RCWCLRP, RCWCLRPA, RCWCLRPAL, RCWCLRPL

Read check write atomic bit clear on quadword in memory

This instruction atomically loads a 128-bit quadword from memory, performs a bitwise AND with the complement of the value held in a pair of registers on it, and conditionally stores the result back to memory. Storing of the result back to memory is conditional on RCW Checks. The value initially loaded from memory is returned in the same pair of registers. This instruction updates the condition flags based on the result of the update of memory.

• RCWCLRPA and RCWCLRPAL load from memory with acquire semantics.
• RCWCLRPL and RCWCLRPAL store to memory with release semantics.
• RCWCLRP has neither acquire nor release semantics.

Integer
(FEAT_D128 && FEAT_THE)

Decode for all variants of this encoding

if !IsFeatureImplemented(FEAT_D128) || !IsFeatureImplemented(FEAT_THE) then EndOfDecode(Decode_UNDEF); end; if Rt == '11111' then EndOfDecode(Decode_UNDEF); end; if Rt2 == '11111' then EndOfDecode(Decode_UNDEF); end; let t : integer{} = UInt(Rt); let t2 : integer{} = UInt(Rt2); let n : integer{} = UInt(Rn); let soft : boolean = FALSE; let acquire : boolean = A == '1'; let release : boolean = R == '1'; let tagchecked : boolean = n != 31; var rt_unknown : boolean = FALSE; if t == t2 then let c : Constraint = ConstrainUnpredictable(Unpredictable_LSE128OVERLAP); assert c IN {Constraint_UNKNOWN, Constraint_UNDEF, Constraint_NOP}; case c of when Constraint_UNKNOWN => rt_unknown = TRUE; // result is UNKNOWN when Constraint_UNDEF => EndOfDecode(Decode_UNDEF); when Constraint_NOP => EndOfDecode(Decode_NOP); end; end;

Assembler Symbols