fallback: legalize: G_FSUB <32 x s16>

Run:	main-04ca53e65f-20261014-113325
Kind:	fallback
Category:	legalize: G_FSUB <32 x s16> NEW
Occurrences:	1 in 1 configs, 1 test files
Snippet from:	fastcc-half.03f0f86ff4.ll (mutant of fastcc-half.ll) @callee via llvm-extract
Config:	`-mtriple=riscv32 -mattr=+zfhmin -target-abi=ilp32 -verify-machineinstrs`
Local check:	reproduces at 04ca53e65f
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

@G = external global <32 x half>

; Function Attrs: nounwind
define fastcc half @callee(<32 x half> %A) #0 {
  %LGV = load <32 x half>, ptr @G, align 64
  %A1 = alloca <32 x i1>, align 4
  store <32 x i1> poison, ptr %A1, align 4
  %C = fcmp ord <32 x half> %A, splat (half +inf)
  %B = extractelement <32 x half> %A, i32 0
  store <32 x i1> %C, ptr %A1, align 4
  %B2 = fsub <32 x half> %A, %LGV
  store <32 x half> %B2, ptr @G, align 64
  store <32 x half> %LGV, ptr %A1, align 64
  ret half %B
}

attributes #0 = { nounwind }

Reproduce:

llc -mtriple=riscv32 -mattr=+zfhmin -target-abi=ilp32 -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv32 -mattr=+zfhmin -target-abi=ilp32 -verify-machineinstrs -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %54:_(<32 x s16>) = G_FSUB %0:_, %45:_ (in function: callee)
warning: Instruction selection used fallback path for callee

Occurrences (1):

Input	Function	Config
fastcc-half.03f0f86ff4.ll (mutant of fastcc-half.ll)	callee	`-mtriple=riscv32 -mattr=+zfhmin -target-abi=ilp32 -verify-machineinstrs`

Generated 2026-10-15 08:05 UTC.