1const std = @import("std");
 2const builtin = @import("builtin");
 3const arch = builtin.cpu.arch;
 4const os = builtin.os.tag;
 5const abi = builtin.abi;
 6const common = @import("common.zig");
 7
 8pub const panic = common.panic;
 9
10comptime {
11    if (common.want_windows_x86_msvc_abi) {
12        // Don't let LLVM apply the stdcall name mangling on those MSVC builtins
13        @export(&_allrem, .{ .name = "\x01__allrem", .linkage = common.linkage, .visibility = common.visibility });
14        @export(&_aullrem, .{ .name = "\x01__aullrem", .linkage = common.linkage, .visibility = common.visibility });
15    }
16}
17
18pub fn _allrem(a: i64, b: i64) callconv(.{ .x86_stdcall = .{} }) i64 {
19    const s_a = a >> (64 - 1);
20    const s_b = b >> (64 - 1);
21
22    const an = (a ^ s_a) -% s_a;
23    const bn = (b ^ s_b) -% s_b;
24
25    const r = @as(u64, @bitCast(an)) % @as(u64, @bitCast(bn));
26    const s = s_a ^ s_b;
27    return (@as(i64, @bitCast(r)) ^ s) -% s;
28}
29
30pub fn _aullrem() callconv(.naked) void {
31    @setRuntimeSafety(false);
32
33    // The stack layout is:
34    // ESP+16 divisor (hi)
35    // ESP+12 divisor (low)
36    // ESP+8 dividend (hi)
37    // ESP+4 dividend (low)
38    // ESP   return address
39
40    asm volatile (
41        \\  push   %%ebx
42        \\  mov    0x14(%%esp),%%eax
43        \\  or     %%eax,%%eax
44        \\  jne    1f
45        \\  mov    0x10(%%esp),%%ecx
46        \\  mov    0xc(%%esp),%%eax
47        \\  xor    %%edx,%%edx
48        \\  div    %%ecx
49        \\  mov    0x8(%%esp),%%eax
50        \\  div    %%ecx
51        \\  mov    %%edx,%%eax
52        \\  xor    %%edx,%%edx
53        \\  jmp    6f
54        \\ 1:
55        \\  mov    %%eax,%%ecx
56        \\  mov    0x10(%%esp),%%ebx
57        \\  mov    0xc(%%esp),%%edx
58        \\  mov    0x8(%%esp),%%eax
59        \\ 2:
60        \\  shr    %%ecx
61        \\  rcr    %%ebx
62        \\  shr    %%edx
63        \\  rcr    %%eax
64        \\  or     %%ecx,%%ecx
65        \\  jne    2b
66        \\  div    %%ebx
67        \\  mov    %%eax,%%ecx
68        \\  mull   0x14(%%esp)
69        \\  xchg   %%eax,%%ecx
70        \\  mull   0x10(%%esp)
71        \\  add    %%ecx,%%edx
72        \\  jb     3f
73        \\  cmp    0xc(%%esp),%%edx
74        \\  ja     3f
75        \\  jb     4f
76        \\  cmp    0x8(%%esp),%%eax
77        \\  jbe    4f
78        \\ 3:
79        \\  sub    0x10(%%esp),%%eax
80        \\  sbb    0x14(%%esp),%%edx
81        \\ 4:
82        \\  sub    0x8(%%esp),%%eax
83        \\  sbb    0xc(%%esp),%%edx
84        \\  neg    %%edx
85        \\  neg    %%eax
86        \\  sbb    $0x0,%%edx
87        \\ 6:
88        \\  pop    %%ebx
89        \\  ret    $0x10
90    );
91}