zig/std/special/compiler_rt/aulldiv.zig

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const builtin = @import("builtin");
const linkage = if (builtin.is_test) builtin.GlobalLinkage.Internal else builtin.GlobalLinkage.Strong;
const is_win32 = builtin.os == builtin.Os.windows and builtin.arch == builtin.Arch.i386;
export nakedcc fn _aulldiv() {
if (is_win32) {
@setDebugSafety(this, false);
@setGlobalLinkage(_aulldiv, linkage);
asm volatile (
\\.intel_syntax noprefix
\\
\\ push ebx
\\ push esi
\\ mov eax,dword ptr [esp+18h]
\\ or eax,eax
\\ jne L1
\\ mov ecx,dword ptr [esp+14h]
\\ mov eax,dword ptr [esp+10h]
\\ xor edx,edx
\\ div ecx
\\ mov ebx,eax
\\ mov eax,dword ptr [esp+0Ch]
\\ div ecx
\\ mov edx,ebx
\\ jmp L2
\\ L1:
\\ mov ecx,eax
\\ mov ebx,dword ptr [esp+14h]
\\ mov edx,dword ptr [esp+10h]
\\ mov eax,dword ptr [esp+0Ch]
\\ L3:
\\ shr ecx,1
\\ rcr ebx,1
\\ shr edx,1
\\ rcr eax,1
\\ or ecx,ecx
\\ jne L3
\\ div ebx
\\ mov esi,eax
\\ mul dword ptr [esp+18h]
\\ mov ecx,eax
\\ mov eax,dword ptr [esp+14h]
\\ mul esi
\\ add edx,ecx
\\ jb L4
\\ cmp edx,dword ptr [esp+10h]
\\ ja L4
\\ jb L5
\\ cmp eax,dword ptr [esp+0Ch]
\\ jbe L5
\\ L4:
\\ dec esi
\\ L5:
\\ xor edx,edx
\\ mov eax,esi
\\ L2:
\\ pop esi
\\ pop ebx
\\ ret 10h
);
unreachable;
}
@setGlobalLinkage(_aulldiv, builtin.GlobalLinkage.Internal);
unreachable;
}