authorgravatar for jacobly@ziglang.orgJacob Young <jacobly@ziglang.org> 2023-06-24 23:32:55-04:00
committergravatar for jacobly@ziglang.orgJacob Young <jacobly@ziglang.org> 2023-06-25 19:14:03-04:00
logb4b1ad475be4d4b6331ae56481c3b99d60cf0039
treea354c4842a73b92af53bee3e9769a525f8b4b977
parent3f13987a761ed805656bec3b8e4db591a1cbc8ed

x86_64: truncate packed field value

2 files changed, 23 insertions(+), 3 deletions(-)

src/arch/x86_64/CodeGen.zig+23-2
......@@ -5616,9 +5616,31 @@ fn airStructFieldVal(self: *Self, inst: Air.Inst.Index) !void {
56165616
56175617 switch (src_mcv) {
56185618 .load_frame => |frame_addr| {
5619 const field_abi_size: u32 = @intCast(field_ty.abiSize(mod));
56195620 if (field_off % 8 == 0) {
56205621 const off_mcv =
5621 src_mcv.address().offset(@as(i32, @intCast(@divExact(field_off, 8)))).deref();
5622 src_mcv.address().offset(@intCast(@divExact(field_off, 8))).deref();
5623
5624 if (field_abi_size <= 8) {
5625 const int_ty = try mod.intType(
5626 if (field_ty.isAbiInt(mod)) field_ty.intInfo(mod).signedness else .unsigned,
5627 @intCast(field_ty.bitSize(mod)),
5628 );
5629
5630 const dst_reg =
5631 try self.register_manager.allocReg(if (field_is_gp) inst else null, gp);
5632 const dst_mcv = MCValue{ .register = dst_reg };
5633 const dst_lock = self.register_manager.lockRegAssumeUnused(dst_reg);
5634 defer self.register_manager.unlockReg(dst_lock);
5635
5636 try self.genCopy(int_ty, dst_mcv, off_mcv);
5637 if (self.regExtraBits(field_ty) > 0) try self.truncateRegister(int_ty, dst_reg);
5638 break :result if (field_is_gp)
5639 dst_mcv
5640 else
5641 try self.copyToRegisterWithInstTracking(inst, field_ty, dst_mcv);
5642 }
5643
56225644 if (self.reuseOperand(inst, operand, 0, src_mcv)) break :result off_mcv;
56235645
56245646 const dst_mcv = try self.allocRegOrMem(inst, true);
......@@ -5626,7 +5648,6 @@ fn airStructFieldVal(self: *Self, inst: Air.Inst.Index) !void {
56265648 break :result dst_mcv;
56275649 }
56285650
5629 const field_abi_size = @as(u32, @intCast(field_ty.abiSize(mod)));
56305651 const limb_abi_size: u32 = @min(field_abi_size, 8);
56315652 const limb_abi_bits = limb_abi_size * 8;
56325653 const field_byte_off = @as(i32, @intCast(field_off / limb_abi_bits * limb_abi_size));
test/behavior/struct.zig-1
......@@ -426,7 +426,6 @@ test "packed struct 24bits" {
426426 if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
427427 if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
428428 if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
429 if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
430429 if (builtin.cpu.arch == .wasm32) return error.SkipZigTest; // TODO
431430 if (builtin.cpu.arch == .arm) return error.SkipZigTest; // TODO
432431 if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO