fallback: legalize: G_STRICT_FMA s16

Snippet:

; Function Attrs: nounwind strictfp
define half @fmadd_h(half %a, half %b, half %c) #0 {
  %1 = call half @llvm.experimental.constrained.fma.f16(half %a, half %b, half %c, metadata !"round.dynamic", metadata !"fpexcept.strict") #2
  ret half %1
}

; Function Attrs: nocallback nofree nosync nounwind strictfp willreturn memory(inaccessiblemem: readwrite)
declare half @llvm.experimental.constrained.fma.f16(half, half, half, metadata, metadata) #1

attributes #0 = { nounwind strictfp }
attributes #1 = { nocallback nofree nosync nounwind strictfp willreturn memory(inaccessiblemem: readwrite) }
attributes #2 = { strictfp }

Reproduce:

llc -mtriple=riscv32 -mattr=+zfh -verify-machineinstrs -disable-strictnode-mutation -target-abi ilp32f -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv32 -mattr=+zfh -verify-machineinstrs -disable-strictnode-mutation -target-abi ilp32f -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %3:_(s16) = G_STRICT_FMA %0:_, %1:_, %2:_ (in function: fmadd_h)
warning: Instruction selection used fallback path for fmadd_h

Occurrences (104) (first 50):

Generated 2026-10-15 08:05 UTC.