diff options
Diffstat (limited to 'compiler/rustc_codegen_ssa/src')
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/block.rs | 74 |
1 files changed, 42 insertions, 32 deletions
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs index a2565c4f69d..cb8088e9efb 100644 --- a/compiler/rustc_codegen_ssa/src/mir/block.rs +++ b/compiler/rustc_codegen_ssa/src/mir/block.rs @@ -8,7 +8,7 @@ use rustc_hir::lang_items::LangItem; use rustc_middle::mir::{self, AssertKind, InlineAsmMacro, SwitchTargets, UnwindTerminateReason}; use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf, ValidityRequirement}; use rustc_middle::ty::print::{with_no_trimmed_paths, with_no_visible_paths}; -use rustc_middle::ty::{self, Instance, List, Ty}; +use rustc_middle::ty::{self, Instance, Ty}; use rustc_middle::{bug, span_bug}; use rustc_session::config::OptLevel; use rustc_span::Span; @@ -941,37 +941,55 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { return merging_succ; } - let fn_abi = bx.fn_abi_of_instance(instance, List::empty()); + let result_layout = + self.cx.layout_of(self.monomorphized_place_ty(destination.as_ref())); - let mut llargs = Vec::with_capacity(1); - let ret_dest = self.make_return_dest( - bx, - destination, - &fn_abi.ret, - &mut llargs, - Some(intrinsic), - ); - let dest = match ret_dest { - _ if fn_abi.ret.is_indirect() => llargs[0], - ReturnDest::Nothing => bx.const_undef(bx.type_ptr()), - ReturnDest::IndirectOperand(dst, _) | ReturnDest::Store(dst) => { - dst.val.llval - } - ReturnDest::DirectOperand(_) => { - bug!("Cannot use direct operand with an intrinsic call") + let (result, store_in_local) = if result_layout.is_zst() { + ( + PlaceRef::new_sized(bx.const_undef(bx.type_ptr()), result_layout), + None, + ) + } else if let Some(local) = destination.as_local() { + match self.locals[local] { + LocalRef::Place(dest) => (dest, None), + LocalRef::UnsizedPlace(_) => bug!("return type must be sized"), + LocalRef::PendingOperand => { + // Currently, intrinsics always need a location to store + // the result, so we create a temporary `alloca` for the + // result. + let tmp = PlaceRef::alloca(bx, result_layout); + tmp.storage_live(bx); + (tmp, Some(local)) + } + LocalRef::Operand(_) => { + bug!("place local already assigned to"); + } } + } else { + (self.codegen_place(bx, destination.as_ref()), None) }; + if result.val.align < result.layout.align.abi { + // Currently, MIR code generation does not create calls + // that store directly to fields of packed structs (in + // fact, the calls it creates write only to temps). + // + // If someone changes that, please update this code path + // to create a temporary. + span_bug!(self.mir.span, "can't directly store to unaligned value"); + } + let args: Vec<_> = args.iter().map(|arg| self.codegen_operand(bx, &arg.node)).collect(); - let result = PlaceRef::new_sized(dest, fn_abi.ret.layout); - match self.codegen_intrinsic_call(bx, instance, &args, result, source_info) { Ok(()) => { - if let ReturnDest::IndirectOperand(dst, _) = ret_dest { - self.store_return(bx, ret_dest, &fn_abi.ret, dst.val.llval); + if let Some(local) = store_in_local { + let op = bx.load_operand(result); + result.storage_dead(bx); + self.overwrite_local(local, LocalRef::Operand(op)); + self.debug_introduce_local(bx, local); } return if let Some(target) = target { @@ -1026,7 +1044,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { // We still need to call `make_return_dest` even if there's no `target`, since // `fn_abi.ret` could be `PassMode::Indirect`, even if it is uninhabited, // and `make_return_dest` adds the return-place indirect pointer to `llargs`. - let return_dest = self.make_return_dest(bx, destination, &fn_abi.ret, &mut llargs, None); + let return_dest = self.make_return_dest(bx, destination, &fn_abi.ret, &mut llargs); let destination = target.map(|target| (return_dest, target)); // Split the rust-call tupled arguments off. @@ -1857,7 +1875,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { dest: mir::Place<'tcx>, fn_ret: &ArgAbi<'tcx, Ty<'tcx>>, llargs: &mut Vec<Bx::Value>, - intrinsic: Option<ty::IntrinsicDef>, ) -> ReturnDest<'tcx, Bx::Value> { // If the return is ignored, we can just return a do-nothing `ReturnDest`. if fn_ret.is_ignore() { @@ -1877,13 +1894,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { tmp.storage_live(bx); llargs.push(tmp.val.llval); ReturnDest::IndirectOperand(tmp, index) - } else if intrinsic.is_some() { - // Currently, intrinsics always need a location to store - // the result, so we create a temporary `alloca` for the - // result. - let tmp = PlaceRef::alloca(bx, fn_ret.layout); - tmp.storage_live(bx); - ReturnDest::IndirectOperand(tmp, index) } else { ReturnDest::DirectOperand(index) }; @@ -1893,7 +1903,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { } } } else { - self.codegen_place(bx, mir::PlaceRef { local: dest.local, projection: dest.projection }) + self.codegen_place(bx, dest.as_ref()) }; if fn_ret.is_indirect() { if dest.val.align < dest.layout.align.abi { |