diff options
| -rw-r--r-- | gcc/ChangeLog | 12 | ||||
| -rw-r--r-- | gcc/tree-flow.h | 3 | ||||
| -rw-r--r-- | gcc/tree-ssa-alias.c | 46 | ||||
| -rw-r--r-- | gcc/tree-ssa-alias.h | 2 | ||||
| -rw-r--r-- | gcc/tree-ssa-dce.c | 2 | ||||
| -rw-r--r-- | gcc/tree-ssa-dse.c | 2 | ||||
| -rw-r--r-- | gcc/tree-ssa-sink.c | 72 |
7 files changed, 62 insertions, 77 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9a10611..88b54ac 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,15 @@ +2012-04-27 Richard Guenther <rguenther@suse.de> + + * tree-flow.h (is_hidden_global_store): Remove. + * tree-ssa-sink.c (is_hidden_global_store): Likewise. + * tree-ssa-alias.h (ref_may_alias_global_p): Declare. + (stmt_may_clobber_global_p): Likewise. + * tree-ssa-alias.c (ref_may_alias_global_p): New function. + (stmt_may_clobber_global_p): Likewise. + * tree-ssa-dce.c (mark_stmt_if_obviously_necessary): Call + stmt_may_clobber_global_p. + * tree-ssa-dse.c (dse_possible_dead_store_p): Likewise. + 2012-04-27 Steven Bosscher <steven@gcc.gnu.org> * cfg.c (disconnect_src): Do df_mark_solutions_dirty in the right diff --git a/gcc/tree-flow.h b/gcc/tree-flow.h index 2a17ff1..794047b 100644 --- a/gcc/tree-flow.h +++ b/gcc/tree-flow.h @@ -795,9 +795,6 @@ extern void maybe_remove_unreachable_handlers (void); /* In tree-ssa-pre.c */ void debug_value_expressions (unsigned int); -/* In tree-ssa-sink.c */ -bool is_hidden_global_store (gimple); - /* In tree-loop-linear.c */ extern void linear_transform_loops (void); extern unsigned perfect_loop_nest_depth (struct loop *); diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c index 4a859eb..ec1bbbe 100644 --- a/gcc/tree-ssa-alias.c +++ b/gcc/tree-ssa-alias.c @@ -328,6 +328,52 @@ ptr_deref_may_alias_ref_p_1 (tree ptr, ao_ref *ref) return true; } +/* Return true whether REF may refer to global memory. */ + +bool +ref_may_alias_global_p (tree ref) +{ + tree base = get_base_address (ref); + if (DECL_P (base)) + return is_global_var (base); + else if (TREE_CODE (base) == MEM_REF + || TREE_CODE (base) == TARGET_MEM_REF) + return ptr_deref_may_alias_global_p (TREE_OPERAND (base, 0)); + return true; +} + +/* Return true whether STMT may clobber global memory. */ + +bool +stmt_may_clobber_global_p (gimple stmt) +{ + tree lhs; + + if (!gimple_vdef (stmt)) + return false; + + /* ??? We can ask the oracle whether an artificial pointer + dereference with a pointer with points-to information covering + all global memory (what about non-address taken memory?) maybe + clobbered by this call. As there is at the moment no convenient + way of doing that without generating garbage do some manual + checking instead. + ??? We could make a NULL ao_ref argument to the various + predicates special, meaning any global memory. */ + + switch (gimple_code (stmt)) + { + case GIMPLE_ASSIGN: + lhs = gimple_assign_lhs (stmt); + return (TREE_CODE (lhs) != SSA_NAME + && ref_may_alias_global_p (lhs)); + case GIMPLE_CALL: + return true; + default: + return true; + } +} + /* Dump alias information on FILE. */ diff --git a/gcc/tree-ssa-alias.h b/gcc/tree-ssa-alias.h index 59f0ebc..88f6d86 100644 --- a/gcc/tree-ssa-alias.h +++ b/gcc/tree-ssa-alias.h @@ -99,11 +99,13 @@ extern tree ao_ref_base (ao_ref *); extern alias_set_type ao_ref_alias_set (ao_ref *); extern bool ptr_deref_may_alias_global_p (tree); extern bool ptr_derefs_may_alias_p (tree, tree); +extern bool ref_may_alias_global_p (tree); extern bool refs_may_alias_p (tree, tree); extern bool refs_may_alias_p_1 (ao_ref *, ao_ref *, bool); extern bool refs_anti_dependent_p (tree, tree); extern bool refs_output_dependent_p (tree, tree); extern bool ref_maybe_used_by_stmt_p (gimple, tree); +extern bool stmt_may_clobber_global_p (gimple); extern bool stmt_may_clobber_ref_p (gimple, tree); extern bool stmt_may_clobber_ref_p_1 (gimple, ao_ref *); extern bool call_may_clobber_ref_p (gimple, tree); diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c index ace9ef9..d954f3b 100644 --- a/gcc/tree-ssa-dce.c +++ b/gcc/tree-ssa-dce.c @@ -370,7 +370,7 @@ mark_stmt_if_obviously_necessary (gimple stmt, bool aggressive) return; } - if (is_hidden_global_store (stmt)) + if (stmt_may_clobber_global_p (stmt)) { mark_stmt_necessary (stmt, true); return; diff --git a/gcc/tree-ssa-dse.c b/gcc/tree-ssa-dse.c index 1fdb26c..a859942 100644 --- a/gcc/tree-ssa-dse.c +++ b/gcc/tree-ssa-dse.c @@ -169,7 +169,7 @@ dse_possible_dead_store_p (gimple stmt, gimple *use_stmt) just pretend the stmt makes itself dead. Otherwise fail. */ if (!temp) { - if (is_hidden_global_store (stmt)) + if (stmt_may_clobber_global_p (stmt)) return false; temp = stmt; diff --git a/gcc/tree-ssa-sink.c b/gcc/tree-ssa-sink.c index d42b46a..951e427 100644 --- a/gcc/tree-ssa-sink.c +++ b/gcc/tree-ssa-sink.c @@ -132,78 +132,6 @@ all_immediate_uses_same_place (gimple stmt) return true; } -/* Some global stores don't necessarily have VDEF's of global variables, - but we still must avoid moving them around. */ - -bool -is_hidden_global_store (gimple stmt) -{ - /* Check virtual definitions. If we get here, the only virtual - definitions we should see are those generated by assignment or call - statements. */ - if (gimple_vdef (stmt)) - { - tree lhs; - - gcc_assert (is_gimple_assign (stmt) || is_gimple_call (stmt)); - - /* Note that we must not check the individual virtual operands - here. In particular, if this is an aliased store, we could - end up with something like the following (SSA notation - redacted for brevity): - - foo (int *p, int i) - { - int x; - p_1 = (i_2 > 3) ? &x : p; - - # x_4 = VDEF <x_3> - *p_1 = 5; - - return 2; - } - - Notice that the store to '*p_1' should be preserved, if we - were to check the virtual definitions in that store, we would - not mark it needed. This is because 'x' is not a global - variable. - - Therefore, we check the base address of the LHS. If the - address is a pointer, we check if its name tag or symbol tag is - a global variable. Otherwise, we check if the base variable - is a global. */ - lhs = gimple_get_lhs (stmt); - - if (REFERENCE_CLASS_P (lhs)) - lhs = get_base_address (lhs); - - if (lhs == NULL_TREE) - { - /* If LHS is NULL, it means that we couldn't get the base - address of the reference. In which case, we should not - move this store. */ - return true; - } - else if (DECL_P (lhs)) - { - /* If the store is to a global symbol, we need to keep it. */ - if (is_global_var (lhs)) - return true; - - } - else if (INDIRECT_REF_P (lhs) - || TREE_CODE (lhs) == MEM_REF - || TREE_CODE (lhs) == TARGET_MEM_REF) - return ptr_deref_may_alias_global_p (TREE_OPERAND (lhs, 0)); - else if (CONSTANT_CLASS_P (lhs)) - return true; - else - gcc_unreachable (); - } - - return false; -} - /* Find the nearest common dominator of all of the immediate uses in IMM. */ static basic_block |