So I stumbled across fold_cond_expr_cond and traced it back to
pre-GIMPLE and pre-fold_XXX times. It "folds" all conditions in
a function (but only if they fold to always true/false). It
does this after CFG construction but before cfg-cleanup. It
does that to allow cfg-cleanup to be less expensive - but that's
all no longer true as cfg-cleanup basically does the very same
"folding" as fold_cond_expr_cond.
Then we have the other caller from tree_function_versioning
which folds all copied stmts anyway.
And fold_stmt does sth similar (but doesn't throw away non-true/false
results). It just restricts itself a bit too much, so I removed
the redundant check.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2015-07-23 Richard Biener <rguent...@suse.de>
* gimple-fold.c (fold_gimple_cond): Do not require folding
results to pass valid_gimple_rhs_p.
* tree-cfg.h (fold_cond_expr_cond): Remove.
* tree-cfg.c (fold_cond_expr_cond): Likewise.
(make_edges): Do not call it.
* tree-inline.c (tree_function_versioning): Likewise.
Index: gcc/gimple-fold.c
===================================================================
--- gcc/gimple-fold.c (revision 226091)
+++ gcc/gimple-fold.c (working copy)
@@ -546,7 +546,7 @@ fold_gimple_cond (gcond *stmt)
if (result)
{
STRIP_USELESS_TYPE_CONVERSION (result);
- if (is_gimple_condexpr (result) && valid_gimple_rhs_p (result))
+ if (is_gimple_condexpr (result))
{
gimple_cond_set_condition_from_tree (stmt, result);
return true;
Index: gcc/tree-cfg.h
===================================================================
--- gcc/tree-cfg.h (revision 226091)
+++ gcc/tree-cfg.h (working copy)
@@ -31,7 +31,6 @@ extern void gt_pch_nx (edge_def *e, gt_p
extern void init_empty_tree_cfg_for_function (struct function *);
extern void init_empty_tree_cfg (void);
-extern void fold_cond_expr_cond (void);
extern void start_recording_case_labels (void);
extern void end_recording_case_labels (void);
extern basic_block label_to_block_fn (struct function *, tree);
Index: gcc/tree-cfg.c
===================================================================
--- gcc/tree-cfg.c (revision 226091)
+++ gcc/tree-cfg.c (working copy)
@@ -606,48 +606,6 @@ create_bb (void *h, void *e, basic_block
Edge creation
---------------------------------------------------------------------------*/
-/* Fold COND_EXPR_COND of each COND_EXPR. */
-
-void
-fold_cond_expr_cond (void)
-{
- basic_block bb;
-
- FOR_EACH_BB_FN (bb, cfun)
- {
- gimple stmt = last_stmt (bb);
-
- if (stmt && gimple_code (stmt) == GIMPLE_COND)
- {
- gcond *cond_stmt = as_a <gcond *> (stmt);
- location_t loc = gimple_location (stmt);
- tree cond;
- bool zerop, onep;
-
- fold_defer_overflow_warnings ();
- cond = fold_binary_loc (loc, gimple_cond_code (cond_stmt),
- boolean_type_node,
- gimple_cond_lhs (cond_stmt),
- gimple_cond_rhs (cond_stmt));
- if (cond)
- {
- zerop = integer_zerop (cond);
- onep = integer_onep (cond);
- }
- else
- zerop = onep = false;
-
- fold_undefer_overflow_warnings (zerop || onep,
- stmt,
- WARN_STRICT_OVERFLOW_CONDITIONAL);
- if (zerop)
- gimple_cond_make_false (cond_stmt);
- else if (onep)
- gimple_cond_make_true (cond_stmt);
- }
- }
-}
-
/* If basic block BB has an abnormal edge to a basic block
containing IFN_ABNORMAL_DISPATCHER internal call, return
that the dispatcher's basic block, otherwise return NULL. */
@@ -1000,9 +958,6 @@ make_edges (void)
XDELETE (bb_to_omp_idx);
free_omp_regions ();
-
- /* Fold COND_EXPR_COND of each COND_EXPR. */
- fold_cond_expr_cond ();
}
/* Add SEQ after GSI. Start new bb after GSI, and created further bbs as
Index: gcc/tree-inline.c
===================================================================
--- gcc/tree-inline.c (revision 226091)
+++ gcc/tree-inline.c (working copy)
@@ -5847,7 +5847,6 @@ tree_function_versioning (tree old_decl,
fold_marked_statements (0, id.statements_to_fold);
delete id.statements_to_fold;
- fold_cond_expr_cond ();
delete_unreachable_blocks_update_callgraph (&id);
if (id.dst_node->definition)
cgraph_edge::rebuild_references ();
