authorgravatar for kubkon@jakubkonka.comJakub Konka <kubkon@jakubkonka.com> 2022-02-10 11:27:38+01:00
committergravatar for kubkon@jakubkonka.comJakub Konka <kubkon@jakubkonka.com> 2022-02-10 15:05:12+01:00
loge139c41fd8955f873615b2c2434d162585c0e44c
treeea2a5051cb9d7dd64e3fd0bf31b7d4ff86a24dc9
parentc10fdde5a64a46bc514500e97b8c87d19f86e431

stage2: handle truncate to signed non-pow-two integers


2 files changed, 34 insertions(+), 14 deletions(-)

src/arch/x86_64/CodeGen.zig+34-13
...@@ -958,16 +958,17 @@ fn airTrunc(self: *Self, inst: Air.Inst.Index) !void {...@@ -958,16 +958,17 @@ fn airTrunc(self: *Self, inst: Air.Inst.Index) !void {
958 return self.fail("TODO implement trunc for abi sizes larger than 8", .{});958 return self.fail("TODO implement trunc for abi sizes larger than 8", .{});
959 }959 }
960960
961 const dst_mcv = blk: {961 operand.freezeIfRegister(&self.register_manager);
962 const reg = switch (operand) {962 defer operand.unfreezeIfRegister(&self.register_manager);
963 .register => |reg| reg,963
964 else => inner: {964 const reg: Register = blk: {
965 const reg = try self.register_manager.allocReg(inst);965 if (operand.isRegister()) {
966 try self.genSetReg(src_ty, reg, operand);966 if (self.reuseOperand(inst, ty_op.operand, 0, operand)) {
967 break :inner reg;967 break :blk operand.register;
968 },968 }
969 };969 }
970 break :blk .{ .register = registerAlias(reg, @intCast(u32, dst_ty_size)) };970 const mcv = try self.copyToNewRegister(inst, src_ty, operand);
971 break :blk mcv.register.to64();
971 };972 };
972973
973 // when truncating a `u16` to `u5`, for example, those top 3 bits in the result974 // when truncating a `u16` to `u5`, for example, those top 3 bits in the result
...@@ -975,11 +976,31 @@ fn airTrunc(self: *Self, inst: Air.Inst.Index) !void {...@@ -975,11 +976,31 @@ fn airTrunc(self: *Self, inst: Air.Inst.Index) !void {
975 const dst_bit_size = dst_ty.bitSize(self.target.*);976 const dst_bit_size = dst_ty.bitSize(self.target.*);
976 const is_power_of_two = (dst_bit_size & (dst_bit_size - 1)) == 0;977 const is_power_of_two = (dst_bit_size & (dst_bit_size - 1)) == 0;
977 if (!is_power_of_two or dst_bit_size < 8) {978 if (!is_power_of_two or dst_bit_size < 8) {
978 const mask = (~@as(u64, 0)) >> @intCast(u6, (64 - dst_ty.bitSize(self.target.*)));979 const shift = @intCast(u6, 64 - dst_ty.bitSize(self.target.*));
979 try self.genBinMathOpMir(.@"and", dst_ty, dst_mcv, .{ .immediate = mask });980 const mask = (~@as(u64, 0)) >> shift;
981 try self.genBinMathOpMir(.@"and", Type.usize, .{ .register = reg }, .{ .immediate = mask });
982
983 if (src_ty.intInfo(self.target.*).signedness == .signed) {
984 _ = try self.addInst(.{
985 .tag = .sal,
986 .ops = (Mir.Ops{
987 .reg1 = reg,
988 .flags = 0b10,
989 }).encode(),
990 .data = .{ .imm = shift },
991 });
992 _ = try self.addInst(.{
993 .tag = .sar,
994 .ops = (Mir.Ops{
995 .reg1 = reg,
996 .flags = 0b10,
997 }).encode(),
998 .data = .{ .imm = shift },
999 });
1000 }
980 }1001 }
9811002
982 return self.finishAir(inst, dst_mcv, .{ ty_op.operand, .none, .none });1003 return self.finishAir(inst, .{ .register = reg }, .{ ty_op.operand, .none, .none });
983}1004}
9841005
985fn airBoolToInt(self: *Self, inst: Air.Inst.Index) !void {1006fn airBoolToInt(self: *Self, inst: Air.Inst.Index) !void {
test/behavior/basic.zig-1
...@@ -26,7 +26,6 @@ fn testTruncate(x: u32) u8 {...@@ -26,7 +26,6 @@ fn testTruncate(x: u32) u8 {
2626
27test "truncate to non-power-of-two integers" {27test "truncate to non-power-of-two integers" {
28 if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;28 if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
29 if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
3029
31 try testTrunc(u32, u1, 0b10101, 0b1);30 try testTrunc(u32, u1, 0b10101, 0b1);
32 try testTrunc(u32, u1, 0b10110, 0b0);31 try testTrunc(u32, u1, 0b10110, 0b0);