Commit 5d98abd570
Changed files (1)
src
codegen
src/codegen/wasm.zig
@@ -979,10 +979,15 @@ pub const Context = struct {
.valtype1 = try self.typeToValtype(ty),
});
try writer.writeByte(wasm.opcode(opcode));
+ const int_info = ty.intInfo(self.target);
// write constant
- switch (ty.intInfo(self.target).signedness) {
+ switch (int_info.signedness) {
.signed => try leb.writeILEB128(writer, value.toSignedInt()),
- .unsigned => try leb.writeILEB128(writer, value.toUnsignedInt()),
+ .unsigned => switch (int_info.bits) {
+ 0...32 => try leb.writeILEB128(writer, @bitCast(i32, @intCast(u32, value.toUnsignedInt()))),
+ 33...64 => try leb.writeILEB128(writer, @bitCast(i64, value.toUnsignedInt())),
+ else => |bits| return self.fail("Wasm TODO: emitConstant for integer with {d} bits", .{bits}),
+ },
}
},
.Bool => {
@@ -1280,13 +1285,15 @@ pub const Context = struct {
var extra_index: usize = switch_br.end;
var case_i: u32 = 0;
- // a map that maps each value with its index and body
- var map = std.AutoArrayHashMap(i32, struct {
- index: u32,
+ // a list that maps each value with its value and body based on the order inside the list.
+ const CaseValue = struct { integer: i32, value: Value };
+ var case_list = try std.ArrayList(struct {
+ values: []const CaseValue,
body: []const Air.Inst.Index,
- value: Value,
- }).init(self.gpa);
- defer map.deinit();
+ }).initCapacity(self.gpa, switch_br.data.cases_len);
+ defer for (case_list.items) |case| {
+ self.gpa.free(case.values);
+ } else case_list.deinit();
var lowest: i32 = 0;
var highest: i32 = 0;
@@ -1295,8 +1302,10 @@ pub const Context = struct {
const items = @bitCast([]const Air.Inst.Ref, self.air.extra[case.end..][0..case.data.items_len]);
const case_body = self.air.extra[case.end + items.len ..][0..case.data.body_len];
extra_index = case.end + items.len + case_body.len;
+ const values = try self.gpa.alloc(CaseValue, items.len);
+ errdefer self.gpa.free(values);
- for (items) |ref| {
+ for (items) |ref, i| {
const item_val = self.air.value(ref).?;
const int_val: i32 = blk: {
if (target_ty.intInfo(self.target).signedness == .signed) {
@@ -1305,7 +1314,7 @@ pub const Context = struct {
break :blk @truncate(i32, item_val.toSignedInt());
}
- break :blk @intCast(i32, @truncate(u31, item_val.toUnsignedInt()) - 1);
+ break :blk @bitCast(i32, @truncate(u32, item_val.toUnsignedInt()));
};
if (int_val < lowest) {
lowest = int_val;
@@ -1313,9 +1322,10 @@ pub const Context = struct {
if (int_val > highest) {
highest = int_val;
}
- try map.put(int_val, .{ .index = case_i, .body = case_body, .value = item_val });
+ values[i] = .{ .integer = int_val, .value = item_val };
}
+ case_list.appendAssumeCapacity(.{ .values = values, .body = case_body });
try self.startBlock(.block, blocktype, null);
}
@@ -1350,9 +1360,15 @@ pub const Context = struct {
const depth = highest - lowest + @boolToInt(has_else_body);
try leb.writeILEB128(self.code.writer(), depth);
while (lowest <= highest) : (lowest += 1) {
- const idx = if (map.get(lowest)) |value| blk: {
- break :blk value.index;
- } else if (has_else_body) case_i else unreachable;
+ // idx represents the branch we jump to
+ const idx = blk: {
+ for (case_list.items) |case, idx| {
+ for (case.values) |case_value| {
+ if (case_value.integer == lowest) break :blk @intCast(u32, idx);
+ }
+ }
+ break :blk if (has_else_body) case_i else unreachable;
+ };
try leb.writeULEB128(self.code.writer(), idx);
} else if (has_else_body) {
try leb.writeULEB128(self.code.writer(), @as(u32, case_i)); // default branch
@@ -1368,21 +1384,43 @@ pub const Context = struct {
break :blk target_ty.intInfo(self.target).signedness;
};
- for (map.values()) |val| {
+ for (case_list.items) |case| {
// when sparse, we use if/else-chain, so emit conditional checks
if (is_sparse) {
- try self.emitWValue(target);
- try self.emitConstant(val.value, target_ty);
- const opcode = buildOpcode(.{
- .valtype1 = try self.typeToValtype(target_ty),
- .op = .ne, // not equal, because we want to jump out of this block if it does not match the condition.
- .signedness = signedness,
- });
- try self.code.append(wasm.opcode(opcode));
- try self.code.append(wasm.opcode(.br_if));
- try leb.writeULEB128(self.code.writer(), @as(u32, 0));
+ // for single value prong we can emit a simple if
+ if (case.values.len == 1) {
+ try self.emitWValue(target);
+ try self.emitConstant(case.values[0].value, target_ty);
+ const opcode = buildOpcode(.{
+ .valtype1 = try self.typeToValtype(target_ty),
+ .op = .ne, // not equal, because we want to jump out of this block if it does not match the condition.
+ .signedness = signedness,
+ });
+ try self.code.append(wasm.opcode(opcode));
+ try self.code.append(wasm.opcode(.br_if));
+ try leb.writeULEB128(self.code.writer(), @as(u32, 0));
+ } else {
+ // in multi-value prongs we must check if any prongs match the target value.
+ try self.startBlock(.block, blocktype, null);
+ for (case.values) |value| {
+ try self.emitWValue(target);
+ try self.emitConstant(value.value, target_ty);
+ const opcode = buildOpcode(.{
+ .valtype1 = try self.typeToValtype(target_ty),
+ .op = .eq,
+ .signedness = signedness,
+ });
+ try self.code.append(wasm.opcode(opcode));
+ try self.code.append(wasm.opcode(.br_if));
+ try leb.writeULEB128(self.code.writer(), @as(u32, 0));
+ }
+ // value did not match any of the prong values
+ try self.code.append(wasm.opcode(.br));
+ try leb.writeULEB128(self.code.writer(), @as(u32, 1));
+ try self.endBlock();
+ }
}
- try self.genBody(val.body);
+ try self.genBody(case.body);
try self.endBlock();
}
@@ -1390,7 +1428,6 @@ pub const Context = struct {
try self.genBody(else_body);
try self.endBlock();
}
-
return .none;
}