fallback: legalize: G_FDIV <4 x s32>

Run:	main-bc8218b282-20261015-074651
Kind:	fallback
Category:	legalize: G_FDIV <4 x s32> NEW
Occurrences:	91 in 60 configs, 24 test files
Snippet from:	calling-conv-preserve-most.1eda7aa795.ll (mutant of calling-conv-preserve-most.ll) @preserve_mostcc3 via llvm-extract + llvm-reduce
Config:	`-mtriple=riscv64`
Local check:	reproduces at bc8218b282
Compiler Explorer:	https://godbolt.org/z/15vnfYY4K (llc-assertions-trunk, checked 2026-10-14 11:04 UTC): G reproduces

Snippet:

define <4 x float> @preserve_mostcc3() {
  %B2 = fdiv <4 x float> zeroinitializer, zeroinitializer
  ret <4 x float> %B2
}

Compiler Explorer panes:

Pane	Options	Exit	Insts	stderr
GlobalISel	`-mtriple=riscv64 -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.*`	0	6	remark: <unknown>:0:0: unable to legalize instruction: %3:_(<4 x s32>) = G_FDIV %1:_, %1:_ (in function: preserve_mostcc3) warning: Instruction selection used fallback path for preserve_mostcc3
SelectionDAG (control)	`-mtriple=riscv64 -global-isel=0`	0	6	-

Reproduce:

llc -mtriple=riscv64 -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv64 -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %3:_(<4 x s32>) = G_FDIV %1:_, %1:_ (in function: preserve_mostcc3)
warning: Instruction selection used fallback path for preserve_mostcc3

Occurrences (91) (first 50):

Input	Function	Config
add_sext_shl_constant.1fec1ea7da.ll (mutant of add_sext_shl_constant.ll)	add_sext_shl_moreOneUse_add_inSelect	`-mtriple=riscv64`
add_sext_shl_constant.ef7d200ebc.ll (mutant of add_sext_shl_constant.ll)	add_sext_shl_moreOneUse_add_inSelect	`-mtriple=riscv64 -mattr=+xandesperf`
add_sext_shl_constant.fef8a910a6.ll (mutant of add_sext_shl_constant.ll)	add_sext_shl_moreOneUse_add_inSelect	`-mtriple=riscv64 -mattr=+zba`
bswap-known-bits.ae8c2ff934.ll (mutant of bswap-known-bits.ll)	bswap_src_and_byte0_i32	`-mtriple=riscv64 -mattr=+zbb -verify-machineinstrs`
bswap-known-bits.cf14c0f4e3.ll (mutant of bswap-known-bits.ll)	bswap_src_and_byte0_i32	`-mtriple=riscv32 -mattr=+zbb -verify-machineinstrs`
bswap-shift.ca5832a11c.ll (mutant of bswap-shift.ll)	test_bswap_srli_16_bswap_i32	`-mtriple=riscv32 -mattr=+zbkb -verify-machineinstrs`
bswap-shift.cb17543829.ll (mutant of bswap-shift.ll)	test_bswap_srli_16_bswap_i32	`-mtriple=riscv64 -mattr=+zbb -verify-machineinstrs`
bswap-shift.e75f151178.ll (mutant of bswap-shift.ll)	test_bswap_srli_16_bswap_i32	`-mtriple=riscv64 -mattr=+zbkb -verify-machineinstrs`
bswap-shift.f6ce9b529f.ll (mutant of bswap-shift.ll)	test_bswap_srli_16_bswap_i32	`-mtriple=riscv32 -mattr=+zbb -verify-machineinstrs`
calling-conv-ilp32d.94b9998fc4.ll (mutant of calling-conv-ilp32d.ll)	caller_double_in_fpr_exhausted_gprs	`-mtriple=riscv32 -verify-machineinstrs -mattr=+d -target-abi ilp32d`
calling-conv-preserve-most.1eda7aa795.ll (mutant of calling-conv-preserve-most.ll)	preserve_mostcc3	`-mtriple=riscv64`
calling-conv-preserve-most.599663f347.ll (mutant of calling-conv-preserve-most.ll)	preserve_mostcc3	`-mtriple=riscv32 -mattr=+e -target-abi ilp32e`
calling-conv-preserve-most.6c75bb1426.ll (mutant of calling-conv-preserve-most.ll)	preserve_mostcc3	`-mtriple=riscv32`
calling-conv-preserve-most.743f06cc93.ll (mutant of calling-conv-preserve-most.ll)	preserve_mostcc3	`-mtriple=riscv64 -mattr=+e -target-abi lp64e`
calls.02868da869.ll (mutant of calls.ll)	test_call_defined	`-mtriple=riscv64 -verify-machineinstrs`
calls.245a80bffa.ll (mutant of calls.ll)	test_call_defined	`-code-model=large -mtriple=riscv64 -verify-machineinstrs`
calls.a30459c856.ll (mutant of calls.ll)	test_call_defined	`-code-model=large -mtriple=riscv64 -mattr=experimental-zicfilp -verify-machineinstrs`
calls.d065cbf328.ll (mutant of calls.ll)	test_call_defined	`-code-model=medium -mtriple=riscv64 -verify-machineinstrs`
calls.ddfa90cb94.ll (mutant of calls.ll)	test_call_defined	`-mtriple=riscv32 -verify-machineinstrs`
calls.e3ff891317.ll (mutant of calls.ll)	test_call_defined	`-relocation-model=pic -mtriple=riscv32 -verify-machineinstrs`
calls.f6366692ea.ll (mutant of calls.ll)	test_call_defined	`-code-model=small -mtriple=riscv64 -verify-machineinstrs`
cmov-branch-opt.30516af4a1.ll (mutant of cmov-branch-opt.ll)	test4	`-mtriple=riscv64 -mattr=+short-forward-branch-ialu,+c -verify-machineinstrs`
cmov-branch-opt.44fb8e64ca.ll (mutant of cmov-branch-opt.ll)	test4	`-mtriple=riscv32 -mattr=+xqcicm,+xqcics,+xqcicli,+zca,+short-forward-branch-ialu,+conditional-cmv-fusion -verify-machineinstrs`
cmov-branch-opt.7011504cc0.ll (mutant of cmov-branch-opt.ll)	test4	`-mtriple=riscv64 -mattr=+conditional-cmv-fusion,+c,+zicond -verify-machineinstrs`
cmov-branch-opt.8c06a988fe.ll (mutant of cmov-branch-opt.ll)	test4	`-mtriple=riscv64 -mattr=+short-forward-branch-ialu,+zicond -verify-machineinstrs`
cmov-branch-opt.93032030fb.ll (mutant of cmov-branch-opt.ll)	test4	`-mtriple=riscv64 -mattr=+short-forward-branch-ialu -verify-machineinstrs`
cmov-branch-opt.dcfb4ca913.ll (mutant of cmov-branch-opt.ll)	test4	`-mtriple=riscv64 -mattr=+conditional-cmv-fusion,+c -verify-machineinstrs`
cmov-branch-opt.e5dfbba342.ll (mutant of cmov-branch-opt.ll)	test4	`-mtriple=riscv64 -mattr=+c -verify-machineinstrs`
double-arith.134c144595.ll (mutant of double-arith.ll)	fmsub_d	`-mtriple=riscv32 -mattr=+zdinx -verify-machineinstrs -target-abi=ilp32`
double-arith.19da733307.ll (mutant of double-arith.ll)	fmsub_d	`-mtriple=riscv32 -verify-machineinstrs`
double-arith.8d1584fcb3.ll (mutant of double-arith.ll)	fmsub_d	`-mtriple=riscv64 -mattr=+d -verify-machineinstrs -target-abi=lp64d`
double-arith.d2db606920.ll (mutant of double-arith.ll)	fmsub_d	`-mtriple=riscv64 -mattr=+zdinx -verify-machineinstrs -target-abi=lp64`
double-arith.dd441148aa.ll (mutant of double-arith.ll)	fmsub_d	`-mtriple=riscv64 -verify-machineinstrs`
double-arith.f11c3cc4ba.ll (mutant of double-arith.ll)	fmsub_d	`-mtriple=riscv32 -mattr=+d -verify-machineinstrs -target-abi=ilp32d`
double-round-conv.5bfa4ef018.ll (mutant of double-round-conv.ll)	test_ceil_si8	`-mtriple=riscv32 -mattr=+zdinx -verify-machineinstrs -target-abi=ilp32`
double-round-conv.81bcf4108b.ll (mutant of double-round-conv.ll)	test_ceil_si8	`-mtriple=riscv32 -mattr=+d -verify-machineinstrs -target-abi=ilp32d`
double-round-conv.9903c107f3.ll (mutant of double-round-conv.ll)	test_ceil_si8	`-mtriple=riscv64 -mattr=+d -verify-machineinstrs -target-abi=lp64d`
double-round-conv.e612eb6f30.ll (mutant of double-round-conv.ll)	test_ceil_si8	`-mtriple=riscv64 -mattr=+zdinx -verify-machineinstrs -target-abi=lp64`
double-select-icmp.069bbf5a6a.ll (mutant of double-select-icmp.ll)	select_icmp_uge	`-mtriple=riscv64 -mattr=+zdinx -verify-machineinstrs -target-abi=lp64`
double-select-icmp.6b6d1d032b.ll (mutant of double-select-icmp.ll)	select_icmp_uge	`-mtriple=riscv32 -mattr=+zdinx -verify-machineinstrs -target-abi=ilp32`
double-select-icmp.7afaa7e07b.ll (mutant of double-select-icmp.ll)	select_icmp_uge	`-mtriple=riscv64 -mattr=+d -verify-machineinstrs -target-abi=lp64d`
double-select-icmp.8c309f7b2a.ll (mutant of double-select-icmp.ll)	select_icmp_uge	`-mtriple=riscv32 -mattr=+d -verify-machineinstrs -target-abi=ilp32d`
float-arith.2a00cefc3b.ll (mutant of float-arith.ll)	fmsub_s	`-mtriple=riscv32 -verify-machineinstrs`
float-arith.2be9e36549.ll (mutant of float-arith.ll)	fmsub_s	`-mtriple=riscv64 -mattr=+f -verify-machineinstrs -target-abi=lp64f`
float-arith.837f25249c.ll (mutant of float-arith.ll)	fmsub_s	`-mtriple=riscv64 -verify-machineinstrs`
float-arith.84c23e4628.ll (mutant of float-arith.ll)	fmsub_s	`-mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f`
float-round-conv.401e06f4c1.ll (mutant of float-round-conv.ll)	test_ceil_si8	`-mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f`
float-round-conv.936fe417fa.ll (mutant of float-round-conv.ll)	test_ceil_si8	`-mtriple=riscv64 -mattr=+f -verify-machineinstrs -target-abi=lp64f`
float-select-icmp.a64f04d7fa.ll (mutant of float-select-icmp.ll)	select_icmp_uge	`-mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f`
float-select-icmp.d7e54c66cd.ll (mutant of float-select-icmp.ll)	select_icmp_uge	`-mtriple=riscv64 -mattr=+f -verify-machineinstrs -target-abi=lp64f`

Generated 2026-10-15 08:05 UTC.