authorgravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2019-06-04 14:47:01-04:00
committergravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2019-06-04 14:47:01-04:00
logb19b1c1298f755238e7b6a54e5482616d923f9a8
treec79430c313a914e231f0ff2d26fbb4c2e87311e5
parent057b96006b055ca480167ac4ca66c87c2be89354
signaturelock-open Commit is signed but in an unrecognized format.

no-copy semantics for switch expressions

```zig export fn entry() void { var c: i32 = 1234; var x = switch (c) { 1 => u8(1), 2...4 => u16(2), else => u32(3), }; } ``` ```llvm define void @entry() #2 !dbg !35 { Entry: %c = alloca i32, align 4 %x = alloca i32, align 4 store i32 1234, i32* %c, align 4, !dbg !44 call void @llvm.dbg.declare(metadata i32* %c, metadata !39, metadata !DIExpression()), !dbg !44 %0 = load i32, i32* %c, align 4, !dbg !45 %1 = icmp sge i32 %0, 2, !dbg !46 %2 = icmp sle i32 %0, 4, !dbg !46 %3 = and i1 %1, %2, !dbg !46 br i1 %3, label %SwitchRangeYes, label %SwitchRangeNo, !dbg !46 SwitchRangeYes: ; preds = %Entry br label %SwitchEnd, !dbg !45 SwitchElse: ; preds = %SwitchRangeNo br label %SwitchEnd, !dbg !45 SwitchProng: ; preds = %SwitchRangeNo br label %SwitchEnd, !dbg !45 SwitchEnd: ; preds = %SwitchProng, %SwitchElse, %SwitchRangeYes %4 = phi i32 [ 2, %SwitchRangeYes ], [ 3, %SwitchElse ], [ 1, %SwitchProng ], !dbg !45 store i32 %4, i32* %x, align 4, !dbg !45 call void @llvm.dbg.declare(metadata i32* %x, metadata !42, metadata !DIExpression()), !dbg !47 ret void, !dbg !48 SwitchRangeNo: ; preds = %Entry switch i32 %0, label %SwitchElse [ i32 1, label %SwitchProng ], !dbg !45 } ```

2 files changed, 71 insertions(+), 23 deletions(-)

BRANCH_TODO+6-3
......@@ -1,14 +1,17 @@
11Scratch pad for stuff to do before merging master
22=================================================
33
4migrate ir_build_var_decl_src to use ir_build_alloca_src and explicitly initialize
5
6 * switch expression
4 * if bool - do we need to call lval wrap or just expr wrap?
5 * hook up peer result locs to if optional and if err
6 * hook up peer result locs to while bool, while optional, and while err
7 * hook up peer result locs to for
8 * hook up peer result locs to catch
79 * struct initializations
810 * function call parameters
911 * bitCast
1012
1113look at all the ir_gen_node ir_gen_node_extra calls and make sure result locations are properly propagated
14 return ir_gen_comptime(irb, scope, node, lval);
1215
1316migrate all the alloca_list to alloca_gen_list
1417
src/ir.cpp+65-20
......@@ -6510,7 +6510,7 @@ static bool ir_gen_switch_prong_expr(IrBuilder *irb, Scope *scope, AstNode *swit
65106510 IrBasicBlock *end_block, IrInstruction *is_comptime, IrInstruction *var_is_comptime,
65116511 IrInstruction *target_value_ptr, IrInstruction **prong_values, size_t prong_values_len,
65126512 ZigList<IrBasicBlock *> *incoming_blocks, ZigList<IrInstruction *> *incoming_values,
6513 IrInstructionSwitchElseVar **out_switch_else_var)
6513 IrInstructionSwitchElseVar **out_switch_else_var, LVal lval, ResultLoc *result_loc)
65146514{
65156515 assert(switch_node->type == NodeTypeSwitchExpr);
65166516 assert(prong_node->type == NodeTypeSwitchProng);
......@@ -6528,27 +6528,27 @@ static bool ir_gen_switch_prong_expr(IrBuilder *irb, Scope *scope, AstNode *swit
65286528 ZigVar *var = ir_create_var(irb, var_symbol_node, scope,
65296529 var_name, is_const, is_const, is_shadowable, var_is_comptime);
65306530 child_scope = var->child_scope;
6531 IrInstruction *var_value;
6531 IrInstruction *var_ptr;
65326532 if (out_switch_else_var != nullptr) {
65336533 IrInstructionSwitchElseVar *switch_else_var = ir_build_switch_else_var(irb, scope, var_symbol_node,
65346534 target_value_ptr);
65356535 *out_switch_else_var = switch_else_var;
6536 IrInstruction *var_ptr_value = &switch_else_var->base;
6537 var_value = var_is_ptr ? var_ptr_value : ir_build_load_ptr(irb, scope, var_symbol_node, var_ptr_value);
6536 IrInstruction *payload_ptr = &switch_else_var->base;
6537 var_ptr = var_is_ptr ? ir_build_ref(irb, scope, var_symbol_node, payload_ptr, true, false) : payload_ptr;
65386538 } else if (prong_values != nullptr) {
6539 IrInstruction *var_ptr_value = ir_build_switch_var(irb, scope, var_symbol_node, target_value_ptr,
6539 IrInstruction *payload_ptr = ir_build_switch_var(irb, scope, var_symbol_node, target_value_ptr,
65406540 prong_values, prong_values_len);
6541 var_value = var_is_ptr ? var_ptr_value : ir_build_load_ptr(irb, scope, var_symbol_node, var_ptr_value);
6541 var_ptr = var_is_ptr ? ir_build_ref(irb, scope, var_symbol_node, payload_ptr, true, false) : payload_ptr;
65426542 } else {
6543 var_value = var_is_ptr ? target_value_ptr : ir_build_load_ptr(irb, scope, var_symbol_node,
6544target_value_ptr);
6543 var_ptr = var_is_ptr ?
6544 ir_build_ref(irb, scope, var_symbol_node, target_value_ptr, true, false) : target_value_ptr;
65456545 }
6546 ir_build_var_decl_src(irb, scope, var_symbol_node, var, nullptr, var_value);
6546 ir_build_var_decl_src(irb, scope, var_symbol_node, var, nullptr, var_ptr);
65476547 } else {
65486548 child_scope = scope;
65496549 }
65506550
6551 IrInstruction *expr_result = ir_gen_node(irb, expr_node, child_scope);
6551 IrInstruction *expr_result = ir_gen_node_extra(irb, expr_node, child_scope, lval, result_loc);
65526552 if (expr_result == irb->codegen->invalid_instruction)
65536553 return false;
65546554 if (!instr_is_unreachable(expr_result))
......@@ -6558,7 +6558,15 @@ target_value_ptr);
65586558 return true;
65596559}
65606560
6561static IrInstruction *ir_gen_switch_expr(IrBuilder *irb, Scope *scope, AstNode *node) {
6561static void next_peer_block(ZigList<ResultLocPeer> *list, IrBasicBlock *next_bb) {
6562 if (list->length >= 2) {
6563 list->at(list->length - 2).next_bb = next_bb;
6564 }
6565}
6566
6567static IrInstruction *ir_gen_switch_expr(IrBuilder *irb, Scope *scope, AstNode *node, LVal lval,
6568 ResultLoc *result_loc)
6569{
65626570 assert(node->type == NodeTypeSwitchExpr);
65636571
65646572 AstNode *target_node = node->data.switch_expr.expr;
......@@ -6589,6 +6597,12 @@ static IrInstruction *ir_gen_switch_expr(IrBuilder *irb, Scope *scope, AstNode *
65896597
65906598 IrInstructionSwitchElseVar *switch_else_var = nullptr;
65916599
6600 ResultLocPeerParent *peer_parent = allocate<ResultLocPeerParent>(1);
6601 peer_parent->base.id = ResultLocIdPeerParent;
6602 peer_parent->parent = result_loc;
6603
6604 ZigList<ResultLocPeer> peer_result_locs = {};
6605
65926606 // First do the else and the ranges
65936607 Scope *subexpr_scope = create_runtime_scope(irb->codegen, node, scope, is_comptime);
65946608 Scope *comptime_scope = create_comptime_scope(irb->codegen, node, scope);
......@@ -6597,6 +6611,9 @@ static IrInstruction *ir_gen_switch_expr(IrBuilder *irb, Scope *scope, AstNode *
65976611 AstNode *prong_node = node->data.switch_expr.prongs.at(prong_i);
65986612 size_t prong_item_count = prong_node->data.switch_prong.items.length;
65996613 if (prong_item_count == 0) {
6614 ResultLocPeer *this_peer_result_loc = peer_result_locs.add_one();
6615 this_peer_result_loc->base.id = ResultLocIdPeer;
6616 this_peer_result_loc->parent = peer_parent;
66006617 if (else_prong) {
66016618 ErrorMsg *msg = add_node_error(irb->codegen, prong_node,
66026619 buf_sprintf("multiple else prongs in switch expression"));
......@@ -6607,15 +6624,20 @@ static IrInstruction *ir_gen_switch_expr(IrBuilder *irb, Scope *scope, AstNode *
66076624 else_prong = prong_node;
66086625
66096626 IrBasicBlock *prev_block = irb->current_basic_block;
6627 next_peer_block(&peer_result_locs, else_block);
66106628 ir_set_cursor_at_end_and_append_block(irb, else_block);
66116629 if (!ir_gen_switch_prong_expr(irb, subexpr_scope, node, prong_node, end_block,
66126630 is_comptime, var_is_comptime, target_value_ptr, nullptr, 0, &incoming_blocks, &incoming_values,
6613 &switch_else_var))
6631 &switch_else_var, lval, &this_peer_result_loc->base))
66146632 {
66156633 return irb->codegen->invalid_instruction;
66166634 }
66176635 ir_set_cursor_at_end(irb, prev_block);
66186636 } else if (prong_node->data.switch_prong.any_items_are_range) {
6637 ResultLocPeer *this_peer_result_loc = peer_result_locs.add_one();
6638 this_peer_result_loc->base.id = ResultLocIdPeer;
6639 this_peer_result_loc->parent = peer_parent;
6640
66196641 IrInstruction *ok_bit = nullptr;
66206642 AstNode *last_item_node = nullptr;
66216643 for (size_t item_i = 0; item_i < prong_item_count; item_i += 1) {
......@@ -6675,10 +6697,11 @@ static IrInstruction *ir_gen_switch_expr(IrBuilder *irb, Scope *scope, AstNode *
66756697 ir_mark_gen(ir_build_cond_br(irb, scope, last_item_node, ok_bit, range_block_yes,
66766698 range_block_no, is_comptime));
66776699
6700 next_peer_block(&peer_result_locs, range_block_yes);
66786701 ir_set_cursor_at_end_and_append_block(irb, range_block_yes);
66796702 if (!ir_gen_switch_prong_expr(irb, subexpr_scope, node, prong_node, end_block,
66806703 is_comptime, var_is_comptime, target_value_ptr, nullptr, 0,
6681 &incoming_blocks, &incoming_values, nullptr))
6704 &incoming_blocks, &incoming_values, nullptr, lval, &this_peer_result_loc->base))
66826705 {
66836706 return irb->codegen->invalid_instruction;
66846707 }
......@@ -6696,6 +6719,10 @@ static IrInstruction *ir_gen_switch_expr(IrBuilder *irb, Scope *scope, AstNode *
66966719 if (prong_node->data.switch_prong.any_items_are_range)
66976720 continue;
66986721
6722 ResultLocPeer *this_peer_result_loc = peer_result_locs.add_one();
6723 this_peer_result_loc->base.id = ResultLocIdPeer;
6724 this_peer_result_loc->parent = peer_parent;
6725
66996726 IrBasicBlock *prong_block = ir_create_basic_block(irb, scope, "SwitchProng");
67006727 IrInstruction **items = allocate<IrInstruction *>(prong_item_count);
67016728
......@@ -6719,10 +6746,11 @@ static IrInstruction *ir_gen_switch_expr(IrBuilder *irb, Scope *scope, AstNode *
67196746 }
67206747
67216748 IrBasicBlock *prev_block = irb->current_basic_block;
6749 next_peer_block(&peer_result_locs, prong_block);
67226750 ir_set_cursor_at_end_and_append_block(irb, prong_block);
67236751 if (!ir_gen_switch_prong_expr(irb, subexpr_scope, node, prong_node, end_block,
67246752 is_comptime, var_is_comptime, target_value_ptr, items, prong_item_count,
6725 &incoming_blocks, &incoming_values, nullptr))
6753 &incoming_blocks, &incoming_values, nullptr, lval, &this_peer_result_loc->base))
67266754 {
67276755 return irb->codegen->invalid_instruction;
67286756 }
......@@ -6731,31 +6759,48 @@ static IrInstruction *ir_gen_switch_expr(IrBuilder *irb, Scope *scope, AstNode *
67316759
67326760 }
67336761
6734 IrInstruction *switch_prongs_void = ir_build_check_switch_prongs(irb, scope, node, target_value, check_ranges.items, check_ranges.length,
6735 else_prong != nullptr);
6762 IrInstruction *switch_prongs_void = ir_build_check_switch_prongs(irb, scope, node, target_value,
6763 check_ranges.items, check_ranges.length, else_prong != nullptr);
67366764
6765 IrInstruction *br_instruction;
67376766 if (cases.length == 0) {
6738 ir_build_br(irb, scope, node, else_block, is_comptime);
6767 br_instruction = ir_build_br(irb, scope, node, else_block, is_comptime);
67396768 } else {
67406769 IrInstructionSwitchBr *switch_br = ir_build_switch_br(irb, scope, node, target_value, else_block,
67416770 cases.length, cases.items, is_comptime, switch_prongs_void);
67426771 if (switch_else_var != nullptr) {
67436772 switch_else_var->switch_br = switch_br;
67446773 }
6774 br_instruction = &switch_br->base;
6775 }
6776 for (size_t i = 0; i < peer_result_locs.length; i += 1) {
6777 peer_result_locs.at(i).base.source_instruction = br_instruction;
67456778 }
6779 peer_parent->base.source_instruction = br_instruction;
6780 peer_parent->peer_count = peer_result_locs.length;
6781 peer_parent->peers = peer_result_locs.items;
67466782
67476783 if (!else_prong) {
6784 if (peer_result_locs.length != 0) {
6785 peer_result_locs.last().next_bb = else_block;
6786 }
67486787 ir_set_cursor_at_end_and_append_block(irb, else_block);
67496788 ir_build_unreachable(irb, scope, node);
6789 } else {
6790 if (peer_result_locs.length != 0) {
6791 peer_result_locs.last().next_bb = end_block;
6792 }
67506793 }
67516794
67526795 ir_set_cursor_at_end_and_append_block(irb, end_block);
67536796 assert(incoming_blocks.length == incoming_values.length);
6797 IrInstruction *result_instruction;
67546798 if (incoming_blocks.length == 0) {
6755 return ir_build_const_void(irb, scope, node);
6799 result_instruction = ir_build_const_void(irb, scope, node);
67566800 } else {
6757 return ir_build_phi(irb, scope, node, incoming_blocks.length, incoming_blocks.items, incoming_values.items);
6801 result_instruction = ir_build_phi(irb, scope, node, incoming_blocks.length, incoming_blocks.items, incoming_values.items);
67586802 }
6803 return ir_expr_wrap(irb, scope, result_instruction, result_loc);
67596804}
67606805
67616806static IrInstruction *ir_gen_comptime(IrBuilder *irb, Scope *parent_scope, AstNode *node, LVal lval) {
......@@ -7828,7 +7873,7 @@ static IrInstruction *ir_gen_node_raw(IrBuilder *irb, AstNode *node, Scope *scop
78287873 case NodeTypeIfOptional:
78297874 return ir_lval_wrap(irb, scope, ir_gen_if_optional_expr(irb, scope, node), lval, result_loc);
78307875 case NodeTypeSwitchExpr:
7831 return ir_lval_wrap(irb, scope, ir_gen_switch_expr(irb, scope, node), lval, result_loc);
7876 return ir_gen_switch_expr(irb, scope, node, lval, result_loc);
78327877 case NodeTypeCompTime:
78337878 return ir_gen_comptime(irb, scope, node, lval);
78347879 case NodeTypeErrorType: