fallback: legalize: G_INTRINSIC <2 x s32>,<8 x s8>

Snippet:

define <2 x i32> @test_pm4add_v8i8_v2i32(<8 x i8> %a, <8 x i8> %b) {
  %r = call <2 x i32> @llvm.riscv.pm4add.v2i32.v8i8(<8 x i8> %a, <8 x i8> %b)
  ret <2 x i32> %r
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare <2 x i32> @llvm.riscv.pm4add.v2i32.v8i8(<8 x i8>, <8 x i8>) #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:_(<2 x s32>) = G_INTRINSIC intrinsic(@llvm.riscv.pm4add), %0:_(<8 x s8>), %1:_(<8 x s8>) (in function: test_pm4add_v8i8_v2i32)
warning: Instruction selection used fallback path for test_pm4add_v8i8_v2i32

Occurrences (3):

Generated 2026-10-15 08:05 UTC.