On Thu, Jan 05, 2017 at 07:39:21PM +0100, Jan Hubicka wrote:
> In fact cfglayout was invented to implement bb-reorder originally :)
So, hrm, are there any passes we *want* to do in non-cfglayout mode?
Segher
Segher Boessenkool writes:
> On Wed, Jan 04, 2017 at 10:05:49AM +0100, Richard Biener wrote:
>> > The code size is identical, but the trunk version executes one more
>> > instruction everytime the loop runs (explicit jump to .L5 with trunk vs
>> > fallthrough with 4.8) - it's faster only if the
> On 01/04/2017 03:46 AM, Segher Boessenkool wrote:
> >On Wed, Jan 04, 2017 at 10:05:49AM +0100, Richard Biener wrote:
> >>>The code size is identical, but the trunk version executes one more
> >>>instruction everytime the loop runs (explicit jump to .L5 with trunk vs
> >>>fallthrough with 4.8) -
On 01/04/2017 03:46 AM, Segher Boessenkool wrote:
On Wed, Jan 04, 2017 at 10:05:49AM +0100, Richard Biener wrote:
The code size is identical, but the trunk version executes one more
instruction everytime the loop runs (explicit jump to .L5 with trunk vs
fallthrough with 4.8) - it's faster only
On Wed, Jan 04, 2017 at 10:05:49AM +0100, Richard Biener wrote:
> > The code size is identical, but the trunk version executes one more
> > instruction everytime the loop runs (explicit jump to .L5 with trunk vs
> > fallthrough with 4.8) - it's faster only if the loop never runs. This
> > happens
On Wed, 21 Dec 2016, Senthil Kumar Selvaraj wrote:
> Hi,
>
> For this C code (slightly modified from PR 30908)
>
> void wait(int i)
> {
> while (i-- > 0)
> asm volatile("nop" ::: "memory");
> }
>
> gcc 4.8 at -Os produces
>
> jmp .L2
> .L3:
> nop
>
Hi,
For this C code (slightly modified from PR 30908)
void wait(int i)
{
while (i-- > 0)
asm volatile("nop" ::: "memory");
}
gcc 4.8 at -Os produces
jmp .L2
.L3:
nop
decl%edi
.L2:
testl %edi, %edi
jg .L3
