On Thu, Dec 04, 2014 at 04:43:34PM +0800, Zhenqiang Chen wrote:
> C code:
>
> if (!--*p)
>
> rtl code:
>
> 6: r91:SI=[r90:SI]
> 7: {r88:SI=r91:SI-0x1;clobber flags:CC;}
> 8: [r90:SI]=r88:SI
> 9: flags:CCZ=cmp(r88:SI,0)
>
> expected output:
>
> 8: {flags:CCZ=cmp([r90:SI]-0x1,0);[r90:SI]=[r90:SI]-0x1;}
>
> in assemble, it is
>
> decl (%eax)Combine does not consider combining 9 into 7 because there is no LOG_LINK between them (the link for r88 is between 8 and 7 already). Segher
