1 //! Codegen of a single function
3 use rustc_index::vec::IndexVec;
4 use rustc_middle::ty::adjustment::PointerCast;
5 use rustc_middle::ty::layout::FnAbiExt;
6 use rustc_target::abi::call::FnAbi;
10 pub(crate) fn codegen_fn<'tcx>(
11 cx: &mut crate::CodegenCx<'tcx, impl Module>,
12 instance: Instance<'tcx>,
18 crate::PrintOnPanic(|| format!("{:?} {}", instance, tcx.symbol_name(instance).name));
19 debug_assert!(!instance.substs.needs_infer());
21 let mir = tcx.instance_mir(instance.def);
24 let name = tcx.symbol_name(instance).name.to_string();
25 let sig = get_function_sig(tcx, cx.module.isa().triple(), instance);
26 let func_id = cx.module.declare_function(&name, linkage, &sig).unwrap();
28 cx.cached_context.clear();
30 // Make the FunctionBuilder
31 let mut func_ctx = FunctionBuilderContext::new();
32 let mut func = std::mem::replace(&mut cx.cached_context.func, Function::new());
33 func.name = ExternalName::user(0, func_id.as_u32());
35 func.collect_debug_info();
37 let mut bcx = FunctionBuilder::new(&mut func, &mut func_ctx);
40 let start_block = bcx.create_block();
41 let block_map: IndexVec<BasicBlock, Block> = (0..mir.basic_blocks().len())
42 .map(|_| bcx.create_block())
46 let pointer_type = cx.module.target_config().pointer_type();
47 let clif_comments = crate::pretty_clif::CommentWriter::new(tcx, instance);
49 let mut fx = FunctionCx {
56 fn_abi: Some(FnAbi::of_instance(&RevealAllLayoutCx(tcx), instance, &[])),
60 local_map: IndexVec::with_capacity(mir.local_decls.len()),
61 caller_location: None, // set by `codegen_fn_prelude`
62 cold_blocks: EntitySet::new(),
65 source_info_set: indexmap::IndexSet::new(),
71 let arg_uninhabited = fx.mir.args_iter().any(|arg| {
72 fx.layout_of(fx.monomorphize(&fx.mir.local_decls[arg].ty))
79 .append_block_params_for_function_params(fx.block_map[START_BLOCK]);
80 fx.bcx.switch_to_block(fx.block_map[START_BLOCK]);
81 crate::trap::trap_unreachable(&mut fx, "function has uninhabited argument");
83 tcx.sess.time("codegen clif ir", || {
84 tcx.sess.time("codegen prelude", || {
85 crate::abi::codegen_fn_prelude(&mut fx, start_block)
87 codegen_fn_content(&mut fx);
91 // Recover all necessary data from fx, before accessing func will prevent future access to it.
92 let instance = fx.instance;
93 let mut clif_comments = fx.clif_comments;
94 let source_info_set = fx.source_info_set;
95 let local_map = fx.local_map;
96 let cold_blocks = fx.cold_blocks;
98 // Store function in context
99 let context = &mut cx.cached_context;
102 crate::pretty_clif::write_clif_file(tcx, "unopt", None, instance, &context, &clif_comments);
105 verify_func(tcx, &clif_comments, &context.func);
107 // Perform rust specific optimizations
108 tcx.sess.time("optimize clif ir", || {
109 crate::optimize::optimize_function(
118 // If the return block is not reachable, then the SSA builder may have inserted an `iconst.i128`
119 // instruction, which doesn't have an encoding.
120 context.compute_cfg();
121 context.compute_domtree();
122 context.eliminate_unreachable_code(cx.module.isa()).unwrap();
123 context.dce(cx.module.isa()).unwrap();
124 // Some Cranelift optimizations expect the domtree to not yet be computed and as such don't
125 // invalidate it when it would change.
126 context.domtree.clear();
128 context.want_disasm = crate::pretty_clif::should_write_ir(tcx);
131 let module = &mut cx.module;
132 tcx.sess.time("define function", || {
137 &mut cranelift_codegen::binemit::NullTrapSink {},
142 // Write optimized function to file for debugging
143 crate::pretty_clif::write_clif_file(
146 Some(cx.module.isa()),
152 if let Some(mach_compile_result) = &context.mach_compile_result {
153 if let Some(disasm) = &mach_compile_result.disasm {
154 crate::pretty_clif::write_ir_file(
156 &format!("{}.vcode", tcx.symbol_name(instance).name),
157 |file| file.write_all(disasm.as_bytes()),
162 // Define debuginfo for function
163 let isa = cx.module.isa();
164 let debug_context = &mut cx.debug_context;
165 let unwind_context = &mut cx.unwind_context;
166 tcx.sess.time("generate debug info", || {
167 if let Some(debug_context) = debug_context {
168 debug_context.define_function(
178 unwind_context.add_function(func_id, &context, isa);
181 // Clear context to make it usable for the next function
185 pub(crate) fn verify_func(
187 writer: &crate::pretty_clif::CommentWriter,
190 tcx.sess.time("verify clif ir", || {
191 let flags = cranelift_codegen::settings::Flags::new(cranelift_codegen::settings::builder());
192 match cranelift_codegen::verify_function(&func, &flags) {
195 tcx.sess.err(&format!("{:?}", err));
196 let pretty_error = cranelift_codegen::print_errors::pretty_verifier_error(
199 Some(Box::new(writer)),
203 .fatal(&format!("cranelift verify error:\n{}", pretty_error));
209 fn codegen_fn_content(fx: &mut FunctionCx<'_, '_, impl Module>) {
210 crate::constant::check_constants(fx);
212 for (bb, bb_data) in fx.mir.basic_blocks().iter_enumerated() {
213 let block = fx.get_block(bb);
214 fx.bcx.switch_to_block(block);
216 if bb_data.is_cleanup {
217 // Unwinding after panicking is not supported
220 // FIXME once unwinding is supported uncomment next lines
221 // // Unwinding is unlikely to happen, so mark cleanup block's as cold.
222 // fx.cold_blocks.insert(block);
226 for stmt in &bb_data.statements {
227 fx.set_debug_loc(stmt.source_info);
228 codegen_stmt(fx, block, stmt);
231 #[cfg(debug_assertions)]
233 let mut terminator_head = "\n".to_string();
237 .fmt_head(&mut terminator_head)
239 let inst = fx.bcx.func.layout.last_inst(block).unwrap();
240 fx.add_comment(inst, terminator_head);
243 fx.set_debug_loc(bb_data.terminator().source_info);
245 match &bb_data.terminator().kind {
246 TerminatorKind::Goto { target } => {
247 if let TerminatorKind::Return = fx.mir[*target].terminator().kind {
248 let mut can_immediately_return = true;
249 for stmt in &fx.mir[*target].statements {
250 if let StatementKind::StorageDead(_) = stmt.kind {
252 // FIXME Can sometimes happen, see rust-lang/rust#70531
253 can_immediately_return = false;
258 if can_immediately_return {
259 crate::abi::codegen_return(fx);
264 let block = fx.get_block(*target);
265 fx.bcx.ins().jump(block, &[]);
267 TerminatorKind::Return => {
268 crate::abi::codegen_return(fx);
270 TerminatorKind::Assert {
277 if !fx.tcx.sess.overflow_checks() {
278 if let mir::AssertKind::OverflowNeg(_) = *msg {
279 let target = fx.get_block(*target);
280 fx.bcx.ins().jump(target, &[]);
284 let cond = codegen_operand(fx, cond).load_scalar(fx);
286 let target = fx.get_block(*target);
287 let failure = fx.bcx.create_block();
288 fx.cold_blocks.insert(failure);
291 fx.bcx.ins().brz(cond, failure, &[]);
293 fx.bcx.ins().brnz(cond, failure, &[]);
295 fx.bcx.ins().jump(target, &[]);
297 fx.bcx.switch_to_block(failure);
301 AssertKind::BoundsCheck { ref len, ref index } => {
302 let len = codegen_operand(fx, len).load_scalar(fx);
303 let index = codegen_operand(fx, index).load_scalar(fx);
305 .get_caller_location(bb_data.terminator().source_info.span)
310 rustc_hir::LangItem::PanicBoundsCheck,
311 &[index, len, location],
312 bb_data.terminator().source_info.span,
316 let msg_str = msg.description();
317 codegen_panic(fx, msg_str, bb_data.terminator().source_info.span);
322 TerminatorKind::SwitchInt {
327 let discr = codegen_operand(fx, discr).load_scalar(fx);
329 let use_bool_opt = switch_ty.kind() == fx.tcx.types.bool.kind()
330 || (targets.iter().count() == 1 && targets.iter().next().unwrap().0 == 0);
332 assert_eq!(targets.iter().count(), 1);
333 let (then_value, then_block) = targets.iter().next().unwrap();
334 let then_block = fx.get_block(then_block);
335 let else_block = fx.get_block(targets.otherwise());
336 let test_zero = match then_value {
339 _ => unreachable!("{:?}", targets),
342 let discr = crate::optimize::peephole::maybe_unwrap_bint(&mut fx.bcx, discr);
343 let (discr, is_inverted) =
344 crate::optimize::peephole::maybe_unwrap_bool_not(&mut fx.bcx, discr);
345 let test_zero = if is_inverted { !test_zero } else { test_zero };
346 let discr = crate::optimize::peephole::maybe_unwrap_bint(&mut fx.bcx, discr);
348 crate::optimize::peephole::make_branchable_value(&mut fx.bcx, discr);
349 if let Some(taken) = crate::optimize::peephole::maybe_known_branch_taken(
350 &fx.bcx, discr, test_zero,
353 fx.bcx.ins().jump(then_block, &[]);
355 fx.bcx.ins().jump(else_block, &[]);
359 fx.bcx.ins().brz(discr, then_block, &[]);
360 fx.bcx.ins().jump(else_block, &[]);
362 fx.bcx.ins().brnz(discr, then_block, &[]);
363 fx.bcx.ins().jump(else_block, &[]);
367 let mut switch = ::cranelift_frontend::Switch::new();
368 for (value, block) in targets.iter() {
369 let block = fx.get_block(block);
370 switch.set_entry(value, block);
372 let otherwise_block = fx.get_block(targets.otherwise());
373 switch.emit(&mut fx.bcx, discr, otherwise_block);
376 TerminatorKind::Call {
384 fx.tcx.sess.time("codegen call", || {
385 crate::abi::codegen_terminator_call(
395 TerminatorKind::InlineAsm {
402 crate::inline_asm::codegen_inline_asm(
404 bb_data.terminator().source_info.span,
411 Some(destination) => {
412 let destination_block = fx.get_block(destination);
413 fx.bcx.ins().jump(destination_block, &[]);
416 crate::trap::trap_unreachable(
418 "[corruption] Returned from noreturn inline asm",
423 TerminatorKind::Resume | TerminatorKind::Abort => {
424 trap_unreachable(fx, "[corruption] Unwinding bb reached.");
426 TerminatorKind::Unreachable => {
427 trap_unreachable(fx, "[corruption] Hit unreachable code.");
429 TerminatorKind::Yield { .. }
430 | TerminatorKind::FalseEdge { .. }
431 | TerminatorKind::FalseUnwind { .. }
432 | TerminatorKind::DropAndReplace { .. }
433 | TerminatorKind::GeneratorDrop => {
434 bug!("shouldn't exist at codegen {:?}", bb_data.terminator());
436 TerminatorKind::Drop {
441 let drop_place = codegen_place(fx, *place);
442 crate::abi::codegen_drop(fx, bb_data.terminator().source_info.span, drop_place);
444 let target_block = fx.get_block(*target);
445 fx.bcx.ins().jump(target_block, &[]);
450 fx.bcx.seal_all_blocks();
454 fn codegen_stmt<'tcx>(
455 fx: &mut FunctionCx<'_, 'tcx, impl Module>,
456 #[allow(unused_variables)] cur_block: Block,
457 stmt: &Statement<'tcx>,
459 let _print_guard = crate::PrintOnPanic(|| format!("stmt {:?}", stmt));
461 fx.set_debug_loc(stmt.source_info);
463 #[cfg(false_debug_assertions)]
465 StatementKind::StorageLive(..) | StatementKind::StorageDead(..) => {} // Those are not very useful
467 let inst = fx.bcx.func.layout.last_inst(cur_block).unwrap();
468 fx.add_comment(inst, format!("{:?}", stmt));
473 StatementKind::SetDiscriminant {
477 let place = codegen_place(fx, **place);
478 crate::discriminant::codegen_set_discriminant(fx, place, *variant_index);
480 StatementKind::Assign(to_place_and_rval) => {
481 let lval = codegen_place(fx, to_place_and_rval.0);
482 let dest_layout = lval.layout();
483 match to_place_and_rval.1 {
484 Rvalue::Use(ref operand) => {
485 let val = codegen_operand(fx, operand);
486 lval.write_cvalue(fx, val);
488 Rvalue::Ref(_, _, place) | Rvalue::AddressOf(_, place) => {
489 let place = codegen_place(fx, place);
490 let ref_ = place.place_ref(fx, lval.layout());
491 lval.write_cvalue(fx, ref_);
493 Rvalue::ThreadLocalRef(def_id) => {
494 let val = crate::constant::codegen_tls_ref(fx, def_id, lval.layout());
495 lval.write_cvalue(fx, val);
497 Rvalue::BinaryOp(bin_op, ref lhs, ref rhs) => {
498 let lhs = codegen_operand(fx, lhs);
499 let rhs = codegen_operand(fx, rhs);
501 let res = crate::num::codegen_binop(fx, bin_op, lhs, rhs);
502 lval.write_cvalue(fx, res);
504 Rvalue::CheckedBinaryOp(bin_op, ref lhs, ref rhs) => {
505 let lhs = codegen_operand(fx, lhs);
506 let rhs = codegen_operand(fx, rhs);
508 let res = if !fx.tcx.sess.overflow_checks() {
510 crate::num::codegen_int_binop(fx, bin_op, lhs, rhs).load_scalar(fx);
511 let is_overflow = fx.bcx.ins().iconst(types::I8, 0);
512 CValue::by_val_pair(val, is_overflow, lval.layout())
514 crate::num::codegen_checked_int_binop(fx, bin_op, lhs, rhs)
517 lval.write_cvalue(fx, res);
519 Rvalue::UnaryOp(un_op, ref operand) => {
520 let operand = codegen_operand(fx, operand);
521 let layout = operand.layout();
522 let val = operand.load_scalar(fx);
523 let res = match un_op {
524 UnOp::Not => match layout.ty.kind() {
526 let res = fx.bcx.ins().icmp_imm(IntCC::Equal, val, 0);
527 CValue::by_val(fx.bcx.ins().bint(types::I8, res), layout)
529 ty::Uint(_) | ty::Int(_) => {
530 CValue::by_val(fx.bcx.ins().bnot(val), layout)
532 _ => unreachable!("un op Not for {:?}", layout.ty),
534 UnOp::Neg => match layout.ty.kind() {
535 ty::Int(IntTy::I128) => {
536 // FIXME remove this case once ineg.i128 works
538 CValue::const_val(fx, layout, ty::ScalarInt::null(layout.size));
539 crate::num::codegen_int_binop(fx, BinOp::Sub, zero, operand)
541 ty::Int(_) => CValue::by_val(fx.bcx.ins().ineg(val), layout),
542 ty::Float(_) => CValue::by_val(fx.bcx.ins().fneg(val), layout),
543 _ => unreachable!("un op Neg for {:?}", layout.ty),
546 lval.write_cvalue(fx, res);
549 CastKind::Pointer(PointerCast::ReifyFnPointer),
553 let from_ty = fx.monomorphize(operand.ty(&fx.mir.local_decls, fx.tcx));
554 let to_layout = fx.layout_of(fx.monomorphize(to_ty));
555 match *from_ty.kind() {
556 ty::FnDef(def_id, substs) => {
557 let func_ref = fx.get_function_ref(
558 Instance::resolve_for_fn_ptr(
560 ParamEnv::reveal_all(),
565 .polymorphize(fx.tcx),
567 let func_addr = fx.bcx.ins().func_addr(fx.pointer_type, func_ref);
568 lval.write_cvalue(fx, CValue::by_val(func_addr, to_layout));
570 _ => bug!("Trying to ReifyFnPointer on non FnDef {:?}", from_ty),
574 CastKind::Pointer(PointerCast::UnsafeFnPointer),
579 CastKind::Pointer(PointerCast::MutToConstPointer),
584 CastKind::Pointer(PointerCast::ArrayToPointer),
588 let to_layout = fx.layout_of(fx.monomorphize(to_ty));
589 let operand = codegen_operand(fx, operand);
590 lval.write_cvalue(fx, operand.cast_pointer_to(to_layout));
592 Rvalue::Cast(CastKind::Misc, ref operand, to_ty) => {
593 let operand = codegen_operand(fx, operand);
594 let from_ty = operand.layout().ty;
595 let to_ty = fx.monomorphize(to_ty);
598 fx: &FunctionCx<'_, 'tcx, impl Module>,
601 ty.builtin_deref(true)
607 has_ptr_meta(fx.tcx, pointee_ty)
613 if is_fat_ptr(fx, from_ty) {
614 if is_fat_ptr(fx, to_ty) {
615 // fat-ptr -> fat-ptr
616 lval.write_cvalue(fx, operand.cast_pointer_to(dest_layout));
618 // fat-ptr -> thin-ptr
619 let (ptr, _extra) = operand.load_scalar_pair(fx);
620 lval.write_cvalue(fx, CValue::by_val(ptr, dest_layout))
622 } else if let ty::Adt(adt_def, _substs) = from_ty.kind() {
623 // enum -> discriminant value
624 assert!(adt_def.is_enum());
626 ty::Uint(_) | ty::Int(_) => {}
627 _ => unreachable!("cast adt {} -> {}", from_ty, to_ty),
630 use rustc_target::abi::{Int, TagEncoding, Variants};
632 match operand.layout().variants {
633 Variants::Single { index } => {
637 .discriminant_for_variant(fx.tcx, index)
639 let discr = if discr.ty.is_signed() {
640 fx.layout_of(discr.ty).size.sign_extend(discr.val)
644 let discr = discr.into();
646 let discr = CValue::const_val(fx, fx.layout_of(to_ty), discr);
647 lval.write_cvalue(fx, discr);
652 tag_encoding: TagEncoding::Direct,
655 let cast_to = fx.clif_type(dest_layout.ty).unwrap();
657 // Read the tag/niche-encoded discriminant from memory.
659 operand.value_field(fx, mir::Field::new(tag_field));
660 let encoded_discr = encoded_discr.load_scalar(fx);
662 // Decode the discriminant (specifically if it's niche-encoded).
663 let signed = match tag.value {
664 Int(_, signed) => signed,
667 let val = clif_intcast(fx, encoded_discr, cast_to, signed);
668 let val = CValue::by_val(val, dest_layout);
669 lval.write_cvalue(fx, val);
671 Variants::Multiple { .. } => unreachable!(),
674 let to_clif_ty = fx.clif_type(to_ty).unwrap();
675 let from = operand.load_scalar(fx);
677 let res = clif_int_or_float_cast(
684 lval.write_cvalue(fx, CValue::by_val(res, dest_layout));
688 CastKind::Pointer(PointerCast::ClosureFnPointer(_)),
692 let operand = codegen_operand(fx, operand);
693 match *operand.layout().ty.kind() {
694 ty::Closure(def_id, substs) => {
695 let instance = Instance::resolve_closure(
699 ty::ClosureKind::FnOnce,
701 .polymorphize(fx.tcx);
702 let func_ref = fx.get_function_ref(instance);
703 let func_addr = fx.bcx.ins().func_addr(fx.pointer_type, func_ref);
704 lval.write_cvalue(fx, CValue::by_val(func_addr, lval.layout()));
706 _ => bug!("{} cannot be cast to a fn ptr", operand.layout().ty),
709 Rvalue::Cast(CastKind::Pointer(PointerCast::Unsize), ref operand, _to_ty) => {
710 let operand = codegen_operand(fx, operand);
711 operand.unsize_value(fx, lval);
713 Rvalue::Discriminant(place) => {
714 let place = codegen_place(fx, place);
715 let value = place.to_cvalue(fx);
717 crate::discriminant::codegen_get_discriminant(fx, value, dest_layout);
718 lval.write_cvalue(fx, discr);
720 Rvalue::Repeat(ref operand, times) => {
721 let operand = codegen_operand(fx, operand);
724 .eval(fx.tcx, ParamEnv::reveal_all())
726 .try_to_bits(fx.tcx.data_layout.pointer_size)
728 if fx.clif_type(operand.layout().ty) == Some(types::I8) {
729 let times = fx.bcx.ins().iconst(fx.pointer_type, times as i64);
730 // FIXME use emit_small_memset where possible
731 let addr = lval.to_ptr().get_addr(fx);
732 let val = operand.load_scalar(fx);
734 .call_memset(fx.cx.module.target_config(), addr, val, times);
736 let loop_block = fx.bcx.create_block();
737 let loop_block2 = fx.bcx.create_block();
738 let done_block = fx.bcx.create_block();
739 let index = fx.bcx.append_block_param(loop_block, fx.pointer_type);
740 let zero = fx.bcx.ins().iconst(fx.pointer_type, 0);
741 fx.bcx.ins().jump(loop_block, &[zero]);
743 fx.bcx.switch_to_block(loop_block);
744 let done = fx.bcx.ins().icmp_imm(IntCC::Equal, index, times as i64);
745 fx.bcx.ins().brnz(done, done_block, &[]);
746 fx.bcx.ins().jump(loop_block2, &[]);
748 fx.bcx.switch_to_block(loop_block2);
749 let to = lval.place_index(fx, index);
750 to.write_cvalue(fx, operand);
751 let index = fx.bcx.ins().iadd_imm(index, 1);
752 fx.bcx.ins().jump(loop_block, &[index]);
754 fx.bcx.switch_to_block(done_block);
758 Rvalue::Len(place) => {
759 let place = codegen_place(fx, place);
760 let usize_layout = fx.layout_of(fx.tcx.types.usize);
761 let len = codegen_array_len(fx, place);
762 lval.write_cvalue(fx, CValue::by_val(len, usize_layout));
764 Rvalue::NullaryOp(NullOp::Box, content_ty) => {
765 let usize_type = fx.clif_type(fx.tcx.types.usize).unwrap();
766 let content_ty = fx.monomorphize(content_ty);
767 let layout = fx.layout_of(content_ty);
768 let llsize = fx.bcx.ins().iconst(usize_type, layout.size.bytes() as i64);
772 .iconst(usize_type, layout.align.abi.bytes() as i64);
773 let box_layout = fx.layout_of(fx.tcx.mk_box(content_ty));
776 let def_id = match fx
779 .require(rustc_hir::LangItem::ExchangeMalloc)
785 .fatal(&format!("allocation of `{}` {}", box_layout.ty, s));
788 let instance = ty::Instance::mono(fx.tcx, def_id).polymorphize(fx.tcx);
789 let func_ref = fx.get_function_ref(instance);
790 let call = fx.bcx.ins().call(func_ref, &[llsize, llalign]);
791 let ptr = fx.bcx.inst_results(call)[0];
792 lval.write_cvalue(fx, CValue::by_val(ptr, box_layout));
794 Rvalue::NullaryOp(NullOp::SizeOf, ty) => {
798 .is_sized(fx.tcx.at(stmt.source_info.span), ParamEnv::reveal_all()));
799 let ty_size = fx.layout_of(fx.monomorphize(ty)).size.bytes();
801 CValue::const_val(fx, fx.layout_of(fx.tcx.types.usize), ty_size.into());
802 lval.write_cvalue(fx, val);
804 Rvalue::Aggregate(ref kind, ref operands) => match kind.as_ref() {
805 AggregateKind::Array(_ty) => {
806 for (i, operand) in operands.iter().enumerate() {
807 let operand = codegen_operand(fx, operand);
808 let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
809 let to = lval.place_index(fx, index);
810 to.write_cvalue(fx, operand);
813 _ => unreachable!("shouldn't exist at codegen {:?}", to_place_and_rval.1),
817 StatementKind::StorageLive(_)
818 | StatementKind::StorageDead(_)
820 | StatementKind::FakeRead(..)
821 | StatementKind::Retag { .. }
822 | StatementKind::AscribeUserType(..) => {}
824 StatementKind::LlvmInlineAsm(asm) => {
825 use rustc_span::symbol::Symbol;
831 let rustc_hir::LlvmInlineAsmInner {
832 asm: asm_code, // Name
833 outputs: output_names, // Vec<LlvmInlineAsmOutput>
834 inputs: input_names, // Vec<Name>
835 clobbers, // Vec<Name>
841 match asm_code.as_str().trim() {
845 "mov %rbx, %rsi\n cpuid\n xchg %rbx, %rsi" => {
848 &[Symbol::intern("{eax}"), Symbol::intern("{ecx}")]
850 assert_eq!(output_names.len(), 4);
851 for (i, c) in (&["={eax}", "={esi}", "={ecx}", "={edx}"])
855 assert_eq!(&output_names[i].constraint.as_str(), c);
856 assert!(!output_names[i].is_rw);
857 assert!(!output_names[i].is_indirect);
860 assert_eq!(clobbers, &[]);
863 assert!(!alignstack);
865 assert_eq!(inputs.len(), 2);
866 let leaf = codegen_operand(fx, &inputs[0].1).load_scalar(fx); // %eax
867 let subleaf = codegen_operand(fx, &inputs[1].1).load_scalar(fx); // %ecx
869 let (eax, ebx, ecx, edx) =
870 crate::intrinsics::codegen_cpuid_call(fx, leaf, subleaf);
872 assert_eq!(outputs.len(), 4);
873 codegen_place(fx, outputs[0])
874 .write_cvalue(fx, CValue::by_val(eax, fx.layout_of(fx.tcx.types.u32)));
875 codegen_place(fx, outputs[1])
876 .write_cvalue(fx, CValue::by_val(ebx, fx.layout_of(fx.tcx.types.u32)));
877 codegen_place(fx, outputs[2])
878 .write_cvalue(fx, CValue::by_val(ecx, fx.layout_of(fx.tcx.types.u32)));
879 codegen_place(fx, outputs[3])
880 .write_cvalue(fx, CValue::by_val(edx, fx.layout_of(fx.tcx.types.u32)));
883 assert_eq!(input_names, &[Symbol::intern("{ecx}")]);
885 assert_eq!(output_names.len(), 2);
886 for (i, c) in (&["={eax}", "={edx}"]).iter().enumerate() {
887 assert_eq!(&output_names[i].constraint.as_str(), c);
888 assert!(!output_names[i].is_rw);
889 assert!(!output_names[i].is_indirect);
892 assert_eq!(clobbers, &[]);
895 assert!(!alignstack);
897 crate::trap::trap_unimplemented(fx, "_xgetbv arch intrinsic is not supported");
899 // ___chkstk, ___chkstk_ms and __alloca are only used on Windows
902 .symbol_name(fx.instance)
904 .starts_with("___chkstk") =>
906 crate::trap::trap_unimplemented(fx, "Stack probes are not supported");
908 _ if fx.tcx.symbol_name(fx.instance).name == "__alloca" => {
909 crate::trap::trap_unimplemented(fx, "Alloca is not supported");
911 // Used in sys::windows::abort_internal
913 crate::trap::trap_unimplemented(fx, "Windows abort");
918 .span_fatal(stmt.source_info.span, "Inline assembly is not supported"),
921 StatementKind::Coverage { .. } => fx.tcx.sess.fatal("-Zcoverage is unimplemented"),
925 fn codegen_array_len<'tcx>(
926 fx: &mut FunctionCx<'_, 'tcx, impl Module>,
929 match *place.layout().ty.kind() {
930 ty::Array(_elem_ty, len) => {
933 .eval_usize(fx.tcx, ParamEnv::reveal_all()) as i64;
934 fx.bcx.ins().iconst(fx.pointer_type, len)
936 ty::Slice(_elem_ty) => place
937 .to_ptr_maybe_unsized()
939 .expect("Length metadata for slice place"),
940 _ => bug!("Rvalue::Len({:?})", place),
944 pub(crate) fn codegen_place<'tcx>(
945 fx: &mut FunctionCx<'_, 'tcx, impl Module>,
948 let mut cplace = fx.get_local_place(place.local);
950 for elem in place.projection {
952 PlaceElem::Deref => {
953 cplace = cplace.place_deref(fx);
955 PlaceElem::Field(field, _ty) => {
956 cplace = cplace.place_field(fx, field);
958 PlaceElem::Index(local) => {
959 let index = fx.get_local_place(local).to_cvalue(fx).load_scalar(fx);
960 cplace = cplace.place_index(fx, index);
962 PlaceElem::ConstantIndex {
967 let offset: u64 = offset;
968 let index = if !from_end {
969 fx.bcx.ins().iconst(fx.pointer_type, offset as i64)
971 let len = codegen_array_len(fx, cplace);
972 fx.bcx.ins().iadd_imm(len, -(offset as i64))
974 cplace = cplace.place_index(fx, index);
976 PlaceElem::Subslice { from, to, from_end } => {
977 // These indices are generated by slice patterns.
978 // slice[from:-to] in Python terms.
980 let from: u64 = from;
983 match cplace.layout().ty.kind() {
984 ty::Array(elem_ty, _len) => {
985 assert!(!from_end, "array subslices are never `from_end`");
986 let elem_layout = fx.layout_of(elem_ty);
987 let ptr = cplace.to_ptr();
988 cplace = CPlace::for_ptr(
989 ptr.offset_i64(fx, elem_layout.size.bytes() as i64 * (from as i64)),
990 fx.layout_of(fx.tcx.mk_array(elem_ty, to - from)),
993 ty::Slice(elem_ty) => {
994 assert!(from_end, "slice subslices should be `from_end`");
995 let elem_layout = fx.layout_of(elem_ty);
996 let (ptr, len) = cplace.to_ptr_maybe_unsized();
997 let len = len.unwrap();
998 cplace = CPlace::for_ptr_with_extra(
999 ptr.offset_i64(fx, elem_layout.size.bytes() as i64 * (from as i64)),
1000 fx.bcx.ins().iadd_imm(len, -(from as i64 + to as i64)),
1004 _ => unreachable!(),
1007 PlaceElem::Downcast(_adt_def, variant) => {
1008 cplace = cplace.downcast_variant(fx, variant);
1016 pub(crate) fn codegen_operand<'tcx>(
1017 fx: &mut FunctionCx<'_, 'tcx, impl Module>,
1018 operand: &Operand<'tcx>,
1021 Operand::Move(place) | Operand::Copy(place) => {
1022 let cplace = codegen_place(fx, *place);
1023 cplace.to_cvalue(fx)
1025 Operand::Constant(const_) => crate::constant::codegen_constant(fx, const_),
1029 pub(crate) fn codegen_panic<'tcx>(
1030 fx: &mut FunctionCx<'_, 'tcx, impl Module>,
1034 let location = fx.get_caller_location(span).load_scalar(fx);
1036 let msg_ptr = fx.anonymous_str("assert", msg_str);
1040 .iconst(fx.pointer_type, i64::try_from(msg_str.len()).unwrap());
1041 let args = [msg_ptr, msg_len, location];
1043 codegen_panic_inner(fx, rustc_hir::LangItem::Panic, &args, span);
1046 pub(crate) fn codegen_panic_inner<'tcx>(
1047 fx: &mut FunctionCx<'_, 'tcx, impl Module>,
1048 lang_item: rustc_hir::LangItem,
1056 .unwrap_or_else(|s| fx.tcx.sess.span_fatal(span, &s));
1058 let instance = Instance::mono(fx.tcx, def_id).polymorphize(fx.tcx);
1059 let symbol_name = fx.tcx.symbol_name(instance).name;
1063 vec![fx.pointer_type, fx.pointer_type, fx.pointer_type],
1068 crate::trap::trap_unreachable(fx, "panic lang item returned");