¶void narrowShuffleMaskElts(
    int Scale,
    ArrayRef<int> Mask,
    SmallVectorImpl<int>& ScaledMask)

Description

Replace each shuffle mask index with the scaled sequential indices for an equivalent mask of narrowed elements. Mask elements that are less than 0 (sentinel values) are repeated in the output mask. Example with Scale = 4: < 4 x i32> < 3, 2, 0, -1> --> < 16 x i8> < 12, 13, 14, 15, 8, 9, 10, 11, 0, 1, 2, 3, -1, -1, -1, -1> This is the reverse process of widening shuffle mask elements, but it always succeeds because the indexes can always be multiplied (scaled up) to map to narrower vector elements.

Declared at: llvm/include/llvm/Analysis/VectorUtils.h:380

Parameters

int Scale

ArrayRef<int> Mask

SmallVectorImpl<int>& ScaledMask