[PATCH] Fix PR67915
Richard Biener
rguenther@suse.de
Wed Oct 14 12:55:00 GMT 2015
The following removes GENERIC folding from cleanup_control_expr_graph
in favor of GIMPLE one. This likely doesn't solve the underlying issue
of PR67915 fully but using const_binop as I originally wanted doesn't
catch all cases fold_binary did because stmts that were previously
folded get non-folded as the cgraph state changes (and thus we
can start simplifying aliases and weaks).
I've adjusted match.pd to handle &"ab" < &"ab"[2] and gimplification
to fold the conditions it builds (the C++ FE leaves us with unfolded
COND_EXPR_CONDs).
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2015-10-14 Richard Biener <rguenther@suse.de>
PR tree-optimization/67915
* match.pd: Handle comparisons of addresses of STRING_CSTs.
* gimplify.c (gimplify_cond_expr): Fold the GIMPLE conds we build.
* tree-cfgcleanup.c (cleanup_control_expr_graph): Remove GENERIC
stmt folding in favor of GIMPLE one.
* gcc.dg/torture/pr67915.c: New testcase.
Index: gcc/testsuite/gcc.dg/torture/pr67915.c
===================================================================
*** gcc/testsuite/gcc.dg/torture/pr67915.c (revision 0)
--- gcc/testsuite/gcc.dg/torture/pr67915.c (revision 0)
***************
*** 0 ****
--- 1,23 ----
+ /* { dg-do compile } */
+
+ int a, b, c, d, e, f, g;
+
+ int
+ fn1 (int p1)
+ {
+ return p1;
+ }
+
+ void
+ fn2 ()
+ {
+ lbl:
+ g = b;
+ if (fn1 (c && e))
+ {
+ f = a ? 0 : 1 << 1;
+ short h = b;
+ d = h < 0 || f ? 0 : 1;
+ }
+ goto lbl;
+ }
Index: gcc/match.pd
===================================================================
*** gcc/match.pd (revision 228804)
--- gcc/match.pd (working copy)
*************** (define_operator_list CEXPI BUILT_IN_CEX
*** 1998,2005 ****
&& decl_in_symtab_p (base1))
equal = symtab_node::get_create (base0)
->equal_address_to (symtab_node::get_create (base1));
! else if ((DECL_P (base0) || TREE_CODE (base0) == SSA_NAME)
! && (DECL_P (base1) || TREE_CODE (base1) == SSA_NAME))
equal = (base0 == base1);
}
(if (equal == 1
--- 1998,2009 ----
&& decl_in_symtab_p (base1))
equal = symtab_node::get_create (base0)
->equal_address_to (symtab_node::get_create (base1));
! else if ((DECL_P (base0)
! || TREE_CODE (base0) == SSA_NAME
! || TREE_CODE (base0) == STRING_CST)
! && (DECL_P (base1)
! || TREE_CODE (base1) == SSA_NAME
! || TREE_CODE (base1) == STRING_CST))
equal = (base0 == base1);
}
(if (equal == 1
*************** (define_operator_list CEXPI BUILT_IN_CEX
*** 2007,2015 ****
/* If the offsets are equal we can ignore overflow. */
|| off0 == off1
|| POINTER_TYPE_OVERFLOW_UNDEFINED
! /* Or if we compare using pointers to decls. */
|| (POINTER_TYPE_P (TREE_TYPE (@2))
! && DECL_P (base0))))
(switch
(if (cmp == EQ_EXPR)
{ constant_boolean_node (off0 == off1, type); })
--- 2011,2019 ----
/* If the offsets are equal we can ignore overflow. */
|| off0 == off1
|| POINTER_TYPE_OVERFLOW_UNDEFINED
! /* Or if we compare using pointers to decls or strings. */
|| (POINTER_TYPE_P (TREE_TYPE (@2))
! && (DECL_P (base0) || TREE_CODE (base0) == STRING_CST))))
(switch
(if (cmp == EQ_EXPR)
{ constant_boolean_node (off0 == off1, type); })
Index: gcc/gimplify.c
===================================================================
*** gcc/gimplify.c (revision 228804)
--- gcc/gimplify.c (working copy)
*************** gimplify_cond_expr (tree *expr_p, gimple
*** 3152,3162 ****
gimple_cond_get_ops_from_tree (COND_EXPR_COND (expr), &pred_code, &arm1,
&arm2);
-
cond_stmt = gimple_build_cond (pred_code, arm1, arm2, label_true,
! label_false);
!
gimplify_seq_add_stmt (&seq, cond_stmt);
label_cont = NULL_TREE;
if (!have_then_clause_p)
{
--- 3152,3163 ----
gimple_cond_get_ops_from_tree (COND_EXPR_COND (expr), &pred_code, &arm1,
&arm2);
cond_stmt = gimple_build_cond (pred_code, arm1, arm2, label_true,
! label_false);
gimplify_seq_add_stmt (&seq, cond_stmt);
+ gimple_stmt_iterator gsi = gsi_last (seq);
+ maybe_fold_stmt (&gsi);
+
label_cont = NULL_TREE;
if (!have_then_clause_p)
{
Index: gcc/tree-cfgcleanup.c
===================================================================
*** gcc/tree-cfgcleanup.c (revision 228804)
--- gcc/tree-cfgcleanup.c (working copy)
*************** along with GCC; see the file COPYING3.
*** 56,61 ****
--- 56,64 ----
#include "cfgloop.h"
#include "tree-ssa-propagate.h"
#include "tree-scalar-evolution.h"
+ #include "gimple-match.h"
+ #include "gimple-fold.h"
+
/* The set of blocks in that at least one of the following changes happened:
-- the statement at the end of the block was changed
*************** cleanup_control_expr_graph (basic_block
*** 96,127 ****
edge taken_edge;
bool retval = false;
gimple *stmt = gsi_stmt (gsi);
- tree val;
if (!single_succ_p (bb))
{
edge e;
edge_iterator ei;
bool warned;
! location_t loc;
fold_defer_overflow_warnings ();
- loc = gimple_location (stmt);
switch (gimple_code (stmt))
{
case GIMPLE_COND:
! val = fold_binary_loc (loc, gimple_cond_code (stmt),
! boolean_type_node,
! gimple_cond_lhs (stmt),
! gimple_cond_rhs (stmt));
! break;
case GIMPLE_SWITCH:
val = gimple_switch_index (as_a <gswitch *> (stmt));
break;
default:
! val = NULL_TREE;
}
taken_edge = find_taken_edge (bb, val);
if (!taken_edge)
--- 99,132 ----
edge taken_edge;
bool retval = false;
gimple *stmt = gsi_stmt (gsi);
if (!single_succ_p (bb))
{
edge e;
edge_iterator ei;
bool warned;
! tree val = NULL_TREE;
fold_defer_overflow_warnings ();
switch (gimple_code (stmt))
{
case GIMPLE_COND:
! {
! code_helper rcode;
! tree ops[3] = {};
! if (gimple_simplify (stmt, &rcode, ops, NULL, no_follow_ssa_edges,
! no_follow_ssa_edges)
! && rcode == INTEGER_CST)
! val = ops[0];
! break;
! }
case GIMPLE_SWITCH:
val = gimple_switch_index (as_a <gswitch *> (stmt));
break;
default:
! ;
}
taken_edge = find_taken_edge (bb, val);
if (!taken_edge)
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