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wasm: Fix loading from pointers to support defer

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Previously, the `load` instruction would just pass the pointer to the next instruction
for types that comply to `isByRef`. However, this meant that a defer would directly write
to the reference, rather than a copy. After this commit, we always copy the value.
This commit is contained in:
Luuk de Gram
2022-01-01 16:23:21 +01:00
parent ad1b040996
commit 3de111d993
2 changed files with 34 additions and 28 deletions
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46
src/arch/wasm/CodeGen.zig
View File

@@ -1381,7 +1381,7 @@ fn airRetLoad(self: *Self, inst: Air.Inst.Index) InnerError!WValue {
const ret_ty = self.air.typeOf(un_op).childType();
if (!ret_ty.hasCodeGenBits()) return WValue.none;
if (ret_ty.isSlice() or ret_ty.zigTypeTag() == .ErrorUnion) {
if (isByRef(ret_ty)) {
try self.emitWValue(operand);
} else {
const result = try self.load(operand, ret_ty, 0);
@@ -1521,6 +1521,14 @@ fn store(self: *Self, lhs: WValue, rhs: WValue, ty: Type, offset: u32) InnerErro
switch (rhs) {
.constant => {
if (rhs.constant.val.castTag(.decl_ref)) |_| {
// retrieve values from memory instead
const mem_local = try self.allocLocal(Type.usize);
try self.emitWValue(rhs);
try self.addLabel(.local_set, mem_local.local);
try self.store(lhs, mem_local, ty, 0);
return;
}
// constant will contain both tag and payload,
// so save those in 2 temporary locals before storing them
// in memory
@@ -1616,12 +1624,16 @@ fn store(self: *Self, lhs: WValue, rhs: WValue, ty: Type, offset: u32) InnerErro
// check if we should pass by pointer or value based on ABI size
// TODO: Implement a way to get ABI values from a given type,
// that is portable across the backend, rather than copying logic.
const abi_size = if ((ty.isInt() or ty.isAnyFloat()) and ty.abiSize(self.target) <= 8)
@intCast(u8, ty.abiSize(self.target))
else if (ty.zigTypeTag() == .ErrorSet or ty.zigTypeTag() == .Enum or ty.zigTypeTag() == .Bool)
@intCast(u8, ty.abiSize(self.target))
else
@as(u8, 4);
const abi_size = switch (ty.zigTypeTag()) {
.Int,
.Float,
.ErrorSet,
.Enum,
.Bool,
.ErrorUnion,
=> @intCast(u8, ty.abiSize(self.target)),
else => @as(u8, 4),
};
const opcode = buildOpcode(.{
.valtype1 = valtype,
.width = abi_size * 8, // use bitsize instead of byte size
@@ -1643,7 +1655,9 @@ fn airLoad(self: *Self, inst: Air.Inst.Index) InnerError!WValue {
if (!ty.hasCodeGenBits()) return WValue{ .none = {} };
if (isByRef(ty)) {
return operand;
const new_local = try self.allocStack(ty);
try self.store(new_local, operand, ty, 0);
return new_local;
}
return switch (operand) {
@@ -1662,12 +1676,16 @@ fn load(self: *Self, operand: WValue, ty: Type, offset: u32) InnerError!WValue {
.signed;
// TODO: Implement a way to get ABI values from a given type,
// that is portable across the backend, rather than copying logic.
const abi_size = if ((ty.isInt() or ty.isAnyFloat()) and ty.abiSize(self.target) <= 8)
@intCast(u8, ty.abiSize(self.target))
else if (ty.zigTypeTag() == .ErrorSet or ty.zigTypeTag() == .Enum or ty.zigTypeTag() == .Bool)
@intCast(u8, ty.abiSize(self.target))
else
@as(u8, 4);
const abi_size = switch (ty.zigTypeTag()) {
.Int,
.Float,
.ErrorSet,
.Enum,
.Bool,
.ErrorUnion,
=> @intCast(u8, ty.abiSize(self.target)),
else => @as(u8, 4),
};
const opcode = buildOpcode(.{
.valtype1 = try self.typeToValtype(ty),

16
test/behavior.zig
View File

@@ -39,28 +39,16 @@ test {
_ = @import("behavior/ref_var_in_if_after_if_2nd_switch_prong.zig");
_ = @import("behavior/slice_sentinel_comptime.zig");
_ = @import("behavior/truncate.zig");
_ = @import("behavior/type.zig");
_ = @import("behavior/type_info.zig");
_ = @import("behavior/type.zig");
_ = @import("behavior/usingnamespace.zig");
_ = @import("behavior/underscore.zig");
// Tests that pass for stage1, stage2 and the C backend, but not for the wasm backend
if (!builtin.zig_is_stage2 or builtin.stage2_arch != .wasm32) {
_ = @import("behavior/align.zig");
_ = @import("behavior/array.zig");
_ = @import("behavior/bool.zig");
_ = @import("behavior/bugs/704.zig");
_ = @import("behavior/bugs/2692.zig");
_ = @import("behavior/bugs/2889.zig");
_ = @import("behavior/bugs/3046.zig");
_ = @import("behavior/bugs/3586.zig");
_ = @import("behavior/bugs/4560.zig");
_ = @import("behavior/bugs/4769_a.zig");
_ = @import("behavior/bugs/4769_b.zig");
_ = @import("behavior/bugs/4954.zig");
_ = @import("behavior/byval_arg_var.zig");
_ = @import("behavior/call.zig");
_ = @import("behavior/cast.zig");
_ = @import("behavior/fn_in_struct_in_comptime.zig");
_ = @import("behavior/for.zig");
_ = @import("behavior/generics.zig");
_ = @import("behavior/int128.zig");