sw.aqrl

Store Word Acquire Release

This instruction is defined by:

Encoding

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Synopsis

Store the lowest 32 bits of register xs2 to the address in xs1.

This instruction has both acquire and release semantics. No subsequent memory operations (in program order) from this hart can be observed to occur before this store completes, and no previous memory operations can be observed to occur after this store completes.

The address must be naturally aligned (4-byte aligned); if not, an address-misaligned or access-fault exception will be raised.

Access

M HS U VS VU

Always

Always

Always

Always

Always

Decode Variables

Bits<5> xs2 = $encoding[24:20];
Bits<5> xs1 = $encoding[19:15];

Execution

  • Pruned, XLEN == 64

  • Original

XReg virtual_address = X[xs1];
if (!is_naturally_aligned(32, virtual_address)) {
  raise(ExceptionCode::StoreAmoAddressMisaligned, mode(), virtual_address);
}
write_memory_aligned(32, virtual_address, X[xs2][31:0], $encoding, 1'b1, 1'b1);
XReg virtual_address = X[xs1];
if (!is_naturally_aligned(32, virtual_address)) {
  raise(ExceptionCode::StoreAmoAddressMisaligned, mode(), virtual_address);
}
write_memory_aligned(32, virtual_address, X[xs2][31:0], $encoding, 1'b1, 1'b1);

Exceptions

This instruction may result in the following synchronous exceptions:

  • LoadAccessFault

  • StoreAmoAccessFault

  • StoreAmoAddressMisaligned

  • StoreAmoPageFault