https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81607
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |wrong-code
Status|ASSIGNED |NEW
Component|tree-optimization |c++
Assignee|rguenth at gcc dot gnu.org |unassigned at gcc dot
gnu.org
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
0x000000000088d7d5 in cp_fold (x=<lshift_expr 0x7ffff69e6618>)
at /tmp/trunk/gcc/cp/cp-gimplify.c:2251
2251 x = fold_build2_loc (loc, code, TREE_TYPE (x), op0, op1);
Value returned is $25 = (tree_node *) 0x7ffff69e6640
(gdb) p debug_generic_expr (op1)
a
$26 = void
(gdb) p debug_generic_expr (op0)
(long int) d.c
$27 = void
(gdb) p debug_generic_expr (x)
(1 ? (int) (long int) d.c : 0) << a
$28 = void
because we run into
static tree
cp_fold (tree x)
{
...
case VEC_COND_EXPR:
case COND_EXPR:
...
/* A COND_EXPR might have incompatible types in branches if one or both
arms are bitfields. If folding exposed such a branch, fix it up. */
if (TREE_CODE (x) != code)
if (tree type = is_bitfield_expr_with_lowered_type (x))
x = fold_convert (type, x);
and fold (int) (long int) d.c to (long int) d.c here.
C++ FE bug.
Not sure why this isn't simply the following as we surely have to preserve
the type of the COND_EXPR when folding.
Index: gcc/cp/cp-gimplify.c
===================================================================
--- gcc/cp/cp-gimplify.c (revision 250725)
+++ gcc/cp/cp-gimplify.c (working copy)
@@ -2314,8 +2314,7 @@ cp_fold (tree x)
/* A COND_EXPR might have incompatible types in branches if one or both
arms are bitfields. If folding exposed such a branch, fix it up. */
if (TREE_CODE (x) != code)
- if (tree type = is_bitfield_expr_with_lowered_type (x))
- x = fold_convert (type, x);
+ x = fold_convert (TREE_TYPE (org_x), x);
break;
Leaving to C++ folks.
