Re: [PATCH, rs6000] Use bcdsub. instead of bcdadd. for bcd invalid number checking

On Thu, Apr 18, 2024 at 11:14:42AM +0800, Kewen.Lin wrote: > on 2024/4/18 10:01, HAO CHEN GUI wrote: > > This patch replace bcdadd. with bcdsub. for bcd invalid number checking. > > bcdadd on two same numbers might cause overflow which also set > > overflow/invalid bit so that we can't distinguis

Re: [PATCH, rs6000] Use bcdsub. instead of bcdadd. for bcd invalid number checking

Hi, on 2024/4/18 10:01, HAO CHEN GUI wrote: > Hi, > This patch replace bcdadd. with bcdsub. for bcd invalid number checking. > bcdadd on two same numbers might cause overflow which also set > overflow/invalid bit so that we can't distinguish it's invalid or overflow. > The bcdsub doesn't have th

[PATCH, rs6000] Use bcdsub. instead of bcdadd. for bcd invalid number checking

Hi, This patch replace bcdadd. with bcdsub. for bcd invalid number checking. bcdadd on two same numbers might cause overflow which also set overflow/invalid bit so that we can't distinguish it's invalid or overflow. The bcdsub doesn't have the problem as subtracting on two same number never cause