You copied the Doc URL to your clipboard.

ARM Compiler armasm User Guide : LSL (immediate)

LSL (immediate)

Logical Shift Left (immediate).

This instruction is an alias of UBFM.

Syntax

LSL Wd, Wn, #shift ; 32-bit general registers

Equivalent to UBFM Wd, Wn, #(-shift MOD 32), #(31-shift).

LSL Xd, Xn, #shift ; 64-bit general registers

Equivalent to UBFM Xd, Xn, #(-shift MOD 64), #(63-shift).

Where:

Wd

Is the 32-bit name of the general-purpose destination register.

Wn

Is the 32-bit name of the general-purpose source register.

shift

Depends on the instruction variant:

32-bit general registers

Is the shift amount, in the range 0 to 31.

64-bit general registers

Is the shift amount, in the range 0 to 63.

Xd

Is the 64-bit name of the general-purpose destination register.

Xn

Is the 64-bit name of the general-purpose source register.

Operation

Logical Shift Left (immediate) shifts a register value left by an immediate number of bits, shifting in zeros, and writes the result to the destination register.

Rd = LSL(Rn, shift), where R is either W or X.

Was this page helpful? Yes No