OpenE2K
/
gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

sccvn: Punt on ref->size not multiple of 8 for memset (, 123, ) in 9.x [PR93945] 

And here is the corresponding 9.x change where we the patch just punts if
ref->size is not whole bytes, like we already punt if offseti is not byte
aligned.

2020-02-27  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/93945
	* tree-ssa-sccvn.c (vn_reference_lookup_3): For memset with non-zero
	second operand, require ref->size to be a multiple of BITS_PER_UNIT.

	* gcc.c-torture/execute/pr93945.c: New test.
This commit is contained in:
Jakub Jelinek 2020-02-27 11:21:52 +01:00
parent 526fadb010
commit a460bf38dc
4 changed files with 58 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
gcc/ChangeLog
View File

@ -1,3 +1,9 @@
2020-02-27 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/93945
* tree-ssa-sccvn.c (vn_reference_lookup_3): For memset with non-zero
second operand, require ref->size to be a multiple of BITS_PER_UNIT.
2020-02-26 Carl Love <cel@us.ibm.com>
PR target/91276

5
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,8 @@
2020-02-27 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/93945
* gcc.c-torture/execute/pr93945.c: New test.
2020-02-26 Marek Polacek <polacek@redhat.com>
Jakub Jelinek <jakub@redhat.com>

45
gcc/testsuite/gcc.c-torture/execute/pr93945.c Normal file
View File

@ -0,0 +1,45 @@
/* PR tree-optimization/93945 */
union U { char a[8]; struct S { unsigned int b : 8, c : 13, d : 11; } e; } u;
__attribute__((noipa)) int
foo (void)
{
__builtin_memset (&u.a, 0xf4, sizeof (u.a));
return u.e.c;
}
__attribute__((noipa)) int
bar (void)
{
asm volatile ("" : : "g" (&u) : "memory");
return u.e.c;
}
__attribute__((noipa)) int
baz (void)
{
__builtin_memset (&u.a, 0xf4, sizeof (u.a));
return u.e.d;
}
__attribute__((noipa)) int
qux (void)
{
asm volatile ("" : : "g" (&u) : "memory");
return u.e.d;
}
int
main ()
{
int a = foo ();
int b = bar ();
if (a != b)
__builtin_abort ();
a = baz ();
b = qux ();
if (a != b)
__builtin_abort ();
return 0;
}

3
gcc/tree-ssa-sccvn.c
View File

@ -2113,7 +2113,8 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
|| (INTEGRAL_TYPE_P (vr->type) && known_eq (ref->size, 8)))
&& CHAR_BIT == 8 && BITS_PER_UNIT == 8
&& offset.is_constant (&offseti)
&& offseti % BITS_PER_UNIT == 0))
&& offseti % BITS_PER_UNIT == 0
&& multiple_p (ref->size, BITS_PER_UNIT)))
&& poly_int_tree_p (gimple_call_arg (def_stmt, 2))
&& (TREE_CODE (gimple_call_arg (def_stmt, 0)) == ADDR_EXPR
|| TREE_CODE (gimple_call_arg (def_stmt, 0)) == SSA_NAME))