Arm® A64 Instruction Set Architecture: Armv8, for Armv8-A architecture profile

ADDPL

Add multiple of predicate register size to scalar register.

Add the current predicate register size in bytes multiplied by an immediate in the range -32 to 31 to the 64-bit source general-purpose register or current stack pointer and place the result in the 64-bit destination general-purpose register or current stack pointer.

if !HaveSVE() then UNDEFINED;
integer n = UInt(Rn);
integer d = UInt(Rd);
integer imm = SInt(imm6);

Assembler Symbols

CheckSVEEnabled();
bits(64) operand1 = if n == 31 then SP[] else X[n];
bits(64) result = operand1 + (imm * (PL DIV 8));

if d == 31 then
    SP[] = result;
else
    X[d] = result;