On Sat, Apr 17, 2021 at 01:46:23PM +0200, Willy Tarreau wrote:
> For me the old trick of casting one side as long long still works:
>
> unsigned long long mul3264(unsigned int a, unsigned int b)
> {
> return (unsigned long long)a * b;
> }
>
> i386:
> 00000000 <mul3264>:
> 0: 8b 44 24 08 mov 0x8(%esp),%eax
> 4: f7 64 24 04 mull 0x4(%esp)
> 8: c3 ret
>
> x86_64:
> 0000000000000000 <mul3264>:
> 0: 89 f8 mov %edi,%eax
> 2: 89 f7 mov %esi,%edi
> 4: 48 0f af c7 imul %rdi,%rax
> 8: c3 retq
>
> Or maybe you had something else in mind ?
Last time I tried it, the thing refused :/ which is how we ended up with
mul_u32_u32() in asm.
