fallback: legalize: G_INSERT_SUBVECTOR <vscale x 16 x s32>,<32 x s32>

Run:explore-04ca53e65f-20261014-114124
Kind:fallback
Category:legalize: G_INSERT_SUBVECTOR <vscale x 16 x s32>,<32 x s32>
Occurrences:1 in 1 configs, 1 test files
Snippet from:zero-call-used-regs-v.ll @used_arg_lmul8 via llvm-extract
Config:-verify-machineinstrs -mtriple=riscv64 -mattr=+v
Local check:reproduces at 04ca53e65f
Compiler Explorer:not uploaded (over --godbolt-limit or disabled)

Snippet:

define <32 x i32> @used_arg_lmul8(<32 x i32> %a, <32 x i32> %b) #0 {
entry:
  %sum = add <32 x i32> %a, %b
  ret <32 x i32> %sum
}

attributes #0 = { "zero-call-used-regs"="used-arg" }

Reproduce:

llc -verify-machineinstrs -mtriple=riscv64 -mattr=+v -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -verify-machineinstrs -mtriple=riscv64 -mattr=+v -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %6:_(<vscale x 16 x s32>) = G_INSERT_SUBVECTOR %5:_, %4:_(<32 x s32>), 0 (in function: used_arg_lmul8)
warning: Instruction selection used fallback path for used_arg_lmul8

Occurrences (1):

InputFunctionConfig
zero-call-used-regs-v.llused_arg_lmul8-verify-machineinstrs -mtriple=riscv64 -mattr=+v

Generated 2026-10-15 08:05 UTC.