Re: [PATCH] rs6000: Do not allow GPR0 for addic. if it is split

2014-12-15 Thread David Edelsohn
On Mon, Dec 15, 2014 at 6:11 AM, Segher Boessenkool wrote: > If an addic. is split to addi+cmp (because RA didn't give it CR0), it will > do the wrong thing if the input reg is GPR0 ("addi X,0,N" is "li X,N"). > So don't allow such an input. > > Spotted visually while investigating PR64268. Teste

[PATCH] rs6000: Do not allow GPR0 for addic. if it is split

2014-12-15 Thread Segher Boessenkool
If an addic. is split to addi+cmp (because RA didn't give it CR0), it will do the wrong thing if the input reg is GPR0 ("addi X,0,N" is "li X,N"). So don't allow such an input. Spotted visually while investigating PR64268. Tested etc.; okay for mainline? Segher 2014-12-15 Segher Boessenkool