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const std = @import("std");
const builtin = @import("builtin");
const arch = builtin.cpu.arch;
const abi = builtin.abi;
const common = @import("common.zig");
pub const panic = common.panic;
comptime {
if (arch == .x86 and abi == .msvc and builtin.zig_backend != .stage2_c) {
// Don't let LLVM apply the stdcall name mangling on those MSVC builtins
@export(_alldiv, .{ .name = "\x01__alldiv", .linkage = common.linkage, .visibility = common.visibility });
@export(_aulldiv, .{ .name = "\x01__aulldiv", .linkage = common.linkage, .visibility = common.visibility });
}
}
pub fn _alldiv(a: i64, b: i64) callconv(.Stdcall) i64 {
const s_a = a >> (64 - 1);
const s_b = b >> (64 - 1);
const an = (a ^ s_a) -% s_a;
const bn = (b ^ s_b) -% s_b;
const r = @as(u64, @bitCast(an)) / @as(u64, @bitCast(bn));
const s = s_a ^ s_b;
return (@as(i64, @bitCast(r)) ^ s) -% s;
}
pub fn _aulldiv() callconv(.Naked) void {
@setRuntimeSafety(false);
// The stack layout is:
// ESP+16 divisor (hi)
// ESP+12 divisor (low)
// ESP+8 dividend (hi)
// ESP+4 dividend (low)
// ESP return address
asm volatile (
\\ push %%ebx
\\ push %%esi
\\ mov 0x18(%%esp),%%eax
\\ or %%eax,%%eax
\\ jne 1f
\\ mov 0x14(%%esp),%%ecx
\\ mov 0x10(%%esp),%%eax
\\ xor %%edx,%%edx
\\ div %%ecx
\\ mov %%eax,%%ebx
\\ mov 0xc(%%esp),%%eax
\\ div %%ecx
\\ mov %%ebx,%%edx
\\ jmp 5f
\\ 1:
\\ mov %%eax,%%ecx
\\ mov 0x14(%%esp),%%ebx
\\ mov 0x10(%%esp),%%edx
\\ mov 0xc(%%esp),%%eax
\\ 2:
\\ shr %%ecx
\\ rcr %%ebx
\\ shr %%edx
\\ rcr %%eax
\\ or %%ecx,%%ecx
\\ jne 2b
\\ div %%ebx
\\ mov %%eax,%%esi
\\ mull 0x18(%%esp)
\\ mov %%eax,%%ecx
\\ mov 0x14(%%esp),%%eax
\\ mul %%esi
\\ add %%ecx,%%edx
\\ jb 3f
\\ cmp 0x10(%%esp),%%edx
\\ ja 3f
\\ jb 4f
\\ cmp 0xc(%%esp),%%eax
\\ jbe 4f
\\ 3:
\\ dec %%esi
\\ 4:
\\ xor %%edx,%%edx
\\ mov %%esi,%%eax
\\ 5:
\\ pop %%esi
\\ pop %%ebx
\\ ret $0x10
);
}
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