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SQDMULL (scalar, by element)

Signed saturating Doubling Multiply Long (by element).

Syntax

SQDMULL Vad, Vbn, Vm.Ts[index]

Where:

Va
Is the destination width specifier, and can be either S or D.
d
Is the number of the SIMD and FP destination register.
Vb
Is the source width specifier, and can be either H or S.
n
Is the number of the first SIMD and FP source register.
Vm

Is the name of the second SIMD and FP source register:

  • If Ts is H, then Vm must be in the range V0 to V15.
  • If Ts is S, then Vm must be in the range V0 to V31.
Ts
Is an element size specifier, and can be either H or S.
index
Is the element index, in the range shown in Usage.

Usage

Signed saturating Doubling Multiply Long (by element). This instruction multiplies each vector element in the lower or upper half of the first source SIMD and FP register by the specified vector element of the second source SIMD and FP register, doubles the results, places the final results in a vector, and writes the vector to the destination SIMD and FP register. All the values in this instruction are signed integer values.

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

The SQDMULL instruction extracts the first source vector from the lower half of the first source register, while the SQDMULL2 instruction extracts the first source vector from the upper half of the first source register.

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.

The following table shows the valid specifier combinations:

Table 19-17 SQDMULL (Scalar) specifier combinations

Va Vb Ts index
S H H 0 to 7
D S S 0 to 3
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