1// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
2// See https://llvm.org/LICENSE.txt for license information.
3// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
4
5#include "../assembly.h"
6
7// di_int __muldi3(di_int a, di_int b);
8
9#ifdef __i386__
10
11.text
12.balign 4
13DEFINE_COMPILERRT_FUNCTION(__muldi3)
14 pushl %ebx
15 movl 16(%esp), %eax // b.lo
16 movl 12(%esp), %ecx // a.hi
17 imull %eax, %ecx // b.lo * a.hi
18
19 movl 8(%esp), %edx // a.lo
20 movl 20(%esp), %ebx // b.hi
21 imull %edx, %ebx // a.lo * b.hi
22
23 mull %edx // EDX:EAX = a.lo * b.lo
24 addl %ecx, %ebx // EBX = (a.lo*b.hi + a.hi*b.lo)
25 addl %ebx, %edx
26
27 popl %ebx
28 retl
29END_COMPILERRT_FUNCTION(__muldi3)
30
31#endif // __i386__
32
33NO_EXEC_STACK_DIRECTIVE
34
35

source code of compiler-rt/lib/builtins/i386/muldi3.S