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

re PR c++/78655 (gcc doesn't exploit the fact that the result of pointer addition can not be nullptr)

Browse Source 
2018-08-20  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/78655
	* tree-vrp.c (extract_range_from_binary_expr_1): Make
	pointer + offset nonnull if either operand is nonnull work.

	* gcc.dg/tree-ssa/evrp11.c: New testcase.

From-SVN: r263662
This commit is contained in:
Richard Biener 2018-08-20 14:01:05 +00:00 committed by Richard Biener
parent a2c5e1ae59
commit 4864297f78
4 changed files with 40 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 @@
2018-08-20 Richard Biener <rguenther@suse.de>
PR tree-optimization/78655
* tree-vrp.c (extract_range_from_binary_expr_1): Make
pointer + offset nonnull if either operand is nonnull work.
2018-08-20 Tom de Vries <tdevries@suse.de>
* dwarf2out.c (add_scalar_info): Don't add reference to existing die

5
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,8 @@
2018-08-20 Richard Biener <rguenther@suse.de>
PR tree-optimization/78655
* gcc.dg/tree-ssa/evrp11.c: New testcase.
2018-08-18 Iain Sandoe <iain@sandoe.co.uk>
* gcc.dg/debug/dwarf2/pr80263.c: Suppress pubtypes output

23
gcc/testsuite/gcc.dg/tree-ssa/evrp11.c Normal file
View File

@ -0,0 +1,23 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-evrp" } */
extern void link_error ();
void foo (int *x)
{
int *p = x + 1;
if (p == 0)
link_error ();
}
void bar (char *x, int a)
{
if (a != 0)
{
char *p = x + a;
if (p == 0)
link_error ();
}
}
/* { dg-final { scan-tree-dump-not "link_error" "evrp" } } */

7
gcc/tree-vrp.c
View File

@ -1437,6 +1437,7 @@ extract_range_from_binary_expr_1 (value_range *vr,
&& code != PLUS_EXPR
&& code != MINUS_EXPR
&& code != RSHIFT_EXPR
&& code != POINTER_PLUS_EXPR
&& (vr0.type == VR_VARYING
|| vr1.type == VR_VARYING
|| vr0.type != vr1.type
@ -1467,7 +1468,11 @@ extract_range_from_binary_expr_1 (value_range *vr,
{
/* For pointer types, we are really only interested in asserting
whether the expression evaluates to non-NULL. */
if (range_is_nonnull (&vr0) || range_is_nonnull (&vr1))
if (range_is_nonnull (&vr0)
|| range_is_nonnull (&vr1)
|| (vr1.type == VR_RANGE
&& !symbolic_range_p (&vr1)
&& !range_includes_zero_p (vr1.min, vr1.max)))
set_value_range_to_nonnull (vr, expr_type);
else if (range_is_null (&vr0) && range_is_null (&vr1))
set_value_range_to_null (vr, expr_type);