LDTNP (SIMD&FP)

Load unprivileged pair of SIMD&FP registers, with non-temporal hint

This instruction loads a pair of SIMD&FP registers from memory, issuing a hint to the memory system that the access is non-temporal. The address that is used for the load is calculated from a base register value and an optional immediate offset. For information about non-temporal pair instructions, see Load/Store SIMD and Floating-point non-temporal pair.

Depending on the settings in the CPACR_EL1, CPTR_EL2, and CPTR_EL3 registers, and the current Security state and Exception level, an attempt to execute the instruction might be trapped.

Explicit Memory effects produced by the instruction behave as if the instruction was executed at EL0 if the Effective value of PSTATE.UAO is 0 and either:

• The instruction is executed at EL1.
• The instruction is executed at EL2 when the Effective value of HCR_EL2.{E2H, TGE} is {1, 1}.

Otherwise, the Explicit Memory effects operate with the restrictions determined by the Exception level at which the instruction is executed.

Signed offset
(FEAT_FP && FEAT_LSUI)

Decode for this encoding

if !IsFeatureImplemented(FEAT_FP) || !IsFeatureImplemented(FEAT_LSUI) then EndOfDecode(Decode_UNDEF); constant integer t = UInt(Rt); constant integer t2 = UInt(Rt2); constant integer n = UInt(Rn); constant boolean nontemporal = TRUE; constant integer datasize = 128; constant bits(64) offset = LSL(SignExtend(imm7, 64), 4); constant boolean tagchecked = n != 31; boolean rt_unknown = FALSE; if t == t2 then constant Constraint c = ConstrainUnpredictable(Unpredictable_LDPOVERLAP); 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);

Assembler Symbols