fallback: legalize: G

fallback: legalize: G_SUB <4 x s64>

Run:	explore-bc8218b282-20261015-075519
Kind:	fallback
Category:	legalize: G_SUB <4 x s64>
Occurrences:	12 in 4 configs, 1 test files
Snippet from:	urem-vector-lkk.ll @fold_urem_i64 via llvm-extract
Config:	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
Local check:	reproduces at bc8218b282
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

; Function Attrs: nounwind
define <4 x i64> @fold_urem_i64(<4 x i64> %x) #0 {
  %1 = urem <4 x i64> %x, <i64 1, i64 654, i64 23, i64 5423>
  ret <4 x i64> %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: %33:_(<4 x s64>) = G_SUB %0:_, %32:_ (in function: fold_urem_i64)
warning: Instruction selection used fallback path for fold_urem_i64

Occurrences (12):

Input	Function	Config
urem-vector-lkk.ll	fold_urem_i64	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
urem-vector-lkk.ll	fold_urem_i64	`-mtriple=riscv32 -verify-machineinstrs`
urem-vector-lkk.ll	fold_urem_i64	`-mtriple=riscv64 -mattr=+m -verify-machineinstrs`
urem-vector-lkk.ll	fold_urem_i64	`-mtriple=riscv64 -verify-machineinstrs`
urem-vector-lkk.09b9b33008.ll (mutant of urem-vector-lkk.ll)	fold_urem_i64	`-mtriple=riscv64 -verify-machineinstrs`
urem-vector-lkk.11d1492271.ll (mutant of urem-vector-lkk.ll)	fold_urem_i64	`-mtriple=riscv64 -verify-machineinstrs`
urem-vector-lkk.274664359c.ll (mutant of urem-vector-lkk.ll)	fold_urem_i64	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
urem-vector-lkk.3d3bfd4dc7.ll (mutant of urem-vector-lkk.ll)	fold_urem_i64	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
urem-vector-lkk.b8493589af.ll (mutant of urem-vector-lkk.ll)	fold_urem_i64	`-mtriple=riscv32 -verify-machineinstrs`
urem-vector-lkk.df8df7dde9.ll (mutant of urem-vector-lkk.ll)	fold_urem_i64	`-mtriple=riscv64 -mattr=+m -verify-machineinstrs`
urem-vector-lkk.e202e23a19.ll (mutant of urem-vector-lkk.ll)	fold_urem_i64	`-mtriple=riscv32 -verify-machineinstrs`
urem-vector-lkk.fe06b4b883.ll (mutant of urem-vector-lkk.ll)	fold_urem_i64	`-mtriple=riscv64 -mattr=+m -verify-machineinstrs`

Generated 2026-10-15 08:05 UTC.