Re: [PATCH] Fix PR54240

[Andrew Pinski <pinskia@gmail.com>]

On Tue, Aug 14, 2012 at 2:15 PM, Andrew Pinski <pinskia@gmail.com> wrote:
> On Tue, Aug 14, 2012 at 2:11 PM, William J. Schmidt
> <wschmidt@linux.vnet.ibm.com> wrote:
>> Replace the once vacuously true, and now vacuously false, test for
>> existence of a conditional move instruction for a given mode, with one
>> that actually checks what it's supposed to.  Add a test case so we don't
>> miss such things in future.
>>
>> The test is powerpc-specific.  It would be good to have an i386 version
>> of the test as well, if someone can help with that.
>>
>> Bootstrapped and tested on powerpc64-unknown-linux-gnu with no new
>> regressions.  Ok for trunk?
>
> Here is one which can go into gcc.target/mips :
> /* { dg-do compile } */
> /* { dg-options "-O2 -fdump-tree-phiopt-details" } */

Sorry the dg-options should be:
 /* { dg-options "-O2 -fdump-tree-phiopt-details isa>=4" } */

Thanks,
Andrew

>
> typedef struct s {
>   int v;
>   int b;
>   struct s *l;
>   struct s *r;
> } S;
>
>
> int foo(S *s)
> {
>   S *this;
>   S *next;
>
>   this = s;
>   if (this->b)
>     next = this->l;
>   else
>     next = this->r;
>
>   return next->v;
> }
>
> /* { dg-final { scan-tree-dump "Hoisting adjacent loads" "phiopt1" } } */
> /* { dg-final { cleanup-tree-dump "phiopt1" } } */