fallback: legalize: G_INTRINSIC <4 x s16>

Snippet:

define <4 x i16> @test_paadd_v4i16(<4 x i16> %a, <4 x i16> %b) {
  %res = call <4 x i16> @llvm.riscv.paadd.v4i16(<4 x i16> %a, <4 x i16> %b)
  ret <4 x i16> %res
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare <4 x i16> @llvm.riscv.paadd.v4i16(<4 x i16>, <4 x i16>) #0

attributes #0 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }

Reproduce:

llc -mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %2:_(<4 x s16>) = G_INTRINSIC intrinsic(@llvm.riscv.paadd), %0:_(<4 x s16>), %1:_(<4 x s16>) (in function: test_paadd_v4i16)
warning: Instruction selection used fallback path for test_paadd_v4i16

Occurrences (38):

Generated 2026-10-15 08:05 UTC.