On 02/16/2017 12:34 PM, Richard Biener wrote:
> Yes, we should handle all of the "hidden initialized" cases at
>
> /* A PARM_DECL will not have an SSA_NAME_DEF_STMT. Parameters
> get their initial value from function entry. */
> if (SSA_NAME_VAR (t) && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL)
> continue;
>
> maybe add a predicate for those, like
>
> ssa_defined_default_def_p ()
>
> right next to ssa_undefined_value_p and use it from there as well.
Hi.
Done in second version of patch.
Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.
Firefox w/ -flto and -O3
works fine.
Ready to be installed?
Martin
>From d98ab8fef6d634b73eeca74d11161e3cb7b59776 Mon Sep 17 00:00:00 2001
From: marxin <mli...@suse.cz>
Date: Thu, 16 Feb 2017 17:07:51 +0100
Subject: [PATCH] Introduce ssa_defined_default_def_p function (PR
tree-optimization/79529).
gcc/ChangeLog:
2017-02-16 Martin Liska <mli...@suse.cz>
* tree-ssa-loop-unswitch.c (is_maybe_undefined): Use
ssa_defined_default_def_p to handle cases which are implicitly
defined.
* tree-ssa.c (ssa_defined_default_def_p): New function.
(ssa_undefined_value_p): Use ssa_defined_default_def_p to handle cases
which are implicitly defined.
* tree-ssa.h (ssa_defined_default_def_p): Declare.
---
gcc/tree-ssa-loop-unswitch.c | 4 +---
gcc/tree-ssa.c | 26 +++++++++++++++++++-------
gcc/tree-ssa.h | 2 ++
3 files changed, 22 insertions(+), 10 deletions(-)
diff --git a/gcc/tree-ssa-loop-unswitch.c b/gcc/tree-ssa-loop-unswitch.c
index afa04e9d110..1845148666d 100644
--- a/gcc/tree-ssa-loop-unswitch.c
+++ b/gcc/tree-ssa-loop-unswitch.c
@@ -134,9 +134,7 @@ is_maybe_undefined (const tree name, gimple *stmt, struct loop *loop)
if (ssa_undefined_value_p (t, true))
return true;
- /* A PARM_DECL will not have an SSA_NAME_DEF_STMT. Parameters
- get their initial value from function entry. */
- if (SSA_NAME_VAR (t) && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL)
+ if (ssa_defined_default_def_p (t))
continue;
gimple *def = SSA_NAME_DEF_STMT (t);
diff --git a/gcc/tree-ssa.c b/gcc/tree-ssa.c
index 28020b003f8..831fd61e15f 100644
--- a/gcc/tree-ssa.c
+++ b/gcc/tree-ssa.c
@@ -1251,27 +1251,39 @@ tree_ssa_strip_useless_type_conversions (tree exp)
return exp;
}
-
-/* Return true if T, an SSA_NAME, has an undefined value. PARTIAL is what
- should be returned if the value is only partially undefined. */
+/* Return true if T, as SSA_NAME, has an implicit default defined value. */
bool
-ssa_undefined_value_p (tree t, bool partial)
+ssa_defined_default_def_p (tree t)
{
- gimple *def_stmt;
tree var = SSA_NAME_VAR (t);
if (!var)
;
/* Parameters get their initial value from the function entry. */
else if (TREE_CODE (var) == PARM_DECL)
- return false;
+ return true;
/* When returning by reference the return address is actually a hidden
parameter. */
else if (TREE_CODE (var) == RESULT_DECL && DECL_BY_REFERENCE (var))
- return false;
+ return true;
/* Hard register variables get their initial value from the ether. */
else if (VAR_P (var) && DECL_HARD_REGISTER (var))
+ return true;
+
+ return false;
+}
+
+
+/* Return true if T, an SSA_NAME, has an undefined value. PARTIAL is what
+ should be returned if the value is only partially undefined. */
+
+bool
+ssa_undefined_value_p (tree t, bool partial)
+{
+ gimple *def_stmt;
+
+ if (ssa_defined_default_def_p (t))
return false;
/* The value is undefined iff its definition statement is empty. */
diff --git a/gcc/tree-ssa.h b/gcc/tree-ssa.h
index 6d16ba9f6a0..c99b5eaee82 100644
--- a/gcc/tree-ssa.h
+++ b/gcc/tree-ssa.h
@@ -50,6 +50,8 @@ extern void delete_tree_ssa (function *);
extern bool tree_ssa_useless_type_conversion (tree);
extern tree tree_ssa_strip_useless_type_conversions (tree);
+
+extern bool ssa_defined_default_def_p (tree t);
extern bool ssa_undefined_value_p (tree, bool = true);
extern bool gimple_uses_undefined_value_p (gimple *);
extern void execute_update_addresses_taken (void);
--
2.11.0
