fallback: legalize: G_FMUL <4 x s32>

Run:	explore-04ca53e65f-20261014-114124
Kind:	fallback
Category:	legalize: G_FMUL <4 x s32> NEW
Occurrences:	19 in 15 configs, 6 test files
Snippet from:	add-imm.4c003bcd0b.ll (mutant of add-imm.ll) @add32_sext_accept via llvm-extract + llvm-reduce
Config:	`-mtriple=riscv64 -verify-machineinstrs`
Local check:	reproduces at 04ca53e65f
Compiler Explorer:	https://godbolt.org/z/vjq3WPr3h (llc-assertions-trunk, checked 2026-10-14 11:49 UTC): G reproduces

Snippet:

define <4 x float> @add32_sext_accept() {
  %B = fmul <4 x float> zeroinitializer, zeroinitializer
  ret <4 x float> %B
}

Compiler Explorer panes:

Pane	Options	Exit	Insts	stderr
GlobalISel	`-mtriple=riscv64 -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.*`	0	3	remark: <unknown>:0:0: unable to legalize instruction: %3:_(<4 x s32>) = G_FMUL %1:_, %1:_ (in function: add32_sext_accept) warning: Instruction selection used fallback path for add32_sext_accept
SelectionDAG (control)	`-mtriple=riscv64 -verify-machineinstrs -global-isel=0`	0	3	-

Reproduce:

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

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %3:_(<4 x s32>) = G_FMUL %1:_, %1:_ (in function: add32_sext_accept)
warning: Instruction selection used fallback path for add32_sext_accept

Occurrences (19):

Input	Function	Config
add-imm.4c003bcd0b.ll (mutant of add-imm.ll)	add32_sext_accept	`-mtriple=riscv64 -verify-machineinstrs`
add-imm.95c4020eb7.ll (mutant of add-imm.ll)	add32_sext_accept	`-mtriple=riscv32 -verify-machineinstrs`
alu64.76feba5a5b.ll (mutant of alu64.ll)	and	`-mtriple=riscv32 -verify-machineinstrs`
alu64.ddae9d1234.ll (mutant of alu64.ll)	and	`-mtriple=riscv64 -verify-machineinstrs`
combine-is_fpclass.668db8b0ab.ll (mutant of combine-is_fpclass.ll)	extract_fabs_unknown_idx_isneg	`-mtriple=riscv64 -mattr=+v,+f,+d`
double-arith-strict.337611d685.ll (mutant of double-arith-strict.ll)	fnmadd_d	`-mtriple=riscv32 -mattr=+d -verify-machineinstrs -disable-strictnode-mutation -target-abi=ilp32d`
double-arith-strict.64bfb685ef.ll (mutant of double-arith-strict.ll)	fnmadd_d	`-mtriple=riscv32 -mattr=+zdinx -verify-machineinstrs -disable-strictnode-mutation -target-abi=ilp32`
double-arith-strict.6bb5033c0f.ll (mutant of double-arith-strict.ll)	fnmadd_d	`-mtriple=riscv64 -mattr=+zdinx -verify-machineinstrs -disable-strictnode-mutation -target-abi=lp64`
double-arith-strict.782cbdeaae.ll (mutant of double-arith-strict.ll)	fnmadd_d	`-mtriple=riscv32 -verify-machineinstrs -disable-strictnode-mutation`
double-arith-strict.832b49a042.ll (mutant of double-arith-strict.ll)	fnmadd_d	`-mtriple=riscv64 -verify-machineinstrs -disable-strictnode-mutation`
double-arith-strict.bf8452f136.ll (mutant of double-arith-strict.ll)	fnmadd_d	`-mtriple=riscv64 -mattr=+d -verify-machineinstrs -disable-strictnode-mutation -target-abi=lp64d`
float-arith-strict.03a6dcc718.ll (mutant of float-arith-strict.ll)	fnmadd_s	`-mtriple=riscv32 -verify-machineinstrs -disable-strictnode-mutation`
float-arith-strict.3ec852dad2.ll (mutant of float-arith-strict.ll)	fnmadd_s	`-mtriple=riscv32 -mattr=+zfinx -verify-machineinstrs -disable-strictnode-mutation -target-abi=ilp32`
float-arith-strict.40890905fc.ll (mutant of float-arith-strict.ll)	fnmadd_s	`-mtriple=riscv64 -mattr=+zfinx -verify-machineinstrs -disable-strictnode-mutation -target-abi=lp64`
float-arith-strict.5e59662f21.ll (mutant of float-arith-strict.ll)	fnmadd_s	`-mtriple=riscv32 -mattr=+f -verify-machineinstrs -disable-strictnode-mutation -target-abi=ilp32f`
float-arith-strict.97125ee7e0.ll (mutant of float-arith-strict.ll)	fnmadd_s	`-mtriple=riscv64 -mattr=+f -verify-machineinstrs -disable-strictnode-mutation -target-abi=lp64f`
float-arith-strict.e4dfb2ea10.ll (mutant of float-arith-strict.ll)	fnmadd_s	`-mtriple=riscv64 -verify-machineinstrs -disable-strictnode-mutation`
select-constant-xor.0463f159cf.ll (mutant of select-constant-xor.ll)	icmpasrne	`-mtriple=riscv64`
select-constant-xor.3716c185cb.ll (mutant of select-constant-xor.ll)	icmpasrne	`-mtriple=riscv32`

Generated 2026-10-15 08:05 UTC.