fallback: legalize: G_INSERT_SUBVECTOR <vscale x 1 x s32>,<2 x s32>

Snippet:

define <2 x i32> @and_add_lsr_vec(<2 x i32> %x, <2 x i32> %y) {
  %1 = add <2 x i32> %x, splat (i32 4095)
  %2 = lshr <2 x i32> %y, splat (i32 20)
  %r = and <2 x i32> %2, %1
  ret <2 x i32> %r
}

Reproduce:

llc -mtriple=riscv32 -verify-machineinstrs -mattr=+v -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv32 -verify-machineinstrs -mattr=+v -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %12:_(<vscale x 1 x s32>) = G_INSERT_SUBVECTOR %11:_, %10:_(<2 x s32>), 0 (in function: and_add_lsr_vec)
warning: Instruction selection used fallback path for and_add_lsr_vec

Occurrences (6):

Generated 2026-10-15 08:05 UTC.