diff options
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 72974d6..91f4054 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -92,7 +92,6 @@ static hashval_t size_htab_hash (const void *); static int size_htab_eq (const void *, const void *); static tree fold_convert_const (enum tree_code, tree, tree); static enum tree_code invert_tree_comparison (enum tree_code, bool); -static enum tree_code swap_tree_comparison (enum tree_code); static enum comparison_code comparison_to_compcode (enum tree_code); static enum tree_code compcode_to_comparison (enum comparison_code); static tree combine_comparisons (enum tree_code, enum tree_code, @@ -132,8 +131,6 @@ static tree fold_mathfn_compare (enum built_in_function, enum tree_code, static tree fold_inf_compare (enum tree_code, tree, tree, tree); static tree fold_div_compare (enum tree_code, tree, tree, tree); static bool reorder_operands_p (tree, tree); -static bool tree_swap_operands_p (tree, tree, bool); - static tree fold_negate_const (tree, tree); static tree fold_not_const (tree, tree); static tree fold_relational_const (enum tree_code, tree, tree, tree); @@ -2119,7 +2116,7 @@ invert_tree_comparison (enum tree_code code, bool honor_nans) /* Similar, but return the comparison that results if the operands are swapped. This is safe for floating-point. */ -static enum tree_code +enum tree_code swap_tree_comparison (enum tree_code code) { switch (code) @@ -5527,7 +5524,7 @@ reorder_operands_p (tree arg0, tree arg1) isn't. If REORDER is true, only recommend swapping if we can evaluate the operands in reverse order. */ -static bool +bool tree_swap_operands_p (tree arg0, tree arg1, bool reorder) { STRIP_SIGN_NOPS (arg0); @@ -5574,6 +5571,15 @@ tree_swap_operands_p (tree arg0, tree arg1, bool reorder) if (DECL_P (arg0)) return 1; + /* It is preferable to swap two SSA_NAME to ensure a canonical form + for commutative and comparison operators. Ensuring a canonical + form allows the optimizers to find additional redundancies without + having to explicitly check for both orderings. */ + if (TREE_CODE (arg0) == SSA_NAME + && TREE_CODE (arg1) == SSA_NAME + && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1)) + return 1; + return 0; } |