Commit d35cae551e

Jakub Konka <kubkon@jakubkonka.com>
2022-03-02 13:46:34
x64: rectify and add missing optionals bits
Includes changes/additions to: * `wrap_optional` * `optional_payload` * `isNull` helper
1 parent 2e327d9
Changed files (7)
src/arch/x86_64/CodeGen.zig
@@ -1704,12 +1704,36 @@ fn airShr(self: *Self, inst: Air.Inst.Index) !void {
 
 fn airOptionalPayload(self: *Self, inst: Air.Inst.Index) !void {
     const ty_op = self.air.instructions.items(.data)[inst].ty_op;
-    const result: MCValue = if (self.liveness.isUnused(inst)) .dead else result: {
-        const operand = try self.resolveInst(ty_op.operand);
-        if (self.reuseOperand(inst, ty_op.operand, 0, operand)) {
-            break :result operand;
+    if (self.liveness.isUnused(inst)) {
+        return self.finishAir(inst, .dead, .{ ty_op.operand, .none, .none });
+    }
+
+    const payload_ty = self.air.typeOfIndex(inst);
+    const optional_ty = self.air.typeOf(ty_op.operand);
+    const operand = try self.resolveInst(ty_op.operand);
+    const result: MCValue = result: {
+        if (!payload_ty.hasRuntimeBits()) break :result MCValue.none;
+        if (optional_ty.isPtrLikeOptional()) {
+            if (self.reuseOperand(inst, ty_op.operand, 0, operand)) {
+                break :result operand;
+            }
+            break :result try self.copyToRegisterWithInstTracking(inst, payload_ty, operand);
+        }
+
+        const offset = optional_ty.abiSize(self.target.*) - payload_ty.abiSize(self.target.*);
+        switch (operand) {
+            .stack_offset => |off| {
+                break :result MCValue{ .stack_offset = off - @intCast(i32, offset) };
+            },
+            .register => {
+                // TODO reuse the operand
+                const result = try self.copyToRegisterWithInstTracking(inst, optional_ty, operand);
+                const shift = @intCast(u8, offset * 8);
+                try self.shiftRegister(result.register, @intCast(u8, shift));
+                break :result result;
+            },
+            else => return self.fail("TODO implement optional_payload when operand is {}", .{operand}),
         }
-        break :result try self.copyToRegisterWithInstTracking(inst, self.air.typeOfIndex(inst), operand);
     };
     return self.finishAir(inst, result, .{ ty_op.operand, .none, .none });
 }
@@ -1828,13 +1852,30 @@ fn airErrUnionPayloadPtrSet(self: *Self, inst: Air.Inst.Index) !void {
 fn airWrapOptional(self: *Self, inst: Air.Inst.Index) !void {
     const ty_op = self.air.instructions.items(.data)[inst].ty_op;
     const result: MCValue = if (self.liveness.isUnused(inst)) .dead else result: {
+        const payload_ty = self.air.typeOf(ty_op.operand);
+        if (!payload_ty.hasRuntimeBits()) {
+            break :result MCValue{ .immediate = 1 };
+        }
+
         const optional_ty = self.air.typeOfIndex(inst);
+        const operand = try self.resolveInst(ty_op.operand);
+        if (optional_ty.isPtrLikeOptional()) {
+            // TODO should we check if we can reuse the operand?
+            break :result operand;
+        }
 
-        // Optional with a zero-bit payload type is just a boolean true
-        if (optional_ty.abiSize(self.target.*) == 1)
-            break :result MCValue{ .immediate = 1 };
+        operand.freezeIfRegister(&self.register_manager);
+        defer operand.unfreezeIfRegister(&self.register_manager);
 
-        return self.fail("TODO implement wrap optional for {}", .{self.target.cpu.arch});
+        const optional_abi_size = @intCast(u32, optional_ty.abiSize(self.target.*));
+        const optional_abi_align = optional_ty.abiAlignment(self.target.*);
+        const payload_abi_size = @intCast(u32, payload_ty.abiSize(self.target.*));
+        const offset = optional_abi_size - payload_abi_size;
+
+        const stack_offset = @intCast(i32, try self.allocMem(inst, optional_abi_size, optional_abi_align));
+        try self.genSetStack(Type.bool, stack_offset, .{ .immediate = 1 }, .{});
+        try self.genSetStack(payload_ty, stack_offset - @intCast(i32, offset), operand, .{});
+        break :result MCValue{ .stack_offset = stack_offset };
     };
     return self.finishAir(inst, result, .{ ty_op.operand, .none, .none });
 }
@@ -3761,7 +3802,14 @@ fn isNull(self: *Self, inst: Air.Inst.Index, ty: Type, operand: MCValue) !MCValu
     try self.spillCompareFlagsIfOccupied();
     self.compare_flags_inst = inst;
 
-    try self.genBinMathOpMir(.cmp, ty, operand, MCValue{ .immediate = 0 });
+    const cmp_ty: Type = if (!ty.isPtrLikeOptional()) blk: {
+        var buf: Type.Payload.ElemType = undefined;
+        const payload_ty = ty.optionalChild(&buf);
+        break :blk if (payload_ty.hasRuntimeBits()) Type.bool else ty;
+    } else ty;
+
+    try self.genBinMathOpMir(.cmp, cmp_ty, operand, MCValue{ .immediate = 0 });
+
     return MCValue{ .compare_flags_unsigned = .eq };
 }
 
test/behavior/bugs/2889.zig
@@ -27,7 +27,6 @@ fn parseNote() ?i32 {
 }
 
 test "fixed" {
-    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
 
test/behavior/bugs/3112.zig
@@ -16,7 +16,6 @@ test "zig test crash" {
     if (builtin.zig_backend == .stage1) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
-    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
     var global: State = undefined;
     global.enter = prev;
     global.enter(null);
test/behavior/basic.zig
@@ -728,7 +728,6 @@ test "thread local variable" {
 test "result location is optional inside error union" {
     if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_c) 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
 
test/behavior/cast.zig
@@ -237,7 +237,7 @@ test "@intCast to u0 and use the result" {
 
 test "peer result null and comptime_int" {
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
-    if (builtin.zig_backend == .stage2_x86_64 or builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
 
     const S = struct {
         fn blah(n: i32) ?i32 {
test/behavior/enum.zig
@@ -1083,7 +1083,6 @@ test "@tagName on enum literals" {
 }
 
 test "enum literal casting to optional" {
-    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
 
test/behavior/optional.zig
@@ -7,7 +7,6 @@ const expectEqual = testing.expectEqual;
 test "passing an optional integer as a parameter" {
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
-    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
 
     const S = struct {
         fn entry() bool {
@@ -60,7 +59,6 @@ fn testNullPtrsEql() !void {
 test "optional with void type" {
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
-    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
 
     const Foo = struct {
         x: ?void,
@@ -171,7 +169,6 @@ test "unwrap function call with optional pointer return value" {
 test "nested orelse" {
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
-    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
 
     const S = struct {
         fn entry() !void {
@@ -199,7 +196,6 @@ test "self-referential struct through a slice of optional" {
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
-    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
 
     const S = struct {
         const Node = struct {