LSE (Atomics) Instructions

19 ARM instructions in this extension - click any row for encoding, pseudocode, and full documentation.

Mnemonic ⇅ Syntax Format ⇅ Summary
cas CAS <Ws>, <Wt>, [<Xn|SP>] Atomic Atomic Compare and Swap (32-bit).
cas CAS <Xs>, <Xt>, [<Xn|SP>] Atomic Atomic Compare and Swap (64-bit).
casa CASA <Ws>, <Wt>, [<Xn|SP>] Atomic Atomic CAS with Acquire semantics.
casal CASAL <Ws>, <Wt>, [<Xn|SP>] Atomic Atomic CAS with Acquire and Release semantics.
casl CASL <Ws>, <Wt>, [<Xn|SP>] Atomic Atomic CAS with Release semantics.
casp CASP <Ws>, <W(s+1)>, <Wt>, <W(t+1)>, [<Xn|SP>] Atomic Atomic CAS of a pair of registers (128-bit or 64-bit pair).
ld64b LD64B <Xt>, [<Xn|SP>] Load/Store Loads a 64-byte block of data atomically (Accelerator support).
ldadd LDADD <Ws>, <Wt>, [<Xn|SP>] Atomic Atomic add to memory, return old value.
ldclr LDCLR <Ws>, <Wt>, [<Xn|SP>] Atomic Atomic bit clear (AND NOT) to memory.
ldeor LDEOR <Ws>, <Wt>, [<Xn|SP>] Atomic Atomic XOR to memory.
ldset LDSET <Ws>, <Wt>, [<Xn|SP>] Atomic Atomic bit set (OR) to memory.
ldsmax LDSMAX <Ws>, <Wt>, [<Xn|SP>] Atomic Atomic signed max to memory.
ldsmin LDSMIN <Ws>, <Wt>, [<Xn|SP>] Atomic Atomic signed min to memory.
ldumax LDUMAX <Ws>, <Wt>, [<Xn|SP>] Atomic Atomic unsigned max to memory.
ldumin LDUMIN <Ws>, <Wt>, [<Xn|SP>] Atomic Atomic unsigned min to memory.
st64b ST64B <Xt>, [<Xn|SP>] Load/Store Stores a 64-byte block of data atomically.
st64bv ST64BV <Ws>, <Xt>, [<Xn|SP>] Load/Store Stores 64 bytes atomically and returns status (Success/Fail).
st64bv0 ST64BV0 <Ws>, <Xt>, [<Xn|SP>] Load/Store Stores 64 bytes (eliding the first 8 bytes as zero) and returns status.
swp SWP <Ws>, <Wt>, [<Xn|SP>] Atomic Atomic swap of a word.