fallback: legalize: G_SDIV <4 x s32>

Run:	main-bc8218b282-20261015-074651
Kind:	fallback
Category:	legalize: G_SDIV <4 x s32> NEW
Occurrences:	38 in 32 configs, 6 test files
Snippet from:	prolog-epilogue.20dc027957.ll (mutant of prolog-epilogue.ll) @frame_4096b via llvm-extract + llvm-reduce
Config:	`-mtriple=riscv32 -verify-machineinstrs`
Local check:	reproduces at bc8218b282
Compiler Explorer:	https://godbolt.org/z/o17TT9fds (llc-assertions-trunk, checked 2026-10-14 11:04 UTC): G reproduces

Snippet:

define <4 x i32> @frame_4096b() {
  %B = sdiv <4 x i32> splat (i32 1), zeroinitializer
  ret <4 x i32> %B
}

Compiler Explorer panes:

Pane	Options	Exit	Insts	stderr
GlobalISel	`-mtriple=riscv32 -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.*`	0	1	remark: <unknown>:0:0: unable to legalize instruction: %5:_(<4 x s32>) = G_SDIV %1:_, %3:_ (in function: frame_4096b) warning: Instruction selection used fallback path for frame_4096b
SelectionDAG (control)	`-mtriple=riscv32 -verify-machineinstrs -global-isel=0`	0	1	-

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: %5:_(<4 x s32>) = G_SDIV %1:_, %3:_ (in function: frame_4096b)
warning: Instruction selection used fallback path for frame_4096b

Occurrences (38):

Input	Function	Config
atomic-load-store.1cfe2bd73e.ll (mutant of atomic-load-store.ll)	atomic_load_i16_seq_cst	`-mtriple=riscv64 -verify-machineinstrs`
atomic-load-store.2c30e3ebe9.ll (mutant of atomic-load-store.ll)	atomic_load_i16_seq_cst	`-mtriple=riscv32 -mattr=+zalrsc -verify-machineinstrs`
atomic-load-store.2ee456c648.ll (mutant of atomic-load-store.ll)	atomic_load_i16_seq_cst	`-mtriple=riscv64 -mattr=+a,+zalasr -verify-machineinstrs`
atomic-load-store.433710259f.ll (mutant of atomic-load-store.ll)	atomic_load_i16_seq_cst	`-mtriple=riscv64 -mattr=+a,+ztso,+no-trailing-seq-cst-fence -verify-machineinstrs`
atomic-load-store.4382963c7e.ll (mutant of atomic-load-store.ll)	atomic_load_i16_seq_cst	`-mtriple=riscv64 -mattr=+a,+no-trailing-seq-cst-fence -verify-machineinstrs`
atomic-load-store.463379d0d6.ll (mutant of atomic-load-store.ll)	atomic_load_i16_seq_cst	`-mtriple=riscv32 -verify-machineinstrs`
atomic-load-store.576e5b5fe4.ll (mutant of atomic-load-store.ll)	atomic_load_i16_seq_cst	`-mtriple=riscv64 -mattr=+a -verify-machineinstrs`
atomic-load-store.610c4d2856.ll (mutant of atomic-load-store.ll)	atomic_load_i16_seq_cst	`-mtriple=riscv32 -mattr=+a,+zalasr,+ztso -verify-machineinstrs`
atomic-load-store.7b59fbaa35.ll (mutant of atomic-load-store.ll)	atomic_load_i16_seq_cst	`-mtriple=riscv64 -mattr=+zalrsc -verify-machineinstrs`
atomic-load-store.90e4e68c28.ll (mutant of atomic-load-store.ll)	atomic_load_i16_seq_cst	`-mtriple=riscv32 -mattr=+a,+ztso -verify-machineinstrs`
atomic-load-store.91c6318fa0.ll (mutant of atomic-load-store.ll)	atomic_load_i16_seq_cst	`-mtriple=riscv64 -mattr=+a,+zalasr,+ztso -verify-machineinstrs`
atomic-load-store.a29d9d2da5.ll (mutant of atomic-load-store.ll)	atomic_load_i16_seq_cst	`-mtriple=riscv32 -mattr=+a,+ztso,+no-trailing-seq-cst-fence -verify-machineinstrs`
atomic-load-store.b00e69aba9.ll (mutant of atomic-load-store.ll)	atomic_load_i16_seq_cst	`-mtriple=riscv32 -mattr=+a,+zalasr -verify-machineinstrs`
atomic-load-store.bc13c820be.ll (mutant of atomic-load-store.ll)	atomic_load_i16_seq_cst	`-mtriple=riscv32 -mattr=+a,+no-trailing-seq-cst-fence -verify-machineinstrs`
atomic-load-store.c3ea67baf7.ll (mutant of atomic-load-store.ll)	atomic_load_i16_seq_cst	`-mtriple=riscv64 -mattr=+a,+ztso -verify-machineinstrs`
atomic-load-store.c71ceb250c.ll (mutant of atomic-load-store.ll)	atomic_load_i16_seq_cst	`-mtriple=riscv32 -mattr=+a -verify-machineinstrs`
div.25b92cf649.ll (mutant of div.ll)	udiv8	`-mtriple=riscv64 -verify-machineinstrs`
div.9fb0e4c50b.ll (mutant of div.ll)	udiv8	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
div.a0800043c8.ll (mutant of div.ll)	udiv8	`-mtriple=riscv64 -mattr=+m -verify-machineinstrs`
div.e19394eece.ll (mutant of div.ll)	udiv8	`-mtriple=riscv32 -verify-machineinstrs`
float-intrinsics.768c4be48c.ll (mutant of float-intrinsics.ll)	fma_f32	`-mtriple=riscv32 -mattr=+d -verify-machineinstrs -target-abi=ilp32f`
float-intrinsics.87e138f5e7.ll (mutant of float-intrinsics.ll)	fma_f32	`-mtriple=riscv64 -mattr=+d -verify-machineinstrs -target-abi=lp64d`
float-intrinsics.b5e581fd91.ll (mutant of float-intrinsics.ll)	fma_f32	`-mtriple=riscv32 -verify-machineinstrs`
float-intrinsics.bf2843352f.ll (mutant of float-intrinsics.ll)	fma_f32	`-mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f`
float-intrinsics.dcffec59cf.ll (mutant of float-intrinsics.ll)	fma_f32	`-mtriple=riscv64 -verify-machineinstrs`
float-intrinsics.e59d2358e0.ll (mutant of float-intrinsics.ll)	fma_f32	`-mtriple=riscv64 -mattr=+f -verify-machineinstrs -target-abi=lp64f`
float-zfa.cade3f1354.ll (mutant of float-zfa.ll)	loadfpimm8	`-mtriple=riscv64 -target-abi lp64f -mattr=+zfa`
float-zfa.faa28b56af.ll (mutant of float-zfa.ll)	loadfpimm8	`-mtriple=riscv32 -target-abi ilp32f -mattr=+zfa`
nontemporal.36fffb5e0b.ll (mutant of nontemporal.ll)	test_nontemporal_ALL_store_v4i32	`-mtriple=riscv32 -mattr=+zihintntl,+f,+d,+zfh,+c`
nontemporal.5a59105fcf.ll (mutant of nontemporal.ll)	test_nontemporal_ALL_store_v4i32	`-mtriple=riscv64 -mattr=+zihintntl,+f,+d,+zfh,+c`
nontemporal.86ff13ff91.ll (mutant of nontemporal.ll)	test_nontemporal_ALL_store_v4i32	`-mtriple=riscv64 -mattr=+zihintntl,+f,+d,+zfh`
nontemporal.9d5907877a.ll (mutant of nontemporal.ll)	test_nontemporal_ALL_store_v4i32	`-mtriple=riscv64 -mattr=+zihintntl,+f,+d,+zfh,+v`
nontemporal.b161d32ed5.ll (mutant of nontemporal.ll)	test_nontemporal_ALL_store_v4i32	`-mtriple=riscv32 -mattr=+zihintntl,+f,+d,+zfh,+v`
nontemporal.f6d640b3a7.ll (mutant of nontemporal.ll)	test_nontemporal_ALL_store_v4i32	`-mtriple=riscv32 -mattr=+zihintntl,+f,+d,+zfh`
prolog-epilogue.20dc027957.ll (mutant of prolog-epilogue.ll)	frame_4096b	`-mtriple=riscv32 -verify-machineinstrs`
prolog-epilogue.50939f8c59.ll (mutant of prolog-epilogue.ll)	frame_4096b	`-mtriple=riscv32 -verify-machineinstrs -mattr=+zba`
prolog-epilogue.a37b71e237.ll (mutant of prolog-epilogue.ll)	frame_4096b	`-mtriple=riscv64 -verify-machineinstrs`
prolog-epilogue.db7be5563c.ll (mutant of prolog-epilogue.ll)	frame_4096b	`-mtriple=riscv64 -verify-machineinstrs -mattr=+zba`

Generated 2026-10-15 08:05 UTC.