{, #offset}]32Armv8-A0111100111xxxxxxxxxxxxxxxxxxxxxx
LDRSH Xt, [Xn|SP{, #offset}]64Armv8-A0111100110xxxxxxxxxxxxxxxxxxxxxx
32 bits

Operation

Pseudo-C · selected form
old_base = base
address = (old_base + offset) mod 2^64
Rt = sign_extend(Load16(address), 32)

Simplified pseudocode for the selected form.

What to watch for

  • The base is X0–X30 or SP. The data register may be ZR; loads to ZR still access memory, and stores from ZR supply zero.
  • The operation describes successful ordinary accesses. Data endianness, translation, permissions, alignment and applicable tag checks still apply. No acquire/release ordering is implied.
  • The loaded value is sign-extended to Wt, then the W write clears Xt[63:32]. It is not sign-extended to 64 bits.

Architectural details

Flags
NZCV unchanged.
Destination
Writes data register; each W write clears the corresponding X upper half. No base writeback.
Encoding
0111100111xxxxxxxxxxxxxxxxxxxxxx
Operands
  • Wtwrite · 32 bits · signed
  • Xn|SPread · 64 bits
  • offsetread
  • memory at addressread · 16 bits · signed
Coverage
Selected general-register memory forms with explicitly shown widths and addressing. Register-offset, literal, exclusive, acquire/release and vector forms are outside this selection.
offset
0 to 8190, in steps of 2.
Exception information & execution requirements

    Complete exception conditions have not been imported.

    MRS supplies encoding and availability conditions, not an exhaustive exception model.

    Feature availability alone does not guarantee execution: OS state and execution-level controls also apply. Use the linked architecture documentation for the full exception conditions.

    Performance measurements are not included in this preview. Latency and throughput depend on the exact form and microarchitecture.

    Sources & provenance

    Technical fields are imported from pinned upstream files. Explanations and explorer behavior are maintained separately.

    Architectural references for this form

    These references support the original explanation. Arm MRS supplies encoding patterns (bit 31 first; x means variable) and architectural conditions, but omits execution pseudocode. ACLE supplies intrinsic mappings. Operand restrictions apply separately.

    Arm · aarchmrs
    Revision
    2026-03_rel
    SHA-256
    bf355d263eed08ef6b3e4e680e6bba3642fa7c3dd0be77ffb4783420041a0860
    Terms
    BSD-3-Clause
    View pinned upstream file ↗

    Intel sources are a documentation preview. Arm ACLE mappings are adapted under CC BY-SA 4.0 with an additional patent license. Arm MRS encoding data is distributed under BSD-3-Clause. © Arm Limited and contributors. Coverage and attribution.