diff options
Diffstat (limited to 'gcc/tree-ssa-operands.c')
| -rw-r--r-- | gcc/tree-ssa-operands.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/gcc/tree-ssa-operands.c b/gcc/tree-ssa-operands.c index 02380b66361..f1edfa18e18 100644 --- a/gcc/tree-ssa-operands.c +++ b/gcc/tree-ssa-operands.c @@ -1235,6 +1235,37 @@ get_expr_operands (tree stmt, tree *expr_p, int flags, voperands_t prev_vops) || code == TRUTH_XOR_EXPR || code == COMPOUND_EXPR) { + tree op0 = TREE_OPERAND (expr, 0); + tree op1 = TREE_OPERAND (expr, 1); + + /* If it would be profitable to swap the operands, then do so to + canonicalize the statement, enabling better optimization. + + By placing canonicalization of such expressions here we + transparently keep statements in canonical form, even + when the statement is modified. */ + if (tree_swap_operands_p (op0, op1, false)) + { + /* For relationals we need to swap the operands and change + the code. */ + if (code == LT_EXPR + || code == GT_EXPR + || code == LE_EXPR + || code == GE_EXPR) + { + TREE_SET_CODE (expr, swap_tree_comparison (code)); + TREE_OPERAND (expr, 0) = op1; + TREE_OPERAND (expr, 1) = op0; + } + + /* For a commutative operator we can just swap the operands. */ + if (commutative_tree_code (code)) + { + TREE_OPERAND (expr, 0) = op1; + TREE_OPERAND (expr, 1) = op0; + } + } + get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags, prev_vops); get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags, prev_vops); return; |