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compiler: implement labeled switch/continue

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mlugg 2024-04-28 21:44:57 +01:00
parent 5fb4a7df38
commit 5e12ca9fe3
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22 changed files with 1602 additions and 382 deletions
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54
lib/std/zig/Ast.zig
View file

@ -1184,14 +1184,7 @@ pub fn lastToken(tree: Ast, node: Node.Index) TokenIndex {
n = extra.sentinel;
},
.@"continue" => {
if (datas[n].lhs != 0) {
return datas[n].lhs + end_offset;
} else {
return main_tokens[n] + end_offset;
}
},
.@"break" => {
.@"continue", .@"break" => {
if (datas[n].rhs != 0) {
n = datas[n].rhs;
} else if (datas[n].lhs != 0) {
@ -1895,6 +1888,15 @@ pub fn taggedUnionEnumTag(tree: Ast, node: Node.Index) full.ContainerDecl {
});
}
pub fn switchFull(tree: Ast, node: Node.Index) full.Switch {
const data = &tree.nodes.items(.data)[node];
return tree.fullSwitchComponents(.{
.switch_token = tree.nodes.items(.main_token)[node],
.condition = data.lhs,
.sub_range = data.rhs,
});
}
pub fn switchCaseOne(tree: Ast, node: Node.Index) full.SwitchCase {
const data = &tree.nodes.items(.data)[node];
const values: *[1]Node.Index = &data.lhs;
@ -2206,6 +2208,21 @@ fn fullContainerDeclComponents(tree: Ast, info: full.ContainerDecl.Components) f
return result;
}
fn fullSwitchComponents(tree: Ast, info: full.Switch.Components) full.Switch {
const token_tags = tree.tokens.items(.tag);
const tok_i = info.switch_token -| 1;
var result: full.Switch = .{
.ast = info,
.label_token = null,
};
if (token_tags[tok_i] == .colon and
token_tags[tok_i -| 1] == .identifier)
{
result.label_token = tok_i - 1;
}
return result;
}
fn fullSwitchCaseComponents(tree: Ast, info: full.SwitchCase.Components, node: Node.Index) full.SwitchCase {
const token_tags = tree.tokens.items(.tag);
const node_tags = tree.nodes.items(.tag);
@ -2477,6 +2494,13 @@ pub fn fullContainerDecl(tree: Ast, buffer: *[2]Ast.Node.Index, node: Node.Index
};
}
pub fn fullSwitch(tree: Ast, node: Node.Index) ?full.Switch {
return switch (tree.nodes.items(.tag)[node]) {
.@"switch", .switch_comma => tree.switchFull(node),
else => null,
};
}
pub fn fullSwitchCase(tree: Ast, node: Node.Index) ?full.SwitchCase {
return switch (tree.nodes.items(.tag)[node]) {
.switch_case_one, .switch_case_inline_one => tree.switchCaseOne(node),
@ -2829,6 +2853,17 @@ pub const full = struct {
};
};
pub const Switch = struct {
ast: Components,
label_token: ?TokenIndex,
pub const Components = struct {
switch_token: TokenIndex,
condition: Node.Index,
sub_range: Node.Index,
};
};
pub const SwitchCase = struct {
inline_token: ?TokenIndex,
/// Points to the first token after the `|`. Will either be an identifier or
@ -3287,7 +3322,8 @@ pub const Node = struct {
@"suspend",
/// `resume lhs`. rhs is unused.
@"resume",
/// `continue`. lhs is token index of label if any. rhs is unused.
/// `continue :lhs rhs`
/// both lhs and rhs may be omitted.
@"continue",
/// `break :lhs rhs`
/// both lhs and rhs may be omitted.

113
lib/std/zig/AstGen.zig
View file

@ -1144,7 +1144,7 @@ fn expr(gz: *GenZir, scope: *Scope, ri: ResultInfo, node: Ast.Node.Index) InnerE
.error_set_decl => return errorSetDecl(gz, ri, node),
.array_access => return arrayAccess(gz, scope, ri, node),
.@"comptime" => return comptimeExprAst(gz, scope, ri, node),
.@"switch", .switch_comma => return switchExpr(gz, scope, ri.br(), node),
.@"switch", .switch_comma => return switchExpr(gz, scope, ri.br(), node, tree.fullSwitch(node).?),
.@"nosuspend" => return nosuspendExpr(gz, scope, ri, node),
.@"suspend" => return suspendExpr(gz, scope, node),
@ -2160,6 +2160,11 @@ fn breakExpr(parent_gz: *GenZir, parent_scope: *Scope, node: Ast.Node.Index) Inn
if (break_label != 0) {
if (block_gz.label) |*label| {
if (try astgen.tokenIdentEql(label.token, break_label)) {
const maybe_switch_tag = astgen.instructions.items(.tag)[@intFromEnum(label.block_inst)];
switch (maybe_switch_tag) {
.switch_block, .switch_block_ref => return astgen.failNode(node, "cannot break from switch", .{}),
else => {},
}
label.used = true;
break :blk label.block_inst;
}
@ -2234,6 +2239,11 @@ fn continueExpr(parent_gz: *GenZir, parent_scope: *Scope, node: Ast.Node.Index)
const tree = astgen.tree;
const node_datas = tree.nodes.items(.data);
const break_label = node_datas[node].lhs;
const rhs = node_datas[node].rhs;
if (break_label == 0 and rhs != 0) {
return astgen.failNode(node, "cannot continue with operand without label", .{});
}
// Look for the label in the scope.
var scope = parent_scope;
@ -2258,6 +2268,15 @@ fn continueExpr(parent_gz: *GenZir, parent_scope: *Scope, node: Ast.Node.Index)
if (break_label != 0) blk: {
if (gen_zir.label) |*label| {
if (try astgen.tokenIdentEql(label.token, break_label)) {
const maybe_switch_tag = astgen.instructions.items(.tag)[@intFromEnum(label.block_inst)];
if (rhs != 0) switch (maybe_switch_tag) {
.switch_block, .switch_block_ref => {},
else => return astgen.failNode(node, "cannot continue loop with operand", .{}),
} else switch (maybe_switch_tag) {
.switch_block, .switch_block_ref => return astgen.failNode(node, "cannot continue switch without operand", .{}),
else => {},
}
label.used = true;
break :blk;
}
@ -2265,7 +2284,34 @@ fn continueExpr(parent_gz: *GenZir, parent_scope: *Scope, node: Ast.Node.Index)
// found continue but either it has a different label, or no label
scope = gen_zir.parent;
continue;
} else if (gen_zir.label) |label| {
// This `continue` is unlabeled. If the gz we've found corresponds to a labeled
// `switch`, ignore it and continue to parent scopes.
switch (astgen.instructions.items(.tag)[@intFromEnum(label.block_inst)]) {
.switch_block, .switch_block_ref => {
scope = gen_zir.parent;
continue;
},
else => {},
}
}
if (rhs != 0) {
// We need to figure out the result info to use.
// The type should match
const operand = try reachableExpr(parent_gz, parent_scope, gen_zir.continue_result_info, rhs, node);
try genDefers(parent_gz, scope, parent_scope, .normal_only);
// As our last action before the continue, "pop" the error trace if needed
if (!gen_zir.is_comptime)
_ = try parent_gz.addRestoreErrRetIndex(.{ .block = continue_block }, .always, node);
_ = try parent_gz.addBreakWithSrcNode(.switch_continue, continue_block, operand, rhs);
return Zir.Inst.Ref.unreachable_value;
}
try genDefers(parent_gz, scope, parent_scope, .normal_only);
const break_tag: Zir.Inst.Tag = if (gen_zir.is_inline)
.break_inline
@ -2284,12 +2330,7 @@ fn continueExpr(parent_gz: *GenZir, parent_scope: *Scope, node: Ast.Node.Index)
},
.local_val => scope = scope.cast(Scope.LocalVal).?.parent,
.local_ptr => scope = scope.cast(Scope.LocalPtr).?.parent,
.defer_normal => {
const defer_scope = scope.cast(Scope.Defer).?;
scope = defer_scope.parent;
try parent_gz.addDefer(defer_scope.index, defer_scope.len);
},
.defer_error => scope = scope.cast(Scope.Defer).?.parent,
.defer_normal, .defer_error => scope = scope.cast(Scope.Defer).?.parent,
.namespace => break,
.top => unreachable,
}
@ -2881,6 +2922,7 @@ fn addEnsureResult(gz: *GenZir, maybe_unused_result: Zir.Inst.Ref, statement: As
.panic,
.trap,
.check_comptime_control_flow,
.switch_continue,
=> {
noreturn_src_node = statement;
break :b true;
@ -7546,7 +7588,8 @@ fn switchExpr(
parent_gz: *GenZir,
scope: *Scope,
ri: ResultInfo,
switch_node: Ast.Node.Index,
node: Ast.Node.Index,
switch_full: Ast.full.Switch,
) InnerError!Zir.Inst.Ref {
const astgen = parent_gz.astgen;
const gpa = astgen.gpa;
@ -7555,14 +7598,14 @@ fn switchExpr(
const node_tags = tree.nodes.items(.tag);
const main_tokens = tree.nodes.items(.main_token);
const token_tags = tree.tokens.items(.tag);
const operand_node = node_datas[switch_node].lhs;
const extra = tree.extraData(node_datas[switch_node].rhs, Ast.Node.SubRange);
const operand_node = node_datas[node].lhs;
const extra = tree.extraData(node_datas[node].rhs, Ast.Node.SubRange);
const case_nodes = tree.extra_data[extra.start..extra.end];
const need_rl = astgen.nodes_need_rl.contains(switch_node);
const need_rl = astgen.nodes_need_rl.contains(node);
const block_ri: ResultInfo = if (need_rl) ri else .{
.rl = switch (ri.rl) {
.ptr => .{ .ty = (try ri.rl.resultType(parent_gz, switch_node)).? },
.ptr => .{ .ty = (try ri.rl.resultType(parent_gz, node)).? },
.inferred_ptr => .none,
else => ri.rl,
},
@ -7573,11 +7616,16 @@ fn switchExpr(
const LocTag = @typeInfo(ResultInfo.Loc).@"union".tag_type.?;
const need_result_rvalue = @as(LocTag, block_ri.rl) != @as(LocTag, ri.rl);
if (switch_full.label_token) |label_token| {
try astgen.checkLabelRedefinition(scope, label_token);
}
// We perform two passes over the AST. This first pass is to collect information
// for the following variables, make note of the special prong AST node index,
// and bail out with a compile error if there are multiple special prongs present.
var any_payload_is_ref = false;
var any_has_tag_capture = false;
var any_non_inline_capture = false;
var scalar_cases_len: u32 = 0;
var multi_cases_len: u32 = 0;
var inline_cases_len: u32 = 0;
@ -7595,6 +7643,15 @@ fn switchExpr(
if (token_tags[ident + 1] == .comma) {
any_has_tag_capture = true;
}
// If the first capture is ignored, then there is no runtime-known
// capture, as the tag capture must be for an inline prong.
// This check isn't perfect, because for things like enums, the
// first prong *is* comptime-known for inline prongs! But such
// knowledge requires semantic analysis.
if (!mem.eql(u8, tree.tokenSlice(ident), "_")) {
any_non_inline_capture = true;
}
}
// Check for else/`_` prong.
if (case.ast.values.len == 0) {
@ -7614,7 +7671,7 @@ fn switchExpr(
);
} else if (underscore_src) |some_underscore| {
return astgen.failNodeNotes(
switch_node,
node,
"else and '_' prong in switch expression",
.{},
&[_]u32{
@ -7655,7 +7712,7 @@ fn switchExpr(
);
} else if (else_src) |some_else| {
return astgen.failNodeNotes(
switch_node,
node,
"else and '_' prong in switch expression",
.{},
&[_]u32{
@ -7704,6 +7761,12 @@ fn switchExpr(
const raw_operand = try expr(parent_gz, scope, operand_ri, operand_node);
const item_ri: ResultInfo = .{ .rl = .none };
// If this switch is labeled, it will have `continue`s targeting it, and thus we need the operand type
// to provide a result type.
const raw_operand_ty_ref = if (switch_full.label_token != null) t: {
break :t try parent_gz.addUnNode(.typeof, raw_operand, operand_node);
} else undefined;
// This contains the data that goes into the `extra` array for the SwitchBlock/SwitchBlockMulti,
// except the first cases_nodes.len slots are a table that indexes payloads later in the array, with
// the special case index coming first, then scalar_case_len indexes, then multi_cases_len indexes
@ -7725,7 +7788,22 @@ fn switchExpr(
try emitDbgStmtForceCurrentIndex(parent_gz, operand_lc);
// This gets added to the parent block later, after the item expressions.
const switch_tag: Zir.Inst.Tag = if (any_payload_is_ref) .switch_block_ref else .switch_block;
const switch_block = try parent_gz.makeBlockInst(switch_tag, switch_node);
const switch_block = try parent_gz.makeBlockInst(switch_tag, node);
if (switch_full.label_token) |label_token| {
block_scope.continue_block = switch_block.toOptional();
block_scope.continue_result_info = .{
.rl = if (any_payload_is_ref)
.{ .ref_coerced_ty = raw_operand_ty_ref }
else
.{ .coerced_ty = raw_operand_ty_ref },
};
block_scope.label = .{
.token = label_token,
.block_inst = switch_block,
};
}
// We re-use this same scope for all cases, including the special prong, if any.
var case_scope = parent_gz.makeSubBlock(&block_scope.base);
@ -7946,6 +8024,8 @@ fn switchExpr(
.has_else = special_prong == .@"else",
.has_under = special_prong == .under,
.any_has_tag_capture = any_has_tag_capture,
.any_non_inline_capture = any_non_inline_capture,
.has_continue = switch_full.label_token != null,
.scalar_cases_len = @intCast(scalar_cases_len),
},
});
@ -7982,7 +8062,7 @@ fn switchExpr(
}
if (need_result_rvalue) {
return rvalue(parent_gz, ri, switch_block.toRef(), switch_node);
return rvalue(parent_gz, ri, switch_block.toRef(), node);
} else {
return switch_block.toRef();
}
@ -11824,6 +11904,7 @@ const GenZir = struct {
continue_block: Zir.Inst.OptionalIndex = .none,
/// Only valid when setBreakResultInfo is called.
break_result_info: AstGen.ResultInfo = undefined,
continue_result_info: AstGen.ResultInfo = undefined,
suspend_node: Ast.Node.Index = 0,
nosuspend_node: Ast.Node.Index = 0,

26
lib/std/zig/Parse.zig
View file

@ -924,7 +924,6 @@ fn expectContainerField(p: *Parse) !Node.Index {
/// / KEYWORD_errdefer Payload? BlockExprStatement
/// / IfStatement
/// / LabeledStatement
/// / SwitchExpr
/// / VarDeclExprStatement
fn expectStatement(p: *Parse, allow_defer_var: bool) Error!Node.Index {
if (p.eatToken(.keyword_comptime)) |comptime_token| {
@ -995,7 +994,6 @@ fn expectStatement(p: *Parse, allow_defer_var: bool) Error!Node.Index {
.rhs = try p.expectBlockExprStatement(),
},
}),
.keyword_switch => return p.expectSwitchExpr(),
.keyword_if => return p.expectIfStatement(),
.keyword_enum, .keyword_struct, .keyword_union => {
const identifier = p.tok_i + 1;
@ -1238,7 +1236,7 @@ fn expectIfStatement(p: *Parse) !Node.Index {
});
}
/// LabeledStatement <- BlockLabel? (Block / LoopStatement)
/// LabeledStatement <- BlockLabel? (Block / LoopStatement / SwitchExpr)
fn parseLabeledStatement(p: *Parse) !Node.Index {
const label_token = p.parseBlockLabel();
const block = try p.parseBlock();
@ -1247,6 +1245,9 @@ fn parseLabeledStatement(p: *Parse) !Node.Index {
const loop_stmt = try p.parseLoopStatement();
if (loop_stmt != 0) return loop_stmt;
const switch_expr = try p.parseSwitchExpr();
if (switch_expr != 0) return switch_expr;
if (label_token != 0) {
const after_colon = p.tok_i;
const node = try p.parseTypeExpr();
@ -2072,7 +2073,7 @@ fn expectTypeExpr(p: *Parse) Error!Node.Index {
/// / KEYWORD_break BreakLabel? Expr?
/// / KEYWORD_comptime Expr
/// / KEYWORD_nosuspend Expr
/// / KEYWORD_continue BreakLabel?
/// / KEYWORD_continue BreakLabel? Expr?
/// / KEYWORD_resume Expr
/// / KEYWORD_return Expr?
/// / BlockLabel? LoopExpr
@ -2098,7 +2099,7 @@ fn parsePrimaryExpr(p: *Parse) !Node.Index {
.main_token = p.nextToken(),
.data = .{
.lhs = try p.parseBreakLabel(),
.rhs = undefined,
.rhs = try p.parseExpr(),
},
});
},
@ -2627,7 +2628,6 @@ fn parseSuffixExpr(p: *Parse) !Node.Index {
/// / KEYWORD_anyframe
/// / KEYWORD_unreachable
/// / STRINGLITERAL
/// / SwitchExpr
///
/// ContainerDecl <- (KEYWORD_extern / KEYWORD_packed)? ContainerDeclAuto
///
@ -2647,6 +2647,7 @@ fn parseSuffixExpr(p: *Parse) !Node.Index {
/// LabeledTypeExpr
/// <- BlockLabel Block
/// / BlockLabel? LoopTypeExpr
/// / BlockLabel? SwitchExpr
///
/// LoopTypeExpr <- KEYWORD_inline? (ForTypeExpr / WhileTypeExpr)
fn parsePrimaryTypeExpr(p: *Parse) !Node.Index {
@ -2753,6 +2754,10 @@ fn parsePrimaryTypeExpr(p: *Parse) !Node.Index {
p.tok_i += 2;
return p.parseWhileTypeExpr();
},
.keyword_switch => {
p.tok_i += 2;
return p.expectSwitchExpr();
},
.l_brace => {
p.tok_i += 2;
return p.parseBlock();
@ -3029,8 +3034,17 @@ fn parseWhileTypeExpr(p: *Parse) !Node.Index {
}
/// SwitchExpr <- KEYWORD_switch LPAREN Expr RPAREN LBRACE SwitchProngList RBRACE
fn parseSwitchExpr(p: *Parse) !Node.Index {
const switch_token = p.eatToken(.keyword_switch) orelse return null_node;
return p.expectSwitchSuffix(switch_token);
}
fn expectSwitchExpr(p: *Parse) !Node.Index {
const switch_token = p.assertToken(.keyword_switch);
return p.expectSwitchSuffix(switch_token);
}
fn expectSwitchSuffix(p: *Parse, switch_token: TokenIndex) !Node.Index {
_ = try p.expectToken(.l_paren);
const expr_node = try p.expectExpr();
_ = try p.expectToken(.r_paren);

14
lib/std/zig/Zir.zig
View file

@ -314,6 +314,9 @@ pub const Inst = struct {
/// break instruction in a block, and the target block is the parent.
/// Uses the `break` union field.
break_inline,
/// Branch from within a switch case to the case specified by the operand.
/// Uses the `break` union field. `block_inst` refers to a `switch_block` or `switch_block_ref`.
switch_continue,
/// Checks that comptime control flow does not happen inside a runtime block.
/// Uses the `un_node` union field.
check_comptime_control_flow,
@ -1273,6 +1276,7 @@ pub const Inst = struct {
.panic,
.trap,
.check_comptime_control_flow,
.switch_continue,
=> true,
};
}
@ -1512,6 +1516,7 @@ pub const Inst = struct {
.break_inline,
.condbr,
.condbr_inline,
.switch_continue,
.compile_error,
.ret_node,
.ret_load,
@ -1597,6 +1602,7 @@ pub const Inst = struct {
.bool_br_or = .pl_node,
.@"break" = .@"break",
.break_inline = .@"break",
.switch_continue = .@"break",
.check_comptime_control_flow = .un_node,
.for_len = .pl_node,
.call = .pl_node,
@ -2288,6 +2294,7 @@ pub const Inst = struct {
},
@"break": struct {
operand: Ref,
/// Index of a `Break` payload.
payload_index: u32,
},
dbg_stmt: LineColumn,
@ -2945,9 +2952,13 @@ pub const Inst = struct {
has_under: bool,
/// If true, at least one prong has an inline tag capture.
any_has_tag_capture: bool,
/// If true, at least one prong has a capture which may not
/// be comptime-known via `inline`.
any_non_inline_capture: bool,
has_continue: bool,
scalar_cases_len: ScalarCasesLen,
pub const ScalarCasesLen = u28;
pub const ScalarCasesLen = u26;
pub fn specialProng(bits: Bits) SpecialProng {
const has_else: u2 = @intFromBool(bits.has_else);
@ -3750,6 +3761,7 @@ fn findDeclsInner(
.bool_br_or,
.@"break",
.break_inline,
.switch_continue,
.check_comptime_control_flow,
.builtin_call,
.cmp_lt,

17
src/Air.zig
View file

@ -429,6 +429,14 @@ pub const Inst = struct {
/// Result type is always noreturn; no instructions in a block follow this one.
/// Uses the `pl_op` field. Operand is the condition. Payload is `SwitchBr`.
switch_br,
/// Switch branch which can dispatch back to itself with a different operand.
/// Result type is always noreturn; no instructions in a block follow this one.
/// Uses the `pl_op` field. Operand is the condition. Payload is `SwitchBr`.
loop_switch_br,
/// Dispatches back to a branch of a parent `loop_switch_br`.
/// Result type is always noreturn; no instructions in a block follow this one.
/// Uses the `br` field. `block_inst` is a `loop_switch_br` instruction.
switch_dispatch,
/// Given an operand which is an error union, splits control flow. In
/// case of error, control flow goes into the block that is part of this
/// instruction, which is guaranteed to end with a return instruction
@ -1454,6 +1462,8 @@ pub fn typeOfIndex(air: *const Air, inst: Air.Inst.Index, ip: *const InternPool)
.br,
.cond_br,
.switch_br,
.loop_switch_br,
.switch_dispatch,
.ret,
.ret_safe,
.ret_load,
@ -1618,6 +1628,8 @@ pub fn mustLower(air: Air, inst: Air.Inst.Index, ip: *const InternPool) bool {
.call_never_inline,
.cond_br,
.switch_br,
.loop_switch_br,
.switch_dispatch,
.@"try",
.try_cold,
.try_ptr,
@ -1903,7 +1915,10 @@ pub const UnwrappedSwitch = struct {
pub fn unwrapSwitch(air: *const Air, switch_inst: Inst.Index) UnwrappedSwitch {
const inst = air.instructions.get(@intFromEnum(switch_inst));
assert(inst.tag == .switch_br);
switch (inst.tag) {
.switch_br, .loop_switch_br => {},
else => unreachable, // assertion failure
}
const pl_op = inst.data.pl_op;
const extra = air.extraData(SwitchBr, pl_op.payload);
const hint_bag_count = std.math.divCeil(usize, extra.data.cases_len + 1, 10) catch unreachable;

4
src/Air/types_resolved.zig
View file

@ -222,7 +222,7 @@ fn checkBody(air: Air, body: []const Air.Inst.Index, zcu: *Zcu) bool {
if (!checkRef(data.un_op, zcu)) return false;
},
.br => {
.br, .switch_dispatch => {
if (!checkRef(data.br.operand, zcu)) return false;
},
@ -380,7 +380,7 @@ fn checkBody(air: Air, body: []const Air.Inst.Index, zcu: *Zcu) bool {
)) return false;
},
.switch_br => {
.switch_br, .loop_switch_br => {
const switch_br = air.unwrapSwitch(inst);
if (!checkRef(switch_br.operand, zcu)) return false;
var it = switch_br.iterateCases();

267
src/Liveness.zig
View file

@ -31,6 +31,7 @@ tomb_bits: []usize,
/// * `try`, `try_ptr` - points to a `CondBr` in `extra` at this index. The error path (the block
/// in the instruction) is considered the "else" path, and the rest of the block the "then".
/// * `switch_br` - points to a `SwitchBr` in `extra` at this index.
/// * `loop_switch_br` - points to a `SwitchBr` in `extra` at this index.
/// * `block` - points to a `Block` in `extra` at this index.
/// * `asm`, `call`, `aggregate_init` - the value is a set of bits which are the extra tomb
/// bits of operands.
@ -68,8 +69,8 @@ pub const Block = struct {
/// Liveness analysis runs in several passes. Each pass iterates backwards over instructions in
/// bodies, and recurses into bodies.
const LivenessPass = enum {
/// In this pass, we perform some basic analysis of loops to gain information the main pass
/// needs. In particular, for every `loop`, we track the following information:
/// In this pass, we perform some basic analysis of loops to gain information the main pass needs.
/// In particular, for every `loop` and `loop_switch_br`, we track the following information:
/// * Every outer block which the loop body contains a `br` to.
/// * Every outer loop which the loop body contains a `repeat` to.
/// * Every operand referenced within the loop body but created outside the loop.
@ -91,7 +92,8 @@ fn LivenessPassData(comptime pass: LivenessPass) type {
.loop_analysis => struct {
/// The set of blocks which are exited with a `br` instruction at some point within this
/// body and which we are currently within. Also includes `loop`s which are the target
/// of a `repeat` instruction.
/// of a `repeat` instruction, and `loop_switch_br`s which are the target of a
/// `switch_dispatch` instruction.
breaks: std.AutoHashMapUnmanaged(Air.Inst.Index, void) = .{},
/// The set of operands for which we have seen at least one usage but not their birth.
@ -330,6 +332,7 @@ pub fn categorizeOperand(
.trap,
.breakpoint,
.repeat,
.switch_dispatch,
.dbg_stmt,
.unreach,
.ret_addr,
@ -662,21 +665,17 @@ pub fn categorizeOperand(
return .complex;
},
.@"try", .try_cold => {
return .complex;
},
.try_ptr, .try_ptr_cold => {
return .complex;
},
.loop => {
return .complex;
},
.cond_br => {
return .complex;
},
.switch_br => {
return .complex;
},
.@"try",
.try_cold,
.try_ptr,
.try_ptr_cold,
.loop,
.cond_br,
.switch_br,
.loop_switch_br,
=> return .complex,
.wasm_memory_grow => {
const pl_op = air_datas[@intFromEnum(inst)].pl_op;
if (pl_op.operand == operand_ref) return matchOperandSmallIndex(l, inst, 0, .none);
@ -1206,6 +1205,7 @@ fn analyzeInst(
.br => return analyzeInstBr(a, pass, data, inst),
.repeat => return analyzeInstRepeat(a, pass, data, inst),
.switch_dispatch => return analyzeInstSwitchDispatch(a, pass, data, inst),
.assembly => {
const extra = a.air.extraData(Air.Asm, inst_datas[@intFromEnum(inst)].ty_pl.payload);
@ -1262,7 +1262,8 @@ fn analyzeInst(
.@"try", .try_cold => return analyzeInstCondBr(a, pass, data, inst, .@"try"),
.try_ptr, .try_ptr_cold => return analyzeInstCondBr(a, pass, data, inst, .try_ptr),
.cond_br => return analyzeInstCondBr(a, pass, data, inst, .cond_br),
.switch_br => return analyzeInstSwitchBr(a, pass, data, inst),
.switch_br => return analyzeInstSwitchBr(a, pass, data, inst, false),
.loop_switch_br => return analyzeInstSwitchBr(a, pass, data, inst, true),
.wasm_memory_grow => {
const pl_op = inst_datas[@intFromEnum(inst)].pl_op;
@ -1412,6 +1413,35 @@ fn analyzeInstRepeat(
return analyzeOperands(a, pass, data, inst, .{ .none, .none, .none });
}
fn analyzeInstSwitchDispatch(
a: *Analysis,
comptime pass: LivenessPass,
data: *LivenessPassData(pass),
inst: Air.Inst.Index,
) !void {
// This happens to be identical to `analyzeInstBr`, but is separated anyway for clarity.
const inst_datas = a.air.instructions.items(.data);
const br = inst_datas[@intFromEnum(inst)].br;
const gpa = a.gpa;
switch (pass) {
.loop_analysis => {
try data.breaks.put(gpa, br.block_inst, {});
},
.main_analysis => {
const block_scope = data.block_scopes.get(br.block_inst).?; // we should always be repeating an enclosing loop
const new_live_set = try block_scope.live_set.clone(gpa);
data.live_set.deinit(gpa);
data.live_set = new_live_set;
},
}
return analyzeOperands(a, pass, data, inst, .{ br.operand, .none, .none });
}
fn analyzeInstBlock(
a: *Analysis,
comptime pass: LivenessPass,
@ -1482,6 +1512,102 @@ fn analyzeInstBlock(
}
}
fn writeLoopInfo(
a: *Analysis,
data: *LivenessPassData(.loop_analysis),
inst: Air.Inst.Index,
old_breaks: std.AutoHashMapUnmanaged(Air.Inst.Index, void),
old_live: std.AutoHashMapUnmanaged(Air.Inst.Index, void),
) !void {
const gpa = a.gpa;
// `loop`s are guaranteed to have at least one matching `repeat`.
// Similarly, `loop_switch_br`s have a matching `switch_dispatch`.
// However, we no longer care about repeats of this loop for resolving
// which operands must live within it.
assert(data.breaks.remove(inst));
const extra_index: u32 = @intCast(a.extra.items.len);
const num_breaks = data.breaks.count();
try a.extra.ensureUnusedCapacity(gpa, 1 + num_breaks);
a.extra.appendAssumeCapacity(num_breaks);
var it = data.breaks.keyIterator();
while (it.next()) |key| {
const block_inst = key.*;
a.extra.appendAssumeCapacity(@intFromEnum(block_inst));
}
log.debug("[{}] %{}: includes breaks to {}", .{ LivenessPass.loop_analysis, inst, fmtInstSet(&data.breaks) });
// Now we put the live operands from the loop body in too
const num_live = data.live_set.count();
try a.extra.ensureUnusedCapacity(gpa, 1 + num_live);
a.extra.appendAssumeCapacity(num_live);
it = data.live_set.keyIterator();
while (it.next()) |key| {
const alive = key.*;
a.extra.appendAssumeCapacity(@intFromEnum(alive));
}
log.debug("[{}] %{}: maintain liveness of {}", .{ LivenessPass.loop_analysis, inst, fmtInstSet(&data.live_set) });
try a.special.put(gpa, inst, extra_index);
// Add back operands which were previously alive
it = old_live.keyIterator();
while (it.next()) |key| {
const alive = key.*;
try data.live_set.put(gpa, alive, {});
}
// And the same for breaks
it = old_breaks.keyIterator();
while (it.next()) |key| {
const block_inst = key.*;
try data.breaks.put(gpa, block_inst, {});
}
}
/// When analyzing a loop in the main pass, sets up `data.live_set` to be the set
/// of operands known to be alive when the loop repeats.
fn resolveLoopLiveSet(
a: *Analysis,
data: *LivenessPassData(.main_analysis),
inst: Air.Inst.Index,
) !void {
const gpa = a.gpa;
const extra_idx = a.special.fetchRemove(inst).?.value;
const num_breaks = data.old_extra.items[extra_idx];
const breaks: []const Air.Inst.Index = @ptrCast(data.old_extra.items[extra_idx + 1 ..][0..num_breaks]);
const num_loop_live = data.old_extra.items[extra_idx + num_breaks + 1];
const loop_live: []const Air.Inst.Index = @ptrCast(data.old_extra.items[extra_idx + num_breaks + 2 ..][0..num_loop_live]);
// This is necessarily not in the same control flow branch, because loops are noreturn
data.live_set.clearRetainingCapacity();
try data.live_set.ensureUnusedCapacity(gpa, @intCast(loop_live.len));
for (loop_live) |alive| data.live_set.putAssumeCapacity(alive, {});
log.debug("[{}] %{}: block live set is {}", .{ LivenessPass.main_analysis, inst, fmtInstSet(&data.live_set) });
for (breaks) |block_inst| {
// We might break to this block, so include every operand that the block needs alive
const block_scope = data.block_scopes.get(block_inst).?;
var it = block_scope.live_set.keyIterator();
while (it.next()) |key| {
const alive = key.*;
try data.live_set.put(gpa, alive, {});
}
}
log.debug("[{}] %{}: loop live set is {}", .{ LivenessPass.main_analysis, inst, fmtInstSet(&data.live_set) });
}
fn analyzeInstLoop(
a: *Analysis,
comptime pass: LivenessPass,
@ -1505,86 +1631,14 @@ fn analyzeInstLoop(
try analyzeBody(a, pass, data, body);
// `loop`s are guaranteed to have at least one matching `repeat`.
// However, we no longer care about repeats of this loop itself.
assert(data.breaks.remove(inst));
const extra_index: u32 = @intCast(a.extra.items.len);
const num_breaks = data.breaks.count();
try a.extra.ensureUnusedCapacity(gpa, 1 + num_breaks);
a.extra.appendAssumeCapacity(num_breaks);
var it = data.breaks.keyIterator();
while (it.next()) |key| {
const block_inst = key.*;
a.extra.appendAssumeCapacity(@intFromEnum(block_inst));
}
log.debug("[{}] %{}: includes breaks to {}", .{ pass, inst, fmtInstSet(&data.breaks) });
// Now we put the live operands from the loop body in too
const num_live = data.live_set.count();
try a.extra.ensureUnusedCapacity(gpa, 1 + num_live);
a.extra.appendAssumeCapacity(num_live);
it = data.live_set.keyIterator();
while (it.next()) |key| {
const alive = key.*;
a.extra.appendAssumeCapacity(@intFromEnum(alive));
}
log.debug("[{}] %{}: maintain liveness of {}", .{ pass, inst, fmtInstSet(&data.live_set) });
try a.special.put(gpa, inst, extra_index);
// Add back operands which were previously alive
it = old_live.keyIterator();
while (it.next()) |key| {
const alive = key.*;
try data.live_set.put(gpa, alive, {});
}
// And the same for breaks
it = old_breaks.keyIterator();
while (it.next()) |key| {
const block_inst = key.*;
try data.breaks.put(gpa, block_inst, {});
}
try writeLoopInfo(a, data, inst, old_breaks, old_live);
},
.main_analysis => {
const extra_idx = a.special.fetchRemove(inst).?.value; // remove because this data does not exist after analysis
const num_breaks = data.old_extra.items[extra_idx];
const breaks: []const Air.Inst.Index = @ptrCast(data.old_extra.items[extra_idx + 1 ..][0..num_breaks]);
const num_loop_live = data.old_extra.items[extra_idx + num_breaks + 1];
const loop_live: []const Air.Inst.Index = @ptrCast(data.old_extra.items[extra_idx + num_breaks + 2 ..][0..num_loop_live]);
// This is necessarily not in the same control flow branch, because loops are noreturn
data.live_set.clearRetainingCapacity();
try data.live_set.ensureUnusedCapacity(gpa, @intCast(loop_live.len));
for (loop_live) |alive| {
data.live_set.putAssumeCapacity(alive, {});
}
log.debug("[{}] %{}: block live set is {}", .{ pass, inst, fmtInstSet(&data.live_set) });
for (breaks) |block_inst| {
// We might break to this block, so include every operand that the block needs alive
const block_scope = data.block_scopes.get(block_inst).?;
var it = block_scope.live_set.keyIterator();
while (it.next()) |key| {
const alive = key.*;
try data.live_set.put(gpa, alive, {});
}
}
try resolveLoopLiveSet(a, data, inst);
// Now, `data.live_set` is the operands which must be alive when the loop repeats.
// Move them into a block scope for corresponding `repeat` instructions to notice.
log.debug("[{}] %{}: loop live set is {}", .{ pass, inst, fmtInstSet(&data.live_set) });
try data.block_scopes.putNoClobber(gpa, inst, .{
.live_set = data.live_set.move(),
});
@ -1720,6 +1774,7 @@ fn analyzeInstSwitchBr(
comptime pass: LivenessPass,
data: *LivenessPassData(pass),
inst: Air.Inst.Index,
is_dispatch_loop: bool,
) !void {
const inst_datas = a.air.instructions.items(.data);
const pl_op = inst_datas[@intFromEnum(inst)].pl_op;
@ -1730,6 +1785,17 @@ fn analyzeInstSwitchBr(
switch (pass) {
.loop_analysis => {
var old_breaks: std.AutoHashMapUnmanaged(Air.Inst.Index, void) = .{};
defer old_breaks.deinit(gpa);
var old_live: std.AutoHashMapUnmanaged(Air.Inst.Index, void) = .{};
defer old_live.deinit(gpa);
if (is_dispatch_loop) {
old_breaks = data.breaks.move();
old_live = data.live_set.move();
}
var it = switch_br.iterateCases();
while (it.next()) |case| {
try analyzeBody(a, pass, data, case.body);
@ -1738,9 +1804,24 @@ fn analyzeInstSwitchBr(
const else_body = it.elseBody();
try analyzeBody(a, pass, data, else_body);
}
if (is_dispatch_loop) {
try writeLoopInfo(a, data, inst, old_breaks, old_live);
}
},
.main_analysis => {
if (is_dispatch_loop) {
try resolveLoopLiveSet(a, data, inst);
try data.block_scopes.putNoClobber(gpa, inst, .{
.live_set = data.live_set.move(),
});
}
defer if (is_dispatch_loop) {
log.debug("[{}] %{}: popped loop block scop", .{ pass, inst });
var scope = data.block_scopes.fetchRemove(inst).?.value;
scope.live_set.deinit(gpa);
};
// This is, all in all, just a messier version of the `cond_br` logic. If you're trying
// to understand it, I encourage looking at `analyzeInstCondBr` first.

31
src/Liveness/Verify.zig
View file

@ -447,6 +447,16 @@ fn verifyBody(self: *Verify, body: []const Air.Inst.Index) Error!void {
try self.verifyMatchingLiveness(repeat.loop_inst, expected_live);
},
.switch_dispatch => {
const br = data[@intFromEnum(inst)].br;
try self.verifyOperand(inst, br.operand, self.liveness.operandDies(inst, 0));
const expected_live = self.loops.get(br.block_inst) orelse
return invalid("%{}: loop %{} not in scope", .{ @intFromEnum(inst), @intFromEnum(br.block_inst) });
try self.verifyMatchingLiveness(br.block_inst, expected_live);
},
.block, .dbg_inline_block => |tag| {
const ty_pl = data[@intFromEnum(inst)].ty_pl;
const block_ty = ty_pl.ty.toType();
@ -494,11 +504,11 @@ fn verifyBody(self: *Verify, body: []const Air.Inst.Index) Error!void {
// The same stuff should be alive after the loop as before it.
const gop = try self.loops.getOrPut(self.gpa, inst);
if (gop.found_existing) return invalid("%{}: loop already exists", .{@intFromEnum(inst)});
defer {
var live = self.loops.fetchRemove(inst).?;
live.value.deinit(self.gpa);
}
if (gop.found_existing) return invalid("%{}: loop already exists", .{@intFromEnum(inst)});
gop.value_ptr.* = try self.live.clone(self.gpa);
try self.verifyBody(loop_body);
@ -528,7 +538,7 @@ fn verifyBody(self: *Verify, body: []const Air.Inst.Index) Error!void {
try self.verifyInst(inst);
},
.switch_br => {
.switch_br, .loop_switch_br => {
const switch_br = self.air.unwrapSwitch(inst);
const switch_br_liveness = try self.liveness.getSwitchBr(
self.gpa,
@ -539,13 +549,22 @@ fn verifyBody(self: *Verify, body: []const Air.Inst.Index) Error!void {
try self.verifyOperand(inst, switch_br.operand, self.liveness.operandDies(inst, 0));
var live = self.live.move();
defer live.deinit(self.gpa);
// Excluding the operand (which we just handled), the same stuff should be alive
// after the loop as before it.
{
const gop = try self.loops.getOrPut(self.gpa, inst);
if (gop.found_existing) return invalid("%{}: loop already exists", .{@intFromEnum(inst)});
gop.value_ptr.* = self.live.move();
}
defer {
var live = self.loops.fetchRemove(inst).?;
live.value.deinit(self.gpa);
}
var it = switch_br.iterateCases();
while (it.next()) |case| {
self.live.deinit(self.gpa);
self.live = try live.clone(self.gpa);
self.live = try self.loops.get(inst).?.clone(self.gpa);
for (switch_br_liveness.deaths[case.idx]) |death| try self.verifyDeath(inst, death);
try self.verifyBody(case.body);
@ -554,7 +573,7 @@ fn verifyBody(self: *Verify, body: []const Air.Inst.Index) Error!void {
const else_body = it.elseBody();
if (else_body.len > 0) {
self.live.deinit(self.gpa);
self.live = try live.clone(self.gpa);
self.live = try self.loops.get(inst).?.clone(self.gpa);
for (switch_br_liveness.deaths[switch_br.cases_len]) |death| try self.verifyDeath(inst, death);
try self.verifyBody(else_body);
}

574
src/Sema.zig
View file

@ -503,11 +503,21 @@ pub const Block = struct {
/// to enable more precise compile errors.
/// Same indexes, capacity, length as `results`.
src_locs: std.ArrayListUnmanaged(?LazySrcLoc),
/// Most blocks do not utilize this field. When it is used, its use is
/// contextual. The possible uses are as follows:
/// * for a `switch_block[_ref]`, this refers to dummy `br` instructions
/// which correspond to `switch_continue` ZIR. The switch logic will
/// rewrite these to appropriate AIR switch dispatches.
extra_insts: std.ArrayListUnmanaged(Air.Inst.Index) = .{},
/// Same indexes, capacity, length as `extra_insts`.
extra_src_locs: std.ArrayListUnmanaged(LazySrcLoc) = .{},
pub fn deinit(merges: *@This(), allocator: mem.Allocator) void {
pub fn deinit(merges: *@This(), allocator: Allocator) void {
merges.results.deinit(allocator);
merges.br_list.deinit(allocator);
merges.src_locs.deinit(allocator);
merges.extra_insts.deinit(allocator);
merges.extra_src_locs.deinit(allocator);
}
};
@ -946,14 +956,21 @@ fn analyzeInlineBody(
error.ComptimeBreak => {},
else => |e| return e,
}
const break_inst = sema.comptime_break_inst;
const break_data = sema.code.instructions.items(.data)[@intFromEnum(break_inst)].@"break";
const extra = sema.code.extraData(Zir.Inst.Break, break_data.payload_index).data;
const break_inst = sema.code.instructions.get(@intFromEnum(sema.comptime_break_inst));
switch (break_inst.tag) {
.switch_continue => {
// This is handled by separate logic.
return error.ComptimeBreak;
},
.break_inline, .@"break" => {},
else => unreachable,
}
const extra = sema.code.extraData(Zir.Inst.Break, break_inst.data.@"break".payload_index).data;
if (extra.block_inst != break_target) {
// This control flow goes further up the stack.
return error.ComptimeBreak;
}
return try sema.resolveInst(break_data.operand);
return try sema.resolveInst(break_inst.data.@"break".operand);
}
/// Like `analyzeInlineBody`, but if the body does not break with a value, returns
@ -1571,6 +1588,13 @@ fn analyzeBodyInner(
i = 0;
continue;
},
.switch_continue => if (block.is_comptime) {
sema.comptime_break_inst = inst;
return error.ComptimeBreak;
} else {
try sema.zirSwitchContinue(block, inst);
break;
},
.loop => blk: {
if (!block.is_comptime) break :blk try sema.zirLoop(block, inst);
// Same as `block_inline`. TODO https://github.com/ziglang/zig/issues/8220
@ -6531,6 +6555,56 @@ fn zirBreak(sema: *Sema, start_block: *Block, inst: Zir.Inst.Index) CompileError
}
}
fn zirSwitchContinue(sema: *Sema, start_block: *Block, inst: Zir.Inst.Index) CompileError!void {
const tracy = trace(@src());
defer tracy.end();
const inst_data = sema.code.instructions.items(.data)[@intFromEnum(inst)].@"break";
const extra = sema.code.extraData(Zir.Inst.Break, inst_data.payload_index).data;
assert(extra.operand_src_node != Zir.Inst.Break.no_src_node);
const operand_src = start_block.nodeOffset(extra.operand_src_node);
const uncoerced_operand = try sema.resolveInst(inst_data.operand);
const switch_inst = extra.block_inst;
switch (sema.code.instructions.items(.tag)[@intFromEnum(switch_inst)]) {
.switch_block, .switch_block_ref => {},
else => unreachable, // assertion failure
}
const switch_payload_index = sema.code.instructions.items(.data)[@intFromEnum(switch_inst)].pl_node.payload_index;
const switch_operand_ref = sema.code.extraData(Zir.Inst.SwitchBlock, switch_payload_index).data.operand;
const switch_operand_ty = sema.typeOf(try sema.resolveInst(switch_operand_ref));
const operand = try sema.coerce(start_block, switch_operand_ty, uncoerced_operand, operand_src);
try sema.validateRuntimeValue(start_block, operand_src, operand);
// We want to generate a `switch_dispatch` instruction with the switch condition,
// possibly preceded by a store to the stack alloc containing the raw operand.
// However, to avoid too much special-case state in Sema, this is handled by the
// `switch` lowering logic. As such, we will find the `Block` corresponding to the
// parent `switch_block[_ref]` instruction, create a dummy `br`, and add a merge
// to signal to the switch logic to rewrite this into an appropriate dispatch.
var block = start_block;
while (true) {
if (block.label) |label| {
if (label.zir_block == switch_inst) {
const br_ref = try start_block.addBr(label.merges.block_inst, operand);
try label.merges.extra_insts.append(sema.gpa, br_ref.toIndex().?);
try label.merges.extra_src_locs.append(sema.gpa, operand_src);
block.runtime_index.increment();
if (block.runtime_cond == null and block.runtime_loop == null) {
block.runtime_cond = start_block.runtime_cond orelse start_block.runtime_loop;
block.runtime_loop = start_block.runtime_loop;
}
return;
}
}
block = block.parent.?;
}
}
fn zirDbgStmt(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError!void {
if (block.is_comptime or block.ownerModule().strip) return;
@ -10940,12 +11014,7 @@ const SwitchProngAnalysis = struct {
sema: *Sema,
/// The block containing the `switch_block` itself.
parent_block: *Block,
/// The raw switch operand value (*not* the condition). Always defined.
operand: Air.Inst.Ref,
/// May be `undefined` if no prong has a by-ref capture.
operand_ptr: Air.Inst.Ref,
/// The switch condition value. For unions, `operand` is the union and `cond` is its tag.
cond: Air.Inst.Ref,
operand: Operand,
/// If this switch is on an error set, this is the type to assign to the
/// `else` prong. If `null`, the prong should be unreachable.
else_error_ty: ?Type,
@ -10955,6 +11024,34 @@ const SwitchProngAnalysis = struct {
/// undefined if no prong has a tag capture.
tag_capture_inst: Zir.Inst.Index,
const Operand = union(enum) {
/// This switch will be dispatched only once, with the given operand.
simple: struct {
/// The raw switch operand value. Always defined.
by_val: Air.Inst.Ref,
/// The switch operand *pointer*. Defined only if there is a prong
/// with a by-ref capture.
by_ref: Air.Inst.Ref,
/// The switch condition value. For unions, `operand` is the union
/// and `cond` is its enum tag value.
cond: Air.Inst.Ref,
},
/// This switch may be dispatched multiple times with `continue` syntax.
/// As such, the operand is stored in an alloc if needed.
loop: struct {
/// The `alloc` containing the `switch` operand for the active dispatch.
/// Each prong must load from this `alloc` to get captures.
/// If there are no captures, this may be undefined.
operand_alloc: Air.Inst.Ref,
/// Whether `operand_alloc` contains a by-val operand or a by-ref
/// operand.
operand_is_ref: bool,
/// The switch condition value for the *initial* dispatch. For
/// unions, this is the enum tag value.
init_cond: Air.Inst.Ref,
},
};
/// Resolve a switch prong which is determined at comptime to have no peers.
/// Uses `resolveBlockBody`. Sets up captures as needed.
fn resolveProngComptime(
@ -11086,7 +11183,15 @@ const SwitchProngAnalysis = struct {
const sema = spa.sema;
const pt = sema.pt;
const zcu = pt.zcu;
const operand_ty = sema.typeOf(spa.operand);
const operand_ty = switch (spa.operand) {
.simple => |s| sema.typeOf(s.by_val),
.loop => |l| ty: {
const alloc_ty = sema.typeOf(l.operand_alloc);
const alloc_child = alloc_ty.childType(zcu);
if (l.operand_is_ref) break :ty alloc_child.childType(zcu);
break :ty alloc_child;
},
};
if (operand_ty.zigTypeTag(zcu) != .@"union") {
const tag_capture_src: LazySrcLoc = .{
.base_node_inst = capture_src.base_node_inst,
@ -11117,10 +11222,24 @@ const SwitchProngAnalysis = struct {
const zir_datas = sema.code.instructions.items(.data);
const switch_node_offset = zir_datas[@intFromEnum(spa.switch_block_inst)].pl_node.src_node;
const operand_ty = sema.typeOf(spa.operand);
const operand_ptr_ty = if (capture_byref) sema.typeOf(spa.operand_ptr) else undefined;
const operand_src = block.src(.{ .node_offset_switch_operand = switch_node_offset });
const operand_val, const operand_ptr = switch (spa.operand) {
.simple => |s| .{ s.by_val, s.by_ref },
.loop => |l| op: {
const loaded = try sema.analyzeLoad(block, operand_src, l.operand_alloc, operand_src);
if (l.operand_is_ref) {
const by_val = try sema.analyzeLoad(block, operand_src, loaded, operand_src);
break :op .{ by_val, loaded };
} else {
break :op .{ loaded, undefined };
}
},
};
const operand_ty = sema.typeOf(operand_val);
const operand_ptr_ty = if (capture_byref) sema.typeOf(operand_ptr) else undefined;
if (inline_case_capture != .none) {
const item_val = sema.resolveConstDefinedValue(block, LazySrcLoc.unneeded, inline_case_capture, undefined) catch unreachable;
if (operand_ty.zigTypeTag(zcu) == .@"union") {
@ -11136,16 +11255,16 @@ const SwitchProngAnalysis = struct {
.address_space = operand_ptr_ty.ptrAddressSpace(zcu),
},
});
if (try sema.resolveDefinedValue(block, operand_src, spa.operand_ptr)) |union_ptr| {
if (try sema.resolveDefinedValue(block, operand_src, operand_ptr)) |union_ptr| {
return Air.internedToRef((try union_ptr.ptrField(field_index, pt)).toIntern());
}
return block.addStructFieldPtr(spa.operand_ptr, field_index, ptr_field_ty);
return block.addStructFieldPtr(operand_ptr, field_index, ptr_field_ty);
} else {
if (try sema.resolveDefinedValue(block, operand_src, spa.operand)) |union_val| {
if (try sema.resolveDefinedValue(block, operand_src, operand_val)) |union_val| {
const tag_and_val = ip.indexToKey(union_val.toIntern()).un;
return Air.internedToRef(tag_and_val.val);
}
return block.addStructFieldVal(spa.operand, field_index, field_ty);
return block.addStructFieldVal(operand_val, field_index, field_ty);
}
} else if (capture_byref) {
return sema.uavRef(item_val.toIntern());
@ -11156,17 +11275,17 @@ const SwitchProngAnalysis = struct {
if (is_special_prong) {
if (capture_byref) {
return spa.operand_ptr;
return operand_ptr;
}
switch (operand_ty.zigTypeTag(zcu)) {
.error_set => if (spa.else_error_ty) |ty| {
return sema.bitCast(block, ty, spa.operand, operand_src, null);
return sema.bitCast(block, ty, operand_val, operand_src, null);
} else {
try sema.analyzeUnreachable(block, operand_src, false);
return .unreachable_value;
},
else => return spa.operand,
else => return operand_val,
}
}
@ -11265,19 +11384,19 @@ const SwitchProngAnalysis = struct {
};
};
if (try sema.resolveDefinedValue(block, operand_src, spa.operand_ptr)) |op_ptr_val| {
if (try sema.resolveDefinedValue(block, operand_src, operand_ptr)) |op_ptr_val| {
if (op_ptr_val.isUndef(zcu)) return pt.undefRef(capture_ptr_ty);
const field_ptr_val = try op_ptr_val.ptrField(first_field_index, pt);
return Air.internedToRef((try pt.getCoerced(field_ptr_val, capture_ptr_ty)).toIntern());
}
try sema.requireRuntimeBlock(block, operand_src, null);
return block.addStructFieldPtr(spa.operand_ptr, first_field_index, capture_ptr_ty);
return block.addStructFieldPtr(operand_ptr, first_field_index, capture_ptr_ty);
}
if (try sema.resolveDefinedValue(block, operand_src, spa.operand)) |operand_val| {
if (operand_val.isUndef(zcu)) return pt.undefRef(capture_ty);
const union_val = ip.indexToKey(operand_val.toIntern()).un;
if (try sema.resolveDefinedValue(block, operand_src, operand_val)) |operand_val_val| {
if (operand_val_val.isUndef(zcu)) return pt.undefRef(capture_ty);
const union_val = ip.indexToKey(operand_val_val.toIntern()).un;
if (Value.fromInterned(union_val.tag).isUndef(zcu)) return pt.undefRef(capture_ty);
const uncoerced = Air.internedToRef(union_val.val);
return sema.coerce(block, capture_ty, uncoerced, operand_src);
@ -11286,7 +11405,7 @@ const SwitchProngAnalysis = struct {
try sema.requireRuntimeBlock(block, operand_src, null);
if (same_types) {
return block.addStructFieldVal(spa.operand, first_field_index, capture_ty);
return block.addStructFieldVal(operand_val, first_field_index, capture_ty);
}
// We may have to emit a switch block which coerces the operand to the capture type.
@ -11300,7 +11419,7 @@ const SwitchProngAnalysis = struct {
}
// All fields are in-memory coercible to the resolved type!
// Just take the first field and bitcast the result.
const uncoerced = try block.addStructFieldVal(spa.operand, first_field_index, first_field_ty);
const uncoerced = try block.addStructFieldVal(operand_val, first_field_index, first_field_ty);
return block.addBitCast(capture_ty, uncoerced);
};
@ -11364,7 +11483,7 @@ const SwitchProngAnalysis = struct {
const field_idx = field_indices[idx];
const field_ty = Type.fromInterned(union_obj.field_types.get(ip)[field_idx]);
const uncoerced = try coerce_block.addStructFieldVal(spa.operand, field_idx, field_ty);
const uncoerced = try coerce_block.addStructFieldVal(operand_val, field_idx, field_ty);
const coerced = try sema.coerce(&coerce_block, capture_ty, uncoerced, case_src);
_ = try coerce_block.addBr(capture_block_inst, coerced);
@ -11388,7 +11507,7 @@ const SwitchProngAnalysis = struct {
const first_imc_item_idx = in_mem_coercible.findFirstSet().?;
const first_imc_field_idx = field_indices[first_imc_item_idx];
const first_imc_field_ty = Type.fromInterned(union_obj.field_types.get(ip)[first_imc_field_idx]);
const uncoerced = try coerce_block.addStructFieldVal(spa.operand, first_imc_field_idx, first_imc_field_ty);
const uncoerced = try coerce_block.addStructFieldVal(operand_val, first_imc_field_idx, first_imc_field_ty);
const coerced = try coerce_block.addBitCast(capture_ty, uncoerced);
_ = try coerce_block.addBr(capture_block_inst, coerced);
@ -11404,21 +11523,47 @@ const SwitchProngAnalysis = struct {
const switch_br_inst: u32 = @intCast(sema.air_instructions.len);
try sema.air_instructions.append(sema.gpa, .{
.tag = .switch_br,
.data = .{ .pl_op = .{
.operand = spa.cond,
.data = .{
.pl_op = .{
.operand = undefined, // set by switch below
.payload = sema.addExtraAssumeCapacity(Air.SwitchBr{
.cases_len = @intCast(prong_count),
.else_body_len = @intCast(else_body_len),
}),
} },
},
},
});
sema.air_extra.appendSliceAssumeCapacity(cases_extra.items);
// Set up block body
sema.air_instructions.items(.data)[@intFromEnum(capture_block_inst)].ty_pl.payload = sema.addExtraAssumeCapacity(Air.Block{
switch (spa.operand) {
.simple => |s| {
const air_datas = sema.air_instructions.items(.data);
air_datas[switch_br_inst].pl_op.operand = s.cond;
air_datas[@intFromEnum(capture_block_inst)].ty_pl.payload = sema.addExtraAssumeCapacity(Air.Block{
.body_len = 1,
});
sema.air_extra.appendAssumeCapacity(switch_br_inst);
},
.loop => {
// The block must first extract the tag from the loaded union.
const tag_inst: Air.Inst.Index = @enumFromInt(sema.air_instructions.len);
try sema.air_instructions.append(sema.gpa, .{
.tag = .get_union_tag,
.data = .{ .ty_op = .{
.ty = Air.internedToRef(union_obj.enum_tag_ty),
.operand = operand_val,
} },
});
const air_datas = sema.air_instructions.items(.data);
air_datas[switch_br_inst].pl_op.operand = tag_inst.toRef();
air_datas[@intFromEnum(capture_block_inst)].ty_pl.payload = sema.addExtraAssumeCapacity(Air.Block{
.body_len = 2,
});
sema.air_extra.appendAssumeCapacity(@intFromEnum(tag_inst));
sema.air_extra.appendAssumeCapacity(switch_br_inst);
},
}
return capture_block_inst.toRef();
},
@ -11435,7 +11580,7 @@ const SwitchProngAnalysis = struct {
if (case_vals.len == 1) {
const item_val = sema.resolveConstDefinedValue(block, LazySrcLoc.unneeded, case_vals[0], undefined) catch unreachable;
const item_ty = try pt.singleErrorSetType(item_val.getErrorName(zcu).unwrap().?);
return sema.bitCast(block, item_ty, spa.operand, operand_src, null);
return sema.bitCast(block, item_ty, operand_val, operand_src, null);
}
var names: InferredErrorSet.NameMap = .{};
@ -11445,15 +11590,15 @@ const SwitchProngAnalysis = struct {
names.putAssumeCapacityNoClobber(err_val.getErrorName(zcu).unwrap().?, {});
}
const error_ty = try pt.errorSetFromUnsortedNames(names.keys());
return sema.bitCast(block, error_ty, spa.operand, operand_src, null);
return sema.bitCast(block, error_ty, operand_val, operand_src, null);
},
else => {
// In this case the capture value is just the passed-through value
// of the switch condition.
if (capture_byref) {
return spa.operand_ptr;
return operand_ptr;
} else {
return spa.operand;
return operand_val;
}
},
}
@ -11686,9 +11831,13 @@ fn zirSwitchBlockErrUnion(sema: *Sema, block: *Block, inst: Zir.Inst.Index) Comp
var spa: SwitchProngAnalysis = .{
.sema = sema,
.parent_block = block,
.operand = undefined, // must be set to the unwrapped error code before use
.operand_ptr = .none,
.operand = .{
.simple = .{
.by_val = undefined, // must be set to the unwrapped error code before use
.by_ref = undefined,
.cond = raw_operand_val,
},
},
.else_error_ty = else_error_ty,
.switch_block_inst = inst,
.tag_capture_inst = undefined,
@ -11709,13 +11858,13 @@ fn zirSwitchBlockErrUnion(sema: *Sema, block: *Block, inst: Zir.Inst.Index) Comp
.name = operand_val.getErrorName(zcu).unwrap().?,
},
}));
spa.operand = if (extra.data.bits.payload_is_ref)
spa.operand.simple.by_val = if (extra.data.bits.payload_is_ref)
try sema.analyzeErrUnionCodePtr(block, switch_operand_src, raw_operand_val)
else
try sema.analyzeErrUnionCode(block, switch_operand_src, raw_operand_val);
if (extra.data.bits.any_uses_err_capture) {
sema.inst_map.putAssumeCapacity(err_capture_inst, spa.operand);
sema.inst_map.putAssumeCapacity(err_capture_inst, spa.operand.simple.by_val);
}
defer if (extra.data.bits.any_uses_err_capture) assert(sema.inst_map.remove(err_capture_inst));
@ -11723,7 +11872,7 @@ fn zirSwitchBlockErrUnion(sema: *Sema, block: *Block, inst: Zir.Inst.Index) Comp
sema,
spa,
&child_block,
try sema.switchCond(block, switch_operand_src, spa.operand),
try sema.switchCond(block, switch_operand_src, spa.operand.simple.by_val),
err_val,
operand_err_set_ty,
switch_src_node_offset,
@ -11777,20 +11926,20 @@ fn zirSwitchBlockErrUnion(sema: *Sema, block: *Block, inst: Zir.Inst.Index) Comp
const true_instructions = try sub_block.instructions.toOwnedSlice(gpa);
defer gpa.free(true_instructions);
spa.operand = if (extra.data.bits.payload_is_ref)
spa.operand.simple.by_val = if (extra.data.bits.payload_is_ref)
try sema.analyzeErrUnionCodePtr(&sub_block, switch_operand_src, raw_operand_val)
else
try sema.analyzeErrUnionCode(&sub_block, switch_operand_src, raw_operand_val);
if (extra.data.bits.any_uses_err_capture) {
sema.inst_map.putAssumeCapacity(err_capture_inst, spa.operand);
sema.inst_map.putAssumeCapacity(err_capture_inst, spa.operand.simple.by_val);
}
defer if (extra.data.bits.any_uses_err_capture) assert(sema.inst_map.remove(err_capture_inst));
_ = try sema.analyzeSwitchRuntimeBlock(
spa,
&sub_block,
switch_src,
try sema.switchCond(block, switch_operand_src, spa.operand),
try sema.switchCond(block, switch_operand_src, spa.operand.simple.by_val),
operand_err_set_ty,
switch_operand_src,
case_vals,
@ -11859,17 +12008,63 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
const special_prong_src = block.src(.{ .node_offset_switch_special_prong = src_node_offset });
const extra = sema.code.extraData(Zir.Inst.SwitchBlock, inst_data.payload_index);
const raw_operand_val: Air.Inst.Ref, const raw_operand_ptr: Air.Inst.Ref = blk: {
const operand: SwitchProngAnalysis.Operand, const raw_operand_ty: Type = op: {
const maybe_ptr = try sema.resolveInst(extra.data.operand);
if (operand_is_ref) {
const val = try sema.analyzeLoad(block, src, maybe_ptr, operand_src);
break :blk .{ val, maybe_ptr };
} else {
break :blk .{ maybe_ptr, undefined };
const val, const ref = if (operand_is_ref)
.{ try sema.analyzeLoad(block, src, maybe_ptr, operand_src), maybe_ptr }
else
.{ maybe_ptr, undefined };
const init_cond = try sema.switchCond(block, operand_src, val);
const operand_ty = sema.typeOf(val);
if (extra.data.bits.has_continue and !block.is_comptime) {
// Even if the operand is comptime-known, this `switch` is runtime.
if (try operand_ty.comptimeOnlySema(pt)) {
return sema.failWithOwnedErrorMsg(block, msg: {
const msg = try sema.errMsg(operand_src, "operand of switch loop has comptime-only type '{}'", .{operand_ty.fmt(pt)});
errdefer msg.destroy(gpa);
try sema.errNote(operand_src, msg, "switch loops are evalauted at runtime outside of comptime scopes", .{});
break :msg msg;
});
}
try sema.validateRuntimeValue(block, operand_src, maybe_ptr);
const operand_alloc = if (extra.data.bits.any_non_inline_capture) a: {
const operand_ptr_ty = try pt.singleMutPtrType(sema.typeOf(maybe_ptr));
const operand_alloc = try block.addTy(.alloc, operand_ptr_ty);
_ = try block.addBinOp(.store, operand_alloc, maybe_ptr);
break :a operand_alloc;
} else undefined;
break :op .{
.{ .loop = .{
.operand_alloc = operand_alloc,
.operand_is_ref = operand_is_ref,
.init_cond = init_cond,
} },
operand_ty,
};
}
// We always use `simple` in the comptime case, because as far as the dispatching logic
// is concerned, it really is dispatching a single prong. `resolveSwitchComptime` will
// be resposible for recursively resolving different prongs as needed.
break :op .{
.{ .simple = .{
.by_val = val,
.by_ref = ref,
.cond = init_cond,
} },
operand_ty,
};
};
const operand = try sema.switchCond(block, operand_src, raw_operand_val);
const union_originally = raw_operand_ty.zigTypeTag(zcu) == .@"union";
const err_set = raw_operand_ty.zigTypeTag(zcu) == .error_set;
const cond_ty = switch (raw_operand_ty.zigTypeTag(zcu)) {
.@"union" => raw_operand_ty.unionTagType(zcu).?, // validated by `switchCond` above
else => raw_operand_ty,
};
// AstGen guarantees that the instruction immediately preceding
// switch_block(_ref) is a dbg_stmt
@ -11919,9 +12114,6 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
},
};
const maybe_union_ty = sema.typeOf(raw_operand_val);
const union_originally = maybe_union_ty.zigTypeTag(zcu) == .@"union";
// Duplicate checking variables later also used for `inline else`.
var seen_enum_fields: []?LazySrcLoc = &.{};
var seen_errors = SwitchErrorSet.init(gpa);
@ -11937,13 +12129,10 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
var empty_enum = false;
const operand_ty = sema.typeOf(operand);
const err_set = operand_ty.zigTypeTag(zcu) == .error_set;
var else_error_ty: ?Type = null;
// Validate usage of '_' prongs.
if (special_prong == .under and (!operand_ty.isNonexhaustiveEnum(zcu) or union_originally)) {
if (special_prong == .under and !raw_operand_ty.isNonexhaustiveEnum(zcu)) {
const msg = msg: {
const msg = try sema.errMsg(
src,
@ -11969,11 +12158,11 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
}
// Validate for duplicate items, missing else prong, and invalid range.
switch (operand_ty.zigTypeTag(zcu)) {
switch (cond_ty.zigTypeTag(zcu)) {
.@"union" => unreachable, // handled in `switchCond`
.@"enum" => {
seen_enum_fields = try gpa.alloc(?LazySrcLoc, operand_ty.enumFieldCount(zcu));
empty_enum = seen_enum_fields.len == 0 and !operand_ty.isNonexhaustiveEnum(zcu);
seen_enum_fields = try gpa.alloc(?LazySrcLoc, cond_ty.enumFieldCount(zcu));
empty_enum = seen_enum_fields.len == 0 and !cond_ty.isNonexhaustiveEnum(zcu);
@memset(seen_enum_fields, null);
// `range_set` is used for non-exhaustive enum values that do not correspond to any tags.
@ -11991,7 +12180,7 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
seen_enum_fields,
&range_set,
item_ref,
operand_ty,
cond_ty,
block.src(.{ .switch_case_item = .{
.switch_node_offset = src_node_offset,
.case_idx = .{ .kind = .scalar, .index = @intCast(scalar_i) },
@ -12019,7 +12208,7 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
seen_enum_fields,
&range_set,
item_ref,
operand_ty,
cond_ty,
block.src(.{ .switch_case_item = .{
.switch_node_offset = src_node_offset,
.case_idx = .{ .kind = .multi, .index = @intCast(multi_i) },
@ -12028,7 +12217,7 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
));
}
try sema.validateSwitchNoRange(block, ranges_len, operand_ty, src_node_offset);
try sema.validateSwitchNoRange(block, ranges_len, cond_ty, src_node_offset);
}
}
const all_tags_handled = for (seen_enum_fields) |seen_src| {
@ -12036,7 +12225,7 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
} else true;
if (special_prong == .@"else") {
if (all_tags_handled and !operand_ty.isNonexhaustiveEnum(zcu)) return sema.fail(
if (all_tags_handled and !cond_ty.isNonexhaustiveEnum(zcu)) return sema.fail(
block,
special_prong_src,
"unreachable else prong; all cases already handled",
@ -12053,9 +12242,9 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
for (seen_enum_fields, 0..) |seen_src, i| {
if (seen_src != null) continue;
const field_name = operand_ty.enumFieldName(i, zcu);
const field_name = cond_ty.enumFieldName(i, zcu);
try sema.addFieldErrNote(
operand_ty,
cond_ty,
i,
msg,
"unhandled enumeration value: '{}'",
@ -12063,15 +12252,15 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
);
}
try sema.errNote(
operand_ty.srcLoc(zcu),
cond_ty.srcLoc(zcu),
msg,
"enum '{}' declared here",
.{operand_ty.fmt(pt)},
.{cond_ty.fmt(pt)},
);
break :msg msg;
};
return sema.failWithOwnedErrorMsg(block, msg);
} else if (special_prong == .none and operand_ty.isNonexhaustiveEnum(zcu) and !union_originally) {
} else if (special_prong == .none and cond_ty.isNonexhaustiveEnum(zcu) and !union_originally) {
return sema.fail(
block,
src,
@ -12085,7 +12274,7 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
block,
&seen_errors,
&case_vals,
operand_ty,
cond_ty,
inst_data,
scalar_cases_len,
multi_cases_len,
@ -12106,7 +12295,7 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
block,
&range_set,
item_ref,
operand_ty,
cond_ty,
block.src(.{ .switch_case_item = .{
.switch_node_offset = src_node_offset,
.case_idx = .{ .kind = .scalar, .index = @intCast(scalar_i) },
@ -12133,7 +12322,7 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
block,
&range_set,
item_ref,
operand_ty,
cond_ty,
block.src(.{ .switch_case_item = .{
.switch_node_offset = src_node_offset,
.case_idx = .{ .kind = .multi, .index = @intCast(multi_i) },
@ -12155,7 +12344,7 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
&range_set,
item_first,
item_last,
operand_ty,
cond_ty,
block.src(.{ .switch_case_item = .{
.switch_node_offset = src_node_offset,
.case_idx = .{ .kind = .multi, .index = @intCast(multi_i) },
@ -12171,9 +12360,9 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
}
check_range: {
if (operand_ty.zigTypeTag(zcu) == .int) {
const min_int = try operand_ty.minInt(pt, operand_ty);
const max_int = try operand_ty.maxInt(pt, operand_ty);
if (cond_ty.zigTypeTag(zcu) == .int) {
const min_int = try cond_ty.minInt(pt, cond_ty);
const max_int = try cond_ty.maxInt(pt, cond_ty);
if (try range_set.spans(min_int.toIntern(), max_int.toIntern())) {
if (special_prong == .@"else") {
return sema.fail(
@ -12246,7 +12435,7 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
));
}
try sema.validateSwitchNoRange(block, ranges_len, operand_ty, src_node_offset);
try sema.validateSwitchNoRange(block, ranges_len, cond_ty, src_node_offset);
}
}
switch (special_prong) {
@ -12278,7 +12467,7 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
block,
src,
"else prong required when switching on type '{}'",
.{operand_ty.fmt(pt)},
.{cond_ty.fmt(pt)},
);
}
@ -12299,7 +12488,7 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
block,
&seen_values,
item_ref,
operand_ty,
cond_ty,
block.src(.{ .switch_case_item = .{
.switch_node_offset = src_node_offset,
.case_idx = .{ .kind = .scalar, .index = @intCast(scalar_i) },
@ -12326,7 +12515,7 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
block,
&seen_values,
item_ref,
operand_ty,
cond_ty,
block.src(.{ .switch_case_item = .{
.switch_node_offset = src_node_offset,
.case_idx = .{ .kind = .multi, .index = @intCast(multi_i) },
@ -12335,7 +12524,7 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
));
}
try sema.validateSwitchNoRange(block, ranges_len, operand_ty, src_node_offset);
try sema.validateSwitchNoRange(block, ranges_len, cond_ty, src_node_offset);
}
}
},
@ -12354,16 +12543,14 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
.comptime_float,
.float,
=> return sema.fail(block, operand_src, "invalid switch operand type '{}'", .{
operand_ty.fmt(pt),
raw_operand_ty.fmt(pt),
}),
}
const spa: SwitchProngAnalysis = .{
.sema = sema,
.parent_block = block,
.operand = raw_operand_val,
.operand_ptr = raw_operand_ptr,
.cond = operand,
.operand = operand,
.else_error_ty = else_error_ty,
.switch_block_inst = inst,
.tag_capture_inst = tag_capture_inst,
@ -12407,24 +12594,6 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
defer child_block.instructions.deinit(gpa);
defer merges.deinit(gpa);
if (try sema.resolveDefinedValue(&child_block, src, operand)) |operand_val| {
return resolveSwitchComptime(
sema,
spa,
&child_block,
operand,
operand_val,
operand_ty,
src_node_offset,
special,
case_vals,
scalar_cases_len,
multi_cases_len,
err_set,
empty_enum,
);
}
if (scalar_cases_len + multi_cases_len == 0 and !special.is_inline) {
if (empty_enum) {
return .void_value;
@ -12432,17 +12601,48 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
if (special_prong == .none) {
return sema.fail(block, src, "switch must handle all possibilities", .{});
}
if (err_set and try sema.maybeErrorUnwrap(block, special.body, operand, operand_src, false)) {
return .unreachable_value;
}
if (zcu.backendSupportsFeature(.is_named_enum_value) and block.wantSafety() and operand_ty.zigTypeTag(zcu) == .@"enum" and
(!operand_ty.isNonexhaustiveEnum(zcu) or union_originally))
const init_cond = switch (operand) {
.simple => |s| s.cond,
.loop => |l| l.init_cond,
};
if (zcu.backendSupportsFeature(.is_named_enum_value) and block.wantSafety() and
raw_operand_ty.zigTypeTag(zcu) == .@"enum" and !raw_operand_ty.isNonexhaustiveEnum(zcu))
{
try sema.zirDbgStmt(block, cond_dbg_node_index);
const ok = try block.addUnOp(.is_named_enum_value, operand);
const ok = try block.addUnOp(.is_named_enum_value, init_cond);
try sema.addSafetyCheck(block, src, ok, .corrupt_switch);
}
if (err_set and try sema.maybeErrorUnwrap(block, special.body, init_cond, operand_src, false)) {
return .unreachable_value;
}
}
switch (operand) {
.loop => {}, // always runtime; evaluation in comptime scope uses `simple`
.simple => |s| {
if (try sema.resolveDefinedValue(&child_block, src, s.cond)) |cond_val| {
return resolveSwitchComptimeLoop(
sema,
spa,
&child_block,
if (operand_is_ref)
sema.typeOf(s.by_ref)
else
raw_operand_ty,
cond_ty,
cond_val,
src_node_offset,
special,
case_vals,
scalar_cases_len,
multi_cases_len,
err_set,
empty_enum,
operand_is_ref,
);
}
if (scalar_cases_len + multi_cases_len == 0 and !special.is_inline and !extra.data.bits.has_continue) {
return spa.resolveProngComptime(
&child_block,
.special,
@ -12458,28 +12658,33 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
merges,
);
}
},
}
if (child_block.is_comptime) {
_ = try sema.resolveConstDefinedValue(&child_block, operand_src, operand, .{
_ = try sema.resolveConstDefinedValue(&child_block, operand_src, operand.simple.cond, .{
.needed_comptime_reason = "condition in comptime switch must be comptime-known",
.block_comptime_reason = child_block.comptime_reason,
});
unreachable;
}
_ = try sema.analyzeSwitchRuntimeBlock(
const air_switch_ref = try sema.analyzeSwitchRuntimeBlock(
spa,
&child_block,
src,
operand,
operand_ty,
switch (operand) {
.simple => |s| s.cond,
.loop => |l| l.init_cond,
},
cond_ty,
operand_src,
case_vals,
special,
scalar_cases_len,
multi_cases_len,
union_originally,
maybe_union_ty,
raw_operand_ty,
err_set,
src_node_offset,
special_prong_src,
@ -12492,6 +12697,67 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index, operand_is_r
false,
);
for (merges.extra_insts.items, merges.extra_src_locs.items) |placeholder_inst, dispatch_src| {
var replacement_block = block.makeSubBlock();
defer replacement_block.instructions.deinit(gpa);
assert(sema.air_instructions.items(.tag)[@intFromEnum(placeholder_inst)] == .br);
const new_operand_maybe_ref = sema.air_instructions.items(.data)[@intFromEnum(placeholder_inst)].br.operand;
if (extra.data.bits.any_non_inline_capture) {
_ = try replacement_block.addBinOp(.store, operand.loop.operand_alloc, new_operand_maybe_ref);
}
const new_operand_val = if (operand_is_ref)
try sema.analyzeLoad(&replacement_block, dispatch_src, new_operand_maybe_ref, dispatch_src)
else
new_operand_maybe_ref;
const new_cond = try sema.switchCond(&replacement_block, dispatch_src, new_operand_val);
if (zcu.backendSupportsFeature(.is_named_enum_value) and block.wantSafety() and
cond_ty.zigTypeTag(zcu) == .@"enum" and !cond_ty.isNonexhaustiveEnum(zcu) and
!try sema.isComptimeKnown(new_cond))
{
const ok = try replacement_block.addUnOp(.is_named_enum_value, new_cond);
try sema.addSafetyCheck(&replacement_block, src, ok, .corrupt_switch);
}
_ = try replacement_block.addInst(.{
.tag = .switch_dispatch,
.data = .{ .br = .{
.block_inst = air_switch_ref.toIndex().?,
.operand = new_cond,
} },
});
if (replacement_block.instructions.items.len == 1) {
// Optimization: we don't need a block!
sema.air_instructions.set(
@intFromEnum(placeholder_inst),
sema.air_instructions.get(@intFromEnum(replacement_block.instructions.items[0])),
);
continue;
}
// Replace placeholder with a block.
// No `br` is needed as the block is a switch dispatch so necessarily `noreturn`.
try sema.air_extra.ensureUnusedCapacity(
gpa,
@typeInfo(Air.Block).@"struct".fields.len + replacement_block.instructions.items.len,
);
sema.air_instructions.set(@intFromEnum(placeholder_inst), .{
.tag = .block,
.data = .{ .ty_pl = .{
.ty = .noreturn_type,
.payload = sema.addExtraAssumeCapacity(Air.Block{
.body_len = @intCast(replacement_block.instructions.items.len),
}),
} },
});
sema.air_extra.appendSliceAssumeCapacity(@ptrCast(replacement_block.instructions.items));
}
return sema.resolveAnalyzedBlock(block, src, &child_block, merges, false);
}
@ -13123,7 +13389,7 @@ fn analyzeSwitchRuntimeBlock(
sema.air_extra.appendSliceAssumeCapacity(@ptrCast(else_body));
return try child_block.addInst(.{
.tag = .switch_br,
.tag = if (spa.operand == .loop) .loop_switch_br else .switch_br,
.data = .{ .pl_op = .{
.operand = operand,
.payload = payload_index,
@ -13131,6 +13397,77 @@ fn analyzeSwitchRuntimeBlock(
});
}
fn resolveSwitchComptimeLoop(
sema: *Sema,
init_spa: SwitchProngAnalysis,
child_block: *Block,
maybe_ptr_operand_ty: Type,
cond_ty: Type,
init_cond_val: Value,
switch_node_offset: i32,
special: SpecialProng,
case_vals: std.ArrayListUnmanaged(Air.Inst.Ref),
scalar_cases_len: u32,
multi_cases_len: u32,
err_set: bool,
empty_enum: bool,
operand_is_ref: bool,
) CompileError!Air.Inst.Ref {
var spa = init_spa;
var cond_val = init_cond_val;
while (true) {
if (resolveSwitchComptime(
sema,
spa,
child_block,
spa.operand.simple.cond,
cond_val,
cond_ty,
switch_node_offset,
special,
case_vals,
scalar_cases_len,
multi_cases_len,
err_set,
empty_enum,
)) |result| {
return result;
} else |err| switch (err) {
error.ComptimeBreak => {
const break_inst = sema.code.instructions.get(@intFromEnum(sema.comptime_break_inst));
if (break_inst.tag != .switch_continue) return error.ComptimeBreak;
const extra = sema.code.extraData(Zir.Inst.Break, break_inst.data.@"break".payload_index).data;
if (extra.block_inst != spa.switch_block_inst) return error.ComptimeBreak;
// This is a `switch_continue` targeting this block. Change the operand and start over.
const src = child_block.nodeOffset(extra.operand_src_node);
const new_operand_uncoerced = try sema.resolveInst(break_inst.data.@"break".operand);
const new_operand = try sema.coerce(child_block, maybe_ptr_operand_ty, new_operand_uncoerced, src);
try sema.emitBackwardBranch(child_block, src);
const val, const ref = if (operand_is_ref)
.{ try sema.analyzeLoad(child_block, src, new_operand, src), new_operand }
else
.{ new_operand, undefined };
const cond_ref = try sema.switchCond(child_block, src, val);
cond_val = try sema.resolveConstDefinedValue(child_block, src, cond_ref, .{
.needed_comptime_reason = "condition in comptime switch must be comptime-known",
.block_comptime_reason = child_block.comptime_reason,
});
spa.operand = .{ .simple = .{
.by_val = val,
.by_ref = ref,
.cond = cond_ref,
} };
},
else => |e| return e,
}
}
}
fn resolveSwitchComptime(
sema: *Sema,
spa: SwitchProngAnalysis,
@ -13148,6 +13485,7 @@ fn resolveSwitchComptime(
) CompileError!Air.Inst.Ref {
const merges = &child_block.label.?.merges;
const resolved_operand_val = try sema.resolveLazyValue(operand_val);
var extra_index: usize = special.end;
{
var scalar_i: usize = 0;

1
src/Value.zig
View file

@ -292,6 +292,7 @@ pub fn getUnsignedIntInner(
.none => 0,
else => |payload| Value.fromInterned(payload).getUnsignedIntInner(strat, zcu, tid),
},
.enum_tag => |enum_tag| return Value.fromInterned(enum_tag.int).getUnsignedIntInner(strat, zcu, tid),
else => null,
},
};

2
src/arch/aarch64/CodeGen.zig
View file

@ -735,6 +735,7 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
.block => try self.airBlock(inst),
.br => try self.airBr(inst),
.repeat => return self.fail("TODO implement `repeat`", .{}),
.switch_dispatch => return self.fail("TODO implement `switch_dispatch`", .{}),
.trap => try self.airTrap(),
.breakpoint => try self.airBreakpoint(),
.ret_addr => try self.airRetAddr(inst),
@ -825,6 +826,7 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
.field_parent_ptr => try self.airFieldParentPtr(inst),
.switch_br => try self.airSwitch(inst),
.loop_switch_br => return self.fail("TODO implement `loop_switch_br`", .{}),
.slice_ptr => try self.airSlicePtr(inst),
.slice_len => try self.airSliceLen(inst),

2
src/arch/arm/CodeGen.zig
View file

@ -722,6 +722,7 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
.block => try self.airBlock(inst),
.br => try self.airBr(inst),
.repeat => return self.fail("TODO implement `repeat`", .{}),
.switch_dispatch => return self.fail("TODO implement `switch_dispatch`", .{}),
.trap => try self.airTrap(),
.breakpoint => try self.airBreakpoint(),
.ret_addr => try self.airRetAddr(inst),
@ -812,6 +813,7 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
.field_parent_ptr => try self.airFieldParentPtr(inst),
.switch_br => try self.airSwitch(inst),
.loop_switch_br => return self.fail("TODO implement `loop_switch_br`", .{}),
.slice_ptr => try self.airSlicePtr(inst),
.slice_len => try self.airSliceLen(inst),

2
src/arch/riscv64/CodeGen.zig
View file

@ -1580,6 +1580,7 @@ fn genBody(func: *Func, body: []const Air.Inst.Index) InnerError!void {
.block => try func.airBlock(inst),
.br => try func.airBr(inst),
.repeat => return func.fail("TODO implement `repeat`", .{}),
.switch_dispatch => return func.fail("TODO implement `switch_dispatch`", .{}),
.trap => try func.airTrap(),
.breakpoint => try func.airBreakpoint(),
.ret_addr => try func.airRetAddr(inst),
@ -1669,6 +1670,7 @@ fn genBody(func: *Func, body: []const Air.Inst.Index) InnerError!void {
.field_parent_ptr => try func.airFieldParentPtr(inst),
.switch_br => try func.airSwitchBr(inst),
.loop_switch_br => return func.fail("TODO implement `loop_switch_br`", .{}),
.ptr_slice_len_ptr => try func.airPtrSliceLenPtr(inst),
.ptr_slice_ptr_ptr => try func.airPtrSlicePtrPtr(inst),

2
src/arch/sparc64/CodeGen.zig
View file

@ -577,6 +577,7 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
.block => try self.airBlock(inst),
.br => try self.airBr(inst),
.repeat => return self.fail("TODO implement `repeat`", .{}),
.switch_dispatch => return self.fail("TODO implement `switch_dispatch`", .{}),
.trap => try self.airTrap(),
.breakpoint => try self.airBreakpoint(),
.ret_addr => @panic("TODO try self.airRetAddr(inst)"),
@ -667,6 +668,7 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
.field_parent_ptr => @panic("TODO try self.airFieldParentPtr(inst)"),
.switch_br => try self.airSwitch(inst),
.loop_switch_br => return self.fail("TODO implement `loop_switch_br`", .{}),
.slice_ptr => try self.airSlicePtr(inst),
.slice_len => try self.airSliceLen(inst),

2
src/arch/wasm/CodeGen.zig
View file

@ -1904,6 +1904,7 @@ fn genInst(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
.breakpoint => func.airBreakpoint(inst),
.br => func.airBr(inst),
.repeat => return func.fail("TODO implement `repeat`", .{}),
.switch_dispatch => return func.fail("TODO implement `switch_dispatch`", .{}),
.int_from_bool => func.airIntFromBool(inst),
.cond_br => func.airCondBr(inst),
.intcast => func.airIntcast(inst),
@ -1985,6 +1986,7 @@ fn genInst(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
.field_parent_ptr => func.airFieldParentPtr(inst),
.switch_br => func.airSwitchBr(inst),
.loop_switch_br => return func.fail("TODO implement `loop_switch_br`", .{}),
.trunc => func.airTrunc(inst),
.unreach => func.airUnreachable(inst),

2
src/arch/x86_64/CodeGen.zig
View file

@ -2248,6 +2248,7 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
.block => try self.airBlock(inst),
.br => try self.airBr(inst),
.repeat => return self.fail("TODO implement `repeat`", .{}),
.switch_dispatch => return self.fail("TODO implement `switch_dispatch`", .{}),
.trap => try self.airTrap(),
.breakpoint => try self.airBreakpoint(),
.ret_addr => try self.airRetAddr(inst),
@ -2336,6 +2337,7 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
.field_parent_ptr => try self.airFieldParentPtr(inst),
.switch_br => try self.airSwitchBr(inst),
.loop_switch_br => return self.fail("TODO implement `loop_switch_br`", .{}),
.slice_ptr => try self.airSlicePtr(inst),
.slice_len => try self.airSliceLen(inst),

109
src/codegen/c.zig
View file

@ -321,6 +321,9 @@ pub const Function = struct {
/// by type alignment.
/// The value is whether the alloc needs to be emitted in the header.
allocs: std.AutoArrayHashMapUnmanaged(LocalIndex, bool) = .{},
/// Maps from `loop_switch_br` instructions to the allocated local used
/// for the switch cond. Dispatches should set this local to the new cond.
loop_switch_conds: std.AutoHashMapUnmanaged(Air.Inst.Index, LocalIndex) = .{},
fn resolveInst(f: *Function, ref: Air.Inst.Ref) !CValue {
const gop = try f.value_map.getOrPut(ref);
@ -531,6 +534,7 @@ pub const Function = struct {
f.blocks.deinit(gpa);
f.value_map.deinit();
f.lazy_fns.deinit(gpa);
f.loop_switch_conds.deinit(gpa);
}
fn typeOf(f: *Function, inst: Air.Inst.Ref) Type {
@ -3378,8 +3382,10 @@ fn genBodyInner(f: *Function, body: []const Air.Inst.Index) error{ AnalysisFail,
// Instructions that are known to always be `noreturn` based on their tag.
.br => return airBr(f, inst),
.repeat => return airRepeat(f, inst),
.switch_dispatch => return airSwitchDispatch(f, inst),
.cond_br => return airCondBr(f, inst),
.switch_br => return airSwitchBr(f, inst),
.switch_br => return airSwitchBr(f, inst, false),
.loop_switch_br => return airSwitchBr(f, inst, true),
.loop => return airLoop(f, inst),
.ret => return airRet(f, inst, false),
.ret_safe => return airRet(f, inst, false), // TODO
@ -4786,6 +4792,46 @@ fn airRepeat(f: *Function, inst: Air.Inst.Index) !void {
try writer.print("goto zig_loop_{d};\n", .{@intFromEnum(repeat.loop_inst)});
}
fn airSwitchDispatch(f: *Function, inst: Air.Inst.Index) !void {
const pt = f.object.dg.pt;
const zcu = pt.zcu;
const br = f.air.instructions.items(.data)[@intFromEnum(inst)].br;
const writer = f.object.writer();
if (try f.air.value(br.operand, pt)) |cond_val| {
// Comptime-known dispatch. Iterate the cases to find the correct
// one, and branch directly to the corresponding case.
const switch_br = f.air.unwrapSwitch(br.block_inst);
var it = switch_br.iterateCases();
const target_case_idx: u32 = target: while (it.next()) |case| {
for (case.items) |item| {
const val = Value.fromInterned(item.toInterned().?);
if (cond_val.compareHetero(.eq, val, zcu)) break :target case.idx;
}
for (case.ranges) |range| {
const low = Value.fromInterned(range[0].toInterned().?);
const high = Value.fromInterned(range[1].toInterned().?);
if (cond_val.compareHetero(.gte, low, zcu) and
cond_val.compareHetero(.lte, high, zcu))
{
break :target case.idx;
}
}
} else switch_br.cases_len;
try writer.print("goto zig_switch_{d}_dispatch_{d};\n", .{ @intFromEnum(br.block_inst), target_case_idx });
return;
}
// Runtime-known dispatch. Set the switch condition, and branch back.
const cond = try f.resolveInst(br.operand);
const cond_local = f.loop_switch_conds.get(br.block_inst).?;
try f.writeCValue(writer, .{ .local = cond_local }, .Other);
try writer.writeAll(" = ");
try f.writeCValue(writer, cond, .Initializer);
try writer.writeAll(";\n");
try writer.print("goto zig_switch_{d}_loop;", .{@intFromEnum(br.block_inst)});
}
fn airBitcast(f: *Function, inst: Air.Inst.Index) !CValue {
const ty_op = f.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const inst_ty = f.typeOfIndex(inst);
@ -5004,15 +5050,34 @@ fn airCondBr(f: *Function, inst: Air.Inst.Index) !void {
try genBodyInner(f, else_body);
}
fn airSwitchBr(f: *Function, inst: Air.Inst.Index) !void {
fn airSwitchBr(f: *Function, inst: Air.Inst.Index, is_dispatch_loop: bool) !void {
const pt = f.object.dg.pt;
const zcu = pt.zcu;
const gpa = f.object.dg.gpa;
const switch_br = f.air.unwrapSwitch(inst);
const condition = try f.resolveInst(switch_br.operand);
const init_condition = try f.resolveInst(switch_br.operand);
try reap(f, inst, &.{switch_br.operand});
const condition_ty = f.typeOf(switch_br.operand);
const writer = f.object.writer();
// For dispatches, we will create a local alloc to contain the condition value.
// This may not result in optimal codegen for switch loops, but it minimizes the
// amount of C code we generate, which is probably more desirable here (and is simpler).
const condition = if (is_dispatch_loop) cond: {
const new_local = try f.allocLocal(inst, condition_ty);
try f.writeCValue(writer, new_local, .Other);
try writer.writeAll(" = ");
try f.writeCValue(writer, init_condition, .Initializer);
try writer.writeAll(";\n");
try writer.print("zig_switch_{d}_loop:", .{@intFromEnum(inst)});
try f.loop_switch_conds.put(gpa, inst, new_local.new_local);
break :cond new_local;
} else init_condition;
defer if (is_dispatch_loop) {
assert(f.loop_switch_conds.remove(inst));
};
try writer.writeAll("switch (");
const lowered_condition_ty = if (condition_ty.toIntern() == .bool_type)
@ -5030,7 +5095,6 @@ fn airSwitchBr(f: *Function, inst: Air.Inst.Index) !void {
try writer.writeAll(") {");
f.object.indent_writer.pushIndent();
const gpa = f.object.dg.gpa;
const liveness = try f.liveness.getSwitchBr(gpa, inst, switch_br.cases_len + 1);
defer gpa.free(liveness.deaths);
@ -5045,9 +5109,15 @@ fn airSwitchBr(f: *Function, inst: Air.Inst.Index) !void {
try f.object.indent_writer.insertNewline();
try writer.writeAll("case ");
const item_value = try f.air.value(item, pt);
if (item_value.?.getUnsignedInt(zcu)) |item_int| try writer.print("{}\n", .{
try f.fmtIntLiteral(try pt.intValue(lowered_condition_ty, item_int)),
}) else {
// If `item_value` is a pointer with a known integer address, print the address
// with no cast to avoid a warning.
write_val: {
if (condition_ty.isPtrAtRuntime(zcu)) {
if (item_value.?.getUnsignedInt(zcu)) |item_int| {
try writer.print("{}", .{try f.fmtIntLiteral(try pt.intValue(lowered_condition_ty, item_int))});
break :write_val;
}
}
if (condition_ty.isPtrAtRuntime(zcu)) {
try writer.writeByte('(');
try f.renderType(writer, Type.usize);
@ -5057,9 +5127,14 @@ fn airSwitchBr(f: *Function, inst: Air.Inst.Index) !void {
}
try writer.writeByte(':');
}
try writer.writeByte(' ');
try genBodyResolveState(f, inst, liveness.deaths[case.idx], case.body, false);
try writer.writeAll(" {\n");
f.object.indent_writer.pushIndent();
if (is_dispatch_loop) {
try writer.print("zig_switch_{d}_dispatch_{d}: ", .{ @intFromEnum(inst), case.idx });
}
try genBodyResolveState(f, inst, liveness.deaths[case.idx], case.body, true);
f.object.indent_writer.popIndent();
try writer.writeByte('}');
// The case body must be noreturn so we don't need to insert a break.
}
@ -5095,11 +5170,19 @@ fn airSwitchBr(f: *Function, inst: Air.Inst.Index) !void {
try f.object.dg.renderValue(writer, (try f.air.value(range[1], pt)).?, .Other);
try writer.writeByte(')');
}
try writer.writeAll(") ");
try genBodyResolveState(f, inst, liveness.deaths[case.idx], case.body, false);
try writer.writeAll(") {\n");
f.object.indent_writer.pushIndent();
if (is_dispatch_loop) {
try writer.print("zig_switch_{d}_dispatch_{d}: ", .{ @intFromEnum(inst), case.idx });
}
try genBodyResolveState(f, inst, liveness.deaths[case.idx], case.body, true);
f.object.indent_writer.popIndent();
try writer.writeByte('}');
}
}
if (is_dispatch_loop) {
try writer.print("zig_switch_{d}_dispatch_{d}: ", .{ @intFromEnum(inst), switch_br.cases_len });
}
if (else_body.len > 0) {
// Note that this must be the last case, so we do not need to use `genBodyResolveState` since
// the parent block will do it (because the case body is noreturn).

476
src/codegen/llvm.zig
View file

@ -1721,6 +1721,7 @@ pub const Object = struct {
.func_inst_table = .{},
.blocks = .{},
.loops = .{},
.switch_dispatch_info = .{},
.sync_scope = if (owner_mod.single_threaded) .singlethread else .system,
.file = file,
.scope = subprogram,
@ -4845,6 +4846,10 @@ pub const FuncGen = struct {
/// Maps `loop` instructions to the bb to branch to to repeat the loop.
loops: std.AutoHashMapUnmanaged(Air.Inst.Index, Builder.Function.Block.Index),
/// Maps `loop_switch_br` instructions to the information required to lower
/// dispatches (`switch_dispatch` instructions).
switch_dispatch_info: std.AutoHashMapUnmanaged(Air.Inst.Index, SwitchDispatchInfo),
sync_scope: Builder.SyncScope,
const Fuzz = struct {
@ -4857,6 +4862,33 @@ pub const FuncGen = struct {
}
};
const SwitchDispatchInfo = struct {
/// These are the blocks corresponding to each switch case.
/// The final element corresponds to the `else` case.
/// Slices allocated into `gpa`.
case_blocks: []Builder.Function.Block.Index,
/// This is `.none` if `jmp_table` is set, since we won't use a `switch` instruction to dispatch.
switch_weights: Builder.Function.Instruction.BrCond.Weights,
/// If not `null`, we have manually constructed a jump table to reach the desired block.
/// `table` can be used if the value is between `min` and `max` inclusive.
/// We perform this lowering manually to avoid some questionable behavior from LLVM.
/// See `airSwitchBr` for details.
jmp_table: ?JmpTable,
const JmpTable = struct {
min: Builder.Constant,
max: Builder.Constant,
in_bounds_hint: enum { none, unpredictable, likely, unlikely },
/// Pointer to the jump table itself, to be used with `indirectbr`.
/// The index into the jump table is the dispatch condition minus `min`.
/// The table values are `blockaddress` constants corresponding to blocks in `case_blocks`.
table: Builder.Constant,
/// `true` if `table` conatins a reference to the `else` block.
/// In this case, the `indirectbr` must include the `else` block in its target list.
table_includes_else: bool,
};
};
const BreakList = union {
list: std.MultiArrayList(struct {
bb: Builder.Function.Block.Index,
@ -4872,6 +4904,11 @@ pub const FuncGen = struct {
self.func_inst_table.deinit(gpa);
self.blocks.deinit(gpa);
self.loops.deinit(gpa);
var it = self.switch_dispatch_info.valueIterator();
while (it.next()) |info| {
self.gpa.free(info.case_blocks);
}
self.switch_dispatch_info.deinit(gpa);
}
fn todo(self: *FuncGen, comptime format: []const u8, args: anytype) Error {
@ -5184,8 +5221,10 @@ pub const FuncGen = struct {
// Instructions that are known to always be `noreturn` based on their tag.
.br => return self.airBr(inst),
.repeat => return self.airRepeat(inst),
.switch_dispatch => return self.airSwitchDispatch(inst),
.cond_br => return self.airCondBr(inst),
.switch_br => return self.airSwitchBr(inst),
.switch_br => return self.airSwitchBr(inst, false),
.loop_switch_br => return self.airSwitchBr(inst, true),
.loop => return self.airLoop(inst),
.ret => return self.airRet(inst, false),
.ret_safe => return self.airRet(inst, true),
@ -6093,6 +6132,202 @@ pub const FuncGen = struct {
_ = try self.wip.br(loop_bb);
}
fn lowerSwitchDispatch(
self: *FuncGen,
switch_inst: Air.Inst.Index,
cond_ref: Air.Inst.Ref,
dispatch_info: SwitchDispatchInfo,
) !void {
const o = self.ng.object;
const pt = o.pt;
const zcu = pt.zcu;
const cond_ty = self.typeOf(cond_ref);
const switch_br = self.air.unwrapSwitch(switch_inst);
if (try self.air.value(cond_ref, pt)) |cond_val| {
// Comptime-known dispatch. Iterate the cases to find the correct
// one, and branch to the corresponding element of `case_blocks`.
var it = switch_br.iterateCases();
const target_case_idx = target: while (it.next()) |case| {
for (case.items) |item| {
const val = Value.fromInterned(item.toInterned().?);
if (cond_val.compareHetero(.eq, val, zcu)) break :target case.idx;
}
for (case.ranges) |range| {
const low = Value.fromInterned(range[0].toInterned().?);
const high = Value.fromInterned(range[1].toInterned().?);
if (cond_val.compareHetero(.gte, low, zcu) and
cond_val.compareHetero(.lte, high, zcu))
{
break :target case.idx;
}
}
} else dispatch_info.case_blocks.len - 1;
const target_block = dispatch_info.case_blocks[target_case_idx];
target_block.ptr(&self.wip).incoming += 1;
_ = try self.wip.br(target_block);
return;
}
// Runtime-known dispatch.
const cond = try self.resolveInst(cond_ref);
if (dispatch_info.jmp_table) |jmp_table| {
// We should use the constructed jump table.
// First, check the bounds to branch to the `else` case if needed.
const inbounds = try self.wip.bin(
.@"and",
try self.cmp(.normal, .gte, cond_ty, cond, jmp_table.min.toValue()),
try self.cmp(.normal, .lte, cond_ty, cond, jmp_table.max.toValue()),
"",
);
const jmp_table_block = try self.wip.block(1, "Then");
const else_block = dispatch_info.case_blocks[dispatch_info.case_blocks.len - 1];
else_block.ptr(&self.wip).incoming += 1;
_ = try self.wip.brCond(inbounds, jmp_table_block, else_block, switch (jmp_table.in_bounds_hint) {
.none => .none,
.unpredictable => .unpredictable,
.likely => .then_likely,
.unlikely => .else_likely,
});
self.wip.cursor = .{ .block = jmp_table_block };
// Figure out the list of blocks we might branch to.
// This includes all case blocks, but it might not include the `else` block if
// the table is dense.
const target_blocks_len = dispatch_info.case_blocks.len - @intFromBool(!jmp_table.table_includes_else);
const target_blocks = dispatch_info.case_blocks[0..target_blocks_len];
// Make sure to cast the index to a usize so it's not treated as negative!
const table_index = try self.wip.cast(
.zext,
try self.wip.bin(.@"sub nuw", cond, jmp_table.min.toValue(), ""),
try o.lowerType(Type.usize),
"",
);
const target_ptr_ptr = try self.wip.gep(
.inbounds,
.ptr,
jmp_table.table.toValue(),
&.{table_index},
"",
);
const target_ptr = try self.wip.load(.normal, .ptr, target_ptr_ptr, .default, "");
// Do the branch!
_ = try self.wip.indirectbr(target_ptr, target_blocks);
// Mark all target blocks as having one more incoming branch.
for (target_blocks) |case_block| {
case_block.ptr(&self.wip).incoming += 1;
}
return;
}
// We must lower to an actual LLVM `switch` instruction.
// The switch prongs will correspond to our scalar cases. Ranges will
// be handled by conditional branches in the `else` prong.
const llvm_usize = try o.lowerType(Type.usize);
const cond_int = if (cond.typeOfWip(&self.wip).isPointer(&o.builder))
try self.wip.cast(.ptrtoint, cond, llvm_usize, "")
else
cond;
const llvm_cases_len, const last_range_case = info: {
var llvm_cases_len: u32 = 0;
var last_range_case: ?u32 = null;
var it = switch_br.iterateCases();
while (it.next()) |case| {
if (case.ranges.len > 0) last_range_case = case.idx;
llvm_cases_len += @intCast(case.items.len);
}
break :info .{ llvm_cases_len, last_range_case };
};
// The `else` of the LLVM `switch` is the actual `else` prong only
// if there are no ranges. Otherwise, the `else` will have a
// conditional chain before the "true" `else` prong.
const llvm_else_block = if (last_range_case == null)
dispatch_info.case_blocks[dispatch_info.case_blocks.len - 1]
else
try self.wip.block(0, "RangeTest");
llvm_else_block.ptr(&self.wip).incoming += 1;
var wip_switch = try self.wip.@"switch"(cond_int, llvm_else_block, llvm_cases_len, dispatch_info.switch_weights);
defer wip_switch.finish(&self.wip);
// Construct the actual cases. Set the cursor to the `else` block so
// we can construct ranges at the same time as scalar cases.
self.wip.cursor = .{ .block = llvm_else_block };
var it = switch_br.iterateCases();
while (it.next()) |case| {
const case_block = dispatch_info.case_blocks[case.idx];
for (case.items) |item| {
const llvm_item = (try self.resolveInst(item)).toConst().?;
const llvm_int_item = if (llvm_item.typeOf(&o.builder).isPointer(&o.builder))
try o.builder.castConst(.ptrtoint, llvm_item, llvm_usize)
else
llvm_item;
try wip_switch.addCase(llvm_int_item, case_block, &self.wip);
}
case_block.ptr(&self.wip).incoming += @intCast(case.items.len);
if (case.ranges.len == 0) continue;
// Add a conditional for the ranges, directing to the relevant bb.
// We don't need to consider `cold` branch hints since that information is stored
// in the target bb body, but we do care about likely/unlikely/unpredictable.
const hint = switch_br.getHint(case.idx);
var range_cond: ?Builder.Value = null;
for (case.ranges) |range| {
const llvm_min = try self.resolveInst(range[0]);
const llvm_max = try self.resolveInst(range[1]);
const cond_part = try self.wip.bin(
.@"and",
try self.cmp(.normal, .gte, cond_ty, cond, llvm_min),
try self.cmp(.normal, .lte, cond_ty, cond, llvm_max),
"",
);
if (range_cond) |prev| {
range_cond = try self.wip.bin(.@"or", prev, cond_part, "");
} else range_cond = cond_part;
}
// If the check fails, we either branch to the "true" `else` case,
// or to the next range condition.
const range_else_block = if (case.idx == last_range_case.?)
dispatch_info.case_blocks[dispatch_info.case_blocks.len - 1]
else
try self.wip.block(0, "RangeTest");
_ = try self.wip.brCond(range_cond.?, case_block, range_else_block, switch (hint) {
.none, .cold => .none,
.unpredictable => .unpredictable,
.likely => .then_likely,
.unlikely => .else_likely,
});
case_block.ptr(&self.wip).incoming += 1;
range_else_block.ptr(&self.wip).incoming += 1;
// Construct the next range conditional (if any) in the false branch.
self.wip.cursor = .{ .block = range_else_block };
}
}
fn airSwitchDispatch(self: *FuncGen, inst: Air.Inst.Index) !void {
const br = self.air.instructions.items(.data)[@intFromEnum(inst)].br;
const dispatch_info = self.switch_dispatch_info.get(br.block_inst).?;
return self.lowerSwitchDispatch(br.block_inst, br.operand, dispatch_info);
}
fn airCondBr(self: *FuncGen, inst: Air.Inst.Index) !void {
const pl_op = self.air.instructions.items(.data)[@intFromEnum(inst)].pl_op;
const cond = try self.resolveInst(pl_op.operand);
@ -6257,36 +6492,123 @@ pub const FuncGen = struct {
return fg.wip.extractValue(err_union, &.{offset}, "");
}
fn airSwitchBr(self: *FuncGen, inst: Air.Inst.Index) !void {
fn airSwitchBr(self: *FuncGen, inst: Air.Inst.Index, is_dispatch_loop: bool) !void {
const o = self.ng.object;
const zcu = o.pt.zcu;
const switch_br = self.air.unwrapSwitch(inst);
const cond = try self.resolveInst(switch_br.operand);
// This is not necessarily the actual `else` prong; it first contains conditionals
// for any range cases. It's just the `else` of the LLVM switch.
const llvm_else_block = try self.wip.block(1, "Default");
const case_blocks = try self.gpa.alloc(Builder.Function.Block.Index, switch_br.cases_len);
// For `loop_switch_br`, we need these BBs prepared ahead of time to generate dispatches.
// For `switch_br`, they allow us to sometimes generate better IR by sharing a BB between
// scalar and range cases in the same prong.
// +1 for `else` case. This is not the same as the LLVM `else` prong, as that may first contain
// conditionals to handle ranges.
const case_blocks = try self.gpa.alloc(Builder.Function.Block.Index, switch_br.cases_len + 1);
defer self.gpa.free(case_blocks);
// We set incoming as 0 for now, and increment it as we construct the switch.
for (case_blocks) |*b| b.* = try self.wip.block(0, "Case");
// We set incoming as 0 for now, and increment it as we construct dispatches.
for (case_blocks[0 .. case_blocks.len - 1]) |*b| b.* = try self.wip.block(0, "Case");
case_blocks[case_blocks.len - 1] = try self.wip.block(0, "Default");
const llvm_usize = try o.lowerType(Type.usize);
const cond_int = if (cond.typeOfWip(&self.wip).isPointer(&o.builder))
try self.wip.cast(.ptrtoint, cond, llvm_usize, "")
else
cond;
// There's a special case here to manually generate a jump table in some cases.
//
// Labeled switch in Zig is intended to follow the "direct threading" pattern. We would ideally use a jump
// table, and each `continue` has its own indirect `jmp`, to allow the branch predictor to more accurately
// use data patterns to predict future dispatches. The problem, however, is that LLVM emits fascinatingly
// bad asm for this. Not only does it not share the jump table -- which we really need it to do to prevent
// destroying the cache -- but it also actually generates slightly different jump tables for each case,
// and *a separate conditional branch beforehand* to handle dispatching back to the case we're currently
// within(!!).
//
// This asm is really, really, not what we want. As such, we will construct the jump table manually where
// appropriate (the values are dense and relatively few), and use it when lowering dispatches.
const llvm_cases_len = llvm_cases_len: {
var len: u32 = 0;
const jmp_table: ?SwitchDispatchInfo.JmpTable = jmp_table: {
if (!is_dispatch_loop) break :jmp_table null;
// On a 64-bit target, 1024 pointers in our jump table is about 8K of pointers. This seems just
// about acceptable - it won't fill L1d cache on most CPUs.
const max_table_len = 1024;
const cond_ty = self.typeOf(switch_br.operand);
switch (cond_ty.zigTypeTag(zcu)) {
.bool, .pointer => break :jmp_table null,
.@"enum", .int, .error_set => {},
else => unreachable,
}
if (cond_ty.intInfo(zcu).signedness == .signed) break :jmp_table null;
// Don't worry about the size of the type -- it's irrelevant, because the prong values could be fairly dense.
// If they are, then we will construct a jump table.
const min, const max = self.switchCaseItemRange(switch_br);
const min_int = min.getUnsignedInt(zcu) orelse break :jmp_table null;
const max_int = max.getUnsignedInt(zcu) orelse break :jmp_table null;
const table_len = max_int - min_int + 1;
if (table_len > max_table_len) break :jmp_table null;
const table_elems = try self.gpa.alloc(Builder.Constant, @intCast(table_len));
defer self.gpa.free(table_elems);
// Set them all to the `else` branch, then iterate over the AIR switch
// and replace all values which correspond to other prongs.
@memset(table_elems, try o.builder.blockAddrConst(
self.wip.function,
case_blocks[case_blocks.len - 1],
));
var item_count: u32 = 0;
var it = switch_br.iterateCases();
while (it.next()) |case| len += @intCast(case.items.len);
break :llvm_cases_len len;
while (it.next()) |case| {
const case_block = case_blocks[case.idx];
const case_block_addr = try o.builder.blockAddrConst(
self.wip.function,
case_block,
);
for (case.items) |item| {
const val = Value.fromInterned(item.toInterned().?);
const table_idx = val.toUnsignedInt(zcu) - min_int;
table_elems[@intCast(table_idx)] = case_block_addr;
item_count += 1;
}
for (case.ranges) |range| {
const low = Value.fromInterned(range[0].toInterned().?);
const high = Value.fromInterned(range[1].toInterned().?);
const low_idx = low.toUnsignedInt(zcu) - min_int;
const high_idx = high.toUnsignedInt(zcu) - min_int;
@memset(table_elems[@intCast(low_idx)..@intCast(high_idx + 1)], case_block_addr);
item_count += @intCast(high_idx + 1 - low_idx);
}
}
const table_llvm_ty = try o.builder.arrayType(table_elems.len, .ptr);
const table_val = try o.builder.arrayConst(table_llvm_ty, table_elems);
const table_variable = try o.builder.addVariable(
try o.builder.strtabStringFmt("__jmptab_{d}", .{@intFromEnum(inst)}),
table_llvm_ty,
.default,
);
try table_variable.setInitializer(table_val, &o.builder);
table_variable.setLinkage(.internal, &o.builder);
table_variable.setUnnamedAddr(.unnamed_addr, &o.builder);
const table_includes_else = item_count != table_len;
break :jmp_table .{
.min = try o.lowerValue(min.toIntern()),
.max = try o.lowerValue(max.toIntern()),
.in_bounds_hint = if (table_includes_else) .none else switch (switch_br.getElseHint()) {
.none, .cold => .none,
.unpredictable => .unpredictable,
.likely => .likely,
.unlikely => .unlikely,
},
.table = table_variable.toConst(&o.builder),
.table_includes_else = table_includes_else,
};
};
const weights: Builder.Function.Instruction.BrCond.Weights = weights: {
if (jmp_table != null) break :weights .none; // not used
// First pass. If any weights are `.unpredictable`, unpredictable.
// If all are `.none` or `.cold`, none.
var any_likely = false;
@ -6304,6 +6626,13 @@ pub const FuncGen = struct {
}
if (!any_likely) break :weights .none;
const llvm_cases_len = llvm_cases_len: {
var len: u32 = 0;
var it = switch_br.iterateCases();
while (it.next()) |case| len += @intCast(case.items.len);
break :llvm_cases_len len;
};
var weights = try self.gpa.alloc(Builder.Metadata, llvm_cases_len + 1);
defer self.gpa.free(weights);
@ -6336,75 +6665,66 @@ pub const FuncGen = struct {
break :weights @enumFromInt(@intFromEnum(tuple));
};
var wip_switch = try self.wip.@"switch"(cond_int, llvm_else_block, llvm_cases_len, weights);
defer wip_switch.finish(&self.wip);
const dispatch_info: SwitchDispatchInfo = .{
.case_blocks = case_blocks,
.switch_weights = weights,
.jmp_table = jmp_table,
};
var it = switch_br.iterateCases();
var any_ranges = false;
while (it.next()) |case| {
if (case.ranges.len > 0) any_ranges = true;
const case_block = case_blocks[case.idx];
case_block.ptr(&self.wip).incoming += @intCast(case.items.len);
// Handle scalar items, and generate the block.
// We'll generate conditionals for the ranges later on.
for (case.items) |item| {
const llvm_item = (try self.resolveInst(item)).toConst().?;
const llvm_int_item = if (llvm_item.typeOf(&o.builder).isPointer(&o.builder))
try o.builder.castConst(.ptrtoint, llvm_item, llvm_usize)
else
llvm_item;
try wip_switch.addCase(llvm_int_item, case_block, &self.wip);
if (is_dispatch_loop) {
try self.switch_dispatch_info.putNoClobber(self.gpa, inst, dispatch_info);
}
defer if (is_dispatch_loop) {
assert(self.switch_dispatch_info.remove(inst));
};
// Generate the initial dispatch.
// If this is a simple `switch_br`, this is the only dispatch.
try self.lowerSwitchDispatch(inst, switch_br.operand, dispatch_info);
// Iterate the cases and generate their bodies.
var it = switch_br.iterateCases();
while (it.next()) |case| {
const case_block = case_blocks[case.idx];
self.wip.cursor = .{ .block = case_block };
if (switch_br.getHint(case.idx) == .cold) _ = try self.wip.callIntrinsicAssumeCold();
try self.genBodyDebugScope(null, case.body, .poi);
try self.genBodyDebugScope(null, case.body, .none);
}
self.wip.cursor = .{ .block = case_blocks[case_blocks.len - 1] };
const else_body = it.elseBody();
self.wip.cursor = .{ .block = llvm_else_block };
if (any_ranges) {
const cond_ty = self.typeOf(switch_br.operand);
// Add conditionals for the ranges, directing to the relevant bb.
// We don't need to consider `cold` branch hints since that information is stored
// in the target bb body, but we do care about likely/unlikely/unpredictable.
it = switch_br.iterateCases();
while (it.next()) |case| {
if (case.ranges.len == 0) continue;
const case_block = case_blocks[case.idx];
const hint = switch_br.getHint(case.idx);
case_block.ptr(&self.wip).incoming += 1;
const next_else_block = try self.wip.block(1, "Default");
var range_cond: ?Builder.Value = null;
for (case.ranges) |range| {
const llvm_min = try self.resolveInst(range[0]);
const llvm_max = try self.resolveInst(range[1]);
const cond_part = try self.wip.bin(
.@"and",
try self.cmp(.normal, .gte, cond_ty, cond, llvm_min),
try self.cmp(.normal, .lte, cond_ty, cond, llvm_max),
"",
);
if (range_cond) |prev| {
range_cond = try self.wip.bin(.@"or", prev, cond_part, "");
} else range_cond = cond_part;
}
_ = try self.wip.brCond(range_cond.?, case_block, next_else_block, switch (hint) {
.none, .cold => .none,
.unpredictable => .unpredictable,
.likely => .then_likely,
.unlikely => .else_likely,
});
self.wip.cursor = .{ .block = next_else_block };
}
}
if (switch_br.getElseHint() == .cold) _ = try self.wip.callIntrinsicAssumeCold();
if (else_body.len != 0) {
try self.genBodyDebugScope(null, else_body, .poi);
if (else_body.len > 0) {
try self.genBodyDebugScope(null, it.elseBody(), .none);
} else {
_ = try self.wip.@"unreachable"();
}
}
// No need to reset the insert cursor since this instruction is noreturn.
fn switchCaseItemRange(self: *FuncGen, switch_br: Air.UnwrappedSwitch) [2]Value {
const zcu = self.ng.object.pt.zcu;
var it = switch_br.iterateCases();
var min: ?Value = null;
var max: ?Value = null;
while (it.next()) |case| {
for (case.items) |item| {
const val = Value.fromInterned(item.toInterned().?);
const low = if (min) |m| val.compareHetero(.lt, m, zcu) else true;
const high = if (max) |m| val.compareHetero(.gt, m, zcu) else true;
if (low) min = val;
if (high) max = val;
}
for (case.ranges) |range| {
const vals: [2]Value = .{
Value.fromInterned(range[0].toInterned().?),
Value.fromInterned(range[1].toInterned().?),
};
const low = if (min) |m| vals[0].compareHetero(.lt, m, zcu) else true;
const high = if (max) |m| vals[1].compareHetero(.gt, m, zcu) else true;
if (low) min = vals[0];
if (high) max = vals[1];
}
}
return .{ min.?, max.? };
}
fn airLoop(self: *FuncGen, inst: Air.Inst.Index) !void {

3
src/print_air.zig
View file

@ -296,11 +296,12 @@ const Writer = struct {
.aggregate_init => try w.writeAggregateInit(s, inst),
.union_init => try w.writeUnionInit(s, inst),
.br => try w.writeBr(s, inst),
.switch_dispatch => try w.writeBr(s, inst),
.repeat => try w.writeRepeat(s, inst),
.cond_br => try w.writeCondBr(s, inst),
.@"try", .try_cold => try w.writeTry(s, inst),
.try_ptr, .try_ptr_cold => try w.writeTryPtr(s, inst),
.switch_br => try w.writeSwitchBr(s, inst),
.loop_switch_br, .switch_br => try w.writeSwitchBr(s, inst),
.cmpxchg_weak, .cmpxchg_strong => try w.writeCmpxchg(s, inst),
.fence => try w.writeFence(s, inst),
.atomic_load => try w.writeAtomicLoad(s, inst),

1
src/print_zir.zig
View file

@ -302,6 +302,7 @@ const Writer = struct {
.@"break",
.break_inline,
.switch_continue,
=> try self.writeBreak(stream, inst),
.slice_start => try self.writeSliceStart(stream, inst),

1
test/behavior.zig
View file

@ -88,6 +88,7 @@ test {
_ = @import("behavior/struct_contains_null_ptr_itself.zig");
_ = @import("behavior/struct_contains_slice_of_itself.zig");
_ = @import("behavior/switch.zig");
_ = @import("behavior/switch_loop.zig");
_ = @import("behavior/switch_prong_err_enum.zig");
_ = @import("behavior/switch_prong_implicit_cast.zig");
_ = @import("behavior/switch_on_captured_error.zig");

205
test/behavior/switch_loop.zig Normal file
View file

@ -0,0 +1,205 @@
const builtin = @import("builtin");
const std = @import("std");
const expect = std.testing.expect;
test "simple switch loop" {
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest; // TODO
const S = struct {
fn doTheTest() !void {
var start: u32 = undefined;
start = 32;
const result: u32 = s: switch (start) {
0 => 0,
1 => 1,
2 => 2,
3 => 3,
else => |x| continue :s x / 2,
};
try expect(result == 2);
}
};
try S.doTheTest();
try comptime S.doTheTest();
}
test "switch loop with ranges" {
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest; // TODO
const S = struct {
fn doTheTest() !void {
var start: u32 = undefined;
start = 32;
const result = s: switch (start) {
0...3 => |x| x,
else => |x| continue :s x / 2,
};
try expect(result == 2);
}
};
try S.doTheTest();
try comptime S.doTheTest();
}
test "switch loop on enum" {
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest; // TODO
const S = struct {
const E = enum { a, b, c };
fn doTheTest() !void {
var start: E = undefined;
start = .a;
const result: u32 = s: switch (start) {
.a => continue :s .b,
.b => continue :s .c,
.c => 123,
};
try expect(result == 123);
}
};
try S.doTheTest();
try comptime S.doTheTest();
}
test "switch loop on tagged union" {
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest; // TODO
const S = struct {
const U = union(enum) {
a: u32,
b: f32,
c: f32,
};
fn doTheTest() !void {
var start: U = undefined;
start = .{ .a = 80 };
const result = s: switch (start) {
.a => |x| switch (x) {
0...49 => continue :s .{ .b = @floatFromInt(x) },
50 => continue :s .{ .c = @floatFromInt(x) },
else => continue :s .{ .a = x / 2 },
},
.b => |x| x,
.c => return error.TestFailed,
};
try expect(result == 40.0);
}
};
try S.doTheTest();
try comptime S.doTheTest();
}
test "switch loop dispatching instructions" {
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest; // TODO
const S = struct {
const Inst = union(enum) {
set: u32,
add: u32,
sub: u32,
end,
};
fn doTheTest() !void {
var insts: [5]Inst = undefined;
@memcpy(&insts, &[5]Inst{
.{ .set = 123 },
.{ .add = 100 },
.{ .sub = 50 },
.{ .sub = 10 },
.end,
});
var i: u32 = 0;
var cur: u32 = undefined;
eval: switch (insts[0]) {
.set => |x| {
cur = x;
i += 1;
continue :eval insts[i];
},
.add => |x| {
cur += x;
i += 1;
continue :eval insts[i];
},
.sub => |x| {
cur -= x;
i += 1;
continue :eval insts[i];
},
.end => {},
}
try expect(cur == 163);
}
};
try S.doTheTest();
try comptime S.doTheTest();
}
test "switch loop with pointer capture" {
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest; // TODO
const S = struct {
const U = union(enum) {
a: u32,
b: u32,
c: u32,
};
fn doTheTest() !void {
var a: U = .{ .a = 100 };
var b: U = .{ .b = 200 };
var c: U = .{ .c = 300 };
inc: switch (a) {
.a => |*x| {
x.* += 1;
continue :inc b;
},
.b => |*x| {
x.* += 10;
continue :inc c;
},
.c => |*x| {
x.* += 50;
},
}
try expect(a.a == 101);
try expect(b.b == 210);
try expect(c.c == 350);
}
};
try S.doTheTest();
try comptime S.doTheTest();
}