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x64: ensure 16byte stack alignment across calls

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This commit is contained in:
Jakub Konka 2022-02-18 13:02:08 +01:00
parent d74e9b2d98
commit 0f0bb7e5ea
1 changed files with 7 additions and 17 deletions
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24
src/arch/x86_64/CodeGen.zig
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@ -2581,16 +2581,10 @@ fn airArg(self: *Self, inst: Air.Inst.Index) !void {
self.arg_index += 1;
const mcv = self.args[arg_index];
const max_stack = loop: for (self.args) |arg| {
switch (arg) {
.stack_offset => |last| break :loop last,
else => {},
}
} else 0;
const payload = try self.addExtra(Mir.ArgDbgInfo{
.air_inst = inst,
.arg_index = arg_index,
.max_stack = @intCast(u32, max_stack),
.max_stack = self.max_end_stack,
});
_ = try self.addInst(.{
.tag = .arg_dbg_info,
@ -2607,7 +2601,7 @@ fn airArg(self: *Self, inst: Air.Inst.Index) !void {
break :blk mcv;
},
.stack_offset => |off| {
const offset = max_stack - off + 16;
const offset = @intCast(i32, self.max_end_stack) - off + 16;
break :blk MCValue{ .stack_offset = -offset };
},
else => return self.fail("TODO implement arg for {}", .{mcv}),
@ -2651,7 +2645,6 @@ fn airCall(self: *Self, inst: Air.Inst.Index) !void {
var info = try self.resolveCallingConventionValues(fn_ty);
defer info.deinit(self);
var stack_adjustment: ?u32 = null;
for (args) |arg, arg_i| {
const mc_arg = info.args[arg_i];
const arg_ty = self.air.typeOf(arg);
@ -2666,9 +2659,6 @@ fn airCall(self: *Self, inst: Air.Inst.Index) !void {
},
.stack_offset => |off| {
try self.genSetStackArg(arg_ty, off, arg_mcv);
if (stack_adjustment == null) {
stack_adjustment = @intCast(u32, off);
}
},
.ptr_stack_offset => {
return self.fail("TODO implement calling with MCValue.ptr_stack_offset arg", .{});
@ -2689,14 +2679,14 @@ fn airCall(self: *Self, inst: Air.Inst.Index) !void {
}
}
if (stack_adjustment) |off| {
if (info.stack_byte_count > 0) {
// Adjust the stack
_ = try self.addInst(.{
.tag = .sub,
.ops = (Mir.Ops{
.reg1 = .rsp,
}).encode(),
.data = .{ .imm = off },
.data = .{ .imm = info.stack_byte_count },
});
}
@ -2824,14 +2814,14 @@ fn airCall(self: *Self, inst: Air.Inst.Index) !void {
}
} else unreachable;
if (stack_adjustment) |off| {
if (info.stack_byte_count > 0) {
// Readjust the stack
_ = try self.addInst(.{
.tag = .add,
.ops = (Mir.Ops{
.reg1 = .rsp,
}).encode(),
.data = .{ .imm = off },
.data = .{ .imm = info.stack_byte_count },
});
}
@ -4847,8 +4837,8 @@ fn resolveCallingConventionValues(self: *Self, fn_ty: Type) !CallMCValues {
}
}
result.stack_byte_count = next_stack_offset;
result.stack_align = 16;
result.stack_byte_count = mem.alignForwardGeneric(u32, next_stack_offset, result.stack_align);
},
else => return self.fail("TODO implement function parameters for {} on x86_64", .{cc}),
}