diff --git a/compiler/rustc_mir_transform/src/gvn.rs b/compiler/rustc_mir_transform/src/gvn.rs index 7800aa63729..60ff1dd0d78 100644 --- a/compiler/rustc_mir_transform/src/gvn.rs +++ b/compiler/rustc_mir_transform/src/gvn.rs @@ -443,6 +443,16 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { CastKind::Transmute => { let value = self.evaluated[value].as_ref()?; let to = self.ecx.layout_of(to).ok()?; + // `offset` for immediates only supports scalar/scalar-pair ABIs, + // so bail out if the target is not one. + if value.as_mplace_or_imm().is_right() { + match to.abi { + Abi::Scalar(..) | Abi::ScalarPair(..) => {} + _ if to.is_zst() => {} + Abi::Aggregate { .. } if to.fields.count() == 0 => {} + _ => return None, + } + } value.offset(Size::ZERO, to, &self.ecx).ok()? } _ => return None,