Commit 3f4569bf18

Jacob Young <jacobly0@users.noreply.github.com>
2023-03-20 03:43:59
codegen: fix backend breakage due to optional layout change
1 parent 6c453dd
Changed files (3)
src
arch
test
behavior
src/arch/aarch64/CodeGen.zig
@@ -3011,41 +3011,16 @@ fn optionalPayload(self: *Self, inst: Air.Inst.Index, mcv: MCValue, optional_ty:
         return MCValue{ .register = reg };
     }
 
-    const offset = @intCast(u32, optional_ty.abiSize(self.target.*) - payload_ty.abiSize(self.target.*));
     switch (mcv) {
-        .register => |source_reg| {
+        .register => {
             // TODO should we reuse the operand here?
             const raw_reg = try self.register_manager.allocReg(inst, gp);
             const dest_reg = raw_reg.toX();
 
-            const shift = @intCast(u6, offset * 8);
-            if (shift == 0) {
-                try self.genSetReg(payload_ty, dest_reg, mcv);
-            } else {
-                _ = try self.addInst(.{
-                    .tag = if (payload_ty.isSignedInt())
-                        Mir.Inst.Tag.asr_immediate
-                    else
-                        Mir.Inst.Tag.lsr_immediate,
-                    .data = .{ .rr_shift = .{
-                        .rd = dest_reg,
-                        .rn = source_reg.toX(),
-                        .shift = shift,
-                    } },
-                });
-            }
-
+            try self.genSetReg(payload_ty, dest_reg, mcv);
             return MCValue{ .register = self.registerAlias(dest_reg, payload_ty) };
         },
-        .stack_argument_offset => |off| {
-            return MCValue{ .stack_argument_offset = off + offset };
-        },
-        .stack_offset => |off| {
-            return MCValue{ .stack_offset = off - offset };
-        },
-        .memory => |addr| {
-            return MCValue{ .memory = addr + offset };
-        },
+        .stack_argument_offset, .stack_offset, .memory => return mcv,
         else => unreachable, // invalid MCValue for an error union
     }
 }
@@ -3289,12 +3264,11 @@ fn airWrapOptional(self: *Self, inst: Air.Inst.Index) !void {
 
         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 offset = @intCast(u32, payload_ty.abiSize(self.target.*));
 
         const stack_offset = try self.allocMem(optional_abi_size, optional_abi_align, inst);
-        try self.genSetStack(Type.bool, stack_offset, .{ .immediate = 1 });
-        try self.genSetStack(payload_ty, stack_offset - @intCast(u32, offset), operand);
+        try self.genSetStack(payload_ty, stack_offset, operand);
+        try self.genSetStack(Type.bool, stack_offset - offset, .{ .immediate = 1 });
 
         break :result MCValue{ .stack_offset = stack_offset };
     };
@@ -4834,13 +4808,49 @@ fn airCondBr(self: *Self, inst: Air.Inst.Index) !void {
 }
 
 fn isNull(self: *Self, operand_bind: ReadArg.Bind, operand_ty: Type) !MCValue {
-    const sentinel_ty: Type = if (!operand_ty.isPtrLikeOptional()) blk: {
+    const sentinel: struct { ty: Type, bind: ReadArg.Bind } = if (!operand_ty.isPtrLikeOptional()) blk: {
         var buf: Type.Payload.ElemType = undefined;
         const payload_ty = operand_ty.optionalChild(&buf);
-        break :blk if (payload_ty.hasRuntimeBitsIgnoreComptime()) Type.bool else operand_ty;
-    } else operand_ty;
+        if (!payload_ty.hasRuntimeBitsIgnoreComptime())
+            break :blk .{ .ty = operand_ty, .bind = operand_bind };
+
+        const offset = @intCast(u32, payload_ty.abiSize(self.target.*));
+        const operand_mcv = try operand_bind.resolveToMcv(self);
+        const new_mcv: MCValue = switch (operand_mcv) {
+            .register => |source_reg| new: {
+                // TODO should we reuse the operand here?
+                const raw_reg = try self.register_manager.allocReg(null, gp);
+                const dest_reg = raw_reg.toX();
+
+                const shift = @intCast(u6, offset * 8);
+                if (shift == 0) {
+                    try self.genSetReg(payload_ty, dest_reg, operand_mcv);
+                } else {
+                    _ = try self.addInst(.{
+                        .tag = if (payload_ty.isSignedInt())
+                            Mir.Inst.Tag.asr_immediate
+                        else
+                            Mir.Inst.Tag.lsr_immediate,
+                        .data = .{ .rr_shift = .{
+                            .rd = dest_reg,
+                            .rn = source_reg.toX(),
+                            .shift = shift,
+                        } },
+                    });
+                }
+
+                break :new .{ .register = self.registerAlias(dest_reg, payload_ty) };
+            },
+            .stack_argument_offset => |off| .{ .stack_argument_offset = off + offset },
+            .stack_offset => |off| .{ .stack_offset = off - offset },
+            .memory => |addr| .{ .memory = addr + offset },
+            else => unreachable, // invalid MCValue for an optional
+        };
+
+        break :blk .{ .ty = Type.bool, .bind = .{ .mcv = new_mcv } };
+    } else .{ .ty = operand_ty, .bind = operand_bind };
     const imm_bind: ReadArg.Bind = .{ .mcv = .{ .immediate = 0 } };
-    return self.cmp(operand_bind, imm_bind, sentinel_ty, .eq);
+    return self.cmp(sentinel.bind, imm_bind, sentinel.ty, .eq);
 }
 
 fn isNonNull(self: *Self, operand_bind: ReadArg.Bind, operand_ty: Type) !MCValue {
src/arch/wasm/CodeGen.zig
@@ -2715,20 +2715,7 @@ fn lowerParentPtr(func: *CodeGen, ptr_val: Value, ptr_child_ty: Type) InnerError
         },
         .opt_payload_ptr => {
             const payload_ptr = ptr_val.castTag(.opt_payload_ptr).?.data;
-            const parent_ptr = try func.lowerParentPtr(payload_ptr.container_ptr, payload_ptr.container_ty);
-            var buf: Type.Payload.ElemType = undefined;
-            const payload_ty = payload_ptr.container_ty.optionalChild(&buf);
-            if (!payload_ty.hasRuntimeBitsIgnoreComptime() or payload_ty.optionalReprIsPayload()) {
-                return parent_ptr;
-            }
-
-            const abi_size = payload_ptr.container_ty.abiSize(func.target);
-            const offset = abi_size - payload_ty.abiSize(func.target);
-
-            return WValue{ .memory_offset = .{
-                .pointer = parent_ptr.memory,
-                .offset = @intCast(u32, offset),
-            } };
+            return func.lowerParentPtr(payload_ptr.container_ptr, payload_ptr.container_ty);
         },
         else => |tag| return func.fail("TODO: Implement lowerParentPtr for tag: {}", .{tag}),
     }
@@ -2889,7 +2876,7 @@ fn lowerConstant(func: *CodeGen, arg_val: Value, ty: Type) InnerError!WValue {
             }
         } else {
             const is_pl = val.tag() == .opt_payload;
-            return WValue{ .imm32 = if (is_pl) @as(u32, 1) else 0 };
+            return WValue{ .imm32 = @boolToInt(is_pl) };
         },
         .Struct => {
             const struct_obj = ty.castTag(.@"struct").?.data;
@@ -3882,7 +3869,11 @@ fn isNull(func: *CodeGen, operand: WValue, optional_ty: Type, opcode: wasm.Opcod
         // When payload is zero-bits, we can treat operand as a value, rather than
         // a pointer to the stack value
         if (payload_ty.hasRuntimeBitsIgnoreComptime()) {
-            try func.addMemArg(.i32_load8_u, .{ .offset = operand.offset(), .alignment = 1 });
+            const offset = std.math.cast(u32, payload_ty.abiSize(func.target)) orelse {
+                const module = func.bin_file.base.options.module.?;
+                return func.fail("Optional type {} too big to fit into stack frame", .{optional_ty.fmt(module)});
+            };
+            try func.addMemArg(.i32_load8_u, .{ .offset = operand.offset() + offset, .alignment = 1 });
         }
     } else if (payload_ty.isSlice()) {
         switch (func.arch()) {
@@ -3911,13 +3902,11 @@ fn airOptionalPayload(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
         const operand = try func.resolveInst(ty_op.operand);
         if (opt_ty.optionalReprIsPayload()) break :result func.reuseOperand(ty_op.operand, operand);
 
-        const offset = opt_ty.abiSize(func.target) - payload_ty.abiSize(func.target);
-
         if (isByRef(payload_ty, func.target)) {
-            break :result try func.buildPointerOffset(operand, offset, .new);
+            break :result try func.buildPointerOffset(operand, 0, .new);
         }
 
-        const payload = try func.load(operand, payload_ty, @intCast(u32, offset));
+        const payload = try func.load(operand, payload_ty, 0);
         break :result try payload.toLocal(func, payload_ty);
     };
     func.finishAir(inst, result, &.{ty_op.operand});
@@ -3936,8 +3925,7 @@ fn airOptionalPayloadPtr(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
             break :result func.reuseOperand(ty_op.operand, operand);
         }
 
-        const offset = opt_ty.abiSize(func.target) - payload_ty.abiSize(func.target);
-        break :result try func.buildPointerOffset(operand, offset, .new);
+        break :result try func.buildPointerOffset(operand, 0, .new);
     };
     func.finishAir(inst, result, &.{ty_op.operand});
 }
@@ -3956,16 +3944,16 @@ fn airOptionalPayloadPtrSet(func: *CodeGen, inst: Air.Inst.Index) InnerError!voi
         return func.finishAir(inst, operand, &.{ty_op.operand});
     }
 
-    const offset = std.math.cast(u32, opt_ty.abiSize(func.target) - payload_ty.abiSize(func.target)) orelse {
+    const offset = std.math.cast(u32, payload_ty.abiSize(func.target)) orelse {
         const module = func.bin_file.base.options.module.?;
         return func.fail("Optional type {} too big to fit into stack frame", .{opt_ty.fmt(module)});
     };
 
     try func.emitWValue(operand);
     try func.addImm32(1);
-    try func.addMemArg(.i32_store8, .{ .offset = operand.offset(), .alignment = 1 });
+    try func.addMemArg(.i32_store8, .{ .offset = operand.offset() + offset, .alignment = 1 });
 
-    const result = try func.buildPointerOffset(operand, offset, .new);
+    const result = try func.buildPointerOffset(operand, 0, .new);
     return func.finishAir(inst, result, &.{ty_op.operand});
 }
 
@@ -3988,7 +3976,7 @@ fn airWrapOptional(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
         if (op_ty.optionalReprIsPayload()) {
             break :result func.reuseOperand(ty_op.operand, operand);
         }
-        const offset = std.math.cast(u32, op_ty.abiSize(func.target) - payload_ty.abiSize(func.target)) orelse {
+        const offset = std.math.cast(u32, payload_ty.abiSize(func.target)) orelse {
             const module = func.bin_file.base.options.module.?;
             return func.fail("Optional type {} too big to fit into stack frame", .{op_ty.fmt(module)});
         };
@@ -3997,9 +3985,9 @@ fn airWrapOptional(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
         const result_ptr = try func.allocStack(op_ty);
         try func.emitWValue(result_ptr);
         try func.addImm32(1);
-        try func.addMemArg(.i32_store8, .{ .offset = result_ptr.offset(), .alignment = 1 });
+        try func.addMemArg(.i32_store8, .{ .offset = result_ptr.offset() + offset, .alignment = 1 });
 
-        const payload_ptr = try func.buildPointerOffset(result_ptr, offset, .new);
+        const payload_ptr = try func.buildPointerOffset(result_ptr, 0, .new);
         try func.store(payload_ptr, operand, payload_ty, 0);
         break :result result_ptr;
     };
@@ -4719,7 +4707,6 @@ fn cmpOptionals(func: *CodeGen, lhs: WValue, rhs: WValue, operand_ty: Type, op:
     assert(op == .eq or op == .neq);
     var buf: Type.Payload.ElemType = undefined;
     const payload_ty = operand_ty.optionalChild(&buf);
-    const offset = @intCast(u32, operand_ty.abiSize(func.target) - payload_ty.abiSize(func.target));
 
     // We store the final result in here that will be validated
     // if the optional is truly equal.
@@ -4732,8 +4719,8 @@ fn cmpOptionals(func: *CodeGen, lhs: WValue, rhs: WValue, operand_ty: Type, op:
     try func.addTag(.i32_ne); // inverse so we can exit early
     try func.addLabel(.br_if, 0);
 
-    _ = try func.load(lhs, payload_ty, offset);
-    _ = try func.load(rhs, payload_ty, offset);
+    _ = try func.load(lhs, payload_ty, 0);
+    _ = try func.load(rhs, payload_ty, 0);
     const opcode = buildOpcode(.{ .op = .ne, .valtype1 = typeToValtype(payload_ty, func.target) });
     try func.addTag(Mir.Inst.Tag.fromOpcode(opcode));
     try func.addLabel(.br_if, 0);
test/behavior/error.zig
@@ -874,6 +874,7 @@ test "field access of anyerror results in smaller error set" {
 }
 
 test "optional error union return type" {
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
 
     const S = struct {