authorgravatar for luuk@degram.devLuuk de Gram <luuk@degram.dev> 2021-12-03 21:44:24+01:00
committergravatar for luuk@degram.devLuuk de Gram <luuk@degram.dev> 2021-12-04 19:22:08+01:00
logb7fe958f44160af17ef19e8e71f1bfb6930f190a
tree259b8b4602e8d1a4240a83e1102b93ed464464c7
parent52fb0446698c81272ac5224df81b8f965628575e
signaturelock-open Commit is signed but in an unrecognized format.

wasm: Implement slice as return type and argument

1 files changed, 60 insertions(+), 38 deletions(-)

src/arch/wasm/CodeGen.zig+60-38
......@@ -1048,7 +1048,7 @@ fn resolveCallingConventionValues(self: *Self, fn_ty: Type) InnerError!CallWValu
10481048
10491049 const ret_ty = fn_ty.fnReturnType();
10501050 switch (ret_ty.zigTypeTag()) {
1051 .ErrorUnion, .Optional => result.return_value = try self.allocLocal(Type.initTag(.i32)),
1051 .ErrorUnion, .Optional, .Pointer => result.return_value = try self.allocLocal(Type.initTag(.i32)),
10521052 .Int, .Float, .Bool, .Void, .NoReturn => {},
10531053 else => return self.fail("TODO: Implement function return type {}", .{ret_ty}),
10541054 }
......@@ -1062,6 +1062,11 @@ fn resolveCallingConventionValues(self: *Self, fn_ty: Type) InnerError!CallWValu
10621062 };
10631063
10641064 try self.moveStack(offset, result.return_value.local);
1065
1066 // We want to make sure the return value's stack value doesn't get overwritten,
1067 // so set initial stack value to current's position instead.
1068 try self.addLabel(.global_get, 0);
1069 try self.addLabel(.local_set, self.initial_stack_value.local);
10651070 }
10661071 },
10671072 else => return self.fail("TODO implement function parameters for cc '{}' on wasm", .{cc}),
......@@ -1076,10 +1081,6 @@ fn initializeStack(self: *Self) !void {
10761081 assert(self.initial_stack_value == .none);
10771082 // reserve space for immediate value
10781083 // get stack pointer global
1079 // TODO: For now, we hardcode the stack pointer to index '0',
1080 // once the linker is further implemented, we can replace this by inserting
1081 // a relocation and have the linker resolve the correct index to the stack pointer global.
1082 // NOTE: relocations of the type GLOBAL_INDEX_LEB are 5-bytes big
10831084 try self.addLabel(.global_get, 0);
10841085
10851086 // Reserve a local to store the current stack pointer
......@@ -1108,8 +1109,6 @@ fn restoreStackPointer(self: *Self) !void {
11081109/// the result back into the stack pointer.
11091110fn moveStack(self: *Self, offset: u32, local: u32) !void {
11101111 if (offset == 0) return;
1111 // TODO: Rather than hardcode the stack pointer to position 0,
1112 // have the linker resolve its relocation
11131112 try self.addLabel(.global_get, 0);
11141113 try self.addImm32(@bitCast(i32, offset));
11151114 try self.addTag(.i32_sub);
......@@ -1170,11 +1169,15 @@ fn genInst(self: *Self, inst: Air.Inst.Index) !WValue {
11701169 .load => self.airLoad(inst),
11711170 .loop => self.airLoop(inst),
11721171 .not => self.airNot(inst),
1172 .optional_payload => self.airOptionalPayload(inst),
1173 .optional_payload_ptr => self.airOptionalPayload(inst),
1174 .optional_payload_ptr_set => self.airOptionalPayloadPtrSet(inst),
11731175 .ret => self.airRet(inst),
11741176 .ret_ptr => self.airRetPtr(inst),
11751177 .ret_load => self.airRetLoad(inst),
11761178 .slice_len => self.airSliceLen(inst),
11771179 .slice_elem_val => self.airSliceElemVal(inst),
1180 .slice_ptr => self.airSlicePtr(inst),
11781181 .store => self.airStore(inst),
11791182 .struct_field_ptr => self.airStructFieldPtr(inst),
11801183 .struct_field_ptr_index_0 => self.airStructFieldPtrIndex(inst, 0),
......@@ -1183,17 +1186,14 @@ fn genInst(self: *Self, inst: Air.Inst.Index) !WValue {
11831186 .struct_field_ptr_index_3 => self.airStructFieldPtrIndex(inst, 3),
11841187 .struct_field_val => self.airStructFieldVal(inst),
11851188 .switch_br => self.airSwitchBr(inst),
1189 .trunc => self.airTrunc(inst),
11861190 .unreach => self.airUnreachable(inst),
1187 .wrap_optional => self.airWrapOptional(inst),
11881191
1192 .wrap_optional => self.airWrapOptional(inst),
11891193 .unwrap_errunion_payload => self.airUnwrapErrUnionPayload(inst),
11901194 .unwrap_errunion_err => self.airUnwrapErrUnionError(inst),
11911195 .wrap_errunion_payload => self.airWrapErrUnionPayload(inst),
11921196 .wrap_errunion_err => self.airWrapErrUnionErr(inst),
1193
1194 .optional_payload => self.airOptionalPayload(inst),
1195 .optional_payload_ptr => self.airOptionalPayload(inst),
1196 .optional_payload_ptr_set => self.airOptionalPayloadPtrSet(inst),
11971197 else => |tag| self.fail("TODO: Implement wasm inst: {s}", .{@tagName(tag)}),
11981198 };
11991199}
......@@ -1273,8 +1273,25 @@ fn airCall(self: *Self, inst: Air.Inst.Index) InnerError!WValue {
12731273 };
12741274
12751275 for (args) |arg| {
1276 const arg_val = self.resolveInst(@intToEnum(Air.Inst.Ref, arg));
1277 try self.emitWValue(arg_val);
1276 const arg_ref = @intToEnum(Air.Inst.Ref, arg);
1277 const arg_val = self.resolveInst(arg_ref);
1278
1279 const arg_ty = self.air.typeOf(arg_ref);
1280 switch (arg_ty.zigTypeTag()) {
1281 .Struct, .Pointer, .Optional, .ErrorUnion => {
1282 // single pointer can be passed directly
1283 if (arg_ty.isSinglePointer() or arg_val != .constant) {
1284 try self.emitWValue(arg_val);
1285 continue;
1286 }
1287 const abi_size = arg_ty.abiSize(self.target);
1288 const arg_local = try self.allocLocal(Type.initTag(.i32));
1289 try self.moveStack(@intCast(u32, abi_size), arg_local.local);
1290 try self.store(arg_local, arg_val, arg_ty, 0);
1291 try self.emitWValue(arg_local);
1292 },
1293 else => try self.emitWValue(arg_val),
1294 }
12781295 }
12791296
12801297 if (target) |direct| {
......@@ -1296,14 +1313,12 @@ fn airCall(self: *Self, inst: Air.Inst.Index) InnerError!WValue {
12961313 }
12971314
12981315 const ret_ty = fn_ty.fnReturnType();
1299 switch (ret_ty.zigTypeTag()) {
1300 .Void, .NoReturn => return WValue.none,
1301 else => {
1302 const result_local = try self.allocLocal(ret_ty);
1303 try self.addLabel(.local_set, result_local.local);
1304 return result_local;
1305 },
1306 }
1316 if (!ret_ty.hasCodeGenBits()) return WValue.none;
1317
1318 const result_local = try self.allocLocal(ret_ty);
1319 try self.addLabel(.local_set, result_local.local);
1320 // if the result was allocated on the virtual stack, we must load
1321 return result_local;
13071322}
13081323
13091324fn airAlloc(self: *Self, inst: Air.Inst.Index) InnerError!WValue {
......@@ -1407,6 +1422,18 @@ fn store(self: *Self, lhs: WValue, rhs: WValue, ty: Type, offset: u32) InnerErro
14071422 }
14081423 return;
14091424 },
1425 .Pointer => {
1426 if (ty.isSlice() and rhs == .constant) {
1427 try self.emitWValue(rhs);
1428 const len_local = try self.allocLocal(Type.usize);
1429 const ptr_local = try self.allocLocal(Type.usize);
1430 try self.addLabel(.local_set, len_local.local);
1431 try self.addLabel(.local_set, ptr_local.local);
1432 try self.store(lhs, ptr_local, Type.usize, 0);
1433 try self.store(lhs, len_local, Type.usize, self.target.cpu.arch.ptrBitWidth() / 8);
1434 return;
1435 }
1436 },
14101437 else => {},
14111438 }
14121439 try self.emitWValue(lhs);
......@@ -1598,7 +1625,11 @@ fn emitConstant(self: *Self, val: Value, ty: Type) InnerError!void {
15981625 }
15991626 },
16001627 .Pointer => {
1601 if (val.castTag(.decl_ref)) |payload| {
1628 if (val.castTag(.slice)) |slice| {
1629 var buf: Type.SlicePtrFieldTypeBuffer = undefined;
1630 try self.emitConstant(slice.data.ptr, ty.slicePtrFieldType(&buf));
1631 try self.emitConstant(slice.data.len, Type.usize);
1632 } else if (val.castTag(.decl_ref)) |payload| {
16021633 const decl = payload.data;
16031634 decl.alive = true;
16041635 try self.addLabel(.memory_address, decl.link.wasm.sym_index);
......@@ -2258,20 +2289,6 @@ fn airSliceLen(self: *Self, inst: Air.Inst.Index) InnerError!WValue {
22582289 const pointer_width = self.target.cpu.arch.ptrBitWidth() / 8;
22592290
22602291 return try self.load(operand, Type.usize, pointer_width);
2261
2262 // // Get pointer to slice
2263 // try self.emitWValue(operand);
2264 // // length of slice is stored after the pointer of the slice
2265 // const extra_index = try self.addExtra(Mir.MemArg{
2266 // .offset = pointer_width,
2267 // .alignment = pointer_width,
2268 // });
2269 // try self.addInst(.{ .tag = .i32_load, .data = .{ .payload = extra_index } });
2270
2271 // const result = try self.allocLocal(Type.initTag(.i32)); // pointer is always i32
2272 // // store slice length in local
2273 // try self.addLabel(.local_set, result.local);
2274 // return result;
22752292}
22762293
22772294fn airSliceElemVal(self: *Self, inst: Air.Inst.Index) InnerError!WValue {
......@@ -2296,7 +2313,12 @@ fn airSliceElemVal(self: *Self, inst: Air.Inst.Index) InnerError!WValue {
22962313
22972314 const result = try self.allocLocal(elem_ty);
22982315 try self.addLabel(.local_set, result.local);
2299 return result;
2316 return switch (elem_ty.zigTypeTag()) {
2317 // pass as pointer
2318 .Pointer, .Struct, .Optional => result,
2319 // pass by value
2320 else => try self.load(result, elem_ty, 0),
2321 };
23002322}
23012323
23022324fn airSlicePtr(self: *Self, inst: Air.Inst.Index) InnerError!WValue {