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Re: Empty loop elimination in 4.0 ?


On Jan 11, 2005, at 2:13 PM, Luca Benini wrote:

This:
int *f;
int i;
for (i=0;i<10;i++)
 f[i] = 0;

will be converted to:

memset (f, 0, i * sizeof(*f));
for (i=0;i<10;i++)
 ;
....but

for (i=0;i<10;i++)
  f[i] = x;

can't be converted in

memset (f, x, i * sizeof(*f));

for every x. 

Yes I know that :)
We can convert it if the sizeof(*f) is 1 or if f is a pattern
which can converted for use with memset.  The reason why I said 0 is
because that is the most common place where people should/could be using
memset.

-- Pinski

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