===================================================================
@@ -46,6 +46,7 @@ along with GCC; see the file COPYING3.
/* Forwarders. */
static gimple build_and_add_sum (tree, tree, tree, enum tree_code);
+static void remove_stmt_chain (tree);
/* This is a simple global reassociation pass. It is, in part, based
on the LLVM pass of the same name (They do some things more/less
@@ -53,8 +54,11 @@ static gimple build_and_add_sum (tree, t
It consists of five steps:
- 1. Breaking up subtract operations into addition + negate, where
+ 1. Breaking up expressions
+ 1.1. Breaking up subtract operations into addition + negate, where
it would promote the reassociation of adds.
+ 1.2. Breaking up to normalized form for bitwise-not operations
+ on bitwise-binary and for bitwise-not operation on compares.
2. Left linearization of the expression trees, so that (A+B)+(C+D)
becomes (((A+B)+C)+D), which is easier for us to rewrite later.
@@ -560,6 +564,265 @@ get_unary_op (tree name, enum tree_code
return NULL_TREE;
}
+/* Create a temporary register expression with type TYPE, tree code CODE, and
+ operands OP1 and OP2. If REF_DEF is a valid gimple statement, we use its
+ location information for new generated temporary.
+ Function returns left-hand-side of new generated temporary register. */
+
+static tree
+make_new_tmp_statement (tree type, enum tree_code code, tree op1, tree op2,
+ gimple ref_def)
+{
+ gimple sum;
+ tree tmpvar = create_tmp_reg (type, NULL);
+ add_referenced_var (tmpvar);
+ sum = build_and_add_sum (tmpvar, op1, op2, code);
+ if (ref_def)
+ gimple_set_location (sum, gimple_location (ref_def));
+ return gimple_get_lhs (sum);
+}
+
+/* Perform on tree LHS with optional definition statement EXPR
+ the logic-not operation. TYPE is of kind boolean. */
+
+static tree
+expand_not_bitwise_binary (tree type, tree lhs, gimple expr)
+{
+ enum tree_code code = ERROR_MARK;
+ tree op1 = NULL, op2 = NULL;
+ gimple s1 = NULL, s2 = NULL;
+
+ if (TREE_CODE (lhs) == INTEGER_CST)
+ return fold_build1 (BIT_NOT_EXPR, type, lhs);
+
+ if (expr && is_gimple_assign (expr))
+ code = gimple_assign_rhs_code (expr);
+
+ /* If statement lhs isn't a single-use statement,
+ we don't want to modify it. So we can do only default-case
+ operation for it. */
+ if (code != ERROR_MARK && !has_single_use (lhs))
+ code = ERROR_MARK;
+
+ if (TREE_CODE_CLASS (code) == tcc_comparison
+ || code == BIT_XOR_EXPR
+ || code == BIT_AND_EXPR
+ || code == BIT_IOR_EXPR)
+ {
+ op1 = gimple_assign_rhs1 (expr);
+ op2 = gimple_assign_rhs2 (expr);
+ }
+ /* ~(~X) -> X. */
+ else if (code == BIT_NOT_EXPR)
+ return gimple_assign_rhs1 (expr);
+ else
+ return make_new_tmp_statement (TREE_TYPE (lhs), BIT_NOT_EXPR, lhs,
+ NULL_TREE, expr);
+
+ /* ~(X cmp Y) -> X cmp' Y, with cmp'=inverted comparison code, if allowed.
+ Otherwise fall through to default case. */
+ if (TREE_CODE_CLASS (code) == tcc_comparison)
+ {
+ enum tree_code ncode;
+ tree op1type = TREE_TYPE (op1);
+
+ ncode = invert_tree_comparison (code,
+ HONOR_NANS (TYPE_MODE (op1type)));
+ if (ncode != ERROR_MARK)
+ return make_new_tmp_statement (type, ncode, op1, op2, expr);
+ }
+ /* Handle transformation for ~(A & B) -> ~A | ~B or ~(A | B) -> ~A & ~B. */
+ else if (code == BIT_AND_EXPR || code == BIT_IOR_EXPR)
+ {
+ /* See if left-hand operand is a gimple-assign, and has single-use. */
+ if (TREE_CODE (op1) != SSA_NAME
+ || !(s1 = SSA_NAME_DEF_STMT (op1))
+ || !is_gimple_assign (s1)
+ || !has_single_use (op1))
+ s1 = NULL;
+ /* See if right-hand operand is a gimple-assign, and has
+ single-use. */
+ if (TREE_CODE (op2) != SSA_NAME
+ || !(s2 = SSA_NAME_DEF_STMT (op2))
+ || !is_gimple_assign (s2)
+ || !has_single_use (op2))
+ s2 = NULL;
+
+ /* We have to do inversion in one step to avoid looping. */
+ op1 = expand_not_bitwise_binary (type, op1, s1);
+ op2 = expand_not_bitwise_binary (type, op2, s2);
+
+ code = (code == BIT_AND_EXPR ? BIT_IOR_EXPR : BIT_AND_EXPR);
+
+ if (TREE_CODE (op2) == INTEGER_CST)
+ {
+ if ((code == BIT_AND_EXPR && integer_zerop (op2))
+ || (code == BIT_IOR_EXPR && integer_all_onesp (op2)))
+ {
+ remove_stmt_chain (op1);
+ return op2;
+ }
+ else if ((code == BIT_AND_EXPR && integer_all_onesp (op2))
+ || (code == BIT_IOR_EXPR && integer_zerop (op2)))
+ return op1;
+ }
+ return make_new_tmp_statement (type, code, op1, op2, expr);
+ }
+ /* ~(A ^ B) -> ~A ^ B. Handle here special cases for B being
+ an integer constant, or being a logical-not. */
+ else if (code == BIT_XOR_EXPR)
+ {
+ /* See if left-hand operand is a gimple-assign, and has single-use. */
+ if (TREE_CODE (op1) != SSA_NAME
+ || !(s1 = SSA_NAME_DEF_STMT (op1))
+ || !is_gimple_assign (s1)
+ || !has_single_use (op1))
+ s1 = NULL;
+ /* See if right-hand operand is a gimple-assign, and has
+ single-use. */
+ if (TREE_CODE (op2) != SSA_NAME
+ || !(s2 = SSA_NAME_DEF_STMT (op2))
+ || !is_gimple_assign (s2)
+ || !has_single_use (op2))
+ s2 = NULL;
+
+ /* If right-hand operand isn't a bit-not expression and not
+ an integeral constant, then we apply bit-not on left-hand
+ operand. */
+ if (TREE_CODE (op2) != INTEGER_CST
+ && (!s2 || gimple_assign_rhs_code (s2) != BIT_NOT_EXPR))
+ op1 = expand_not_bitwise_binary (type, op1, s1);
+ else
+ op2 = expand_not_bitwise_binary (type, op2, s2);
+
+ if (TREE_CODE (op2) == INTEGER_CST && integer_zerop (op2))
+ return op1;
+ if (TREE_CODE (op2) == INTEGER_CST && integer_all_onesp (op2))
+ {
+ remove_stmt_chain (op2);
+ return make_new_tmp_statement (type, BIT_NOT_EXPR, op1, NULL, expr);
+ }
+ return make_new_tmp_statement (type, BIT_XOR_EXPR, op1, op2, expr);
+ }
+
+ gcc_assert (types_compatible_p (type, TREE_TYPE (lhs)));
+
+ /* Default case lhs -> ~lhs */
+ return make_new_tmp_statement (TREE_TYPE (lhs), BIT_NOT_EXPR, lhs,
+ NULL_TREE, expr);
+}
+
+/* Break up STMT if it is a combined statement made out of
+ bitwise operations. Handle expansion of ~(A op B). */
+
+static bool
+break_up_bitwise_combined_stmt (gimple stmt)
+{
+ tree op1, op2, old_op1, old_op2;
+ gimple op1_def, op2_def;
+ enum tree_code code = gimple_assign_rhs_code (stmt);
+ tree type = TREE_TYPE (gimple_assign_lhs (stmt));
+ gimple_stmt_iterator gsi;
+
+ op1 = gimple_assign_rhs1 (stmt);
+ old_op1 = op1;
+ old_op2 = op2 = NULL_TREE;
+
+ /* Check that CODE can be handled and that left-hand operand
+ is of kind SSA_NAME. */
+ if (code != BIT_NOT_EXPR
+ || TREE_CODE (op1) != SSA_NAME)
+ return false;
+
+ /* If left-hand operand isn't a gimple-assign, or isn't single-used,
+ the we can't do anything. */
+ op1_def = SSA_NAME_DEF_STMT (op1);
+ if (!op1_def
+ || !is_gimple_assign (op1_def)
+ || !has_single_use (op1))
+ return false;
+
+ /* Handle expansion for ~X. */
+ if (code == BIT_NOT_EXPR)
+ {
+ enum tree_code inner_code = gimple_assign_rhs_code (op1_def);
+
+ if (inner_code == BIT_NOT_EXPR)
+ {
+ op1 = gimple_assign_rhs1 (op1_def);
+ gsi = gsi_for_stmt (stmt);
+ gimple_assign_set_rhs_from_tree (&gsi, op1);
+ update_stmt (gsi_stmt (gsi));
+ remove_stmt_chain (old_op1);
+ return true;
+ }
+ else if (TREE_CODE_CLASS (inner_code) == tcc_comparison)
+ {
+ enum tree_code ncode;
+ tree op1type;
+
+ op1 = gimple_assign_rhs1 (op1_def);
+ op2 = gimple_assign_rhs2 (op1_def);
+ op1type = TREE_TYPE (op1);
+ ncode = invert_tree_comparison (inner_code,
+ HONOR_NANS (TYPE_MODE (op1type)));
+ if (ncode == ERROR_MARK)
+ return false;
+ gsi = gsi_for_stmt (stmt);
+ gimple_assign_set_rhs_with_ops (&gsi, ncode, op1, op2);
+ update_stmt (gsi_stmt (gsi));
+ remove_stmt_chain (old_op1);
+ return true;
+ }
+ if (inner_code != BIT_AND_EXPR && inner_code != BIT_IOR_EXPR
+ && inner_code != BIT_XOR_EXPR)
+ return false;
+
+ op1 = gimple_assign_rhs1 (op1_def);
+ op2 = gimple_assign_rhs2 (op1_def);
+
+ op1_def = op2_def = NULL;
+
+ if (TREE_CODE (op1) != SSA_NAME
+ || (op1_def = SSA_NAME_DEF_STMT (op1)) == NULL
+ || !is_gimple_assign (op1_def))
+ op1_def = NULL;
+
+ if (TREE_CODE (op2) != SSA_NAME
+ || (op2_def = SSA_NAME_DEF_STMT (op2)) == NULL
+ || !is_gimple_assign (op2_def))
+ op2_def = NULL;
+
+ /* Transform as best representation either from
+ ~(X ^ Y) to ~X ^ Y, or from ~(X ^ Y) to X ^ Y. */
+ if (inner_code == BIT_XOR_EXPR)
+ {
+ if (TREE_CODE (op2) != INTEGER_CST
+ && (!op2_def || !is_gimple_assign (op2_def)
+ || !has_single_use (op2)
+ || gimple_assign_rhs_code (op2_def) != BIT_NOT_EXPR))
+ op1 = expand_not_bitwise_binary (type, op1, op1_def);
+ else
+ op2 = expand_not_bitwise_binary (type, op2, op2_def);
+ }
+ /* Transform ~(X | Y) -> ~X & Y, or ~(X & Y) -> ~X | ~Y. */
+ else
+ {
+ op1 = expand_not_bitwise_binary (type, op1, op1_def);
+ op2 = expand_not_bitwise_binary (type, op2, op2_def);
+ inner_code = (inner_code == BIT_AND_EXPR ? BIT_IOR_EXPR
+ : BIT_AND_EXPR);
+ }
+ gsi = gsi_for_stmt (stmt);
+ gimple_assign_set_rhs_with_ops (&gsi, inner_code, op1, op2);
+ update_stmt (gsi_stmt (gsi));
+ remove_stmt_chain (old_op1);
+ return true;
+ }
+
+ return false;
+}
+
/* If CURR and LAST are a pair of ops that OPCODE allows us to
eliminate through equivalences, do so, remove them from OPS, and
return true. Otherwise, return false. */
@@ -2076,6 +2339,49 @@ remove_visited_stmt_chain (tree var)
}
}
+/* Remove def stmt of VAR if VAR has zero uses and recurse
+ on rhs1, rhs2, and rhs3 operand if so. */
+
+static void
+remove_stmt_chain (tree var)
+{
+ gimple stmt;
+ gimple_stmt_iterator gsi;
+ tree var2, var3;
+
+ while (1)
+ {
+ if (TREE_CODE (var) != SSA_NAME || !has_zero_uses (var))
+ return;
+ stmt = SSA_NAME_DEF_STMT (var);
+ if (!stmt || !is_gimple_assign (stmt))
+ return;
+ var = gimple_assign_rhs1 (stmt);
+ var2 = var3 = NULL_TREE;
+
+ switch (get_gimple_rhs_class (gimple_assign_rhs_code (stmt)))
+ {
+ case GIMPLE_TERNARY_RHS:
+ var3 = gimple_assign_rhs3 (stmt);
+ /* Fall through. */
+ case GIMPLE_BINARY_RHS:
+ var2 = gimple_assign_rhs2 (stmt);
+ break;
+ default:
+ break;
+ }
+ gsi = gsi_for_stmt (stmt);
+ gsi_remove (&gsi, true);
+ release_defs (stmt);
+ /* Recurse on optional second and third operand,
+ if those arguments are of kind SSA_NAME. */
+ if (var2 && TREE_CODE (var2) == SSA_NAME)
+ remove_stmt_chain (var2);
+ if (var3 && TREE_CODE (var3) == SSA_NAME)
+ remove_stmt_chain (var3);
+ }
+}
+
/* This function checks three consequtive operands in
passed operands vector OPS starting from OPINDEX and
swaps two operands if it is profitable for binary operation
@@ -2777,6 +3083,14 @@ can_reassociate_p (tree op)
we want to break up k = t - q, but we won't until we've transformed q
= b - r, which won't be broken up until we transform b = c - d.
+ Break up logical-not expressions of bitwise boolean-typed and/or/xor
+ operations for being able to optimize wihin combined conditions.
+ ~(A | B) -> ~A | ~B
+ ~(A & B) -> ~A & ~B
+ ~(A ^ B) -> A ^ ~B (special case if B is a constant)
+ If A or B are comparisons or are bitwise-not statement, then sink bit-not
+ into expression, if it is a single-use statement.
+
En passant, clear the GIMPLE visited flag on every statement. */
static void
@@ -2785,21 +3099,34 @@ break_up_expr_bb (basic_block bb)
gimple_stmt_iterator gsi;
basic_block son;
- for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); )
{
gimple stmt = gsi_stmt (gsi);
gimple_set_visited (stmt, false);
- if (!is_gimple_assign (stmt)
- || !can_reassociate_p (gimple_assign_lhs (stmt)))
+ if (!is_gimple_assign (stmt))
+ {
+ gsi_next (&gsi);
+ continue;
+ }
+ if (break_up_bitwise_combined_stmt (stmt))
continue;
+ if (!can_reassociate_p (gimple_assign_lhs (stmt)))
+ {
+ gsi_next (&gsi);
+ continue;
+ }
+
/* Look for simple gimple subtract operations. */
if (gimple_assign_rhs_code (stmt) == MINUS_EXPR)
{
if (!can_reassociate_p (gimple_assign_rhs1 (stmt))
|| !can_reassociate_p (gimple_assign_rhs2 (stmt)))
- continue;
+ {
+ gsi_next (&gsi);
+ continue;
+ }
/* Check for a subtract used only in an addition. If this
is the case, transform it into add of a negate for better
@@ -2811,6 +3138,8 @@ break_up_expr_bb (basic_block bb)
else if (gimple_assign_rhs_code (stmt) == NEGATE_EXPR
&& can_reassociate_p (gimple_assign_rhs1 (stmt)))
VEC_safe_push (tree, heap, plus_negates, gimple_assign_lhs (stmt));
+
+ gsi_next (&gsi);
}
for (son = first_dom_son (CDI_DOMINATORS, bb);
son;
===================================================================
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized -ffast-math" } */
+
+int foo (int a, int b, int c, int d)
+{
+ int r1 = ~(a | b | c);
+ int r2 = (a | d | c) | ~b;
+ return (~r1 | r2);
+}
+
+/* { dg-final { scan-tree-dump-times "return -1" 1 "optimized"} } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
+
===================================================================
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized -ffast-math" } */
+
+int foo (int a, int b, int c, int d)
+{
+ int r1 = a & ~c & b;
+ int r2 = ~a | b | ~d;
+ return (~r1 | r2);
+}
+
+/* { dg-final { scan-tree-dump-times "return -1" 1 "optimized"} } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
+
===================================================================
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized -ffast-math" } */
+
+int foo (int a, int b, int c, int d)
+{
+ int r1 = a & ~c & b;
+ int r2 = ~a | b | ~d;
+ return (r1 & ~r2);
+}
+
+/* { dg-final { scan-tree-dump-times "return 0" 1 "optimized"} } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
+