Fix points_to_local_or_readonly_memory_p wrt TARGET_MEM_REF

TARGET_MEM_REF can be used to offset constant base into a memory object (to
produce lea instruction).  This confuses points_to_local_or_readonly_memory_p
which treats the constant address as a base of the access.

Bootstrapped/regtsted x86_64-linux, comitted.
Honza

gcc/ChangeLog:

	PR ipa/113787
	* ipa-fnsummary.cc (points_to_local_or_readonly_memory_p): Do not
	look into TARGET_MEM_REFS with constant opreand 0.

gcc/testsuite/ChangeLog:

	* gcc.c-torture/execute/pr113787.c: New test.

(cherry picked from commit 96d53252aefcbc2fe419c4c3b4bcd3fc03d4d187)
This commit is contained in:
Jan Hubicka 2024-05-16 15:33:55 +02:00 committed by Richard Biener
parent 0f593e4cd8
commit 0b7ec50ae2
2 changed files with 41 additions and 1 deletions

View file

@ -2644,7 +2644,9 @@ points_to_local_or_readonly_memory_p (tree t)
return true;
return !ptr_deref_may_alias_global_p (t, false);
}
if (TREE_CODE (t) == ADDR_EXPR)
if (TREE_CODE (t) == ADDR_EXPR
&& (TREE_CODE (TREE_OPERAND (t, 0)) != TARGET_MEM_REF
|| TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) != INTEGER_CST))
return refs_local_or_readonly_memory_p (TREE_OPERAND (t, 0));
return false;
}

View file

@ -0,0 +1,38 @@
void foo(int x, int y, int z, int d, int *buf)
{
for(int i = z; i < y-z; ++i)
for(int j = 0; j < d; ++j)
/* buf[x(i+1) + j] = buf[x(i+1)-j-1] */
buf[i*x+(x-z+j)] = buf[i*x+(x-z-1-j)];
}
void bar(int x, int y, int z, int d, int *buf)
{
for(int i = 0; i < d; ++i)
for(int j = z; j < x-z; ++j)
/* buf[j+(y+i)*x] = buf[j+(y-1-i)*x] */
buf[j+(y-z+i)*x] = buf[j+(y-z-1-i)*x];
}
__attribute__((noipa))
void baz(int x, int y, int d, int *buf)
{
foo(x, y, 0, d, buf);
bar(x, y, 0, d, buf);
}
int main(void)
{
int a[] = { 1, 2, 3 };
baz (1, 2, 1, a);
/* foo does:
buf[1] = buf[0];
buf[2] = buf[1];
bar does:
buf[2] = buf[1]; (no-op)
so we should have { 1, 1, 1 }. */
for (int i = 0; i < 3; i++)
if (a[i] != 1)
__builtin_abort ();
}