]> git.lizzy.rs Git - rust.git/blobdiff - src/base.rs
Merge commit '15c8d31392b9fbab3b3368b67acc4bbe5983115a' into cranelift-rebase
[rust.git] / src / base.rs
index d2841b25f5ea9b2e1b91297daa31000af521ac6e..3ec5c14ff17a2d8308657936aa5c21f15cfc6160 100644 (file)
-use rustc::ty::adjustment::PointerCast;
+//! Codegen of a single function
+
+use cranelift_codegen::binemit::{NullStackMapSink, NullTrapSink};
 use rustc_index::vec::IndexVec;
+use rustc_middle::ty::adjustment::PointerCast;
+use rustc_middle::ty::layout::FnAbiExt;
+use rustc_target::abi::call::FnAbi;
 
+use crate::constant::ConstantCx;
 use crate::prelude::*;
 
-pub(crate) fn trans_fn<'clif, 'tcx, B: Backend + 'static>(
-    cx: &mut crate::CodegenCx<'clif, 'tcx, B>,
+pub(crate) fn codegen_fn<'tcx>(
+    cx: &mut crate::CodegenCx<'tcx>,
+    module: &mut dyn Module,
     instance: Instance<'tcx>,
-    linkage: Linkage,
 ) {
     let tcx = cx.tcx;
 
-    let mir = *tcx.instance_mir(instance.def);
+    let _inst_guard =
+        crate::PrintOnPanic(|| format!("{:?} {}", instance, tcx.symbol_name(instance).name));
+    debug_assert!(!instance.substs.needs_infer());
+
+    let mir = tcx.instance_mir(instance.def);
 
     // Declare function
-    let (name, sig) = get_function_name_and_sig(tcx, cx.module.isa().triple(), instance, false);
-    let func_id = cx.module.declare_function(&name, linkage, &sig).unwrap();
-    let mut debug_context = cx
-        .debug_context
-        .as_mut()
-        .map(|debug_context| FunctionDebugContext::new(debug_context, instance, func_id, &name));
-
-    // Make FunctionBuilder
-    let context = &mut cx.cached_context;
-    context.clear();
-    context.func.name = ExternalName::user(0, func_id.as_u32());
-    context.func.signature = sig;
-    context.func.collect_debug_info();
+    let symbol_name = tcx.symbol_name(instance);
+    let sig = get_function_sig(tcx, module.isa().triple(), instance);
+    let func_id = module.declare_function(symbol_name.name, Linkage::Local, &sig).unwrap();
+
+    cx.cached_context.clear();
+
+    // Make the FunctionBuilder
     let mut func_ctx = FunctionBuilderContext::new();
-    let mut bcx = FunctionBuilder::new(&mut context.func, &mut func_ctx);
+    let mut func = std::mem::replace(&mut cx.cached_context.func, Function::new());
+    func.name = ExternalName::user(0, func_id.as_u32());
+    func.signature = sig;
+    func.collect_debug_info();
+
+    let mut bcx = FunctionBuilder::new(&mut func, &mut func_ctx);
 
-    // Predefine block's
+    // Predefine blocks
     let start_block = bcx.create_block();
-    let block_map: IndexVec<BasicBlock, Block> = (0..mir.basic_blocks().len()).map(|_| bcx.create_block()).collect();
+    let block_map: IndexVec<BasicBlock, Block> =
+        (0..mir.basic_blocks().len()).map(|_| bcx.create_block()).collect();
 
     // Make FunctionCx
-    let pointer_type = cx.module.target_config().pointer_type();
+    let pointer_type = module.target_config().pointer_type();
     let clif_comments = crate::pretty_clif::CommentWriter::new(tcx, instance);
 
     let mut fx = FunctionCx {
+        cx,
+        module,
         tcx,
-        module: cx.module,
         pointer_type,
+        vtables: FxHashMap::default(),
+        constants_cx: ConstantCx::new(),
 
         instance,
+        symbol_name,
         mir,
+        fn_abi: Some(FnAbi::of_instance(&RevealAllLayoutCx(tcx), instance, &[])),
 
         bcx,
         block_map,
-        local_map: HashMap::new(),
+        local_map: IndexVec::with_capacity(mir.local_decls.len()),
         caller_location: None, // set by `codegen_fn_prelude`
-        cold_blocks: EntitySet::new(),
 
         clif_comments,
-        constants_cx: &mut cx.constants_cx,
-        vtables: &mut cx.vtables,
         source_info_set: indexmap::IndexSet::new(),
+        next_ssa_var: 0,
+
+        inline_asm_index: 0,
     };
 
-    let arg_uninhabited = fx.mir.args_iter().any(|arg| fx.layout_of(fx.monomorphize(&fx.mir.local_decls[arg].ty)).abi.is_uninhabited());
-    let is_call_once_for_box = name.starts_with("_ZN83_$LT$alloc..boxed..Box$LT$F$GT$$u20$as$u20$core..ops..function..FnOnce$LT$A$GT$$GT$9call_once");
+    let arg_uninhabited = fx
+        .mir
+        .args_iter()
+        .any(|arg| fx.layout_of(fx.monomorphize(&fx.mir.local_decls[arg].ty)).abi.is_uninhabited());
 
-    if arg_uninhabited {
+    if !crate::constant::check_constants(&mut fx) {
         fx.bcx.append_block_params_for_function_params(fx.block_map[START_BLOCK]);
         fx.bcx.switch_to_block(fx.block_map[START_BLOCK]);
-        crate::trap::trap_unreachable(&mut fx, "function has uninhabited argument");
-    } else if is_call_once_for_box {
-        // HACK implement `<Box<F> as FnOnce>::call_once` without `alloca`.
-        tcx.sess.time("codegen prelude", || crate::abi::codegen_fn_prelude(&mut fx, start_block, false));
+        crate::trap::trap_unreachable(&mut fx, "compilation should have been aborted");
+    } else if arg_uninhabited {
+        fx.bcx.append_block_params_for_function_params(fx.block_map[START_BLOCK]);
         fx.bcx.switch_to_block(fx.block_map[START_BLOCK]);
-        let bb_data = &fx.mir.basic_blocks()[START_BLOCK];
-        let destination = match &bb_data.terminator().kind {
-            TerminatorKind::Call {
-                func,
-                args,
-                destination,
-                cleanup: _,
-                from_hir_call: _,
-            } => {
-                assert_eq!(args.len(), 2);
-
-                let closure_arg = Local::new(1);
-                let closure_local = args[0].place().unwrap().as_local().unwrap();
-                assert_eq!(fx.mir.local_decls[closure_local].ty, fx.mir.local_decls[closure_arg].ty.builtin_deref(true).unwrap().ty);
-                let closure_deref = fx.local_map[&closure_arg].place_deref(&mut fx);
-                fx.local_map.insert(closure_local, closure_deref);
-
-                let args_arg = Local::new(2);
-                let args_local = args[1].place().unwrap().as_local().unwrap();
-                assert_eq!(fx.mir.local_decls[args_local].ty, fx.mir.local_decls[args_arg].ty);
-                fx.local_map.insert(args_local, fx.local_map[&args_arg]);
-
-                fx.tcx.sess.time("codegen call", || crate::abi::codegen_terminator_call(
-                    &mut fx,
-                    bb_data.terminator().source_info.span,
-                    func,
-                    args,
-                    destination,
-                ));
-                destination.map(|(_ret_place, ret_block)| ret_block)
-            }
-            _ => unreachable!(),
-        };
-
-        let destination = if let Some(destination) = destination {
-            fx.bcx.switch_to_block(fx.block_map[destination]);
-            let bb_data = &fx.mir.basic_blocks()[destination];
-            match &bb_data.terminator().kind {
-                TerminatorKind::Call {
-                    func,
-                    args,
-                    destination,
-                    cleanup: _,
-                    from_hir_call: _,
-                } => {
-                    match destination {
-                        Some((ret_place, _ret_block)) => {
-                            fx.local_map.insert(ret_place.as_local().unwrap(), CPlace::no_place(fx.layout_of(fx.tcx.mk_unit())));
-                        }
-                        None => {}
-                    }
-
-                    assert_eq!(args.len(), 1);
-                    fx.tcx.sess.time("codegen call", || crate::abi::codegen_terminator_call(
-                        &mut fx,
-                        bb_data.terminator().source_info.span,
-                        func,
-                        args,
-                        destination,
-                    ));
-                    destination.map(|(_ret_place, ret_block)| ret_block)
-                }
-                _ => unreachable!(),
-            }
-        } else {
-            None
-        };
-
-        if let Some(destination) = destination {
-            fx.bcx.switch_to_block(fx.block_map[destination]);
-            let bb_data = &fx.mir.basic_blocks()[destination];
-            match &bb_data.terminator().kind {
-                TerminatorKind::Return => crate::abi::codegen_return(&mut fx),
-                _ => unreachable!(),
-            }
-        }
+        crate::trap::trap_unreachable(&mut fx, "function has uninhabited argument");
     } else {
         tcx.sess.time("codegen clif ir", || {
-            tcx.sess.time("codegen prelude", || crate::abi::codegen_fn_prelude(&mut fx, start_block, true));
+            tcx.sess
+                .time("codegen prelude", || crate::abi::codegen_fn_prelude(&mut fx, start_block));
             codegen_fn_content(&mut fx);
         });
     }
@@ -156,80 +98,107 @@ pub(crate) fn trans_fn<'clif, 'tcx, B: Backend + 'static>(
     let mut clif_comments = fx.clif_comments;
     let source_info_set = fx.source_info_set;
     let local_map = fx.local_map;
-    let cold_blocks = fx.cold_blocks;
 
-    #[cfg(debug_assertions)]
-    crate::pretty_clif::write_clif_file(cx.tcx, "unopt", instance, &context.func, &clif_comments, None);
+    fx.constants_cx.finalize(fx.tcx, &mut *fx.module);
+
+    // Store function in context
+    let context = &mut cx.cached_context;
+    context.func = func;
+
+    crate::pretty_clif::write_clif_file(tcx, "unopt", None, instance, &context, &clif_comments);
 
     // Verify function
     verify_func(tcx, &clif_comments, &context.func);
 
     // Perform rust specific optimizations
     tcx.sess.time("optimize clif ir", || {
-        crate::optimize::optimize_function(tcx, instance, context, &cold_blocks, &mut clif_comments);
+        crate::optimize::optimize_function(tcx, instance, context, &mut clif_comments);
     });
 
+    // If the return block is not reachable, then the SSA builder may have inserted an `iconst.i128`
+    // instruction, which doesn't have an encoding.
+    context.compute_cfg();
+    context.compute_domtree();
+    context.eliminate_unreachable_code(module.isa()).unwrap();
+    context.dce(module.isa()).unwrap();
+    // Some Cranelift optimizations expect the domtree to not yet be computed and as such don't
+    // invalidate it when it would change.
+    context.domtree.clear();
+
+    context.want_disasm = crate::pretty_clif::should_write_ir(tcx);
+
     // Define function
-    let module = &mut cx.module;
-    tcx.sess.time(
-        "define function",
-        || module.define_function(
-            func_id,
-            context,
-            &mut cranelift_codegen::binemit::NullTrapSink {},
-        ).unwrap(),
-    );
+    tcx.sess.time("define function", || {
+        module
+            .define_function(func_id, context, &mut NullTrapSink {}, &mut NullStackMapSink {})
+            .unwrap()
+    });
 
     // Write optimized function to file for debugging
-    #[cfg(debug_assertions)]
-    {
-        let value_ranges = context
-            .build_value_labels_ranges(cx.module.isa())
-            .expect("value location ranges");
-
-        crate::pretty_clif::write_clif_file(
-            cx.tcx,
-            "opt",
-            instance,
-            &context.func,
-            &clif_comments,
-            Some(&value_ranges),
-        );
+    crate::pretty_clif::write_clif_file(
+        tcx,
+        "opt",
+        Some(module.isa()),
+        instance,
+        &context,
+        &clif_comments,
+    );
+
+    if let Some(disasm) = &context.mach_compile_result.as_ref().unwrap().disasm {
+        crate::pretty_clif::write_ir_file(
+            tcx,
+            || format!("{}.vcode", tcx.symbol_name(instance).name),
+            |file| file.write_all(disasm.as_bytes()),
+        )
     }
 
     // Define debuginfo for function
-    let isa = cx.module.isa();
+    let isa = module.isa();
+    let debug_context = &mut cx.debug_context;
+    let unwind_context = &mut cx.unwind_context;
     tcx.sess.time("generate debug info", || {
-        debug_context
-            .as_mut()
-            .map(|x| x.define(context, isa, &source_info_set, local_map));
+        if let Some(debug_context) = debug_context {
+            debug_context.define_function(
+                instance,
+                func_id,
+                symbol_name.name,
+                isa,
+                context,
+                &source_info_set,
+                local_map,
+            );
+        }
+        unwind_context.add_function(func_id, &context, isa);
     });
 
     // Clear context to make it usable for the next function
     context.clear();
 }
 
-pub(crate) fn verify_func(tcx: TyCtxt, writer: &crate::pretty_clif::CommentWriter, func: &Function) {
+pub(crate) fn verify_func(
+    tcx: TyCtxt<'_>,
+    writer: &crate::pretty_clif::CommentWriter,
+    func: &Function,
+) {
     tcx.sess.time("verify clif ir", || {
-        let flags = settings::Flags::new(settings::builder());
-        match ::cranelift_codegen::verify_function(&func, &flags) {
+        let flags = cranelift_codegen::settings::Flags::new(cranelift_codegen::settings::builder());
+        match cranelift_codegen::verify_function(&func, &flags) {
             Ok(_) => {}
             Err(err) => {
                 tcx.sess.err(&format!("{:?}", err));
-                let pretty_error = ::cranelift_codegen::print_errors::pretty_verifier_error(
+                let pretty_error = cranelift_codegen::print_errors::pretty_verifier_error(
                     &func,
                     None,
                     Some(Box::new(writer)),
                     err,
                 );
-                tcx.sess
-                    .fatal(&format!("cranelift verify error:\n{}", pretty_error));
+                tcx.sess.fatal(&format!("cranelift verify error:\n{}", pretty_error));
             }
         }
     });
 }
 
-fn codegen_fn_content(fx: &mut FunctionCx<'_, '_, impl Backend>) {
+fn codegen_fn_content(fx: &mut FunctionCx<'_, '_, '_>) {
     for (bb, bb_data) in fx.mir.basic_blocks().iter_enumerated() {
         let block = fx.get_block(bb);
         fx.bcx.switch_to_block(block);
@@ -238,25 +207,19 @@ fn codegen_fn_content(fx: &mut FunctionCx<'_, '_, impl Backend>) {
             // Unwinding after panicking is not supported
             continue;
 
-            // FIXME once unwinding is supported uncomment next lines
-            // // Unwinding is unlikely to happen, so mark cleanup block's as cold.
-            // fx.cold_blocks.insert(block);
+            // FIXME Once unwinding is supported and Cranelift supports marking blocks as cold, do
+            // so for cleanup blocks.
         }
 
         fx.bcx.ins().nop();
         for stmt in &bb_data.statements {
             fx.set_debug_loc(stmt.source_info);
-            trans_stmt(fx, block, stmt);
+            codegen_stmt(fx, block, stmt);
         }
 
-        #[cfg(debug_assertions)]
-        {
+        if fx.clif_comments.enabled() {
             let mut terminator_head = "\n".to_string();
-            bb_data
-                .terminator()
-                .kind
-                .fmt_head(&mut terminator_head)
-                .unwrap();
+            bb_data.terminator().kind.fmt_head(&mut terminator_head).unwrap();
             let inst = fx.bcx.func.layout.last_inst(block).unwrap();
             fx.add_comment(inst, terminator_head);
         }
@@ -265,31 +228,42 @@ fn codegen_fn_content(fx: &mut FunctionCx<'_, '_, impl Backend>) {
 
         match &bb_data.terminator().kind {
             TerminatorKind::Goto { target } => {
+                if let TerminatorKind::Return = fx.mir[*target].terminator().kind {
+                    let mut can_immediately_return = true;
+                    for stmt in &fx.mir[*target].statements {
+                        if let StatementKind::StorageDead(_) = stmt.kind {
+                        } else {
+                            // FIXME Can sometimes happen, see rust-lang/rust#70531
+                            can_immediately_return = false;
+                            break;
+                        }
+                    }
+
+                    if can_immediately_return {
+                        crate::abi::codegen_return(fx);
+                        continue;
+                    }
+                }
+
                 let block = fx.get_block(*target);
                 fx.bcx.ins().jump(block, &[]);
             }
             TerminatorKind::Return => {
                 crate::abi::codegen_return(fx);
             }
-            TerminatorKind::Assert {
-                cond,
-                expected,
-                msg,
-                target,
-                cleanup: _,
-            } => {
+            TerminatorKind::Assert { cond, expected, msg, target, cleanup: _ } => {
                 if !fx.tcx.sess.overflow_checks() {
-                    if let mir::AssertKind::OverflowNeg = *msg {
+                    if let mir::AssertKind::OverflowNeg(_) = *msg {
                         let target = fx.get_block(*target);
                         fx.bcx.ins().jump(target, &[]);
                         continue;
                     }
                 }
-                let cond = trans_operand(fx, cond).load_scalar(fx);
+                let cond = codegen_operand(fx, cond).load_scalar(fx);
 
                 let target = fx.get_block(*target);
                 let failure = fx.bcx.create_block();
-                fx.cold_blocks.insert(failure);
+                // FIXME Mark failure block as cold once Cranelift supports it
 
                 if *expected {
                     fx.bcx.ins().brz(cond, failure, &[]);
@@ -299,45 +273,119 @@ fn codegen_fn_content(fx: &mut FunctionCx<'_, '_, impl Backend>) {
                 fx.bcx.ins().jump(target, &[]);
 
                 fx.bcx.switch_to_block(failure);
-                trap_panic(
-                    fx,
-                    format!(
-                        "[panic] Assert {:?} at {:?} failed.",
-                        msg,
-                        bb_data.terminator().source_info.span
-                    ),
-                );
+                fx.bcx.ins().nop();
+
+                match msg {
+                    AssertKind::BoundsCheck { ref len, ref index } => {
+                        let len = codegen_operand(fx, len).load_scalar(fx);
+                        let index = codegen_operand(fx, index).load_scalar(fx);
+                        let location = fx
+                            .get_caller_location(bb_data.terminator().source_info.span)
+                            .load_scalar(fx);
+
+                        codegen_panic_inner(
+                            fx,
+                            rustc_hir::LangItem::PanicBoundsCheck,
+                            &[index, len, location],
+                            bb_data.terminator().source_info.span,
+                        );
+                    }
+                    _ => {
+                        let msg_str = msg.description();
+                        codegen_panic(fx, msg_str, bb_data.terminator().source_info.span);
+                    }
+                }
             }
 
-            TerminatorKind::SwitchInt {
-                discr,
-                switch_ty: _,
-                values,
-                targets,
-            } => {
-                let discr = trans_operand(fx, discr).load_scalar(fx);
-                let mut switch = ::cranelift_frontend::Switch::new();
-                for (i, value) in values.iter().enumerate() {
-                    let block = fx.get_block(targets[i]);
-                    switch.set_entry(*value as u64, block);
+            TerminatorKind::SwitchInt { discr, switch_ty, targets } => {
+                let discr = codegen_operand(fx, discr).load_scalar(fx);
+
+                let use_bool_opt = switch_ty.kind() == fx.tcx.types.bool.kind()
+                    || (targets.iter().count() == 1 && targets.iter().next().unwrap().0 == 0);
+                if use_bool_opt {
+                    assert_eq!(targets.iter().count(), 1);
+                    let (then_value, then_block) = targets.iter().next().unwrap();
+                    let then_block = fx.get_block(then_block);
+                    let else_block = fx.get_block(targets.otherwise());
+                    let test_zero = match then_value {
+                        0 => true,
+                        1 => false,
+                        _ => unreachable!("{:?}", targets),
+                    };
+
+                    let discr = crate::optimize::peephole::maybe_unwrap_bint(&mut fx.bcx, discr);
+                    let (discr, is_inverted) =
+                        crate::optimize::peephole::maybe_unwrap_bool_not(&mut fx.bcx, discr);
+                    let test_zero = if is_inverted { !test_zero } else { test_zero };
+                    let discr = crate::optimize::peephole::maybe_unwrap_bint(&mut fx.bcx, discr);
+                    let discr =
+                        crate::optimize::peephole::make_branchable_value(&mut fx.bcx, discr);
+                    if let Some(taken) = crate::optimize::peephole::maybe_known_branch_taken(
+                        &fx.bcx, discr, test_zero,
+                    ) {
+                        if taken {
+                            fx.bcx.ins().jump(then_block, &[]);
+                        } else {
+                            fx.bcx.ins().jump(else_block, &[]);
+                        }
+                    } else {
+                        if test_zero {
+                            fx.bcx.ins().brz(discr, then_block, &[]);
+                            fx.bcx.ins().jump(else_block, &[]);
+                        } else {
+                            fx.bcx.ins().brnz(discr, then_block, &[]);
+                            fx.bcx.ins().jump(else_block, &[]);
+                        }
+                    }
+                } else {
+                    let mut switch = ::cranelift_frontend::Switch::new();
+                    for (value, block) in targets.iter() {
+                        let block = fx.get_block(block);
+                        switch.set_entry(value, block);
+                    }
+                    let otherwise_block = fx.get_block(targets.otherwise());
+                    switch.emit(&mut fx.bcx, discr, otherwise_block);
                 }
-                let otherwise_block = fx.get_block(targets[targets.len() - 1]);
-                switch.emit(&mut fx.bcx, discr, otherwise_block);
             }
             TerminatorKind::Call {
                 func,
                 args,
                 destination,
+                fn_span,
                 cleanup: _,
                 from_hir_call: _,
             } => {
-                fx.tcx.sess.time("codegen call", || crate::abi::codegen_terminator_call(
+                fx.tcx.sess.time("codegen call", || {
+                    crate::abi::codegen_terminator_call(fx, *fn_span, func, args, *destination)
+                });
+            }
+            TerminatorKind::InlineAsm {
+                template,
+                operands,
+                options,
+                destination,
+                line_spans: _,
+            } => {
+                crate::inline_asm::codegen_inline_asm(
                     fx,
                     bb_data.terminator().source_info.span,
-                    func,
-                    args,
-                    destination,
-                ));
+                    template,
+                    operands,
+                    *options,
+                );
+
+                match *destination {
+                    Some(destination) => {
+                        let destination_block = fx.get_block(destination);
+                        fx.bcx.ins().jump(destination_block, &[]);
+                    }
+                    None => {
+                        crate::trap::trap_unreachable(
+                            fx,
+                            "[corruption] Returned from noreturn inline asm",
+                        );
+                    }
+                }
             }
             TerminatorKind::Resume | TerminatorKind::Abort => {
                 trap_unreachable(fx, "[corruption] Unwinding bb reached.");
@@ -346,18 +394,14 @@ fn codegen_fn_content(fx: &mut FunctionCx<'_, '_, impl Backend>) {
                 trap_unreachable(fx, "[corruption] Hit unreachable code.");
             }
             TerminatorKind::Yield { .. }
-            | TerminatorKind::FalseEdges { .. }
+            | TerminatorKind::FalseEdge { .. }
             | TerminatorKind::FalseUnwind { .. }
             | TerminatorKind::DropAndReplace { .. }
             | TerminatorKind::GeneratorDrop => {
-                bug!("shouldn't exist at trans {:?}", bb_data.terminator());
+                bug!("shouldn't exist at codegen {:?}", bb_data.terminator());
             }
-            TerminatorKind::Drop {
-                location,
-                target,
-                unwind: _,
-            } => {
-                let drop_place = trans_place(fx, location);
+            TerminatorKind::Drop { place, target, unwind: _ } => {
+                let drop_place = codegen_place(fx, *place);
                 crate::abi::codegen_drop(fx, bb_data.terminator().source_info.span, drop_place);
 
                 let target_block = fx.get_block(*target);
@@ -370,109 +414,117 @@ fn codegen_fn_content(fx: &mut FunctionCx<'_, '_, impl Backend>) {
     fx.bcx.finalize();
 }
 
-fn trans_stmt<'tcx>(
-    fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
-    #[allow(unused_variables)]
-    cur_block: Block,
+fn codegen_stmt<'tcx>(
+    fx: &mut FunctionCx<'_, '_, 'tcx>,
+    #[allow(unused_variables)] cur_block: Block,
     stmt: &Statement<'tcx>,
 ) {
-    let _print_guard = PrintOnPanic(|| format!("stmt {:?}", stmt));
+    let _print_guard = crate::PrintOnPanic(|| format!("stmt {:?}", stmt));
 
     fx.set_debug_loc(stmt.source_info);
 
-    #[cfg(false_debug_assertions)]
+    #[cfg(disabled)]
     match &stmt.kind {
         StatementKind::StorageLive(..) | StatementKind::StorageDead(..) => {} // Those are not very useful
         _ => {
-            let inst = fx.bcx.func.layout.last_inst(cur_block).unwrap();
-            fx.add_comment(inst, format!("{:?}", stmt));
+            if fx.clif_comments.enabled() {
+                let inst = fx.bcx.func.layout.last_inst(cur_block).unwrap();
+                fx.add_comment(inst, format!("{:?}", stmt));
+            }
         }
     }
 
     match &stmt.kind {
-        StatementKind::SetDiscriminant {
-            place,
-            variant_index,
-        } => {
-            let place = trans_place(fx, place);
+        StatementKind::SetDiscriminant { place, variant_index } => {
+            let place = codegen_place(fx, **place);
             crate::discriminant::codegen_set_discriminant(fx, place, *variant_index);
         }
         StatementKind::Assign(to_place_and_rval) => {
-            let lval = trans_place(fx, &to_place_and_rval.0);
+            let lval = codegen_place(fx, to_place_and_rval.0);
             let dest_layout = lval.layout();
-            match &to_place_and_rval.1 {
-                Rvalue::Use(operand) => {
-                    let val = trans_operand(fx, operand);
+            match to_place_and_rval.1 {
+                Rvalue::Use(ref operand) => {
+                    let val = codegen_operand(fx, operand);
                     lval.write_cvalue(fx, val);
                 }
                 Rvalue::Ref(_, _, place) | Rvalue::AddressOf(_, place) => {
-                    let place = trans_place(fx, place);
-                    place.write_place_ref(fx, lval);
+                    let place = codegen_place(fx, place);
+                    let ref_ = place.place_ref(fx, lval.layout());
+                    lval.write_cvalue(fx, ref_);
                 }
-                Rvalue::BinaryOp(bin_op, lhs, rhs) => {
-                    let lhs = trans_operand(fx, lhs);
-                    let rhs = trans_operand(fx, rhs);
+                Rvalue::ThreadLocalRef(def_id) => {
+                    let val = crate::constant::codegen_tls_ref(fx, def_id, lval.layout());
+                    lval.write_cvalue(fx, val);
+                }
+                Rvalue::BinaryOp(bin_op, ref lhs_rhs) => {
+                    let lhs = codegen_operand(fx, &lhs_rhs.0);
+                    let rhs = codegen_operand(fx, &lhs_rhs.1);
 
-                    let res = crate::num::codegen_binop(fx, *bin_op, lhs, rhs);
+                    let res = crate::num::codegen_binop(fx, bin_op, lhs, rhs);
                     lval.write_cvalue(fx, res);
                 }
-                Rvalue::CheckedBinaryOp(bin_op, lhs, rhs) => {
-                    let lhs = trans_operand(fx, lhs);
-                    let rhs = trans_operand(fx, rhs);
+                Rvalue::CheckedBinaryOp(bin_op, ref lhs_rhs) => {
+                    let lhs = codegen_operand(fx, &lhs_rhs.0);
+                    let rhs = codegen_operand(fx, &lhs_rhs.1);
 
                     let res = if !fx.tcx.sess.overflow_checks() {
                         let val =
-                            crate::num::trans_int_binop(fx, *bin_op, lhs, rhs).load_scalar(fx);
+                            crate::num::codegen_int_binop(fx, bin_op, lhs, rhs).load_scalar(fx);
                         let is_overflow = fx.bcx.ins().iconst(types::I8, 0);
                         CValue::by_val_pair(val, is_overflow, lval.layout())
                     } else {
-                        crate::num::trans_checked_int_binop(fx, *bin_op, lhs, rhs)
+                        crate::num::codegen_checked_int_binop(fx, bin_op, lhs, rhs)
                     };
 
                     lval.write_cvalue(fx, res);
                 }
-                Rvalue::UnaryOp(un_op, operand) => {
-                    let operand = trans_operand(fx, operand);
+                Rvalue::UnaryOp(un_op, ref operand) => {
+                    let operand = codegen_operand(fx, operand);
                     let layout = operand.layout();
                     let val = operand.load_scalar(fx);
                     let res = match un_op {
-                        UnOp::Not => {
-                            match layout.ty.kind {
-                                ty::Bool => {
-                                    let res = fx.bcx.ins().icmp_imm(IntCC::Equal, val, 0);
-                                    CValue::by_val(fx.bcx.ins().bint(types::I8, res), layout)
-                                }
-                                ty::Uint(_) | ty::Int(_) => {
-                                    CValue::by_val(fx.bcx.ins().bnot(val), layout)
-                                }
-                                _ => unreachable!("un op Not for {:?}", layout.ty),
+                        UnOp::Not => match layout.ty.kind() {
+                            ty::Bool => {
+                                let res = fx.bcx.ins().icmp_imm(IntCC::Equal, val, 0);
+                                CValue::by_val(fx.bcx.ins().bint(types::I8, res), layout)
                             }
-                        }
-                        UnOp::Neg => match layout.ty.kind {
+                            ty::Uint(_) | ty::Int(_) => {
+                                CValue::by_val(fx.bcx.ins().bnot(val), layout)
+                            }
+                            _ => unreachable!("un op Not for {:?}", layout.ty),
+                        },
+                        UnOp::Neg => match layout.ty.kind() {
                             ty::Int(IntTy::I128) => {
                                 // FIXME remove this case once ineg.i128 works
-                                let zero = CValue::const_val(fx, layout, 0);
-                                crate::num::trans_int_binop(fx, BinOp::Sub, zero, operand)
-                            }
-                            ty::Int(_) => {
-                                CValue::by_val(fx.bcx.ins().ineg(val), layout)
-                            }
-                            ty::Float(_) => {
-                                CValue::by_val(fx.bcx.ins().fneg(val), layout)
+                                let zero =
+                                    CValue::const_val(fx, layout, ty::ScalarInt::null(layout.size));
+                                crate::num::codegen_int_binop(fx, BinOp::Sub, zero, operand)
                             }
+                            ty::Int(_) => CValue::by_val(fx.bcx.ins().ineg(val), layout),
+                            ty::Float(_) => CValue::by_val(fx.bcx.ins().fneg(val), layout),
                             _ => unreachable!("un op Neg for {:?}", layout.ty),
                         },
                     };
                     lval.write_cvalue(fx, res);
                 }
-                Rvalue::Cast(CastKind::Pointer(PointerCast::ReifyFnPointer), operand, to_ty) => {
-                    let from_ty = fx.monomorphize(&operand.ty(&fx.mir.local_decls, fx.tcx));
+                Rvalue::Cast(
+                    CastKind::Pointer(PointerCast::ReifyFnPointer),
+                    ref operand,
+                    to_ty,
+                ) => {
+                    let from_ty = fx.monomorphize(operand.ty(&fx.mir.local_decls, fx.tcx));
                     let to_layout = fx.layout_of(fx.monomorphize(to_ty));
-                    match from_ty.kind {
+                    match *from_ty.kind() {
                         ty::FnDef(def_id, substs) => {
                             let func_ref = fx.get_function_ref(
-                                Instance::resolve_for_fn_ptr(fx.tcx, ParamEnv::reveal_all(), def_id, substs)
-                                    .unwrap(),
+                                Instance::resolve_for_fn_ptr(
+                                    fx.tcx,
+                                    ParamEnv::reveal_all(),
+                                    def_id,
+                                    substs,
+                                )
+                                .unwrap()
+                                .polymorphize(fx.tcx),
                             );
                             let func_addr = fx.bcx.ins().func_addr(fx.pointer_type, func_ref);
                             lval.write_cvalue(fx, CValue::by_val(func_addr, to_layout));
@@ -480,55 +532,70 @@ fn trans_stmt<'tcx>(
                         _ => bug!("Trying to ReifyFnPointer on non FnDef {:?}", from_ty),
                     }
                 }
-                Rvalue::Cast(CastKind::Pointer(PointerCast::UnsafeFnPointer), operand, to_ty)
-                | Rvalue::Cast(CastKind::Pointer(PointerCast::MutToConstPointer), operand, to_ty)
-                | Rvalue::Cast(CastKind::Pointer(PointerCast::ArrayToPointer), operand, to_ty) => {
+                Rvalue::Cast(
+                    CastKind::Pointer(PointerCast::UnsafeFnPointer),
+                    ref operand,
+                    to_ty,
+                )
+                | Rvalue::Cast(
+                    CastKind::Pointer(PointerCast::MutToConstPointer),
+                    ref operand,
+                    to_ty,
+                )
+                | Rvalue::Cast(
+                    CastKind::Pointer(PointerCast::ArrayToPointer),
+                    ref operand,
+                    to_ty,
+                ) => {
                     let to_layout = fx.layout_of(fx.monomorphize(to_ty));
-                    let operand = trans_operand(fx, operand);
-                    lval.write_cvalue(fx, operand.unchecked_cast_to(to_layout));
+                    let operand = codegen_operand(fx, operand);
+                    lval.write_cvalue(fx, operand.cast_pointer_to(to_layout));
                 }
-                Rvalue::Cast(CastKind::Misc, operand, to_ty) => {
-                    let operand = trans_operand(fx, operand);
+                Rvalue::Cast(CastKind::Misc, ref operand, to_ty) => {
+                    let operand = codegen_operand(fx, operand);
                     let from_ty = operand.layout().ty;
                     let to_ty = fx.monomorphize(to_ty);
 
-                    fn is_fat_ptr<'tcx>(
-                        fx: &FunctionCx<'_, 'tcx, impl Backend>,
-                        ty: Ty<'tcx>,
-                    ) -> bool {
+                    fn is_fat_ptr<'tcx>(fx: &FunctionCx<'_, '_, 'tcx>, ty: Ty<'tcx>) -> bool {
                         ty.builtin_deref(true)
-                            .map(
-                                |ty::TypeAndMut {
-                                     ty: pointee_ty,
-                                     mutbl: _,
-                                 }| has_ptr_meta(fx.tcx, pointee_ty),
-                            )
+                            .map(|ty::TypeAndMut { ty: pointee_ty, mutbl: _ }| {
+                                has_ptr_meta(fx.tcx, pointee_ty)
+                            })
                             .unwrap_or(false)
                     }
 
                     if is_fat_ptr(fx, from_ty) {
                         if is_fat_ptr(fx, to_ty) {
                             // fat-ptr -> fat-ptr
-                            lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
+                            lval.write_cvalue(fx, operand.cast_pointer_to(dest_layout));
                         } else {
                             // fat-ptr -> thin-ptr
                             let (ptr, _extra) = operand.load_scalar_pair(fx);
                             lval.write_cvalue(fx, CValue::by_val(ptr, dest_layout))
                         }
-                    } else if let ty::Adt(adt_def, _substs) = from_ty.kind {
+                    } else if let ty::Adt(adt_def, _substs) = from_ty.kind() {
                         // enum -> discriminant value
                         assert!(adt_def.is_enum());
-                        match to_ty.kind {
+                        match to_ty.kind() {
                             ty::Uint(_) | ty::Int(_) => {}
                             _ => unreachable!("cast adt {} -> {}", from_ty, to_ty),
                         }
+                        let to_clif_ty = fx.clif_type(to_ty).unwrap();
 
-                        let discr = crate::discriminant::codegen_get_discriminant(
+                        let discriminant = crate::discriminant::codegen_get_discriminant(
                             fx,
                             operand,
-                            fx.layout_of(to_ty),
+                            fx.layout_of(operand.layout().ty.discriminant_ty(fx.tcx)),
+                        )
+                        .load_scalar(fx);
+
+                        let res = crate::cast::clif_intcast(
+                            fx,
+                            discriminant,
+                            to_clif_ty,
+                            to_ty.is_signed(),
                         );
-                        lval.write_cvalue(fx, discr);
+                        lval.write_cvalue(fx, CValue::by_val(res, dest_layout));
                     } else {
                         let to_clif_ty = fx.clif_type(to_ty).unwrap();
                         let from = operand.load_scalar(fx);
@@ -543,16 +610,21 @@ fn is_fat_ptr<'tcx>(
                         lval.write_cvalue(fx, CValue::by_val(res, dest_layout));
                     }
                 }
-                Rvalue::Cast(CastKind::Pointer(PointerCast::ClosureFnPointer(_)), operand, _to_ty) => {
-                    let operand = trans_operand(fx, operand);
-                    match operand.layout().ty.kind {
+                Rvalue::Cast(
+                    CastKind::Pointer(PointerCast::ClosureFnPointer(_)),
+                    ref operand,
+                    _to_ty,
+                ) => {
+                    let operand = codegen_operand(fx, operand);
+                    match *operand.layout().ty.kind() {
                         ty::Closure(def_id, substs) => {
                             let instance = Instance::resolve_closure(
                                 fx.tcx,
                                 def_id,
                                 substs,
                                 ty::ClosureKind::FnOnce,
-                            );
+                            )
+                            .polymorphize(fx.tcx);
                             let func_ref = fx.get_function_ref(instance);
                             let func_addr = fx.bcx.ins().func_addr(fx.pointer_type, func_ref);
                             lval.write_cvalue(fx, CValue::by_val(func_addr, lval.layout()));
@@ -560,84 +632,107 @@ fn is_fat_ptr<'tcx>(
                         _ => bug!("{} cannot be cast to a fn ptr", operand.layout().ty),
                     }
                 }
-                Rvalue::Cast(CastKind::Pointer(PointerCast::Unsize), operand, _to_ty) => {
-                    let operand = trans_operand(fx, operand);
+                Rvalue::Cast(CastKind::Pointer(PointerCast::Unsize), ref operand, _to_ty) => {
+                    let operand = codegen_operand(fx, operand);
                     operand.unsize_value(fx, lval);
                 }
                 Rvalue::Discriminant(place) => {
-                    let place = trans_place(fx, place);
+                    let place = codegen_place(fx, place);
                     let value = place.to_cvalue(fx);
                     let discr =
                         crate::discriminant::codegen_get_discriminant(fx, value, dest_layout);
                     lval.write_cvalue(fx, discr);
                 }
-                Rvalue::Repeat(operand, times) => {
-                    let operand = trans_operand(fx, operand);
+                Rvalue::Repeat(ref operand, times) => {
+                    let operand = codegen_operand(fx, operand);
                     let times = fx
                         .monomorphize(times)
                         .eval(fx.tcx, ParamEnv::reveal_all())
                         .val
                         .try_to_bits(fx.tcx.data_layout.pointer_size)
                         .unwrap();
-                    for i in 0..times {
-                        let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
+                    if operand.layout().size.bytes() == 0 {
+                        // Do nothing for ZST's
+                    } else if fx.clif_type(operand.layout().ty) == Some(types::I8) {
+                        let times = fx.bcx.ins().iconst(fx.pointer_type, times as i64);
+                        // FIXME use emit_small_memset where possible
+                        let addr = lval.to_ptr().get_addr(fx);
+                        let val = operand.load_scalar(fx);
+                        fx.bcx.call_memset(fx.module.target_config(), addr, val, times);
+                    } else {
+                        let loop_block = fx.bcx.create_block();
+                        let loop_block2 = fx.bcx.create_block();
+                        let done_block = fx.bcx.create_block();
+                        let index = fx.bcx.append_block_param(loop_block, fx.pointer_type);
+                        let zero = fx.bcx.ins().iconst(fx.pointer_type, 0);
+                        fx.bcx.ins().jump(loop_block, &[zero]);
+
+                        fx.bcx.switch_to_block(loop_block);
+                        let done = fx.bcx.ins().icmp_imm(IntCC::Equal, index, times as i64);
+                        fx.bcx.ins().brnz(done, done_block, &[]);
+                        fx.bcx.ins().jump(loop_block2, &[]);
+
+                        fx.bcx.switch_to_block(loop_block2);
                         let to = lval.place_index(fx, index);
                         to.write_cvalue(fx, operand);
+                        let index = fx.bcx.ins().iadd_imm(index, 1);
+                        fx.bcx.ins().jump(loop_block, &[index]);
+
+                        fx.bcx.switch_to_block(done_block);
+                        fx.bcx.ins().nop();
                     }
                 }
                 Rvalue::Len(place) => {
-                    let place = trans_place(fx, place);
+                    let place = codegen_place(fx, place);
                     let usize_layout = fx.layout_of(fx.tcx.types.usize);
                     let len = codegen_array_len(fx, place);
                     lval.write_cvalue(fx, CValue::by_val(len, usize_layout));
                 }
                 Rvalue::NullaryOp(NullOp::Box, content_ty) => {
-                    use rustc::middle::lang_items::ExchangeMallocFnLangItem;
-
                     let usize_type = fx.clif_type(fx.tcx.types.usize).unwrap();
                     let content_ty = fx.monomorphize(content_ty);
                     let layout = fx.layout_of(content_ty);
                     let llsize = fx.bcx.ins().iconst(usize_type, layout.size.bytes() as i64);
-                    let llalign = fx
-                        .bcx
-                        .ins()
-                        .iconst(usize_type, layout.align.abi.bytes() as i64);
+                    let llalign = fx.bcx.ins().iconst(usize_type, layout.align.abi.bytes() as i64);
                     let box_layout = fx.layout_of(fx.tcx.mk_box(content_ty));
 
                     // Allocate space:
-                    let def_id = match fx.tcx.lang_items().require(ExchangeMallocFnLangItem) {
-                        Ok(id) => id,
-                        Err(s) => {
-                            fx.tcx
-                                .sess
-                                .fatal(&format!("allocation of `{}` {}", box_layout.ty, s));
-                        }
-                    };
-                    let instance = ty::Instance::mono(fx.tcx, def_id);
+                    let def_id =
+                        match fx.tcx.lang_items().require(rustc_hir::LangItem::ExchangeMalloc) {
+                            Ok(id) => id,
+                            Err(s) => {
+                                fx.tcx
+                                    .sess
+                                    .fatal(&format!("allocation of `{}` {}", box_layout.ty, s));
+                            }
+                        };
+                    let instance = ty::Instance::mono(fx.tcx, def_id).polymorphize(fx.tcx);
                     let func_ref = fx.get_function_ref(instance);
                     let call = fx.bcx.ins().call(func_ref, &[llsize, llalign]);
                     let ptr = fx.bcx.inst_results(call)[0];
                     lval.write_cvalue(fx, CValue::by_val(ptr, box_layout));
                 }
                 Rvalue::NullaryOp(NullOp::SizeOf, ty) => {
-                    assert!(lval
-                        .layout()
-                        .ty
-                        .is_sized(fx.tcx.at(stmt.source_info.span), ParamEnv::reveal_all()));
+                    assert!(
+                        lval.layout()
+                            .ty
+                            .is_sized(fx.tcx.at(stmt.source_info.span), ParamEnv::reveal_all())
+                    );
                     let ty_size = fx.layout_of(fx.monomorphize(ty)).size.bytes();
-                    let val = CValue::const_val(fx, fx.layout_of(fx.tcx.types.usize), ty_size.into());
+                    let val =
+                        CValue::const_val(fx, fx.layout_of(fx.tcx.types.usize), ty_size.into());
                     lval.write_cvalue(fx, val);
                 }
-                Rvalue::Aggregate(kind, operands) => match **kind {
+                Rvalue::Aggregate(ref kind, ref operands) => match kind.as_ref() {
                     AggregateKind::Array(_ty) => {
-                        for (i, operand) in operands.into_iter().enumerate() {
-                            let operand = trans_operand(fx, operand);
+                        for (i, operand) in operands.iter().enumerate() {
+                            let operand = codegen_operand(fx, operand);
                             let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
                             let to = lval.place_index(fx, index);
                             to.write_cvalue(fx, operand);
                         }
                     }
-                    _ => unreachable!("shouldn't exist at trans {:?}", to_place_and_rval.1),
+                    _ => unreachable!("shouldn't exist at codegen {:?}", to_place_and_rval.1),
                 },
             }
         }
@@ -649,102 +744,56 @@ fn is_fat_ptr<'tcx>(
         | StatementKind::AscribeUserType(..) => {}
 
         StatementKind::LlvmInlineAsm(asm) => {
-            use rustc_ast::ast::Name;
-            let LlvmInlineAsm {
-                asm,
-                outputs: _,
-                inputs: _,
-            } = &**asm;
-            let rustc_hir::LlvmInlineAsmInner {
-                asm: asm_code, // Name
-                outputs,       // Vec<Name>
-                inputs,        // Vec<Name>
-                clobbers,      // Vec<Name>
-                volatile,      // bool
-                alignstack,    // bool
-                dialect: _,    // rustc_ast::ast::AsmDialect
-                asm_str_style: _,
-            } = asm;
-            match &*asm_code.as_str() {
+            match asm.asm.asm.as_str().trim() {
                 "" => {
-                    assert_eq!(inputs, &[Name::intern("r")]);
-                    assert!(outputs.is_empty(), "{:?}", outputs);
-
                     // Black box
                 }
-                "cpuid" | "cpuid\n" => {
-                    assert_eq!(inputs, &[Name::intern("{eax}"), Name::intern("{ecx}")]);
-
-                    assert_eq!(outputs.len(), 4);
-                    for (i, c) in (&["={eax}", "={ebx}", "={ecx}", "={edx}"])
-                        .iter()
-                        .enumerate()
-                    {
-                        assert_eq!(&outputs[i].constraint.as_str(), c);
-                        assert!(!outputs[i].is_rw);
-                        assert!(!outputs[i].is_indirect);
-                    }
-
-                    assert_eq!(clobbers, &[Name::intern("rbx")]);
-
-                    assert!(!volatile);
-                    assert!(!alignstack);
-
-                    crate::trap::trap_unimplemented(
-                        fx,
-                        "__cpuid_count arch intrinsic is not supported",
-                    );
-                }
-                "xgetbv" => {
-                    assert_eq!(inputs, &[Name::intern("{ecx}")]);
-
-                    assert_eq!(outputs.len(), 2);
-                    for (i, c) in (&["={eax}", "={edx}"]).iter().enumerate() {
-                        assert_eq!(&outputs[i].constraint.as_str(), c);
-                        assert!(!outputs[i].is_rw);
-                        assert!(!outputs[i].is_indirect);
-                    }
-
-                    assert_eq!(clobbers, &[]);
-
-                    assert!(!volatile);
-                    assert!(!alignstack);
-
-                    crate::trap::trap_unimplemented(fx, "_xgetbv arch intrinsic is not supported");
-                }
-                _ => unimpl_fatal!(fx.tcx, stmt.source_info.span, "Inline assembly is not supported"),
+                _ => fx.tcx.sess.span_fatal(
+                    stmt.source_info.span,
+                    "Legacy `llvm_asm!` inline assembly is not supported. \
+                    Try using the new `asm!` instead.",
+                ),
             }
         }
+        StatementKind::Coverage { .. } => fx.tcx.sess.fatal("-Zcoverage is unimplemented"),
+        StatementKind::CopyNonOverlapping(inner) => {
+            let dst = codegen_operand(fx, &inner.dst);
+            let pointee = dst
+                .layout()
+                .pointee_info_at(fx, rustc_target::abi::Size::ZERO)
+                .expect("Expected pointer");
+            let dst = dst.load_scalar(fx);
+            let src = codegen_operand(fx, &inner.src).load_scalar(fx);
+            let count = codegen_operand(fx, &inner.count).load_scalar(fx);
+            let elem_size: u64 = pointee.size.bytes();
+            let bytes =
+                if elem_size != 1 { fx.bcx.ins().imul_imm(count, elem_size as i64) } else { count };
+            fx.bcx.call_memcpy(fx.module.target_config(), dst, src, bytes);
+        }
     }
 }
 
-fn codegen_array_len<'tcx>(
-    fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
-    place: CPlace<'tcx>,
-) -> Value {
-    match place.layout().ty.kind {
+fn codegen_array_len<'tcx>(fx: &mut FunctionCx<'_, '_, 'tcx>, place: CPlace<'tcx>) -> Value {
+    match *place.layout().ty.kind() {
         ty::Array(_elem_ty, len) => {
-            let len = fx.monomorphize(&len)
-                .eval(fx.tcx, ParamEnv::reveal_all())
-                .eval_usize(fx.tcx, ParamEnv::reveal_all()) as i64;
+            let len = fx.monomorphize(len).eval_usize(fx.tcx, ParamEnv::reveal_all()) as i64;
             fx.bcx.ins().iconst(fx.pointer_type, len)
         }
-        ty::Slice(_elem_ty) => place
-            .to_ptr_maybe_unsized(fx)
-            .1
-            .expect("Length metadata for slice place"),
+        ty::Slice(_elem_ty) => {
+            place.to_ptr_maybe_unsized().1.expect("Length metadata for slice place")
+        }
         _ => bug!("Rvalue::Len({:?})", place),
     }
 }
 
-pub(crate) fn trans_place<'tcx>(
-    fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
-    place: &Place<'tcx>,
+pub(crate) fn codegen_place<'tcx>(
+    fx: &mut FunctionCx<'_, '_, 'tcx>,
+    place: Place<'tcx>,
 ) -> CPlace<'tcx> {
     let mut cplace = fx.get_local_place(place.local);
 
-    for elem in &*place.projection {
-        match *elem {
+    for elem in place.projection {
+        match elem {
             PlaceElem::Deref => {
                 cplace = cplace.place_deref(fx);
             }
@@ -755,11 +804,8 @@ pub(crate) fn trans_place<'tcx>(
                 let index = fx.get_local_place(local).to_cvalue(fx).load_scalar(fx);
                 cplace = cplace.place_index(fx, index);
             }
-            PlaceElem::ConstantIndex {
-                offset,
-                min_length: _,
-                from_end,
-            } => {
+            PlaceElem::ConstantIndex { offset, min_length: _, from_end } => {
+                let offset: u64 = offset;
                 let index = if !from_end {
                     fx.bcx.ins().iconst(fx.pointer_type, offset as i64)
                 } else {
@@ -772,23 +818,26 @@ pub(crate) fn trans_place<'tcx>(
                 // These indices are generated by slice patterns.
                 // slice[from:-to] in Python terms.
 
-                match cplace.layout().ty.kind {
+                let from: u64 = from;
+                let to: u64 = to;
+
+                match cplace.layout().ty.kind() {
                     ty::Array(elem_ty, _len) => {
                         assert!(!from_end, "array subslices are never `from_end`");
                         let elem_layout = fx.layout_of(elem_ty);
-                        let ptr = cplace.to_ptr(fx);
+                        let ptr = cplace.to_ptr();
                         cplace = CPlace::for_ptr(
-                            ptr.offset_i64(fx, elem_layout.size.bytes() as i64 * from as i64),
-                            fx.layout_of(fx.tcx.mk_array(elem_ty, to as u64 - from as u64)),
+                            ptr.offset_i64(fx, elem_layout.size.bytes() as i64 * (from as i64)),
+                            fx.layout_of(fx.tcx.mk_array(elem_ty, to - from)),
                         );
                     }
                     ty::Slice(elem_ty) => {
                         assert!(from_end, "slice subslices should be `from_end`");
                         let elem_layout = fx.layout_of(elem_ty);
-                        let (ptr, len) = cplace.to_ptr_maybe_unsized(fx);
+                        let (ptr, len) = cplace.to_ptr_maybe_unsized();
                         let len = len.unwrap();
                         cplace = CPlace::for_ptr_with_extra(
-                            ptr.offset_i64(fx, elem_layout.size.bytes() as i64 * from as i64),
+                            ptr.offset_i64(fx, elem_layout.size.bytes() as i64 * (from as i64)),
                             fx.bcx.ins().iadd_imm(len, -(from as i64 + to as i64)),
                             cplace.layout(),
                         );
@@ -805,15 +854,51 @@ pub(crate) fn trans_place<'tcx>(
     cplace
 }
 
-pub(crate) fn trans_operand<'tcx>(
-    fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
+pub(crate) fn codegen_operand<'tcx>(
+    fx: &mut FunctionCx<'_, '_, 'tcx>,
     operand: &Operand<'tcx>,
 ) -> CValue<'tcx> {
     match operand {
         Operand::Move(place) | Operand::Copy(place) => {
-            let cplace = trans_place(fx, place);
+            let cplace = codegen_place(fx, *place);
             cplace.to_cvalue(fx)
         }
-        Operand::Constant(const_) => crate::constant::trans_constant(fx, const_),
+        Operand::Constant(const_) => crate::constant::codegen_constant(fx, const_),
     }
 }
+
+pub(crate) fn codegen_panic<'tcx>(fx: &mut FunctionCx<'_, '_, 'tcx>, msg_str: &str, span: Span) {
+    let location = fx.get_caller_location(span).load_scalar(fx);
+
+    let msg_ptr = fx.anonymous_str("assert", msg_str);
+    let msg_len = fx.bcx.ins().iconst(fx.pointer_type, i64::try_from(msg_str.len()).unwrap());
+    let args = [msg_ptr, msg_len, location];
+
+    codegen_panic_inner(fx, rustc_hir::LangItem::Panic, &args, span);
+}
+
+pub(crate) fn codegen_panic_inner<'tcx>(
+    fx: &mut FunctionCx<'_, '_, 'tcx>,
+    lang_item: rustc_hir::LangItem,
+    args: &[Value],
+    span: Span,
+) {
+    let def_id =
+        fx.tcx.lang_items().require(lang_item).unwrap_or_else(|s| fx.tcx.sess.span_fatal(span, &s));
+
+    let instance = Instance::mono(fx.tcx, def_id).polymorphize(fx.tcx);
+    let symbol_name = fx.tcx.symbol_name(instance).name;
+
+    fx.lib_call(
+        &*symbol_name,
+        vec![
+            AbiParam::new(fx.pointer_type),
+            AbiParam::new(fx.pointer_type),
+            AbiParam::new(fx.pointer_type),
+        ],
+        vec![],
+        args,
+    );
+
+    crate::trap::trap_unreachable(fx, "panic lang item returned");
+}