20.178 SQDMULH (vector, by element)

Signed saturating Doubling Multiply returning High half (by element).

Syntax

SQDMULH Vd.T, Vn.T, Vm.Ts[index]

Where:

Vd
Is the name of the SIMD and FP destination register.
T
Is an arrangement specifier, and can be one of the values shown in Usage.
Vn
Is the name 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 returning High half (by element). This instruction multiplies each vector element in 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 most significant half of the final results into a vector, and writes the vector to the destination SIMD and FP register.

The results are truncated. For rounded results, see 20.187 SQRDMULH (vector, by element).

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 20-61 SQDMULH (Vector) specifier combinations

T Ts index
4H H 0 to 7
8H H 0 to 7
2S S 0 to 3
4S S 0 to 3
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