fallback: legalize: G

fallback: legalize: G_CLMUL s8

Run:	explore-04ca53e65f-20261014-114124
Kind:	fallback
Category:	legalize: G_CLMUL s8
Occurrences:	140 in 11 configs, 4 test files
Snippet from:	clmul.ll @clmul_i8 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 i8 @clmul_i8(i8 %a, i8 %b) #0 {
  %res = call i8 @llvm.clmul.i8(i8 %a, i8 %b)
  ret i8 %res
}

; Function Attrs: nocallback nocreateundeforpoison nofree nosync nounwind speculatable willreturn memory(none)
declare i8 @llvm.clmul.i8(i8, i8) #1

attributes #0 = { nounwind }
attributes #1 = { nocallback nocreateundeforpoison nofree nosync nounwind speculatable willreturn memory(none) }

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: %4:_(s8) = G_CLMUL %0:_, %1:_ (in function: clmul_i8)
warning: Instruction selection used fallback path for clmul_i8

Occurrences (140) (first 50):

Input	Function	Config
clmul.ll	clmul_i8	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
clmul.ll	commutative_clmul_i8	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
clmul.ll	mul_use_commutative_clmul_i8	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
clmul.ll	neg_commutative_clmul_i8	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
clmul.ll	clmul_i8	`-mtriple=riscv32 -mattr=+m,+zbc -verify-machineinstrs`
clmul.ll	commutative_clmul_i8	`-mtriple=riscv32 -mattr=+m,+zbc -verify-machineinstrs`
clmul.ll	mul_use_commutative_clmul_i8	`-mtriple=riscv32 -mattr=+m,+zbc -verify-machineinstrs`
clmul.ll	neg_commutative_clmul_i8	`-mtriple=riscv32 -mattr=+m,+zbc -verify-machineinstrs`
clmul.ll	clmul_i8	`-mtriple=riscv32 -mattr=+m,+zbs -verify-machineinstrs`
clmul.ll	commutative_clmul_i8	`-mtriple=riscv32 -mattr=+m,+zbs -verify-machineinstrs`
clmul.ll	mul_use_commutative_clmul_i8	`-mtriple=riscv32 -mattr=+m,+zbs -verify-machineinstrs`
clmul.ll	neg_commutative_clmul_i8	`-mtriple=riscv32 -mattr=+m,+zbs -verify-machineinstrs`
clmul.ll	clmul_i8	`-mtriple=riscv32 -mattr=+m,+zvbc -verify-machineinstrs`
clmul.ll	commutative_clmul_i8	`-mtriple=riscv32 -mattr=+m,+zvbc -verify-machineinstrs`
clmul.ll	mul_use_commutative_clmul_i8	`-mtriple=riscv32 -mattr=+m,+zvbc -verify-machineinstrs`
clmul.ll	neg_commutative_clmul_i8	`-mtriple=riscv32 -mattr=+m,+zvbc -verify-machineinstrs`
clmul.ll	clmul_i8	`-mtriple=riscv32 -verify-machineinstrs`
clmul.ll	commutative_clmul_i8	`-mtriple=riscv32 -verify-machineinstrs`
clmul.ll	mul_use_commutative_clmul_i8	`-mtriple=riscv32 -verify-machineinstrs`
clmul.ll	neg_commutative_clmul_i8	`-mtriple=riscv32 -verify-machineinstrs`
clmul.ll	clmul_i8	`-mtriple=riscv64 -mattr=+m -verify-machineinstrs`
clmul.ll	commutative_clmul_i8	`-mtriple=riscv64 -mattr=+m -verify-machineinstrs`
clmul.ll	mul_use_commutative_clmul_i8	`-mtriple=riscv64 -mattr=+m -verify-machineinstrs`
clmul.ll	neg_commutative_clmul_i8	`-mtriple=riscv64 -mattr=+m -verify-machineinstrs`
clmul.ll	clmul_i8	`-mtriple=riscv64 -mattr=+m,+zbc -verify-machineinstrs`
clmul.ll	commutative_clmul_i8	`-mtriple=riscv64 -mattr=+m,+zbc -verify-machineinstrs`
clmul.ll	mul_use_commutative_clmul_i8	`-mtriple=riscv64 -mattr=+m,+zbc -verify-machineinstrs`
clmul.ll	neg_commutative_clmul_i8	`-mtriple=riscv64 -mattr=+m,+zbc -verify-machineinstrs`
clmul.ll	clmul_i8	`-mtriple=riscv64 -mattr=+m,+zbs -verify-machineinstrs`
clmul.ll	commutative_clmul_i8	`-mtriple=riscv64 -mattr=+m,+zbs -verify-machineinstrs`
clmul.ll	mul_use_commutative_clmul_i8	`-mtriple=riscv64 -mattr=+m,+zbs -verify-machineinstrs`
clmul.ll	neg_commutative_clmul_i8	`-mtriple=riscv64 -mattr=+m,+zbs -verify-machineinstrs`
clmul.ll	clmul_i8	`-mtriple=riscv64 -mattr=+m,+zvbc -verify-machineinstrs`
clmul.ll	commutative_clmul_i8	`-mtriple=riscv64 -mattr=+m,+zvbc -verify-machineinstrs`
clmul.ll	mul_use_commutative_clmul_i8	`-mtriple=riscv64 -mattr=+m,+zvbc -verify-machineinstrs`
clmul.ll	neg_commutative_clmul_i8	`-mtriple=riscv64 -mattr=+m,+zvbc -verify-machineinstrs`
clmul.ll	clmul_i8	`-mtriple=riscv64 -verify-machineinstrs`
clmul.ll	commutative_clmul_i8	`-mtriple=riscv64 -verify-machineinstrs`
clmul.ll	mul_use_commutative_clmul_i8	`-mtriple=riscv64 -verify-machineinstrs`
clmul.ll	neg_commutative_clmul_i8	`-mtriple=riscv64 -verify-machineinstrs`
clmulh.ll	clmulh_i4	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
clmulh.ll	clmulh_i4	`-mtriple=riscv32 -mattr=+m,+zbc -verify-machineinstrs`
clmulh.ll	clmulh_i4	`-mtriple=riscv32 -mattr=+m,+zbs -verify-machineinstrs`
clmulh.ll	clmulh_i4	`-mtriple=riscv32 -mattr=+m,+zvbc -verify-machineinstrs`
clmulh.ll	clmulh_i4	`-mtriple=riscv32 -verify-machineinstrs`
clmulh.ll	clmulh_i4	`-mtriple=riscv64 -mattr=+m -verify-machineinstrs`
clmulh.ll	clmulh_i4	`-mtriple=riscv64 -mattr=+m,+zbc -verify-machineinstrs`
clmulh.ll	clmulh_i4	`-mtriple=riscv64 -mattr=+m,+zbs -verify-machineinstrs`
clmulh.ll	clmulh_i4	`-mtriple=riscv64 -mattr=+m,+zvbc -verify-machineinstrs`
clmulh.ll	clmulh_i4	`-mtriple=riscv64 -verify-machineinstrs`

Generated 2026-10-15 08:05 UTC.