convertFixedMaskToScalableVector expects the mask input to honour the BoolContents scheme employed by the target. For AArch64 this means a mask should be zero or all ones, and thus when promoting a mask we must use a sign extend.
convertFixedMaskToScalableVector expects the mask input to honour the BoolContents scheme employed by the target. For AArch64 this means a mask should be zero or all ones, and thus when promoting a mask we must use a sign extend.