Commit 97d7fddfb78d17132749cae59fea36fe661bf642 | zig

author	Andrew Kelley <andrew@ziglang.org> 2021-04-02 19:11:51-07:00
committer	Andrew Kelley <andrew@ziglang.org> 2021-04-02 19:11:51-07:00
log	97d7fddfb78d17132749cae59fea36fe661bf642
tree	5b01a32f9ee35e6cef838cffb5058e5f0f777229
parent	43d364afef7f0609f9d897c7ff129ba6b9b3cab0

stage2: progress towards basic structs

Introduce `ResultLoc.none_or_ref` which is used by field access
expressions to avoid unnecessary loads when the field access itself
will do the load. This turns:

```zig
p.y - p.x - p.x
```

from

```zir
  %14 = load(%4) node_offset:8:12
  %15 = field_val(%14, "y") node_offset:8:13
  %16 = load(%4) node_offset:8:18
  %17 = field_val(%16, "x") node_offset:8:19
  %18 = sub(%15, %17) node_offset:8:16
  %19 = load(%4) node_offset:8:24
  %20 = field_val(%19, "x") node_offset:8:25
```

to

```zir
  %14 = field_val(%4, "y") node_offset:8:13
  %15 = field_val(%4, "x") node_offset:8:19
  %16 = sub(%14, %15) node_offset:8:16
  %17 = field_val(%4, "x") node_offset:8:25
```

Much more compact. This requires `Sema.zirFieldVal` to support both
pointers and non-pointers.

C backend: Implement typedefs for struct types, as well as the following
TZIR instructions:
 * mul
 * mulwrap
 * addwrap
 * subwrap
 * ref
 * struct_field_ptr

Note that add, addwrap, sub, subwrap, mul, mulwrap instructions are all
incorrect currently and need to be updated to properly handle wrapping
and non wrapping for signed and unsigned.

C backend: change indentation delta to 1, to make the output smaller and
to process fewer bytes.

I promise I will add a test case as soon as I fix those warnings that
are being printed for my test case.

6 files changed, 148 insertions(+), 29 deletions(-)

src
- AstGen.zig
- Module.zig
- Sema.zig
- codegen
  - c.zig
- zir.zig
test
- stage2
  - cbe.zig

src/AstGen.zig+25-13

...	@@ -124,6 +124,9 @@ pub const ResultLoc = union(enum) {	...	@@ -124,6 +124,9 @@ pub const ResultLoc = union(enum) {
124	/// The expression must generate a pointer rather than a value. For example, the left hand side	124	/// The expression must generate a pointer rather than a value. For example, the left hand side
125	/// of an assignment uses this kind of result location.	125	/// of an assignment uses this kind of result location.
126	ref,	126	ref,
		127	/// The callee will accept a ref, but it is not necessary, and the `ResultLoc`
		128	/// may be treated as `none` instead.
		129	none_or_ref,
127	/// The expression will be coerced into this type, but it will be evaluated as an rvalue.	130	/// The expression will be coerced into this type, but it will be evaluated as an rvalue.
128	ty: zir.Inst.Ref,	131	ty: zir.Inst.Ref,
129	/// The expression must store its result into this typed pointer. The result instruction	132	/// The expression must store its result into this typed pointer. The result instruction
...	@@ -157,7 +160,7 @@ pub const ResultLoc = union(enum) {	...	@@ -157,7 +160,7 @@ pub const ResultLoc = union(enum) {
157	var elide_store_to_block_ptr_instructions = false;	160	var elide_store_to_block_ptr_instructions = false;
158	switch (rl) {	161	switch (rl) {
159	// In this branch there will not be any store_to_block_ptr instructions.	162	// In this branch there will not be any store_to_block_ptr instructions.
160	.discard, .none, .ty, .ref => return .{	163	.discard, .none, .none_or_ref, .ty, .ref => return .{
161	.tag = .break_operand,	164	.tag = .break_operand,
162	.elide_store_to_block_ptr_instructions = false,	165	.elide_store_to_block_ptr_instructions = false,
163	},	166	},
...	@@ -606,8 +609,13 @@ pub fn expr(gz: GenZir, scope: Scope, rl: ResultLoc, node: ast.Node.Index) Inn	...	@@ -606,8 +609,13 @@ pub fn expr(gz: GenZir, scope: Scope, rl: ResultLoc, node: ast.Node.Index) Inn
606		609
607	.deref => {	610	.deref => {
608	const lhs = try expr(gz, scope, .none, node_datas[node].lhs);	611	const lhs = try expr(gz, scope, .none, node_datas[node].lhs);
609	const result = try gz.addUnNode(.load, lhs, node);	612	switch (rl) {
610	return rvalue(gz, scope, rl, result, node);	613	.ref, .none_or_ref => return lhs,
		614	else => {
		615	const result = try gz.addUnNode(.load, lhs, node);
		616	return rvalue(gz, scope, rl, result, node);
		617	},
		618	}
611	},	619	},
612	.address_of => {	620	.address_of => {
613	const result = try expr(gz, scope, .ref, node_datas[node].lhs);	621	const result = try expr(gz, scope, .ref, node_datas[node].lhs);
...	@@ -816,7 +824,7 @@ pub fn structInitExpr(	...	@@ -816,7 +824,7 @@ pub fn structInitExpr(
816	}	824	}
817	switch (rl) {	825	switch (rl) {
818	.discard => return mod.failNode(scope, node, "TODO implement structInitExpr discard", .{}),	826	.discard => return mod.failNode(scope, node, "TODO implement structInitExpr discard", .{}),
819	.none => return mod.failNode(scope, node, "TODO implement structInitExpr none", .{}),	827	.none, .none_or_ref => return mod.failNode(scope, node, "TODO implement structInitExpr none", .{}),
820	.ref => unreachable, // struct literal not valid as l-value	828	.ref => unreachable, // struct literal not valid as l-value
821	.ty => \|ty_inst\| {	829	.ty => \|ty_inst\| {
822	return mod.failNode(scope, node, "TODO implement structInitExpr ty", .{});	830	return mod.failNode(scope, node, "TODO implement structInitExpr ty", .{});
...	@@ -1980,7 +1988,7 @@ fn orelseCatchExpr(	...	@@ -1980,7 +1988,7 @@ fn orelseCatchExpr(
1980	// TODO handle catch	1988	// TODO handle catch
1981	const operand_rl: ResultLoc = switch (block_scope.break_result_loc) {	1989	const operand_rl: ResultLoc = switch (block_scope.break_result_loc) {
1982	.ref => .ref,	1990	.ref => .ref,
1983	.discard, .none, .block_ptr, .inferred_ptr => .none,	1991	.discard, .none, .none_or_ref, .block_ptr, .inferred_ptr => .none,
1984	.ty => \|elem_ty\| blk: {	1992	.ty => \|elem_ty\| blk: {
1985	const wrapped_ty = try block_scope.addUnNode(.optional_type, elem_ty, node);	1993	const wrapped_ty = try block_scope.addUnNode(.optional_type, elem_ty, node);
1986	break :blk .{ .ty = wrapped_ty };	1994	break :blk .{ .ty = wrapped_ty };
...	@@ -2156,7 +2164,7 @@ pub fn fieldAccess(	...	@@ -2156,7 +2164,7 @@ pub fn fieldAccess(
2156	.field_name_start = str_index,	2164	.field_name_start = str_index,
2157	}),	2165	}),
2158	else => return rvalue(gz, scope, rl, try gz.addPlNode(.field_val, node, zir.Inst.Field{	2166	else => return rvalue(gz, scope, rl, try gz.addPlNode(.field_val, node, zir.Inst.Field{
2159	.lhs = try expr(gz, scope, .none, object_node),	2167	.lhs = try expr(gz, scope, .none_or_ref, object_node),
2160	.field_name_start = str_index,	2168	.field_name_start = str_index,
2161	}), node),	2169	}), node),
2162	}	2170	}
...	@@ -3474,9 +3482,13 @@ fn identifier(	...	@@ -3474,9 +3482,13 @@ fn identifier(
3474	.local_ptr => {	3482	.local_ptr => {
3475	const local_ptr = s.cast(Scope.LocalPtr).?;	3483	const local_ptr = s.cast(Scope.LocalPtr).?;
3476	if (mem.eql(u8, local_ptr.name, ident_name)) {	3484	if (mem.eql(u8, local_ptr.name, ident_name)) {
3477	if (rl == .ref) return local_ptr.ptr;	3485	switch (rl) {
3478	const loaded = try gz.addUnNode(.load, local_ptr.ptr, ident);	3486	.ref, .none_or_ref => return local_ptr.ptr,
3479	return rvalue(gz, scope, rl, loaded, ident);	3487	else => {
		3488	const loaded = try gz.addUnNode(.load, local_ptr.ptr, ident);
		3489	return rvalue(gz, scope, rl, loaded, ident);
		3490	},
		3491	}
3480	}	3492	}
3481	s = local_ptr.parent;	3493	s = local_ptr.parent;
3482	},	3494	},
...	@@ -3493,7 +3505,7 @@ fn identifier(	...	@@ -3493,7 +3505,7 @@ fn identifier(
3493	}	3505	}
3494	const decl_index = @intCast(u32, gop.index);	3506	const decl_index = @intCast(u32, gop.index);
3495	switch (rl) {	3507	switch (rl) {
3496	.ref => return gz.addDecl(.decl_ref, decl_index, ident),	3508	.ref, .none_or_ref => return gz.addDecl(.decl_ref, decl_index, ident),
3497	else => return rvalue(gz, scope, rl, try gz.addDecl(.decl_val, decl_index, ident), ident),	3509	else => return rvalue(gz, scope, rl, try gz.addDecl(.decl_val, decl_index, ident), ident),
3498	}	3510	}
3499	}	3511	}
...	@@ -3697,7 +3709,7 @@ fn as(	...	@@ -3697,7 +3709,7 @@ fn as(
3697	) InnerError!zir.Inst.Ref {	3709	) InnerError!zir.Inst.Ref {
3698	const dest_type = try typeExpr(gz, scope, lhs);	3710	const dest_type = try typeExpr(gz, scope, lhs);
3699	switch (rl) {	3711	switch (rl) {
3700	.none, .discard, .ref, .ty => {	3712	.none, .none_or_ref, .discard, .ref, .ty => {
3701	const result = try expr(gz, scope, .{ .ty = dest_type }, rhs);	3713	const result = try expr(gz, scope, .{ .ty = dest_type }, rhs);
3702	return rvalue(gz, scope, rl, result, node);	3714	return rvalue(gz, scope, rl, result, node);
3703	},	3715	},
...	@@ -3781,7 +3793,7 @@ fn bitCast(	...	@@ -3781,7 +3793,7 @@ fn bitCast(
3781	});	3793	});
3782	return rvalue(gz, scope, rl, result, node);	3794	return rvalue(gz, scope, rl, result, node);
3783	},	3795	},
3784	.ref => unreachable, // `@bitCast` is not allowed as an r-value.	3796	.ref, .none_or_ref => unreachable, // `@bitCast` is not allowed as an r-value.
3785	.ptr => \|result_ptr\| {	3797	.ptr => \|result_ptr\| {
3786	const casted_result_ptr = try gz.addUnNode(.bitcast_result_ptr, result_ptr, node);	3798	const casted_result_ptr = try gz.addUnNode(.bitcast_result_ptr, result_ptr, node);
3787	return expr(gz, scope, .{ .ptr = casted_result_ptr }, rhs);	3799	return expr(gz, scope, .{ .ptr = casted_result_ptr }, rhs);
...	@@ -4354,7 +4366,7 @@ fn rvalue(	...	@@ -4354,7 +4366,7 @@ fn rvalue(
4354	src_node: ast.Node.Index,	4366	src_node: ast.Node.Index,
4355	) InnerError!zir.Inst.Ref {	4367	) InnerError!zir.Inst.Ref {
4356	switch (rl) {	4368	switch (rl) {
4357	.none => return result,	4369	.none, .none_or_ref => return result,
4358	.discard => {	4370	.discard => {
4359	// Emit a compile error for discarding error values.	4371	// Emit a compile error for discarding error values.
4360	_ = try gz.addUnNode(.ensure_result_non_error, result, src_node);	4372	_ = try gz.addUnNode(.ensure_result_non_error, result, src_node);

src/Module.zig+8

 @@ -373,6 +373,11 @@ pub const Struct = struct {
         /// Uses `unreachable_value` to indicate no default.
         default_val: Value,
     };
+    pub fn getFullyQualifiedName(struct_obj: *Struct, gpa: *Allocator) ![]u8 {
+        // TODO this should return e.g. "std.fs.Dir.OpenOptions"
+        return gpa.dupe(u8, mem.spanZ(struct_obj.owner_decl.name));
+    }
 };
 /// Some Fn struct memory is owned by the Decl's TypedValue.Managed arena allocator.
 @@ -1048,6 +1053,9 @@ pub const Scope = struct {
                     gz.rl_ty_inst = ty_inst;
                     gz.break_result_loc = parent_rl;
                 },
+                .none_or_ref => {
+                    gz.break_result_loc = .ref;
+                },
                 .discard, .none, .ptr, .ref => {
                     gz.break_result_loc = parent_rl;
                 },

src/Sema.zig+6-2

src/codegen/c.zig+106-12

...	@@ -44,22 +44,34 @@ fn formatTypeAsCIdentifier(	...	@@ -44,22 +44,34 @@ fn formatTypeAsCIdentifier(
44	var buffer = [1]u8{0} ** 128;	44	var buffer = [1]u8{0} ** 128;
45	// We don't care if it gets cut off, it's still more unique than a number	45	// We don't care if it gets cut off, it's still more unique than a number
46	var buf = std.fmt.bufPrint(&buffer, "{}", .{data}) catch &buffer;	46	var buf = std.fmt.bufPrint(&buffer, "{}", .{data}) catch &buffer;
		47	return formatIdent(buf, "", .{}, writer);
		48	}
		49
		50	pub fn typeToCIdentifier(t: Type) std.fmt.Formatter(formatTypeAsCIdentifier) {
		51	return .{ .data = t };
		52	}
47		53
48	for (buf) \|c, i\| {	54	fn formatIdent(
		55	ident: []const u8,
		56	comptime fmt: []const u8,
		57	options: std.fmt.FormatOptions,
		58	writer: anytype,
		59	) !void {
		60	for (ident) \|c, i\| {
49	switch (c) {	61	switch (c) {
50	0 => return writer.writeAll(buf[0..i]),	62	'a'...'z', 'A'...'Z', '_' => try writer.writeByte(c),
51	'a'...'z', 'A'...'Z', '_', '$' => {},
52	'0'...'9' => if (i == 0) {	63	'0'...'9' => if (i == 0) {
53	buf[i] = '_';	64	try writer.print("${x:2}", .{c});
		65	} else {
		66	try writer.writeByte(c);
54	},	67	},
55	else => buf[i] = '_',	68	else => try writer.print("${x:2}", .{c}),
56	}	69	}
57	}	70	}
58	return writer.writeAll(buf);
59	}	71	}
60		72
61	pub fn typeToCIdentifier(t: Type) std.fmt.Formatter(formatTypeAsCIdentifier) {	73	pub fn fmtIdent(ident: []const u8) std.fmt.Formatter(formatIdent) {
62	return .{ .data = t };	74	return .{ .data = ident };
63	}	75	}
64		76
65	/// This data is available when outputting .c code for a Module.	77	/// This data is available when outputting .c code for a Module.
...	@@ -430,6 +442,36 @@ pub const DeclGen = struct {	...	@@ -430,6 +442,36 @@ pub const DeclGen = struct {
430	try w.writeAll(name);	442	try w.writeAll(name);
431	dg.typedefs.putAssumeCapacityNoClobber(t, .{ .name = name, .rendered = rendered });	443	dg.typedefs.putAssumeCapacityNoClobber(t, .{ .name = name, .rendered = rendered });
432	},	444	},
		445	.Struct => {
		446	if (dg.typedefs.get(t)) \|some\| {
		447	return w.writeAll(some.name);
		448	}
		449	const struct_obj = t.castTag(.@"struct").?.data; // Handle 0 bit types elsewhere.
		450	const fqn = try struct_obj.getFullyQualifiedName(dg.typedefs.allocator);
		451	defer dg.typedefs.allocator.free(fqn);
		452
		453	var buffer = std.ArrayList(u8).init(dg.typedefs.allocator);
		454	defer buffer.deinit();
		455
		456	try buffer.appendSlice("typedef struct {\n");
		457	for (struct_obj.fields.entries.items) \|entry\| {
		458	try buffer.append(' ');
		459	try dg.renderType(buffer.writer(), entry.value.ty);
		460	try buffer.writer().print(" {s};\n", .{fmtIdent(entry.key)});
		461	}
		462	try buffer.appendSlice("} ");
		463
		464	const name_start = buffer.items.len;
		465	try buffer.writer().print("zig_S_{s};\n", .{fmtIdent(fqn)});
		466
		467	const rendered = buffer.toOwnedSlice();
		468	errdefer dg.typedefs.allocator.free(rendered);
		469	const name = rendered[name_start .. rendered.len - 2];
		470
		471	try dg.typedefs.ensureCapacity(dg.typedefs.capacity() + 1);
		472	try w.writeAll(name);
		473	dg.typedefs.putAssumeCapacityNoClobber(t, .{ .name = name, .rendered = rendered });
		474	},
433	.Null, .Undefined => unreachable, // must be const or comptime	475	.Null, .Undefined => unreachable, // must be const or comptime
434	else => \|e\| return dg.fail(.{ .node_offset = 0 }, "TODO: C backend: implement type {s}", .{	476	else => \|e\| return dg.fail(.{ .node_offset = 0 }, "TODO: C backend: implement type {s}", .{
435	@tagName(e),	477	@tagName(e),
...	@@ -525,8 +567,23 @@ pub fn genBody(o: *Object, body: ir.Body) error{ AnalysisFail, OutOfMemory }!voi	...	@@ -525,8 +567,23 @@ pub fn genBody(o: *Object, body: ir.Body) error{ AnalysisFail, OutOfMemory }!voi
525		567
526	for (body.instructions) \|inst\| {	568	for (body.instructions) \|inst\| {
527	const result_value = switch (inst.tag) {	569	const result_value = switch (inst.tag) {
528	.constant => unreachable, // excluded from function bodies	570	// TODO use a different strategy for add that communicates to the optimizer
		571	// that wrapping is UB.
529	.add => try genBinOp(o, inst.castTag(.add).?, " + "),	572	.add => try genBinOp(o, inst.castTag(.add).?, " + "),
		573	// TODO make this do wrapping arithmetic for signed ints
		574	.addwrap => try genBinOp(o, inst.castTag(.add).?, " + "),
		575	// TODO use a different strategy for sub that communicates to the optimizer
		576	// that wrapping is UB.
		577	.sub => try genBinOp(o, inst.castTag(.sub).?, " - "),
		578	// TODO make this do wrapping arithmetic for signed ints
		579	.subwrap => try genBinOp(o, inst.castTag(.sub).?, " - "),
		580	// TODO use a different strategy for mul that communicates to the optimizer
		581	// that wrapping is UB.
		582	.mul => try genBinOp(o, inst.castTag(.sub).?, " * "),
		583	// TODO make this do wrapping multiplication for signed ints
		584	.mulwrap => try genBinOp(o, inst.castTag(.sub).?, " * "),
		585
		586	.constant => unreachable, // excluded from function bodies
530	.alloc => try genAlloc(o, inst.castTag(.alloc).?),	587	.alloc => try genAlloc(o, inst.castTag(.alloc).?),
531	.arg => genArg(o),	588	.arg => genArg(o),
532	.assembly => try genAsm(o, inst.castTag(.assembly).?),	589	.assembly => try genAsm(o, inst.castTag(.assembly).?),
...	@@ -546,7 +603,6 @@ pub fn genBody(o: *Object, body: ir.Body) error{ AnalysisFail, OutOfMemory }!voi	...	@@ -546,7 +603,6 @@ pub fn genBody(o: *Object, body: ir.Body) error{ AnalysisFail, OutOfMemory }!voi
546	.ret => try genRet(o, inst.castTag(.ret).?),	603	.ret => try genRet(o, inst.castTag(.ret).?),
547	.retvoid => try genRetVoid(o),	604	.retvoid => try genRetVoid(o),
548	.store => try genStore(o, inst.castTag(.store).?),	605	.store => try genStore(o, inst.castTag(.store).?),
549	.sub => try genBinOp(o, inst.castTag(.sub).?, " - "),
550	.unreach => try genUnreach(o, inst.castTag(.unreach).?),	606	.unreach => try genUnreach(o, inst.castTag(.unreach).?),
551	.loop => try genLoop(o, inst.castTag(.loop).?),	607	.loop => try genLoop(o, inst.castTag(.loop).?),
552	.condbr => try genCondBr(o, inst.castTag(.condbr).?),	608	.condbr => try genCondBr(o, inst.castTag(.condbr).?),
...	@@ -567,17 +623,24 @@ pub fn genBody(o: *Object, body: ir.Body) error{ AnalysisFail, OutOfMemory }!voi	...	@@ -567,17 +623,24 @@ pub fn genBody(o: *Object, body: ir.Body) error{ AnalysisFail, OutOfMemory }!voi
567	.wrap_optional => try genWrapOptional(o, inst.castTag(.wrap_optional).?),	623	.wrap_optional => try genWrapOptional(o, inst.castTag(.wrap_optional).?),
568	.optional_payload => try genOptionalPayload(o, inst.castTag(.optional_payload).?),	624	.optional_payload => try genOptionalPayload(o, inst.castTag(.optional_payload).?),
569	.optional_payload_ptr => try genOptionalPayload(o, inst.castTag(.optional_payload_ptr).?),	625	.optional_payload_ptr => try genOptionalPayload(o, inst.castTag(.optional_payload_ptr).?),
		626	.ref => try genRef(o, inst.castTag(.ref).?),
		627	.struct_field_ptr => try genStructFieldPtr(o, inst.castTag(.struct_field_ptr).?),
		628
570	.is_err => try genIsErr(o, inst.castTag(.is_err).?),	629	.is_err => try genIsErr(o, inst.castTag(.is_err).?),
571	.is_err_ptr => try genIsErr(o, inst.castTag(.is_err_ptr).?),	630	.is_err_ptr => try genIsErr(o, inst.castTag(.is_err_ptr).?),
572	.error_to_int => try genErrorToInt(o, inst.castTag(.error_to_int).?),	631	.error_to_int => try genErrorToInt(o, inst.castTag(.error_to_int).?),
573	.int_to_error => try genIntToError(o, inst.castTag(.int_to_error).?),	632	.int_to_error => try genIntToError(o, inst.castTag(.int_to_error).?),
		633
574	.unwrap_errunion_payload => try genUnwrapErrUnionPay(o, inst.castTag(.unwrap_errunion_payload).?),	634	.unwrap_errunion_payload => try genUnwrapErrUnionPay(o, inst.castTag(.unwrap_errunion_payload).?),
575	.unwrap_errunion_err => try genUnwrapErrUnionErr(o, inst.castTag(.unwrap_errunion_err).?),	635	.unwrap_errunion_err => try genUnwrapErrUnionErr(o, inst.castTag(.unwrap_errunion_err).?),
576	.unwrap_errunion_payload_ptr => try genUnwrapErrUnionPay(o, inst.castTag(.unwrap_errunion_payload_ptr).?),	636	.unwrap_errunion_payload_ptr => try genUnwrapErrUnionPay(o, inst.castTag(.unwrap_errunion_payload_ptr).?),
577	.unwrap_errunion_err_ptr => try genUnwrapErrUnionErr(o, inst.castTag(.unwrap_errunion_err_ptr).?),	637	.unwrap_errunion_err_ptr => try genUnwrapErrUnionErr(o, inst.castTag(.unwrap_errunion_err_ptr).?),
578	.wrap_errunion_payload => try genWrapErrUnionPay(o, inst.castTag(.wrap_errunion_payload).?),	638	.wrap_errunion_payload => try genWrapErrUnionPay(o, inst.castTag(.wrap_errunion_payload).?),
579	.wrap_errunion_err => try genWrapErrUnionErr(o, inst.castTag(.wrap_errunion_err).?),	639	.wrap_errunion_err => try genWrapErrUnionErr(o, inst.castTag(.wrap_errunion_err).?),
580	else => \|e\| return o.dg.fail(.{ .node_offset = 0 }, "TODO: C backend: implement codegen for {}", .{e}),	640	.br_block_flat => return o.dg.fail(.{ .node_offset = 0 }, "TODO: C backend: implement codegen for br_block_flat", .{}),
		641	.ptrtoint => return o.dg.fail(.{ .node_offset = 0 }, "TODO: C backend: implement codegen for ptrtoint", .{}),
		642	.varptr => return o.dg.fail(.{ .node_offset = 0 }, "TODO: C backend: implement codegen for varptr", .{}),
		643	.floatcast => return o.dg.fail(.{ .node_offset = 0 }, "TODO: C backend: implement codegen for floatcast", .{}),
581	};	644	};
582	switch (result_value) {	645	switch (result_value) {
583	.none => {},	646	.none => {},
...	@@ -996,6 +1059,37 @@ fn genOptionalPayload(o: Object, inst: Inst.UnOp) !CValue {	...	@@ -996,6 +1059,37 @@ fn genOptionalPayload(o: Object, inst: Inst.UnOp) !CValue {
996	return local;	1059	return local;
997	}	1060	}
998		1061
		1062	fn genRef(o: Object, inst: Inst.UnOp) !CValue {
		1063	const writer = o.writer();
		1064	const operand = try o.resolveInst(inst.operand);
		1065
		1066	const local = try o.allocLocal(inst.base.ty, .Const);
		1067	try writer.writeAll(" = ");
		1068	try o.writeCValue(writer, operand);
		1069	try writer.writeAll(";\n");
		1070	return local;
		1071	}
		1072
		1073	fn genStructFieldPtr(o: Object, inst: Inst.StructFieldPtr) !CValue {
		1074	const writer = o.writer();
		1075	const struct_ptr = try o.resolveInst(inst.struct_ptr);
		1076	const struct_obj = inst.struct_ptr.ty.elemType().castTag(.@"struct").?.data;
		1077	const field_name = struct_obj.fields.entries.items[inst.field_index].key;
		1078
		1079	const local = try o.allocLocal(inst.base.ty, .Const);
		1080	switch (struct_ptr) {
		1081	.local_ref => \|i\| {
		1082	try writer.print(" = &t{d}.{};\n", .{ i, fmtIdent(field_name) });
		1083	},
		1084	else => {
		1085	try writer.writeAll(" = &");
		1086	try o.writeCValue(writer, struct_ptr);
		1087	try writer.print("->{};\n", .{fmtIdent(field_name)});
		1088	},
		1089	}
		1090	return local;
		1091	}
		1092
999	// (E!T) -> E NOT E	1093	// (E!T) -> E NOT E
1000	fn genUnwrapErrUnionErr(o: Object, inst: Inst.UnOp) !CValue {	1094	fn genUnwrapErrUnionErr(o: Object, inst: Inst.UnOp) !CValue {
1001	const writer = o.writer();	1095	const writer = o.writer();
...	@@ -1088,7 +1182,7 @@ fn IndentWriter(comptime UnderlyingWriter: type) type {	...	@@ -1088,7 +1182,7 @@ fn IndentWriter(comptime UnderlyingWriter: type) type {
1088	pub const Error = UnderlyingWriter.Error;	1182	pub const Error = UnderlyingWriter.Error;
1089	pub const Writer = std.io.Writer(*Self, Error, write);	1183	pub const Writer = std.io.Writer(*Self, Error, write);
1090		1184
1091	pub const indent_delta = 4;	1185	pub const indent_delta = 1;
1092		1186
1093	underlying_writer: UnderlyingWriter,	1187	underlying_writer: UnderlyingWriter,
1094	indent_count: usize = 0,	1188	indent_count: usize = 0,

src/zir.zig+1

...	@@ -338,6 +338,7 @@ pub const Inst = struct {	...	@@ -338,6 +338,7 @@ pub const Inst = struct {
338	field_ptr,	338	field_ptr,
339	/// Given a struct or object that contains virtual fields, returns the named field.	339	/// Given a struct or object that contains virtual fields, returns the named field.
340	/// The field name is stored in string_bytes. Used by a.b syntax.	340	/// The field name is stored in string_bytes. Used by a.b syntax.
		341	/// This instruction also accepts a pointer.
341	/// Uses `pl_node` field. The AST node is the a.b syntax. Payload is Field.	342	/// Uses `pl_node` field. The AST node is the a.b syntax. Payload is Field.
342	field_val,	343	field_val,
343	/// Given a pointer to a struct or object that contains virtual fields, returns a pointer	344	/// Given a pointer to a struct or object that contains virtual fields, returns a pointer

test/stage2/cbe.zig+2-2

...	@@ -489,8 +489,8 @@ pub fn addCases(ctx: *TestContext) !void {	...	@@ -489,8 +489,8 @@ pub fn addCases(ctx: *TestContext) !void {
489	\\ZIG_EXTERN_C zig_noreturn void _start(void);	489	\\ZIG_EXTERN_C zig_noreturn void _start(void);
490	\\	490	\\
491	\\zig_noreturn void _start(void) {	491	\\zig_noreturn void _start(void) {
492	\\ zig_breakpoint();	492	\\ zig_breakpoint();
493	\\ zig_unreachable();	493	\\ zig_unreachable();
494	\\}	494	\\}
495	\\	495	\\
496	);	496	);

...	@@ -600,6 +600,7 @@ fn zirStructDecl(	...	@@ -600,6 +600,7 @@ fn zirStructDecl(
600		600
601	const struct_obj = try new_decl_arena.allocator.create(Module.Struct);	601	const struct_obj = try new_decl_arena.allocator.create(Module.Struct);
602	const struct_ty = try Type.Tag.@"struct".create(&new_decl_arena.allocator, struct_obj);	602	const struct_ty = try Type.Tag.@"struct".create(&new_decl_arena.allocator, struct_obj);
		603	const struct_val = try Value.Tag.ty.create(&new_decl_arena.allocator, struct_ty);
603	struct_obj.* = .{	604	struct_obj.* = .{
604	.owner_decl = sema.owner_decl,	605	.owner_decl = sema.owner_decl,
605	.fields = fields_map,	606	.fields = fields_map,
...	@@ -611,7 +612,7 @@ fn zirStructDecl(	...	@@ -611,7 +612,7 @@ fn zirStructDecl(
611	};	612	};
612	const new_decl = try sema.mod.createAnonymousDecl(&block.base, &new_decl_arena, .{	613	const new_decl = try sema.mod.createAnonymousDecl(&block.base, &new_decl_arena, .{
613	.ty = Type.initTag(.type),	614	.ty = Type.initTag(.type),
614	.val = try Value.Tag.ty.create(gpa, struct_ty),	615	.val = struct_val,
615	});	616	});
616	return sema.analyzeDeclVal(block, src, new_decl);	617	return sema.analyzeDeclVal(block, src, new_decl);
617	}	618	}
...	@@ -2139,7 +2140,10 @@ fn zirFieldVal(sema: Sema, block: Scope.Block, inst: zir.Inst.Index) InnerErro	...	@@ -2139,7 +2140,10 @@ fn zirFieldVal(sema: Sema, block: Scope.Block, inst: zir.Inst.Index) InnerErro
2139	const extra = sema.code.extraData(zir.Inst.Field, inst_data.payload_index).data;	2140	const extra = sema.code.extraData(zir.Inst.Field, inst_data.payload_index).data;
2140	const field_name = sema.code.nullTerminatedString(extra.field_name_start);	2141	const field_name = sema.code.nullTerminatedString(extra.field_name_start);
2141	const object = try sema.resolveInst(extra.lhs);	2142	const object = try sema.resolveInst(extra.lhs);
2142	const object_ptr = try sema.analyzeRef(block, src, object);	2143	const object_ptr = if (object.ty.zigTypeTag() == .Pointer)
		2144	object
		2145	else
		2146	try sema.analyzeRef(block, src, object);
2143	const result_ptr = try sema.namedFieldPtr(block, src, object_ptr, field_name, field_name_src);	2147	const result_ptr = try sema.namedFieldPtr(block, src, object_ptr, field_name, field_name_src);
2144	return sema.analyzeLoad(block, src, result_ptr, result_ptr.src);	2148	return sema.analyzeLoad(block, src, result_ptr, result_ptr.src);
2145	}	2149	}