| ... | ... | @@ -1361,13 +1361,46 @@ fn airOverflow(self: *Self, inst: Air.Inst.Index) !void { |
| 1361 | 1361 | const lhs_ty = self.air.typeOf(extra.lhs); |
| 1362 | 1362 | const rhs_ty = self.air.typeOf(extra.rhs); |
| 1363 | 1363 | |
| 1364 | const tuple_ty = self.air.typeOfIndex(inst); |
| 1365 | const tuple_size = @intCast(u32, tuple_ty.abiSize(self.target.*)); |
| 1366 | const tuple_align = tuple_ty.abiAlignment(self.target.*); |
| 1367 | const overflow_bit_offset = @intCast(u32, tuple_ty.structFieldOffset(1, self.target.*)); |
| 1368 | |
| 1364 | 1369 | switch (lhs_ty.zigTypeTag()) { |
| 1365 | 1370 | .Vector => return self.fail("TODO implement add_with_overflow/sub_with_overflow for vectors", .{}), |
| 1366 | 1371 | .Int => { |
| 1367 | 1372 | assert(lhs_ty.eql(rhs_ty, self.target.*)); |
| 1368 | 1373 | const int_info = lhs_ty.intInfo(self.target.*); |
| 1369 | 1374 | if (int_info.bits < 32) { |
| 1370 | | return self.fail("TODO ARM overflow operations on integers < u32/i32", .{}); |
| 1375 | const stack_offset = try self.allocMem(inst, tuple_size, tuple_align); |
| 1376 | |
| 1377 | try self.spillCompareFlagsIfOccupied(); |
| 1378 | self.compare_flags_inst = null; |
| 1379 | |
| 1380 | const base_tag: Air.Inst.Tag = switch (tag) { |
| 1381 | .add_with_overflow => .add, |
| 1382 | .sub_with_overflow => .sub, |
| 1383 | else => unreachable, |
| 1384 | }; |
| 1385 | const dest = try self.binOp(base_tag, null, lhs, rhs, lhs_ty, rhs_ty); |
| 1386 | const dest_reg = dest.register; |
| 1387 | self.register_manager.freezeRegs(&.{dest_reg}); |
| 1388 | defer self.register_manager.unfreezeRegs(&.{dest_reg}); |
| 1389 | |
| 1390 | const truncated_reg = try self.register_manager.allocReg(null); |
| 1391 | self.register_manager.freezeRegs(&.{truncated_reg}); |
| 1392 | defer self.register_manager.unfreezeRegs(&.{truncated_reg}); |
| 1393 | |
| 1394 | // sbfx/ubfx truncated, dest, #0, #bits |
| 1395 | try self.truncRegister(dest_reg, truncated_reg, int_info.signedness, int_info.bits); |
| 1396 | |
| 1397 | // cmp dest, truncated |
| 1398 | _ = try self.binOp(.cmp_eq, null, dest, .{ .register = truncated_reg }, Type.usize, Type.usize); |
| 1399 | |
| 1400 | try self.genSetStack(lhs_ty, stack_offset, .{ .register = truncated_reg }); |
| 1401 | try self.genSetStack(Type.initTag(.u1), stack_offset - overflow_bit_offset, .{ .compare_flags_unsigned = .neq }); |
| 1402 | |
| 1403 | break :result MCValue{ .stack_offset = stack_offset }; |
| 1371 | 1404 | } else if (int_info.bits == 32) { |
| 1372 | 1405 | // Only say yes if the operation is |
| 1373 | 1406 | // commutative, i.e. we can swap both of the |
Joachim Schmidt <joachim.schmidt557@outlook.com> 2022-03-29 20:19:25+02:00
Commit is signed but in an unrecognized format.
src