20.255 UQSHL (vector, register)

Unsigned saturating Shift Left (register).

Syntax

UQSHL Vd.T, Vn.T, Vm.T

Where:

Vd
Is the name of the SIMD and FP destination register.
T
Is an arrangement specifier, and can be one of 8B, 16B, 4H, 8H, 2S, 4S or 2D.
Vn
Is the name of the first SIMD and FP source register.
Vm
Is the name of the second SIMD and FP source register.

Usage

Unsigned saturating Shift Left (register). This instruction takes each element in the vector of the first source SIMD and FP register, shifts the element by a value from the least significant byte of the corresponding element of the second source SIMD and FP register, places the results in a vector, and writes the vector to the destination SIMD and FP register.

If the shift value is positive, the operation is a left shift. Otherwise, it is a right shift. The results are truncated. For rounded results, see 20.252 UQRSHL (vector).

If overflow occurs with any of the results, those results are saturated. If saturation occurs, the cumulative saturation bit FPSR.QC is set.

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.

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