fallback: legalize: G

fallback: legalize: G_UMULH s64

Run:	explore-04ca53e65f-20261014-114124
Kind:	fallback
Category:	legalize: G_UMULH s64
Occurrences:	74 in 31 configs, 28 test files
Snippet from:	div.ll @udiv64_constant via llvm-extract
Config:	`-mtriple=riscv32 -verify-machineinstrs`
Local check:	reproduces at 04ca53e65f
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

; Function Attrs: nounwind
define i64 @udiv64_constant(i64 %a) #0 {
  %1 = udiv i64 %a, 5
  ret i64 %1
}

attributes #0 = { nounwind }

Reproduce:

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

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %11:_(s64) = G_UMULH %0:_, %8:_ (in function: udiv64_constant)
warning: Instruction selection used fallback path for udiv64_constant

Occurrences (74) (first 50):

Input	Function	Config
bitint-fp-conv-200.ll	test_float_to_bitint_200	`-mtriple=riscv32 -verify-machineinstrs`
div.ll	udiv64_constant	`-mtriple=riscv32 -verify-machineinstrs`
fp128.ll	fptosi_fp128_to_i96	`-mtriple=riscv32 -verify-machineinstrs`
fpclamptosat.ll	stest_f64i64	`-mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f`
fpclamptosat.ll	ustest_f64i64	`-mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f`
fpclamptosat.ll	stest_f32i64	`-mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f`
fpclamptosat.ll	ustest_f32i64	`-mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f`
fpclamptosat.ll	stest_f64i64_mm	`-mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f`
fpclamptosat.ll	ustest_f64i64_mm	`-mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f`
fpclamptosat.ll	stest_f32i64_mm	`-mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f`
fpclamptosat.ll	ustest_f32i64_mm	`-mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f`
mul.ll	muli128_m3840	`-mtriple=riscv32 -verify-machineinstrs`
mul.ll	muli128_m63	`-mtriple=riscv32 -verify-machineinstrs`
mul.ll	mulhsu_i64	`-mtriple=riscv32 -verify-machineinstrs`
umulh.ll	umulh_i64	`-mtriple=riscv32`
umulh.ll	umulh_v1i64	`-mtriple=riscv32`
urem-lkk.ll	dont_fold_urem_i64	`-mtriple=riscv32 -verify-machineinstrs`
abdu-neg.b180ede9de.ll (mutant of abdu-neg.ll)	abd_ext_i32_undef	`-mtriple=riscv32`
abdu-neg.bec6c3193e.ll (mutant of abdu-neg.ll)	abd_ext_i32_undef	`-mtriple=riscv32 -mattr=+zbb`
abdu.4b18b36544.ll (mutant of abdu.ll)	abd_ext_i32_undef	`-mtriple=riscv32`
abdu.e728f877d4.ll (mutant of abdu.ll)	abd_ext_i32_undef	`-mtriple=riscv32 -mattr=+zbb`
add-before-shl.5ad79ae0b6.ll (mutant of add-before-shl.ll)	add_wide_operand	`-mtriple=riscv32 -mattr=+c -verify-machineinstrs -M no-aliases`
add-before-shl.781ead846d.ll (mutant of add-before-shl.ll)	add_wide_operand	`-mtriple=riscv32 -verify-machineinstrs -M no-aliases`
add-before-shl.81065c912f.ll (mutant of add-before-shl.ll)	add_wide_operand	`-mtriple=riscv32 -mattr=+zca -verify-machineinstrs -M no-aliases`
atomic-fence.3799f6c6c6.ll (mutant of atomic-fence.ll)	fence_singlethread_acquire	`-mtriple=riscv32 -mattr=+a,+ztso -verify-machineinstrs`
atomic-fence.422ee53f2e.ll (mutant of atomic-fence.ll)	fence_singlethread_acquire	`-mtriple=riscv32 -mattr=+a -verify-machineinstrs`
atomic-fence.76107451f6.ll (mutant of atomic-fence.ll)	fence_singlethread_acquire	`-mtriple=riscv32 -mattr=+zalrsc -verify-machineinstrs`
atomic-fence.7b542961cb.ll (mutant of atomic-fence.ll)	fence_singlethread_acquire	`-mtriple=riscv32 -verify-machineinstrs`
atomic-rmw-minmax.3f9aa9775c.ll (mutant of atomic-rmw-minmax.ll)	atomicrmw_max_i64_seq_cst	`-mtriple=riscv32 -mattr=+b,+zalrsc -verify-machineinstrs`
atomic-rmw-minmax.8a19e34eca.ll (mutant of atomic-rmw-minmax.ll)	atomicrmw_max_i64_seq_cst	`-mtriple=riscv32 -mattr=+b,+zalrsc,+permissive-zalrsc -verify-machineinstrs`
atomic-rmw-minmax.e860e95e12.ll (mutant of atomic-rmw-minmax.ll)	atomicrmw_max_i64_seq_cst	`-mtriple=riscv32 -mattr=+b,+zalrsc,+permissive-zalrsc,+a -verify-machineinstrs`
atomicrmw-cond-sub-clamp.01c3e3511a.ll (mutant of atomicrmw-cond-sub-clamp.ll)	atomicrmw_usub_sat_i8	`-mtriple=riscv32 -mattr=+a -verify-machineinstrs`
atomicrmw-cond-sub-clamp.24bd5b0313.ll (mutant of atomicrmw-cond-sub-clamp.ll)	atomicrmw_usub_sat_i8	`-mtriple=riscv32 -mattr=+a,+ztso -verify-machineinstrs`
atomicrmw-cond-sub-clamp.7358bdde9b.ll (mutant of atomicrmw-cond-sub-clamp.ll)	atomicrmw_usub_sat_i8	`-mtriple=riscv32 -verify-machineinstrs`
atomicrmw-uinc-udec-wrap.508e722342.ll (mutant of atomicrmw-uinc-udec-wrap.ll)	atomicrmw_udec_wrap_i8	`-mtriple=riscv32 -verify-machineinstrs`
atomicrmw-uinc-udec-wrap.693181db43.ll (mutant of atomicrmw-uinc-udec-wrap.ll)	atomicrmw_udec_wrap_i8	`-mtriple=riscv32 -mattr=+a,+ztso -verify-machineinstrs`
atomicrmw-uinc-udec-wrap.db353115b9.ll (mutant of atomicrmw-uinc-udec-wrap.ll)	atomicrmw_udec_wrap_i8	`-mtriple=riscv32 -mattr=+a -verify-machineinstrs`
bitint-fp-conv-200.8f85fabff9.ll (mutant of bitint-fp-conv-200.ll)	test_float_to_bitint_200	`-mtriple=riscv32 -verify-machineinstrs`
calling-conv-half.04ad88347c.ll (mutant of calling-conv-half.ll)	callee_half_on_stack_exhausted_gprs_fprs	`-mtriple=riscv32 -mattr=+f -target-abi=ilp32 -verify-machineinstrs`
calling-conv-half.1179a9e699.ll (mutant of calling-conv-half.ll)	callee_half_on_stack_exhausted_gprs_fprs	`-mtriple=riscv32 -mattr=+f -mattr=+zfh -verify-machineinstrs -target-abi ilp32 -O1`
calling-conv-half.39e5ce6fed.ll (mutant of calling-conv-half.ll)	callee_half_on_stack_exhausted_gprs_fprs	`-mtriple=riscv32 -verify-machineinstrs`
calling-conv-half.79681ea424.ll (mutant of calling-conv-half.ll)	callee_half_on_stack_exhausted_gprs_fprs	`-mtriple=riscv32 -mattr=+f -mattr=+zfh -verify-machineinstrs -target-abi ilp32f -O1`
calling-conv-half.c63e0d49ab.ll (mutant of calling-conv-half.ll)	callee_half_on_stack_exhausted_gprs_fprs	`-mtriple=riscv32 -mattr=+f -target-abi=ilp32f -verify-machineinstrs`
calling-conv-half.dd62ff68b0.ll (mutant of calling-conv-half.ll)	callee_half_on_stack_exhausted_gprs_fprs	`-mtriple=riscv32 -mattr=+f,+zfhmin -target-abi=ilp32f -verify-machineinstrs`
fmax-fmin.643884bb8d.ll (mutant of fmax-fmin.ll)	minnum_f32	`-mtriple=riscv32 -verify-machineinstrs`
iabs.7560c8b4ca.ll (mutant of iabs.ll)	select_abs128	`-mtriple=riscv32 -mattr=+zbb -verify-machineinstrs`
iabs.d3c29ae8f4.ll (mutant of iabs.ll)	select_abs128	`-mtriple=riscv32 -verify-machineinstrs`
lrint-conv.39954ad767.ll (mutant of lrint-conv.ll)	test_lrint_ixx_f64	`-mtriple=riscv32`
lrint-conv.39954ad767.ll (mutant of lrint-conv.ll)	test_lrint_ixx_f64	`-mtriple=riscv32`
mul.04ea0b0bab.ll (mutant of mul.ll)	muli128_m63	`-mtriple=riscv32 -verify-machineinstrs`

Generated 2026-10-15 08:05 UTC.