fallback: legalize: G

fallback: legalize: G_SUB <4 x s64>

Run:	explore-04ca53e65f-20261014-114124
Kind:	fallback
Category:	legalize: G_SUB <4 x s64>
Occurrences:	16 in 4 configs, 2 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 04ca53e65f
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 (16):

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`
srem-vector-lkk.24fd01bee2.ll (mutant of srem-vector-lkk.ll)	dont_fold_srem_i64	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
srem-vector-lkk.3b4c93368e.ll (mutant of srem-vector-lkk.ll)	dont_fold_srem_i64	`-mtriple=riscv64 -mattr=+m -verify-machineinstrs`
srem-vector-lkk.69d46f671e.ll (mutant of srem-vector-lkk.ll)	dont_fold_srem_i64	`-mtriple=riscv64 -verify-machineinstrs`
srem-vector-lkk.88b5b1ed60.ll (mutant of srem-vector-lkk.ll)	dont_fold_srem_i64	`-mtriple=riscv32 -verify-machineinstrs`
urem-vector-lkk.01cbfc66ed.ll (mutant of urem-vector-lkk.ll)	fold_urem_i64	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
urem-vector-lkk.10dbcc42a5.ll (mutant of urem-vector-lkk.ll)	fold_urem_i64	`-mtriple=riscv64 -mattr=+m -verify-machineinstrs`
urem-vector-lkk.1e8c9fcadd.ll (mutant of urem-vector-lkk.ll)	fold_urem_i64	`-mtriple=riscv64 -mattr=+m -verify-machineinstrs`
urem-vector-lkk.829869a54f.ll (mutant of urem-vector-lkk.ll)	fold_urem_i64	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
urem-vector-lkk.98177d7128.ll (mutant of urem-vector-lkk.ll)	fold_urem_i64	`-mtriple=riscv64 -verify-machineinstrs`
urem-vector-lkk.982e8409d7.ll (mutant of urem-vector-lkk.ll)	fold_urem_i64	`-mtriple=riscv32 -verify-machineinstrs`
urem-vector-lkk.bcbaa306be.ll (mutant of urem-vector-lkk.ll)	fold_urem_i64	`-mtriple=riscv32 -verify-machineinstrs`
urem-vector-lkk.f42704128b.ll (mutant of urem-vector-lkk.ll)	fold_urem_i64	`-mtriple=riscv64 -verify-machineinstrs`

Generated 2026-10-15 08:05 UTC.