Messages in this thread | | | Subject | Re: RFC: Petition Intel/AMD to add POPF_IF insn | From | Denys Vlasenko <> | Date | Thu, 18 Aug 2016 19:49:10 +0200 |
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On 08/18/2016 07:47 PM, Denys Vlasenko wrote: > On 08/18/2016 07:24 PM, Linus Torvalds wrote: >> That said, your numbers really aren't very convincing. If popf really >> is just 10 cycles on modern Intel hardware, it's already fast enough >> that I really don't think it matters. > > It's 20 cycles. I was wrong in my email, I forgot that the insn count > also counts "push %ebx" insns. > > Since I already made a mistake, let me double-check. > > 200 million iterations of this loop execute under 17 seconds: > > 400100: b8 00 c2 eb 0b mov $0xbebc200,%eax # 1000*1000*1000
Grr. It's 200*1000*1000, not one billion. Sorry.
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