From: "Stefan Kanthak" <stefan.kanthak@nexgo.de>
To: <gcc@gnu.org>, "LIU Hao" <lh_mouse@126.com>
Subject: Re: Widening multiplication, but no narrowing division [i386/AMD64]
Date: Mon, 9 Jan 2023 14:19:45 +0100 [thread overview]
Message-ID: <BEABAAE8508A4A27A5B9AB961CB2821C@H270> (raw)
In-Reply-To: <dd434f54-975d-7cd3-5609-3bd22509ae14@126.com>
LIU Hao wrote:
>在 2023/1/9 20:20, Stefan Kanthak 写道:
>> Hi,
>>
>> GCC (and other C compilers too) support the widening multiplication
>> of i386/AMD64 processors, but DON'T support their narrowing division:
>>
>>
>
> QWORD-DWORD division would change the behavior of your program.
[...]
> If DIV was used, it would effect an exception:
Guess why I use "schoolbook" division?
Please read the end of my post until you understand the code.
regards
Stefan
next prev parent reply other threads:[~2023-01-09 13:25 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-09 12:20 Stefan Kanthak
2023-01-09 13:10 ` LIU Hao
2023-01-09 13:19 ` Stefan Kanthak [this message]
2023-01-09 14:23 ` Paul Koning
2023-01-09 15:20 ` Stefan Kanthak
2023-01-09 15:30 ` Paul Koning
2023-01-09 16:27 ` Stefan Kanthak
2023-01-10 16:49 ` Paul Koning
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