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(&_alldiv, .{ .name = "\x01__alldiv", .linkage = common.linkage, .visibility = common.visibility });
14        @export(&_aulldiv, .{ .name = "\x01__aulldiv", .linkage = common.linkage, .visibility = common.visibility });
15    }
16}
17
18pub fn _alldiv(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 _aulldiv() 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        \\  push   %%esi
43        \\  mov    0x18(%%esp),%%eax
44        \\  or     %%eax,%%eax
45        \\  jne    1f
46        \\  mov    0x14(%%esp),%%ecx
47        \\  mov    0x10(%%esp),%%eax
48        \\  xor    %%edx,%%edx
49        \\  div    %%ecx
50        \\  mov    %%eax,%%ebx
51        \\  mov    0xc(%%esp),%%eax
52        \\  div    %%ecx
53        \\  mov    %%ebx,%%edx
54        \\  jmp    5f
55        \\ 1:
56        \\  mov    %%eax,%%ecx
57        \\  mov    0x14(%%esp),%%ebx
58        \\  mov    0x10(%%esp),%%edx
59        \\  mov    0xc(%%esp),%%eax
60        \\ 2:
61        \\  shr    %%ecx
62        \\  rcr    %%ebx
63        \\  shr    %%edx
64        \\  rcr    %%eax
65        \\  or     %%ecx,%%ecx
66        \\  jne    2b
67        \\  div    %%ebx
68        \\  mov    %%eax,%%esi
69        \\  mull   0x18(%%esp)
70        \\  mov    %%eax,%%ecx
71        \\  mov    0x14(%%esp),%%eax
72        \\  mul    %%esi
73        \\  add    %%ecx,%%edx
74        \\  jb     3f
75        \\  cmp    0x10(%%esp),%%edx
76        \\  ja     3f
77        \\  jb     4f
78        \\  cmp    0xc(%%esp),%%eax
79        \\  jbe    4f
80        \\ 3:
81        \\  dec    %%esi
82        \\ 4:
83        \\  xor    %%edx,%%edx
84        \\  mov    %%esi,%%eax
85        \\ 5:
86        \\  pop    %%esi
87        \\  pop    %%ebx
88        \\  ret    $0x10
89    );
90}