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MSUBPT -- A64

MSUBPT

Multiply-subtract checked pointer

This instruction multiplies two register values, subtracts the product from a third register value, and writes the result to the destination register. The intermediate product is treated as the offset.

If the operation would have generated a result where the most significant 8 bits of the result register differ from the most significant 8 bits of the base register, then the result is modified such that it is likely to be non-canonical when used as an address.

If the intermediate product cannot be correctly represented as a 64-bit two's complement value, then the result is modified such that it is likely to be non-canonical when used as an address.

Integer
(FEAT_CPA)

313029282726252423222120191817161514131211109876543210
10011011011Rm1RaRnRd
sfop54op31o0

Encoding

MSUBPT <Xd>, <Xn>, <Xm>, <Xa>

Decode for this encoding

if !IsFeatureImplemented(FEAT_CPA) then EndOfDecode(Decode_UNDEF); end; let d : integer{} = UInt(Rd); let n : integer{} = UInt(Rn); let m : integer{} = UInt(Rm); let a : integer{} = UInt(Ra);

Assembler Symbols

<Xd>

Is the 64-bit name of the general-purpose destination register, encoded in the "Rd" field.

<Xn>

Is the 64-bit name of the first general-purpose source register holding the multiplicand, encoded in the "Rn" field.

<Xm>

Is the 64-bit name of the second general-purpose source register holding the multiplier, encoded in the "Rm" field.

<Xa>

Is the 64-bit name of the third general-purpose source register holding the minuend, encoded in the "Ra" field.


2025-09_rel_asl1 2026-03-12 12:57:38

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