1const std = @import("std");
2const bits = @import("bits.zig");
3const Register = bits.Register;
4const RegisterManagerFn = @import("../../register_manager.zig").RegisterManager;
5
6// SPARCv9 SysV ABI stack constants.
7// See: Registers and the Stack Frame, page 3P-8, SCD 2.4.1.
8
9// The ABI specifies that %sp points to top of stack - stack bias,
10// and %fp points to top of previous frame - stack bias.
11pub const stack_bias = 2047;
12
13// The first 128 bytes of the stack is reserved for register saving purposes.
14// The ABI also requires to reserve space in the stack for the first six
15// outgoing arguments, even though they are usually passed in registers.
16// TODO Don't allocate the argument space in leaf functions
17// TODO Save an RO copy of outgoing arguments in reserved area when building in Debug
18// TODO Should we also save it in ReleaseSafe? Solaris and OpenBSD binaries seem to ship
19// with argument copying enabled and it doesn't seem to give them big slowdowns so
20// I guess it would be okay to do in ReleaseSafe?
21pub const stack_reserved_area = 128 + 48;
22
23// There are no callee-preserved registers since the windowing
24// mechanism already takes care of them.
25// We still need to preserve %o0-%o5, %g1, %g4, and %g5 before calling
26// something, though, as those are shared with the callee and might be
27// thrashed by it.
28pub const caller_preserved_regs = [_]Register{ .o0, .o1, .o2, .o3, .o4, .o5, .g1, .g4, .g5 };
29
30// Try to allocate i, l, o, then g sets of registers, in order of priority.
31const allocatable_regs = [_]Register{
32 // zig fmt: off
33 .@"i0", .@"i1", .@"i2", .@"i3", .@"i4", .@"i5",
34 .l0, .l1, .l2, .l3, .l4, .l5, .l6, .l7,
35 .o0, .o1, .o2, .o3, .o4, .o5,
36 .g1, .g4, .g5,
37 // zig fmt: on
38};
39
40pub const c_abi_int_param_regs_caller_view = [_]Register{ .o0, .o1, .o2, .o3, .o4, .o5 };
41pub const c_abi_int_param_regs_callee_view = [_]Register{ .i0, .i1, .i2, .i3, .i4, .i5 };
42
43pub const c_abi_int_return_regs_caller_view = [_]Register{ .o0, .o1, .o2, .o3 };
44pub const c_abi_int_return_regs_callee_view = [_]Register{ .i0, .i1, .i2, .i3 };
45
46pub const RegisterManager = RegisterManagerFn(@import("CodeGen.zig"), Register, &allocatable_regs);
47
48// Register classes
49const RegisterBitSet = RegisterManager.RegisterBitSet;
50pub const RegisterClass = struct {
51 pub const gp: RegisterBitSet = blk: {
52 var set = RegisterBitSet.empty;
53 set.setRangeValue(.{
54 .start = 0,
55 .end = allocatable_regs.len,
56 }, true);
57 break :blk set;
58 };
59};