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LDP (SIMD and FP)

Load Pair of SIMD and FP registers.

Syntax

LDP St1, St2, [Xn|SP], #imm ; 32-bit

LDP Dt1, Dt2, [Xn|SP], #imm ; 64-bit

LDP Qt1, Qt2, [Xn|SP], #imm ; 128-bit FP/SIMD registers, Post-index

LDP St1, St2, [Xn|SP, #imm]! ; 32-bit

LDP Dt1, Dt2, [Xn|SP, #imm]! ; 64-bit

LDP Qt1, Qt2, [Xn|SP, #imm]! ; 128-bit FP/SIMD registers, Pre-index

LDP St1, St2, [Xn|SP{, #imm}] ; 32-bit

LDP Dt1, Dt2, [Xn|SP{, #imm}] ; 64-bit

LDP Qt1, Qt2, [Xn|SP{, #imm}] ; 128-bit FP/SIMD registers, Signed offset

Where:

St1
Is the 32-bit name of the first SIMD and FP register to be transferred.
St2
Is the 32-bit name of the second SIMD and FP register to be transferred.
imm

Depends on the instruction variant:

32-bit FP/SIMD registers
Is the signed immediate byte offset, a multiple of 4 in the range -256 to 252.
64-bit FP/SIMD registers
Is the signed immediate byte offset, a multiple of 8 in the range -512 to 504.
128-bit FP/SIMD registers
Is the signed immediate byte offset, a multiple of 16 in the range -1024 to 1008.
Dt1
Is the 64-bit name of the first SIMD and FP register to be transferred.
Dt2
Is the 64-bit name of the second SIMD and FP register to be transferred.
Qt1
Is the 128-bit name of the first SIMD and FP register to be transferred.
Qt2
Is the 128-bit name of the second SIMD and FP register to be transferred.
Xn|SP
Is the 64-bit name of the general-purpose base register or stack pointer.

Usage

Load Pair of SIMD and FP registers. This instruction loads a pair of SIMD and FP registers from memory. The address that is used for the load is calculated from a base register value and an optional immediate offset.

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.

Note

For information about the constrained unpredictable behavior of this instruction, see Architectural Constraints on UNPREDICTABLE behaviors in the ARM Architecture Reference Manual ARMv8, for ARMv8-A architecture profile, and particularly LDP (SIMD and FP).
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