[Bug middle-end/65330] restrict should be considered when folding through references from global vars
hubicka at ucw dot cz
gcc-bugzilla@gcc.gnu.org
Sat Mar 7 00:08:00 GMT 2015
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65330
--- Comment #3 from Jan Hubicka <hubicka at ucw dot cz> ---
> I was thinking of sth else first - make sure that points-to analysis processes
> initializers of readonly globals (when they bind to the current def). In
when ctor_for_folding returns non-NULL;
> your testcase the globals are not readonly - or did you mean to write
>
> int * const varptr = &var;
> int * const __restrict__ varptr2 = &var;
>
> ? Your testcase also misses a declaration of 'var'.
I did not quite finish the testcase because the restrict qualifier I was
interested in was ignored. Yes, they would need to be declared either const or
static (so the DECL_READONLY is derived by IPA code).
This should be full testcase (-fmerge-all-constants is needed to get merging
done, but to expose any problems testrestrict/testrestrict2 codegen would need
to differ):
int var;
static const int *varptr=&var;
static const int *__restrict__ varptr2=&var;
static int *__restrict__ varptr3 = &var;
static int *__restrict__ varptr4 = &var;
int *
return_valptr(int i)
{
return varptr[i];
}
int * __restrict__
return_valptr2(int i)
{
return varptr2[i];
}
int
testrestrict ()
{
int *ptr = return_valptr (0);
*ptr = 0;
*varptr3 = 1;
return *ptr;
}
int
testrestrict2 ()
{
int *ptr = return_valptr2 (0);
*ptr = 0;
*varptr3 = 1;
return *ptr;
}
int
testrestrict4 ()
{
*varptr4 = 0;
*varptr3 = 1;
return *varptr4;
}
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