Currently fold_stmt via gimple_cond_set_condition_from_tree and
gimple_cond_get_ops_from_tree and gimple_cond_make_false and
gimple_cond_make_true do not agree on the canonical form of
if (true) and if (false) resulting in spurious foldings.
The following makes gimple_cond_make_false/true follow the
!= 0 canoncalization that gimple_cond_get_ops_from_tree performs
and thus produce already folded conditions.
Bootstrap and regtest running on x86_64-unknown-linux-gnu.
Richard.
2015-07-22 Richard Biener <rguent...@suse.de>
* gimple.h (gimple_cond_make_false): Use 0 != 0.
(gimple_cond_make_true): Use 1 != 0.
Index: gcc/gimple.h
===================================================================
--- gcc/gimple.h (revision 226059)
+++ gcc/gimple.h (working copy)
@@ -3187,9 +3187,9 @@ gimple_cond_false_label (const gcond *gs
static inline void
gimple_cond_make_false (gcond *gs)
{
- gimple_cond_set_lhs (gs, boolean_true_node);
+ gimple_cond_set_lhs (gs, boolean_false_node);
gimple_cond_set_rhs (gs, boolean_false_node);
- gs->subcode = EQ_EXPR;
+ gs->subcode = NE_EXPR;
}
@@ -3199,8 +3199,8 @@ static inline void
gimple_cond_make_true (gcond *gs)
{
gimple_cond_set_lhs (gs, boolean_true_node);
- gimple_cond_set_rhs (gs, boolean_true_node);
- gs->subcode = EQ_EXPR;
+ gimple_cond_set_rhs (gs, boolean_false_node);
+ gs->subcode = NE_EXPR;
}
/* Check if conditional statemente GS is of the form 'if (1 == 1)',
