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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.lang.c
Subject: Re: How to avoid an overflow during multiplication?
Date: Thu, 20 Jan 2022 19:41:10 -0800
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pa@see.signature.invalid (Pierre Asselin) writes:

> Tim Rentsch <tr.17687@z991.linuxsc.com> wrote:
>
>> [ ... ]
>> These identities suggest two alternate formulations:
>>
>>     uint32_t
>>     ticks2time( uint32_t ticks, uint32_t scale, uint16_t tempo ){
>>         return  ticks*(tempo/scale) + ticks*(tempo%scale)/scale;
>>     }
>>
>>     uint32_t
>>     ticks2time( uint32_t ticks, uint32_t scale, uint16_t tempo ){
>>         return  tempo*(ticks/scale) + tempo*(ticks%scale)/scale;
>>     }
>
> I was thinking along those lines myself, except, in Tim's first
> formula, using the div() function to compute (tempo/scale) and
> (tempo%scale) together.  [...]

These days I expect compilers to be smart enough to see that both
the division and the remainder are being computed, and generate
single instruction that produces both values.  And if there is no
such instruction then div() probably doesn't help much.