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re PR tree-optimization/43784 (-Os -fkeep-inline-functions causes FAIL: gcc.c-torture/execute/builtins/pr22237.c execution)

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2010-07-26  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/43784
	* tree-nrv.c (dest_safe_for_nrv_p): It's not safe to NRV
	if the destination is used by the call.

	* gcc.c-torture/execute/pr43784.c: New testcase.
	* g++.dg/torture/pr43784.C: Likewise.

From-SVN: r162539
This commit is contained in:
Richard Guenther 2010-07-26 16:01:55 +00:00 • committed by Richard Biener
parent 6a2ba1839d
commit 7f8ac3d7f9
5 changed files with 73 additions and 4 deletions
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6
gcc/ChangeLog
View file

@ -1,3 +1,9 @@
2010-07-26 Richard Guenther <rguenther@suse.de>
PR tree-optimization/43784
* tree-nrv.c (dest_safe_for_nrv_p): It's not safe to NRV
if the destination is used by the call.
2010-07-26 Richard Guenther <rguenther@suse.de>
PR middle-end/45073

6
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,9 @@
2010-07-26 Richard Guenther <rguenther@suse.de>
PR tree-optimization/43784
* gcc.c-torture/execute/pr43784.c: New testcase.
* g++.dg/torture/pr43784.C: Likewise.
2010-07-26 Richard Guenther <rguenther@suse.de>
PR middle-end/45056

24
gcc/testsuite/g++.dg/torture/pr43784.C Normal file
View file

@ -0,0 +1,24 @@
/* { dg-do run } */
/* { dg-options "-fno-tree-sra" } */
struct S {int x, y, makemelarge[5];};
S __attribute__((noinline)) f (S &s) {
S r;
r.x = s.y;
r.y = s.x;
return r;
}
int __attribute__((noinline)) glob (int a, int b)
{
S local = { a, b };
local = f (local);
return local.y;
}
extern "C" void abort (void);
int main (void)
{
if (glob (1, 3) != 1)
abort ();
return 0;
}

33
gcc/testsuite/gcc.c-torture/execute/pr43784.c Normal file
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@ -0,0 +1,33 @@
struct s {
unsigned char a[256];
};
union u {
struct { struct s b; int c; } d;
struct { int c; struct s b; } e;
};
static union u v;
static struct s *p = &v.d.b;
static struct s *q = &v.e.b;
static struct s __attribute__((noinline)) rp(void)
{
return *p;
}
static void qp(void)
{
*q = rp();
}
int main()
{
int i;
for (i = 0; i < 256; i++)
p->a[i] = i;
qp();
for (i = 0; i < 256; i++)
if (q->a[i] != i)
__builtin_abort();
return 0;
}

8
gcc/tree-nrv.c
View file

@ -296,7 +296,7 @@ struct gimple_opt_pass pass_nrv =
optimization, where DEST is expected to be the LHS of a modify
expression where the RHS is a function returning an aggregate.
DEST is available if it is not clobbered by the call. */
DEST is available if it is not clobbered or used by the call. */
static bool
dest_safe_for_nrv_p (gimple call)
@ -310,7 +310,8 @@ dest_safe_for_nrv_p (gimple call)
if (TREE_CODE (dest) == SSA_NAME)
return true;
if (call_may_clobber_ref_p (call, dest))
if (call_may_clobber_ref_p (call, dest)
|| ref_maybe_used_by_stmt_p (call, dest))
return false;
return true;
@ -345,8 +346,7 @@ execute_return_slot_opt (void)
&& gimple_call_lhs (stmt)
&& !gimple_call_return_slot_opt_p (stmt)
&& aggregate_value_p (TREE_TYPE (gimple_call_lhs (stmt)),
gimple_call_fndecl (stmt))
)
gimple_call_fndecl (stmt)))
{
/* Check if the location being assigned to is
clobbered by the call. */