fallback: legalize: G

fallback: legalize: G_CLMUL s48

Run:	explore-bc8218b282-20261015-075519
Kind:	fallback
Category:	legalize: G_CLMUL s48
Occurrences:	20 in 10 configs, 1 test files
Snippet from:	clmul.ll @clmul_i48 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 i48 @clmul_i48(i48 %a, i48 %b) #0 {
  %res = call i48 @llvm.clmul.i48(i48 %a, i48 %b)
  ret i48 %res
}

; Function Attrs: nocallback nocreateundeforpoison nofree nosync nounwind speculatable willreturn memory(none)
declare i48 @llvm.clmul.i48(i48, i48) #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: %8:_(s48) = G_CLMUL %0:_, %1:_ (in function: clmul_i48)
warning: Instruction selection used fallback path for clmul_i48

Occurrences (20):

Input	Function	Config
clmul.ll	clmul_i48	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
clmul.ll	clmul_i48	`-mtriple=riscv32 -mattr=+m,+zbc -verify-machineinstrs`
clmul.ll	clmul_i48	`-mtriple=riscv32 -mattr=+m,+zbs -verify-machineinstrs`
clmul.ll	clmul_i48	`-mtriple=riscv32 -mattr=+m,+zvbc -verify-machineinstrs`
clmul.ll	clmul_i48	`-mtriple=riscv32 -verify-machineinstrs`
clmul.ll	clmul_i48	`-mtriple=riscv64 -mattr=+m -verify-machineinstrs`
clmul.ll	clmul_i48	`-mtriple=riscv64 -mattr=+m,+zbc -verify-machineinstrs`
clmul.ll	clmul_i48	`-mtriple=riscv64 -mattr=+m,+zbs -verify-machineinstrs`
clmul.ll	clmul_i48	`-mtriple=riscv64 -mattr=+m,+zvbc -verify-machineinstrs`
clmul.ll	clmul_i48	`-mtriple=riscv64 -verify-machineinstrs`
clmul.0496fa590c.ll (mutant of clmul.ll)	clmul_i48	`-mtriple=riscv32 -mattr=+m,+zbs -verify-machineinstrs`
clmul.0f5735b99f.ll (mutant of clmul.ll)	clmul_i48	`-mtriple=riscv64 -verify-machineinstrs`
clmul.1824459440.ll (mutant of clmul.ll)	clmul_i48	`-mtriple=riscv64 -mattr=+m,+zbs -verify-machineinstrs`
clmul.1aab5cbcdd.ll (mutant of clmul.ll)	clmul_i48	`-mtriple=riscv32 -verify-machineinstrs`
clmul.1c0684c19c.ll (mutant of clmul.ll)	clmul_i48	`-mtriple=riscv64 -mattr=+m,+zvbc -verify-machineinstrs`
clmul.233000f046.ll (mutant of clmul.ll)	clmul_i48	`-mtriple=riscv64 -mattr=+m -verify-machineinstrs`
clmul.40a8470c1f.ll (mutant of clmul.ll)	clmul_i48	`-mtriple=riscv64 -mattr=+m,+zbc -verify-machineinstrs`
clmul.8b9db93b5d.ll (mutant of clmul.ll)	clmul_i48	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
clmul.9b7cc29b76.ll (mutant of clmul.ll)	clmul_i48	`-mtriple=riscv32 -mattr=+m,+zbc -verify-machineinstrs`
clmul.f570c195ed.ll (mutant of clmul.ll)	clmul_i48	`-mtriple=riscv32 -mattr=+m,+zvbc -verify-machineinstrs`

Generated 2026-10-15 08:05 UTC.