fallback: legalize: G_INSERT_VECTOR_ELT <4 x s16>,s16,s32

Run:main-04ca53e65f-20261014-113325
Kind:fallback
Category:legalize: G_INSERT_VECTOR_ELT <4 x s16>,s16,s32 NEW
Occurrences:4 in 2 configs, 2 test files
Snippet from:urem-vector-lkk.b8dd432fd9.ll (mutant of urem-vector-lkk.ll) @dont_fold_urem_i16_smax via llvm-extract
Config:-mtriple=riscv32 -mattr=+m -verify-machineinstrs
Local check:reproduces at 04ca53e65f
Compiler Explorer:not uploaded (over --godbolt-limit or disabled)

Snippet:

; Function Attrs: nounwind
define <4 x i16> @dont_fold_urem_i16_smax(<4 x i16> %x) #0 {
  %1 = urem <4 x i16> %x, <i16 1, i16 0, i16 23, i16 5423>
  %I = insertelement <4 x i16> %x, i16 1, i64 0
  store <4 x i16> %I, ptr poison, align 8
  ret <4 x i16> %1
}

attributes #0 = { nounwind }

Reproduce:

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

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %9:_(<4 x s16>) = G_INSERT_VECTOR_ELT %0:_, %4:_(s16), %10:_(s32) (in function: dont_fold_urem_i16_smax)
warning: Instruction selection used fallback path for dont_fold_urem_i16_smax

Occurrences (4):

InputFunctionConfig
srem-vector-lkk.118f993e47.ll (mutant of srem-vector-lkk.ll)dont_fold_urem_i16_smax-mtriple=riscv32 -mattr=+m -verify-machineinstrs
srem-vector-lkk.bb658332e2.ll (mutant of srem-vector-lkk.ll)dont_fold_urem_i16_smax-mtriple=riscv32 -verify-machineinstrs
urem-vector-lkk.b8dd432fd9.ll (mutant of urem-vector-lkk.ll)dont_fold_urem_i16_smax-mtriple=riscv32 -mattr=+m -verify-machineinstrs
urem-vector-lkk.ce5e56b10e.ll (mutant of urem-vector-lkk.ll)dont_fold_urem_i16_smax-mtriple=riscv32 -verify-machineinstrs

Generated 2026-10-15 08:05 UTC.