PR tree-optimization/44508

	* tree-ssa-propagate.h (substitute_and_fold): Add DO_DCE
	argument.
	* tree-ssa-propagate.c (substitute_and_fold): If !DO_DCE,
	don't eliminate trivially dead stmts.
	* tree-vrp.c (vrp_finalize): Pass false as last argument
	to substitute_and_fold.
	* tree-ssa-copy.c (fini_copy_prop): Pass true as last argument
	to substitute_and_fold.
	* tree-ssa-ccp.c (ccp_finalize): Likewise.

	* gcc.dg/tree-ssa/pr21086.c: Adjust.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@160749 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a2778ae..b7c8aec 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,16 @@
 2010-06-14  Jakub Jelinek  <jakub@redhat.com>
 
+       PR tree-optimization/44508
+       * tree-ssa-propagate.h (substitute_and_fold): Add DO_DCE
+       argument.
+       * tree-ssa-propagate.c (substitute_and_fold): If !DO_DCE,
+       don't eliminate trivially dead stmts.
+       * tree-vrp.c (vrp_finalize): Pass false as last argument
+       to substitute_and_fold.
+       * tree-ssa-copy.c (fini_copy_prop): Pass true as last argument
+       to substitute_and_fold.
+       * tree-ssa-ccp.c (ccp_finalize): Likewise.
+
        PR bootstrap/44509
        * c-config-lang.in (gtfiles): Add c-family/c-cppbuiltin.c.
        * c-family/c-cppbuiltin.c: Include gt-c-family-c-cppbuiltin.h.

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 013f3bf..4492f0d 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2010-06-14  Jakub Jelinek  <jakub@redhat.com>
 
+       PR tree-optimization/44508
+       * gcc.dg/tree-ssa/pr21086.c: Adjust.
+
        PR bootstrap/44509
        * gcc.dg/pr44509.c: New test.
 

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr21086.c b/gcc/testsuite/gcc.dg/tree-ssa/pr21086.c
index 2409608..f924d26 100644 (file)
--- a/gcc/testsuite/gcc.dg/tree-ssa/pr21086.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr21086.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-vrp1" } */
+/* { dg-options "-O2 -fdump-tree-vrp1 -fdump-tree-dce1" } */
 
 int
 foo (int *p)
@@ -16,8 +16,9 @@ foo (int *p)
 }
 
 /* Target with fno-delete-null-pointer-checks should not fold checks */
-/* { dg-final { scan-tree-dump-times "Folding predicate " 1 "vrp1" { target { ! keeps_null_pointer_checks } } } } */
+/* { dg-final { scan-tree-dump "Folding predicate " "vrp1" { target { ! keeps_null_pointer_checks } } } } */
 /* { dg-final { scan-tree-dump-times "Folding predicate " 0 "vrp1" { target {   keeps_null_pointer_checks } } } } */
-/* { dg-final { scan-tree-dump-not "b_. =" "vrp1" { target { ! avr-*-* } } } } */
-/* { dg-final { scan-tree-dump "b_. =" "vrp1" { target { avr-*-* } } } } */
+/* { dg-final { scan-tree-dump-not "b_. =" "dce1" { target { ! avr-*-* } } } } */
+/* { dg-final { scan-tree-dump "b_. =" "dce1" { target { avr-*-* } } } } */
 /* { dg-final { cleanup-tree-dump "vrp1" } } */
+/* { dg-final { cleanup-tree-dump "dce1" } } */

diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index 44e284f..2b6139b 100644 (file)
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -682,7 +682,7 @@ ccp_finalize (void)
 
   do_dbg_cnt ();
   /* Perform substitutions based on the known constant values.  */
-  something_changed = substitute_and_fold (const_val, ccp_fold_stmt);
+  something_changed = substitute_and_fold (const_val, ccp_fold_stmt, true);
 
   free (const_val);
   const_val = NULL;

diff --git a/gcc/tree-ssa-copy.c b/gcc/tree-ssa-copy.c
index 7a4c099..87d8968 100644 (file)
--- a/gcc/tree-ssa-copy.c
+++ b/gcc/tree-ssa-copy.c
@@ -854,7 +854,7 @@ fini_copy_prop (void)
        duplicate_ssa_name_ptr_info (tmp[i].value, SSA_NAME_PTR_INFO (var));
     }
 
-  substitute_and_fold (tmp, NULL);
+  substitute_and_fold (tmp, NULL, true);
 
   free (cached_last_copy_of);
   free (copy_of);

diff --git a/gcc/tree-ssa-propagate.c b/gcc/tree-ssa-propagate.c
index 879e0db..5f2ecce 100644 (file)
--- a/gcc/tree-ssa-propagate.c
+++ b/gcc/tree-ssa-propagate.c
@@ -964,10 +964,13 @@ replace_phi_args_in (gimple phi, prop_value_t *prop_value)
    If FOLD_FN is non-NULL the function will be invoked on all statements
    before propagating values for pass specific simplification.
 
+   DO_DCE is true if trivially dead stmts can be removed.
+
    Return TRUE when something changed.  */
 
 bool
-substitute_and_fold (prop_value_t *prop_value, ssa_prop_fold_stmt_fn fold_fn)
+substitute_and_fold (prop_value_t *prop_value, ssa_prop_fold_stmt_fn fold_fn,
+                    bool do_dce)
 {
   basic_block bb;
   bool something_changed = false;
@@ -1012,8 +1015,12 @@ substitute_and_fold (prop_value_t *prop_value, ssa_prop_fold_stmt_fn fold_fn)
            continue;
 
          /* No point propagating into a stmt whose result is not used,
-            but instead we might be able to remove a trivially dead stmt.  */
-         if (gimple_get_lhs (stmt)
+            but instead we might be able to remove a trivially dead stmt.
+            Don't do this when called from VRP, since the SSA_NAME which
+            is going to be released could be still referenced in VRP
+            ranges.  */
+         if (do_dce
+             && gimple_get_lhs (stmt)
              && TREE_CODE (gimple_get_lhs (stmt)) == SSA_NAME
              && has_zero_uses (gimple_get_lhs (stmt))
              && !stmt_could_throw_p (stmt)

diff --git a/gcc/tree-ssa-propagate.h b/gcc/tree-ssa-propagate.h
index e8f4f03..029d28a 100644 (file)
--- a/gcc/tree-ssa-propagate.h
+++ b/gcc/tree-ssa-propagate.h
@@ -1,6 +1,6 @@
 /* Data structures and function declarations for the SSA value propagation
    engine.
-   Copyright (C) 2004, 2005, 2007, 2008 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2005, 2007, 2008, 2010 Free Software Foundation, Inc.
    Contributed by Diego Novillo <dnovillo@redhat.com>
 
 This file is part of GCC.
@@ -120,6 +120,6 @@ bool valid_gimple_call_p (tree);
 void move_ssa_defining_stmt_for_defs (gimple, gimple);
 bool update_call_from_tree (gimple_stmt_iterator *, tree);
 bool stmt_makes_single_store (gimple);
-bool substitute_and_fold (prop_value_t *, ssa_prop_fold_stmt_fn);
+bool substitute_and_fold (prop_value_t *, ssa_prop_fold_stmt_fn, bool);
 
 #endif /* _TREE_SSA_PROPAGATE_H  */

diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index f0e9ce6..cce2470 100644 (file)
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -7343,7 +7343,7 @@ vrp_finalize (void)
       single_val_range = NULL;
     }
 
-  substitute_and_fold (single_val_range, vrp_fold_stmt);
+  substitute_and_fold (single_val_range, vrp_fold_stmt, false);
 
   if (warn_array_bounds)
     check_all_array_refs ();