From f8ecf734ddb7fb486855929b16f84af55b346711 Mon Sep 17 00:00:00 2001
From: Richard Guenther <rguenther@suse.de>
Date: Wed, 20 Jul 2011 15:13:58 +0000
Subject: [PATCH] tree-ssa-forwprop.c (remove_prop_source_from_use): Robustify
against already removed statements.
2011-07-20 Richard Guenther <rguenther@suse.de>
* tree-ssa-forwprop.c (remove_prop_source_from_use): Robustify
against already removed statements.
(forward_propagate_into_comparison): Remove dead defining stmts.
(forward_propagate_into_gimple_cond): Likewise.
(forward_propagate_into_cond): Simplify.
(ssa_forward_propagate_and_combine): Handle changed cfg from
forward_propagate_into_comparison.
* tree-ssa-phiopt.c (conditional_replacement): Use proper
locations for newly built statements.
From-SVN: r176517
---
gcc/ChangeLog | 12 ++++++++
gcc/tree-ssa-forwprop.c | 65 ++++++++++++++++++++++-------------------
gcc/tree-ssa-phiopt.c | 8 +++--
3 files changed, 52 insertions(+), 33 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6f09fc5bfe22..2df70f0aba57 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2011-07-20 Richard Guenther <rguenther@suse.de>
+
+ * tree-ssa-forwprop.c (remove_prop_source_from_use): Robustify
+ against already removed statements.
+ (forward_propagate_into_comparison): Remove dead defining stmts.
+ (forward_propagate_into_gimple_cond): Likewise.
+ (forward_propagate_into_cond): Simplify.
+ (ssa_forward_propagate_and_combine): Handle changed cfg from
+ forward_propagate_into_comparison.
+ * tree-ssa-phiopt.c (conditional_replacement): Use proper
+ locations for newly built statements.
+
2011-07-20 Georg-Johann Lay <avr@gjlay.de>
* config/avr/avr.c (avr_rtx_costs): Set cost of SYMBOL_REF to 0.
diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
index 577609b20149..5d04fc32ce4f 100644
--- a/gcc/tree-ssa-forwprop.c
+++ b/gcc/tree-ssa-forwprop.c
@@ -313,8 +313,10 @@ remove_prop_source_from_use (tree name)
return cfg_changed;
stmt = SSA_NAME_DEF_STMT (name);
- gsi = gsi_for_stmt (stmt);
bb = gimple_bb (stmt);
+ if (!bb)
+ return cfg_changed;
+ gsi = gsi_for_stmt (stmt);
release_defs (stmt);
gsi_remove (&gsi, true);
cfg_changed |= gimple_purge_dead_eh_edges (bb);
@@ -437,29 +439,36 @@ forward_propagate_into_comparison_1 (location_t loc,
/* Propagate from the ssa name definition statements of the assignment
from a comparison at *GSI into the conditional if that simplifies it.
- Returns true if the stmt was modified, false if not. */
+ Returns 1 if the stmt was modified and 2 if the CFG needs cleanup,
+ otherwise returns 0. */
-static bool
+static int
forward_propagate_into_comparison (gimple_stmt_iterator *gsi)
{
gimple stmt = gsi_stmt (*gsi);
tree tmp;
+ bool cfg_changed = false;
+ tree rhs1 = gimple_assign_rhs1 (stmt);
+ tree rhs2 = gimple_assign_rhs2 (stmt);
/* Combine the comparison with defining statements. */
tmp = forward_propagate_into_comparison_1 (gimple_location (stmt),
gimple_assign_rhs_code (stmt),
TREE_TYPE
(gimple_assign_lhs (stmt)),
- gimple_assign_rhs1 (stmt),
- gimple_assign_rhs2 (stmt));
+ rhs1, rhs2);
if (tmp)
{
gimple_assign_set_rhs_from_tree (gsi, tmp);
update_stmt (stmt);
- return true;
+ if (TREE_CODE (rhs1) == SSA_NAME)
+ cfg_changed |= remove_prop_source_from_use (rhs1);
+ if (TREE_CODE (rhs2) == SSA_NAME)
+ cfg_changed |= remove_prop_source_from_use (rhs2);
+ return cfg_changed ? 2 : 1;
}
- return false;
+ return 0;
}
/* Propagate from the ssa name definition statements of COND_EXPR
@@ -472,10 +481,12 @@ forward_propagate_into_comparison (gimple_stmt_iterator *gsi)
static int
forward_propagate_into_gimple_cond (gimple stmt)
{
- int did_something = 0;
location_t loc = gimple_location (stmt);
tree tmp;
enum tree_code code = gimple_cond_code (stmt);
+ bool cfg_changed = false;
+ tree rhs1 = gimple_cond_lhs (stmt);
+ tree rhs2 = gimple_cond_rhs (stmt);
/* We can do tree combining on SSA_NAME and comparison expressions. */
if (TREE_CODE_CLASS (gimple_cond_code (stmt)) != tcc_comparison)
@@ -483,18 +494,13 @@ forward_propagate_into_gimple_cond (gimple stmt)
tmp = forward_propagate_into_comparison_1 (loc, code,
boolean_type_node,
- gimple_cond_lhs (stmt),
- gimple_cond_rhs (stmt));
+ rhs1, rhs2);
if (tmp)
{
if (dump_file && tmp)
{
- tree cond = build2 (gimple_cond_code (stmt),
- boolean_type_node,
- gimple_cond_lhs (stmt),
- gimple_cond_rhs (stmt));
fprintf (dump_file, " Replaced '");
- print_generic_expr (dump_file, cond, 0);
+ print_gimple_expr (dump_file, stmt, 0, 0);
fprintf (dump_file, "' with '");
print_generic_expr (dump_file, tmp, 0);
fprintf (dump_file, "'\n");
@@ -503,14 +509,14 @@ forward_propagate_into_gimple_cond (gimple stmt)
gimple_cond_set_condition_from_tree (stmt, unshare_expr (tmp));
update_stmt (stmt);
- /* Remove defining statements. */
- if (is_gimple_min_invariant (tmp))
- did_something = 2;
- else if (did_something == 0)
- did_something = 1;
+ if (TREE_CODE (rhs1) == SSA_NAME)
+ cfg_changed |= remove_prop_source_from_use (rhs1);
+ if (TREE_CODE (rhs2) == SSA_NAME)
+ cfg_changed |= remove_prop_source_from_use (rhs2);
+ return (cfg_changed || is_gimple_min_invariant (tmp)) ? 2 : 1;
}
- return did_something;
+ return 0;
}
@@ -526,7 +532,6 @@ forward_propagate_into_cond (gimple_stmt_iterator *gsi_p)
{
gimple stmt = gsi_stmt (*gsi_p);
location_t loc = gimple_location (stmt);
- int did_something = 0;
tree tmp = NULL_TREE;
tree cond = gimple_assign_rhs1 (stmt);
@@ -541,7 +546,7 @@ forward_propagate_into_cond (gimple_stmt_iterator *gsi_p)
tree name = cond, rhs0;
gimple def_stmt = get_prop_source_stmt (name, true, NULL);
if (!def_stmt || !can_propagate_from (def_stmt))
- return did_something;
+ return 0;
rhs0 = gimple_assign_rhs1 (def_stmt);
tmp = combine_cond_expr_cond (loc, NE_EXPR, boolean_type_node, rhs0,
@@ -564,14 +569,10 @@ forward_propagate_into_cond (gimple_stmt_iterator *gsi_p)
stmt = gsi_stmt (*gsi_p);
update_stmt (stmt);
- /* Remove defining statements. */
- if (is_gimple_min_invariant (tmp))
- did_something = 2;
- else if (did_something == 0)
- did_something = 1;
+ return is_gimple_min_invariant (tmp) ? 2 : 1;
}
- return did_something;
+ return 0;
}
/* We've just substituted an ADDR_EXPR into stmt. Update all the
@@ -2441,11 +2442,15 @@ ssa_forward_propagate_and_combine (void)
else if (TREE_CODE_CLASS (code) == tcc_comparison)
{
bool no_warning = gimple_no_warning_p (stmt);
+ int did_something;
fold_defer_overflow_warnings ();
- changed = forward_propagate_into_comparison (&gsi);
+ did_something = forward_propagate_into_comparison (&gsi);
+ if (did_something == 2)
+ cfg_changed = true;
fold_undefer_overflow_warnings
(!no_warning && changed,
stmt, WARN_STRICT_OVERFLOW_CONDITIONAL);
+ changed = did_something != 0;
}
else if (code == BIT_AND_EXPR
|| code == BIT_IOR_EXPR
diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c
index 79e8e015fda2..ed8f9795e788 100644
--- a/gcc/tree-ssa-phiopt.c
+++ b/gcc/tree-ssa-phiopt.c
@@ -544,8 +544,9 @@ conditional_replacement (basic_block cond_bb, basic_block middle_bb,
/* To handle special cases like floating point comparison, it is easier and
less error-prone to build a tree and gimplify it on the fly though it is
less efficient. */
- cond = fold_build2 (gimple_cond_code (stmt), boolean_type_node,
- gimple_cond_lhs (stmt), gimple_cond_rhs (stmt));
+ cond = fold_build2_loc (gimple_location (stmt),
+ gimple_cond_code (stmt), boolean_type_node,
+ gimple_cond_lhs (stmt), gimple_cond_rhs (stmt));
/* We need to know which is the true edge and which is the false
edge so that we know when to invert the condition below. */
@@ -554,7 +555,8 @@ conditional_replacement (basic_block cond_bb, basic_block middle_bb,
|| (e0 == false_edge && integer_onep (arg0))
|| (e1 == true_edge && integer_zerop (arg1))
|| (e1 == false_edge && integer_onep (arg1)))
- cond = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (cond), cond);
+ cond = fold_build1_loc (gimple_location (stmt),
+ TRUTH_NOT_EXPR, TREE_TYPE (cond), cond);
/* Insert our new statements at the end of conditional block before the
COND_STMT. */
--
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