/* Forward propagation of expressions for single use variables.
- Copyright (C) 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2004, 2005, 2007, 2008, 2009, 2010, 2011
+ Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
+the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to
-the Free Software Foundation, 51 Franklin Street, Fifth Floor,
-Boston, MA 02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
-#include "ggc.h"
#include "tree.h"
-#include "rtl.h"
#include "tm_p.h"
#include "basic-block.h"
#include "timevar.h"
-#include "diagnostic.h"
+#include "tree-pretty-print.h"
#include "tree-flow.h"
#include "tree-pass.h"
#include "tree-dump.h"
#include "langhooks.h"
+#include "flags.h"
+#include "gimple.h"
+#include "expr.h"
/* This pass propagates the RHS of assignment statements into use
sites of the LHS of the assignment. It's basically a specialized
form of tree combination. It is hoped all of this can disappear
when we have a generalized tree combiner.
- Note carefully that after propagation the resulting statement
- must still be a proper gimple statement. Right now we simply
- only perform propagations we know will result in valid gimple
- code. One day we'll want to generalize this code.
-
One class of common cases we handle is forward propagating a single use
- variable into a COND_EXPR.
+ variable into a COND_EXPR.
bb0:
x = a COND b;
bb0:
if (a COND b) goto ... else goto ...
-
+
Similarly for the tests (x == 0), (x != 0), (x == 1) and (x != 1).
Or (assuming c1 and c2 are constants):
bb0:
- x = a + c1;
+ x = a + c1;
if (x EQ/NEQ c2) goto ... else goto ...
Will be transformed into:
if (a EQ/NEQ (c2 - c1)) goto ... else goto ...
Similarly for x = a - c1.
-
+
Or
bb0:
res = x->y->z;
Or
+ ptr = (type1*)&type2var;
+ res = *ptr
+
+ Will get turned into (if type1 and type2 are the same size
+ and neither have volatile on them):
+ res = VIEW_CONVERT_EXPR<type1>(type2var)
+
+ Or
ptr = &x[0];
ptr2 = ptr + <constant>;
ptr2 = &x[index];
+ Or
+ ssa = (int) decl
+ res = ssa & 1
+
+ Provided that decl has known alignment >= 2, will get turned into
+
+ res = 0
+
We also propagate casts into SWITCH_EXPR and COND_EXPR conditions to
allow us to remove the cast and {NOT_EXPR,NEG_EXPR} into a subsequent
{NOT_EXPR,NEG_EXPR}.
/* Set to true if we delete EH edges during the optimization. */
static bool cfg_changed;
+static tree rhs_to_tree (tree type, gimple stmt);
-/* Given an SSA_NAME VAR, return true if and only if VAR is defined by
- a comparison. */
+/* Get the next statement we can propagate NAME's value into skipping
+ trivial copies. Returns the statement that is suitable as a
+ propagation destination or NULL_TREE if there is no such one.
+ This only returns destinations in a single-use chain. FINAL_NAME_P
+ if non-NULL is written to the ssa name that represents the use. */
-static bool
-ssa_name_defined_by_comparison_p (tree var)
+static gimple
+get_prop_dest_stmt (tree name, tree *final_name_p)
{
- tree def = SSA_NAME_DEF_STMT (var);
+ use_operand_p use;
+ gimple use_stmt;
- if (TREE_CODE (def) == GIMPLE_MODIFY_STMT)
- {
- tree rhs = GIMPLE_STMT_OPERAND (def, 1);
- return COMPARISON_CLASS_P (rhs);
- }
+ do {
+ /* If name has multiple uses, bail out. */
+ if (!single_imm_use (name, &use, &use_stmt))
+ return NULL;
+
+ /* If this is not a trivial copy, we found it. */
+ if (!gimple_assign_ssa_name_copy_p (use_stmt)
+ || gimple_assign_rhs1 (use_stmt) != name)
+ break;
- return 0;
+ /* Continue searching uses of the copy destination. */
+ name = gimple_assign_lhs (use_stmt);
+ } while (1);
+
+ if (final_name_p)
+ *final_name_p = name;
+
+ return use_stmt;
}
-/* Forward propagate a single-use variable into COND once. Return a
- new condition if successful. Return NULL_TREE otherwise. */
+/* Get the statement we can propagate from into NAME skipping
+ trivial copies. Returns the statement which defines the
+ propagation source or NULL_TREE if there is no such one.
+ If SINGLE_USE_ONLY is set considers only sources which have
+ a single use chain up to NAME. If SINGLE_USE_P is non-null,
+ it is set to whether the chain to NAME is a single use chain
+ or not. SINGLE_USE_P is not written to if SINGLE_USE_ONLY is set. */
-static tree
-forward_propagate_into_cond_1 (tree cond, tree *test_var_p)
+static gimple
+get_prop_source_stmt (tree name, bool single_use_only, bool *single_use_p)
{
- tree new_cond = NULL_TREE;
- enum tree_code cond_code = TREE_CODE (cond);
- tree test_var = NULL_TREE;
- tree def;
- tree def_rhs;
-
- /* If the condition is not a lone variable or an equality test of an
- SSA_NAME against an integral constant, then we do not have an
- optimizable case.
-
- Note these conditions also ensure the COND_EXPR has no
- virtual operands or other side effects. */
- if (cond_code != SSA_NAME
- && !((cond_code == EQ_EXPR || cond_code == NE_EXPR)
- && TREE_CODE (TREE_OPERAND (cond, 0)) == SSA_NAME
- && CONSTANT_CLASS_P (TREE_OPERAND (cond, 1))
- && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (cond, 1)))))
- return NULL_TREE;
+ bool single_use = true;
+
+ do {
+ gimple def_stmt = SSA_NAME_DEF_STMT (name);
+
+ if (!has_single_use (name))
+ {
+ single_use = false;
+ if (single_use_only)
+ return NULL;
+ }
+
+ /* If name is defined by a PHI node or is the default def, bail out. */
+ if (!is_gimple_assign (def_stmt))
+ return NULL;
+
+ /* If def_stmt is not a simple copy, we possibly found it. */
+ if (!gimple_assign_ssa_name_copy_p (def_stmt))
+ {
+ tree rhs;
+
+ if (!single_use_only && single_use_p)
+ *single_use_p = single_use;
+
+ /* We can look through pointer conversions in the search
+ for a useful stmt for the comparison folding. */
+ rhs = gimple_assign_rhs1 (def_stmt);
+ if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt))
+ && TREE_CODE (rhs) == SSA_NAME
+ && POINTER_TYPE_P (TREE_TYPE (gimple_assign_lhs (def_stmt)))
+ && POINTER_TYPE_P (TREE_TYPE (rhs)))
+ name = rhs;
+ else
+ return def_stmt;
+ }
+ else
+ {
+ /* Continue searching the def of the copy source name. */
+ name = gimple_assign_rhs1 (def_stmt);
+ }
+ } while (1);
+}
- /* Extract the single variable used in the test into TEST_VAR. */
- if (cond_code == SSA_NAME)
- test_var = cond;
- else
- test_var = TREE_OPERAND (cond, 0);
+/* Checks if the destination ssa name in DEF_STMT can be used as
+ propagation source. Returns true if so, otherwise false. */
- /* Now get the defining statement for TEST_VAR. Skip this case if
- it's not defined by some GIMPLE_MODIFY_STMT. */
- def = SSA_NAME_DEF_STMT (test_var);
- if (TREE_CODE (def) != GIMPLE_MODIFY_STMT)
- return NULL_TREE;
+static bool
+can_propagate_from (gimple def_stmt)
+{
+ use_operand_p use_p;
+ ssa_op_iter iter;
+
+ gcc_assert (is_gimple_assign (def_stmt));
- def_rhs = GIMPLE_STMT_OPERAND (def, 1);
+ /* If the rhs has side-effects we cannot propagate from it. */
+ if (gimple_has_volatile_ops (def_stmt))
+ return false;
- /* If TEST_VAR is set by adding or subtracting a constant
- from an SSA_NAME, then it is interesting to us as we
- can adjust the constant in the conditional and thus
- eliminate the arithmetic operation. */
- if (TREE_CODE (def_rhs) == PLUS_EXPR
- || TREE_CODE (def_rhs) == MINUS_EXPR)
+ /* If the rhs is a load we cannot propagate from it. */
+ if (TREE_CODE_CLASS (gimple_assign_rhs_code (def_stmt)) == tcc_reference
+ || TREE_CODE_CLASS (gimple_assign_rhs_code (def_stmt)) == tcc_declaration)
+ return false;
+
+ /* Constants can be always propagated. */
+ if (gimple_assign_single_p (def_stmt)
+ && is_gimple_min_invariant (gimple_assign_rhs1 (def_stmt)))
+ return true;
+
+ /* We cannot propagate ssa names that occur in abnormal phi nodes. */
+ FOR_EACH_SSA_USE_OPERAND (use_p, def_stmt, iter, SSA_OP_USE)
+ if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (USE_FROM_PTR (use_p)))
+ return false;
+
+ /* If the definition is a conversion of a pointer to a function type,
+ then we can not apply optimizations as some targets require
+ function pointers to be canonicalized and in this case this
+ optimization could eliminate a necessary canonicalization. */
+ if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt)))
{
- tree op0 = TREE_OPERAND (def_rhs, 0);
- tree op1 = TREE_OPERAND (def_rhs, 1);
-
- /* The first operand must be an SSA_NAME and the second
- operand must be a constant. */
- if (TREE_CODE (op0) != SSA_NAME
- || !CONSTANT_CLASS_P (op1)
- || !INTEGRAL_TYPE_P (TREE_TYPE (op1)))
- return NULL_TREE;
-
- /* Don't propagate if the first operand occurs in
- an abnormal PHI. */
- if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op0))
- return NULL_TREE;
-
- if (has_single_use (test_var))
- {
- enum tree_code new_code;
- tree t;
-
- /* If the variable was defined via X + C, then we must
- subtract C from the constant in the conditional.
- Otherwise we add C to the constant in the
- conditional. The result must fold into a valid
- gimple operand to be optimizable. */
- new_code = (TREE_CODE (def_rhs) == PLUS_EXPR
- ? MINUS_EXPR : PLUS_EXPR);
- t = int_const_binop (new_code, TREE_OPERAND (cond, 1), op1, 0);
- if (!is_gimple_val (t))
- return NULL_TREE;
-
- new_cond = build2 (cond_code, boolean_type_node, op0, t);
- }
+ tree rhs = gimple_assign_rhs1 (def_stmt);
+ if (POINTER_TYPE_P (TREE_TYPE (rhs))
+ && TREE_CODE (TREE_TYPE (TREE_TYPE (rhs))) == FUNCTION_TYPE)
+ return false;
}
- /* These cases require comparisons of a naked SSA_NAME or
- comparison of an SSA_NAME against zero or one. */
- else if (TREE_CODE (cond) == SSA_NAME
- || integer_zerop (TREE_OPERAND (cond, 1))
- || integer_onep (TREE_OPERAND (cond, 1)))
- {
- /* If TEST_VAR is set from a relational operation
- between two SSA_NAMEs or a combination of an SSA_NAME
- and a constant, then it is interesting. */
- if (COMPARISON_CLASS_P (def_rhs))
- {
- tree op0 = TREE_OPERAND (def_rhs, 0);
- tree op1 = TREE_OPERAND (def_rhs, 1);
-
- /* Both operands of DEF_RHS must be SSA_NAMEs or
- constants. */
- if ((TREE_CODE (op0) != SSA_NAME
- && !is_gimple_min_invariant (op0))
- || (TREE_CODE (op1) != SSA_NAME
- && !is_gimple_min_invariant (op1)))
- return NULL_TREE;
-
- /* Don't propagate if the first operand occurs in
- an abnormal PHI. */
- if (TREE_CODE (op0) == SSA_NAME
- && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op0))
- return NULL_TREE;
-
- /* Don't propagate if the second operand occurs in
- an abnormal PHI. */
- if (TREE_CODE (op1) == SSA_NAME
- && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op1))
- return NULL_TREE;
-
- if (has_single_use (test_var))
- {
- /* TEST_VAR was set from a relational operator. */
- new_cond = build2 (TREE_CODE (def_rhs),
- boolean_type_node, op0, op1);
-
- /* Invert the conditional if necessary. */
- if ((cond_code == EQ_EXPR
- && integer_zerop (TREE_OPERAND (cond, 1)))
- || (cond_code == NE_EXPR
- && integer_onep (TREE_OPERAND (cond, 1))))
- {
- new_cond = invert_truthvalue (new_cond);
-
- /* If we did not get a simple relational
- expression or bare SSA_NAME, then we can
- not optimize this case. */
- if (!COMPARISON_CLASS_P (new_cond)
- && TREE_CODE (new_cond) != SSA_NAME)
- new_cond = NULL_TREE;
- }
- }
- }
+ return true;
+}
- /* If TEST_VAR is set from a TRUTH_NOT_EXPR, then it
- is interesting. */
- else if (TREE_CODE (def_rhs) == TRUTH_NOT_EXPR)
- {
- enum tree_code new_code;
-
- def_rhs = TREE_OPERAND (def_rhs, 0);
-
- /* DEF_RHS must be an SSA_NAME or constant. */
- if (TREE_CODE (def_rhs) != SSA_NAME
- && !is_gimple_min_invariant (def_rhs))
- return NULL_TREE;
-
- /* Don't propagate if the operand occurs in
- an abnormal PHI. */
- if (TREE_CODE (def_rhs) == SSA_NAME
- && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (def_rhs))
- return NULL_TREE;
-
- if (cond_code == SSA_NAME
- || (cond_code == NE_EXPR
- && integer_zerop (TREE_OPERAND (cond, 1)))
- || (cond_code == EQ_EXPR
- && integer_onep (TREE_OPERAND (cond, 1))))
- new_code = EQ_EXPR;
- else
- new_code = NE_EXPR;
+/* Remove a copy chain ending in NAME along the defs.
+ If NAME was replaced in its only use then this function can be used
+ to clean up dead stmts. Returns true if cleanup-cfg has to run. */
- new_cond = build2 (new_code, boolean_type_node, def_rhs,
- fold_convert (TREE_TYPE (def_rhs),
- integer_zero_node));
- }
+static bool
+remove_prop_source_from_use (tree name)
+{
+ gimple_stmt_iterator gsi;
+ gimple stmt;
+ bool cfg_changed = false;
- /* If TEST_VAR was set from a cast of an integer type
- to a boolean type or a cast of a boolean to an
- integral, then it is interesting. */
- else if (TREE_CODE (def_rhs) == NOP_EXPR
- || TREE_CODE (def_rhs) == CONVERT_EXPR)
- {
- tree outer_type;
- tree inner_type;
-
- outer_type = TREE_TYPE (def_rhs);
- inner_type = TREE_TYPE (TREE_OPERAND (def_rhs, 0));
-
- if ((TREE_CODE (outer_type) == BOOLEAN_TYPE
- && INTEGRAL_TYPE_P (inner_type))
- || (TREE_CODE (inner_type) == BOOLEAN_TYPE
- && INTEGRAL_TYPE_P (outer_type)))
- ;
- else if (INTEGRAL_TYPE_P (outer_type)
- && INTEGRAL_TYPE_P (inner_type)
- && TREE_CODE (TREE_OPERAND (def_rhs, 0)) == SSA_NAME
- && ssa_name_defined_by_comparison_p (TREE_OPERAND (def_rhs,
- 0)))
- ;
- else
- return NULL_TREE;
+ do {
+ basic_block bb;
- /* Don't propagate if the operand occurs in
- an abnormal PHI. */
- if (TREE_CODE (TREE_OPERAND (def_rhs, 0)) == SSA_NAME
- && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (TREE_OPERAND
- (def_rhs, 0)))
- return NULL_TREE;
+ if (!has_zero_uses (name))
+ return cfg_changed;
- if (has_single_use (test_var))
- {
- enum tree_code new_code;
- tree new_arg;
-
- if (cond_code == SSA_NAME
- || (cond_code == NE_EXPR
- && integer_zerop (TREE_OPERAND (cond, 1)))
- || (cond_code == EQ_EXPR
- && integer_onep (TREE_OPERAND (cond, 1))))
- new_code = NE_EXPR;
- else
- new_code = EQ_EXPR;
+ stmt = SSA_NAME_DEF_STMT (name);
+ gsi = gsi_for_stmt (stmt);
+ bb = gimple_bb (stmt);
+ release_defs (stmt);
+ gsi_remove (&gsi, true);
+ cfg_changed |= gimple_purge_dead_eh_edges (bb);
- new_arg = TREE_OPERAND (def_rhs, 0);
- new_cond = build2 (new_code, boolean_type_node, new_arg,
- fold_convert (TREE_TYPE (new_arg),
- integer_zero_node));
- }
- }
- }
+ name = (gimple_assign_copy_p (stmt)) ? gimple_assign_rhs1 (stmt) : NULL;
+ } while (name && TREE_CODE (name) == SSA_NAME);
- *test_var_p = test_var;
- return new_cond;
+ return cfg_changed;
}
-/* COND is a condition of the form:
+/* Return the rhs of a gimple_assign STMT in a form of a single tree,
+ converted to type TYPE.
- x == const or x != const
+ This should disappear, but is needed so we can combine expressions and use
+ the fold() interfaces. Long term, we need to develop folding and combine
+ routines that deal with gimple exclusively . */
+
+static tree
+rhs_to_tree (tree type, gimple stmt)
+{
+ location_t loc = gimple_location (stmt);
+ enum tree_code code = gimple_assign_rhs_code (stmt);
+ if (get_gimple_rhs_class (code) == GIMPLE_TERNARY_RHS)
+ return fold_build3_loc (loc, code, type, gimple_assign_rhs1 (stmt),
+ gimple_assign_rhs2 (stmt),
+ gimple_assign_rhs3 (stmt));
+ else if (get_gimple_rhs_class (code) == GIMPLE_BINARY_RHS)
+ return fold_build2_loc (loc, code, type, gimple_assign_rhs1 (stmt),
+ gimple_assign_rhs2 (stmt));
+ else if (get_gimple_rhs_class (code) == GIMPLE_UNARY_RHS)
+ return build1 (code, type, gimple_assign_rhs1 (stmt));
+ else if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS)
+ return gimple_assign_rhs1 (stmt);
+ else
+ gcc_unreachable ();
+}
+
+/* Combine OP0 CODE OP1 in the context of a COND_EXPR. Returns
+ the folded result in a form suitable for COND_EXPR_COND or
+ NULL_TREE, if there is no suitable simplified form. If
+ INVARIANT_ONLY is true only gimple_min_invariant results are
+ considered simplified. */
+
+static tree
+combine_cond_expr_cond (location_t loc, enum tree_code code, tree type,
+ tree op0, tree op1, bool invariant_only)
+{
+ tree t;
- Look back to x's defining statement and see if x is defined as
+ gcc_assert (TREE_CODE_CLASS (code) == tcc_comparison);
- x = (type) y;
+ t = fold_binary_loc (loc, code, type, op0, op1);
+ if (!t)
+ return NULL_TREE;
- If const is unchanged if we convert it to type, then we can build
- the equivalent expression:
+ /* Require that we got a boolean type out if we put one in. */
+ gcc_assert (TREE_CODE (TREE_TYPE (t)) == TREE_CODE (type));
+ /* Canonicalize the combined condition for use in a COND_EXPR. */
+ t = canonicalize_cond_expr_cond (t);
- y == const or y != const
+ /* Bail out if we required an invariant but didn't get one. */
+ if (!t || (invariant_only && !is_gimple_min_invariant (t)))
+ return NULL_TREE;
- Which may allow further optimizations.
+ return t;
+}
- Return the equivalent comparison or NULL if no such equivalent comparison
- was found. */
+/* Combine the comparison OP0 CODE OP1 at LOC with the defining statements
+ of its operand. Return a new comparison tree or NULL_TREE if there
+ were no simplifying combines. */
static tree
-find_equivalent_equality_comparison (tree cond)
+forward_propagate_into_comparison_1 (location_t loc,
+ enum tree_code code, tree type,
+ tree op0, tree op1)
{
- tree op0 = TREE_OPERAND (cond, 0);
- tree op1 = TREE_OPERAND (cond, 1);
- tree def_stmt = SSA_NAME_DEF_STMT (op0);
-
- while (def_stmt
- && TREE_CODE (def_stmt) == GIMPLE_MODIFY_STMT
- && TREE_CODE (GIMPLE_STMT_OPERAND (def_stmt, 1)) == SSA_NAME)
- def_stmt = SSA_NAME_DEF_STMT (GIMPLE_STMT_OPERAND (def_stmt, 1));
-
- /* OP0 might have been a parameter, so first make sure it
- was defined by a GIMPLE_MODIFY_STMT. */
- if (def_stmt && TREE_CODE (def_stmt) == GIMPLE_MODIFY_STMT)
+ tree tmp = NULL_TREE;
+ tree rhs0 = NULL_TREE, rhs1 = NULL_TREE;
+ bool single_use0_p = false, single_use1_p = false;
+
+ /* For comparisons use the first operand, that is likely to
+ simplify comparisons against constants. */
+ if (TREE_CODE (op0) == SSA_NAME)
{
- tree def_rhs = GIMPLE_STMT_OPERAND (def_stmt, 1);
-
- /* If either operand to the comparison is a pointer to
- a function, then we can not apply this optimization
- as some targets require function pointers to be
- canonicalized and in this case this optimization would
- eliminate a necessary canonicalization. */
- if ((POINTER_TYPE_P (TREE_TYPE (op0))
- && TREE_CODE (TREE_TYPE (TREE_TYPE (op0))) == FUNCTION_TYPE)
- || (POINTER_TYPE_P (TREE_TYPE (op1))
- && TREE_CODE (TREE_TYPE (TREE_TYPE (op1))) == FUNCTION_TYPE))
- return NULL;
-
- /* Now make sure the RHS of the GIMPLE_MODIFY_STMT is a typecast. */
- if ((TREE_CODE (def_rhs) == NOP_EXPR
- || TREE_CODE (def_rhs) == CONVERT_EXPR)
- && TREE_CODE (TREE_OPERAND (def_rhs, 0)) == SSA_NAME)
+ gimple def_stmt = get_prop_source_stmt (op0, false, &single_use0_p);
+ if (def_stmt && can_propagate_from (def_stmt))
{
- tree def_rhs_inner = TREE_OPERAND (def_rhs, 0);
- tree def_rhs_inner_type = TREE_TYPE (def_rhs_inner);
- tree new;
-
- if (TYPE_PRECISION (def_rhs_inner_type)
- > TYPE_PRECISION (TREE_TYPE (def_rhs)))
- return NULL;
-
- /* If the inner type of the conversion is a pointer to
- a function, then we can not apply this optimization
- as some targets require function pointers to be
- canonicalized. This optimization would result in
- canonicalization of the pointer when it was not originally
- needed/intended. */
- if (POINTER_TYPE_P (def_rhs_inner_type)
- && TREE_CODE (TREE_TYPE (def_rhs_inner_type)) == FUNCTION_TYPE)
- return NULL;
-
- /* What we want to prove is that if we convert OP1 to
- the type of the object inside the NOP_EXPR that the
- result is still equivalent to SRC.
-
- If that is true, the build and return new equivalent
- condition which uses the source of the typecast and the
- new constant (which has only changed its type). */
- new = fold_build1 (TREE_CODE (def_rhs), def_rhs_inner_type, op1);
- STRIP_USELESS_TYPE_CONVERSION (new);
- if (is_gimple_val (new) && tree_int_cst_equal (new, op1))
- return build2 (TREE_CODE (cond), TREE_TYPE (cond),
- def_rhs_inner, new);
+ rhs0 = rhs_to_tree (TREE_TYPE (op1), def_stmt);
+ tmp = combine_cond_expr_cond (loc, code, type,
+ rhs0, op1, !single_use0_p);
+ if (tmp)
+ return tmp;
}
}
- return NULL;
-}
-/* EXPR is a COND_EXPR
- STMT is the statement containing EXPR.
+ /* If that wasn't successful, try the second operand. */
+ if (TREE_CODE (op1) == SSA_NAME)
+ {
+ gimple def_stmt = get_prop_source_stmt (op1, false, &single_use1_p);
+ if (def_stmt && can_propagate_from (def_stmt))
+ {
+ rhs1 = rhs_to_tree (TREE_TYPE (op0), def_stmt);
+ tmp = combine_cond_expr_cond (loc, code, type,
+ op0, rhs1, !single_use1_p);
+ if (tmp)
+ return tmp;
+ }
+ }
- This routine attempts to find equivalent forms of the condition
- which we may be able to optimize better. */
+ /* If that wasn't successful either, try both operands. */
+ if (rhs0 != NULL_TREE
+ && rhs1 != NULL_TREE)
+ tmp = combine_cond_expr_cond (loc, code, type,
+ rhs0, rhs1,
+ !(single_use0_p && single_use1_p));
-static void
-simplify_cond (tree cond_expr, tree stmt)
-{
- tree cond = COND_EXPR_COND (cond_expr);
+ return tmp;
+}
- if (COMPARISON_CLASS_P (cond))
+/* 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. */
+
+static bool
+forward_propagate_into_comparison (gimple_stmt_iterator *gsi)
+{
+ gimple stmt = gsi_stmt (*gsi);
+ tree tmp;
+
+ /* 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));
+ if (tmp)
{
- tree op0 = TREE_OPERAND (cond, 0);
- tree op1 = TREE_OPERAND (cond, 1);
+ gimple_assign_set_rhs_from_tree (gsi, tmp);
+ update_stmt (stmt);
+ return true;
+ }
- if (TREE_CODE (op0) == SSA_NAME && is_gimple_min_invariant (op1))
- {
- /* First see if we have test of an SSA_NAME against a constant
- where the SSA_NAME is defined by an earlier typecast which
- is irrelevant when performing tests against the given
- constant. */
- if (TREE_CODE (cond) == EQ_EXPR || TREE_CODE (cond) == NE_EXPR)
- {
- tree new_cond = find_equivalent_equality_comparison (cond);
+ return false;
+}
- if (new_cond)
- {
- COND_EXPR_COND (cond_expr) = new_cond;
- update_stmt (stmt);
- }
- }
+/* Propagate from the ssa name definition statements of COND_EXPR
+ in GIMPLE_COND statement STMT into the conditional if that simplifies it.
+ Returns zero if no statement was changed, one if there were
+ changes and two if cfg_cleanup needs to run.
+
+ This must be kept in sync with forward_propagate_into_cond. */
+
+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);
+
+ /* We can do tree combining on SSA_NAME and comparison expressions. */
+ if (TREE_CODE_CLASS (gimple_cond_code (stmt)) != tcc_comparison)
+ return 0;
+
+ tmp = forward_propagate_into_comparison_1 (loc, code,
+ boolean_type_node,
+ gimple_cond_lhs (stmt),
+ gimple_cond_rhs (stmt));
+ 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);
+ fprintf (dump_file, "' with '");
+ print_generic_expr (dump_file, tmp, 0);
+ fprintf (dump_file, "'\n");
}
+
+ 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;
}
+
+ return did_something;
}
-/* Forward propagate a single-use variable into COND_EXPR as many
- times as possible. */
-static void
-forward_propagate_into_cond (tree cond_expr, tree stmt)
+/* Propagate from the ssa name definition statements of COND_EXPR
+ in the rhs of statement STMT into the conditional if that simplifies it.
+ Returns zero if no statement was changed, one if there were
+ changes and two if cfg_cleanup needs to run.
+
+ This must be kept in sync with forward_propagate_into_gimple_cond. */
+
+static int
+forward_propagate_into_cond (gimple_stmt_iterator *gsi_p)
{
- gcc_assert (TREE_CODE (cond_expr) == COND_EXPR);
+ 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);
- while (1)
+ /* We can do tree combining on SSA_NAME and comparison expressions. */
+ if (COMPARISON_CLASS_P (cond))
+ tmp = forward_propagate_into_comparison_1 (loc, TREE_CODE (cond),
+ boolean_type_node,
+ TREE_OPERAND (cond, 0),
+ TREE_OPERAND (cond, 1));
+ else if (TREE_CODE (cond) == SSA_NAME)
{
- tree test_var = NULL_TREE;
- tree cond = COND_EXPR_COND (cond_expr);
- tree new_cond = forward_propagate_into_cond_1 (cond, &test_var);
-
- /* Return if unsuccessful. */
- if (new_cond == NULL_TREE)
- break;
+ 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;
+
+ rhs0 = gimple_assign_rhs1 (def_stmt);
+ tmp = combine_cond_expr_cond (loc, NE_EXPR, boolean_type_node, rhs0,
+ build_int_cst (TREE_TYPE (rhs0), 0),
+ false);
+ }
- /* Dump details. */
- if (dump_file && (dump_flags & TDF_DETAILS))
+ if (tmp)
+ {
+ if (dump_file && tmp)
{
fprintf (dump_file, " Replaced '");
- print_generic_expr (dump_file, cond, dump_flags);
+ print_generic_expr (dump_file, cond, 0);
fprintf (dump_file, "' with '");
- print_generic_expr (dump_file, new_cond, dump_flags);
+ print_generic_expr (dump_file, tmp, 0);
fprintf (dump_file, "'\n");
}
- COND_EXPR_COND (cond_expr) = new_cond;
+ gimple_assign_set_rhs_from_tree (gsi_p, unshare_expr (tmp));
+ stmt = gsi_stmt (*gsi_p);
update_stmt (stmt);
- if (has_zero_uses (test_var))
- {
- tree def = SSA_NAME_DEF_STMT (test_var);
- block_stmt_iterator bsi = bsi_for_stmt (def);
- bsi_remove (&bsi, true);
- release_defs (def);
- }
+ /* Remove defining statements. */
+ if (is_gimple_min_invariant (tmp))
+ did_something = 2;
+ else if (did_something == 0)
+ did_something = 1;
}
- /* There are further simplifications that can be performed
- on COND_EXPRs. Specifically, when comparing an SSA_NAME
- against a constant where the SSA_NAME is the result of a
- conversion. Perhaps this should be folded into the rest
- of the COND_EXPR simplification code. */
- simplify_cond (cond_expr, stmt);
+ return did_something;
}
-/* We've just substituted an ADDR_EXPR into stmt. Update all the
+/* We've just substituted an ADDR_EXPR into stmt. Update all the
relevant data structures to match. */
static void
-tidy_after_forward_propagate_addr (tree stmt)
+tidy_after_forward_propagate_addr (gimple stmt)
{
/* We may have turned a trapping insn into a non-trapping insn. */
if (maybe_clean_or_replace_eh_stmt (stmt, stmt)
- && tree_purge_dead_eh_edges (bb_for_stmt (stmt)))
+ && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
cfg_changed = true;
- if (TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 1)) == ADDR_EXPR)
- recompute_tree_invariant_for_addr_expr (GIMPLE_STMT_OPERAND (stmt, 1));
-
- mark_symbols_for_renaming (stmt);
+ if (TREE_CODE (gimple_assign_rhs1 (stmt)) == ADDR_EXPR)
+ recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1 (stmt));
}
-/* DEF_RHS defines LHS which is contains the address of the 0th element
- in an array. USE_STMT uses LHS to compute the address of an
+/* DEF_RHS contains the address of the 0th element in an array.
+ USE_STMT uses type of DEF_RHS to compute the address of an
arbitrary element within the array. The (variable) byte offset
of the element is contained in OFFSET.
with the new address computation. */
static bool
-forward_propagate_addr_into_variable_array_index (tree offset, tree lhs,
- tree def_rhs, tree use_stmt)
+forward_propagate_addr_into_variable_array_index (tree offset,
+ tree def_rhs,
+ gimple_stmt_iterator *use_stmt_gsi)
{
- tree index;
-
- /* The offset must be defined by a simple GIMPLE_MODIFY_STMT statement. */
- if (TREE_CODE (offset) != GIMPLE_MODIFY_STMT)
- return false;
-
- /* The RHS of the statement which defines OFFSET must be a gimple
- cast of another SSA_NAME. */
- offset = GIMPLE_STMT_OPERAND (offset, 1);
- if (!is_gimple_cast (offset))
+ tree index, tunit;
+ gimple offset_def, use_stmt = gsi_stmt (*use_stmt_gsi);
+ tree new_rhs, tmp;
+
+ if (TREE_CODE (TREE_OPERAND (def_rhs, 0)) == ARRAY_REF)
+ tunit = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (def_rhs)));
+ else if (TREE_CODE (TREE_TYPE (TREE_OPERAND (def_rhs, 0))) == ARRAY_TYPE)
+ tunit = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (TREE_TYPE (def_rhs))));
+ else
return false;
-
- offset = TREE_OPERAND (offset, 0);
- if (TREE_CODE (offset) != SSA_NAME)
+ if (!host_integerp (tunit, 1))
return false;
- /* Get the defining statement of the offset before type
- conversion. */
- offset = SSA_NAME_DEF_STMT (offset);
+ /* Get the offset's defining statement. */
+ offset_def = SSA_NAME_DEF_STMT (offset);
- /* The statement which defines OFFSET before type conversion
- must be a simple GIMPLE_MODIFY_STMT. */
- if (TREE_CODE (offset) != GIMPLE_MODIFY_STMT)
- return false;
-
- /* The RHS of the statement which defines OFFSET must be a
- multiplication of an object by the size of the array elements.
- This implicitly verifies that the size of the array elements
- is constant. */
- offset = GIMPLE_STMT_OPERAND (offset, 1);
- if (TREE_CODE (offset) != MULT_EXPR
- || TREE_CODE (TREE_OPERAND (offset, 1)) != INTEGER_CST
- || !simple_cst_equal (TREE_OPERAND (offset, 1),
- TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (lhs)))))
- return false;
+ /* Try to find an expression for a proper index. This is either a
+ multiplication expression by the element size or just the ssa name we came
+ along in case the element size is one. In that case, however, we do not
+ allow multiplications because they can be computing index to a higher
+ level dimension (PR 37861). */
+ if (integer_onep (tunit))
+ {
+ if (is_gimple_assign (offset_def)
+ && gimple_assign_rhs_code (offset_def) == MULT_EXPR)
+ return false;
- /* The first operand to the MULT_EXPR is the desired index. */
- index = TREE_OPERAND (offset, 0);
+ index = offset;
+ }
+ else
+ {
+ /* The statement which defines OFFSET before type conversion
+ must be a simple GIMPLE_ASSIGN. */
+ if (!is_gimple_assign (offset_def))
+ return false;
+
+ /* The RHS of the statement which defines OFFSET must be a
+ multiplication of an object by the size of the array elements.
+ This implicitly verifies that the size of the array elements
+ is constant. */
+ if (gimple_assign_rhs_code (offset_def) == MULT_EXPR
+ && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST
+ && tree_int_cst_equal (gimple_assign_rhs2 (offset_def), tunit))
+ {
+ /* The first operand to the MULT_EXPR is the desired index. */
+ index = gimple_assign_rhs1 (offset_def);
+ }
+ /* If we have idx * tunit + CST * tunit re-associate that. */
+ else if ((gimple_assign_rhs_code (offset_def) == PLUS_EXPR
+ || gimple_assign_rhs_code (offset_def) == MINUS_EXPR)
+ && TREE_CODE (gimple_assign_rhs1 (offset_def)) == SSA_NAME
+ && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST
+ && (tmp = div_if_zero_remainder (EXACT_DIV_EXPR,
+ gimple_assign_rhs2 (offset_def),
+ tunit)) != NULL_TREE)
+ {
+ gimple offset_def2 = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (offset_def));
+ if (is_gimple_assign (offset_def2)
+ && gimple_assign_rhs_code (offset_def2) == MULT_EXPR
+ && TREE_CODE (gimple_assign_rhs2 (offset_def2)) == INTEGER_CST
+ && tree_int_cst_equal (gimple_assign_rhs2 (offset_def2), tunit))
+ {
+ index = fold_build2 (gimple_assign_rhs_code (offset_def),
+ TREE_TYPE (offset),
+ gimple_assign_rhs1 (offset_def2), tmp);
+ }
+ else
+ return false;
+ }
+ else
+ return false;
+ }
/* Replace the pointer addition with array indexing. */
- GIMPLE_STMT_OPERAND (use_stmt, 1) = unshare_expr (def_rhs);
- TREE_OPERAND (TREE_OPERAND (GIMPLE_STMT_OPERAND (use_stmt, 1), 0), 1)
- = index;
+ index = force_gimple_operand_gsi (use_stmt_gsi, index, true, NULL_TREE,
+ true, GSI_SAME_STMT);
+ if (TREE_CODE (TREE_OPERAND (def_rhs, 0)) == ARRAY_REF)
+ {
+ new_rhs = unshare_expr (def_rhs);
+ TREE_OPERAND (TREE_OPERAND (new_rhs, 0), 1) = index;
+ }
+ else
+ {
+ new_rhs = build4 (ARRAY_REF, TREE_TYPE (TREE_TYPE (TREE_TYPE (def_rhs))),
+ unshare_expr (TREE_OPERAND (def_rhs, 0)),
+ index, integer_zero_node, NULL_TREE);
+ new_rhs = build_fold_addr_expr (new_rhs);
+ if (!useless_type_conversion_p (TREE_TYPE (gimple_assign_lhs (use_stmt)),
+ TREE_TYPE (new_rhs)))
+ {
+ new_rhs = force_gimple_operand_gsi (use_stmt_gsi, new_rhs, true,
+ NULL_TREE, true, GSI_SAME_STMT);
+ new_rhs = fold_convert (TREE_TYPE (gimple_assign_lhs (use_stmt)),
+ new_rhs);
+ }
+ }
+ gimple_assign_set_rhs_from_tree (use_stmt_gsi, new_rhs);
+ use_stmt = gsi_stmt (*use_stmt_gsi);
/* That should have created gimple, so there is no need to
record information to undo the propagation. */
Try to forward propagate the ADDR_EXPR into the use USE_STMT.
Often this will allow for removal of an ADDR_EXPR and INDIRECT_REF
node or for recovery of array indexing from pointer arithmetic.
-
+
Return true if the propagation was successful (the propagation can
be not totally successful, yet things may have been changed). */
static bool
-forward_propagate_addr_expr_1 (tree name, tree def_rhs, tree use_stmt)
+forward_propagate_addr_expr_1 (tree name, tree def_rhs,
+ gimple_stmt_iterator *use_stmt_gsi,
+ bool single_use_p)
{
- tree lhs, rhs, array_ref;
+ tree lhs, rhs, rhs2, array_ref;
+ gimple use_stmt = gsi_stmt (*use_stmt_gsi);
+ enum tree_code rhs_code;
+ bool res = true;
+
+ gcc_assert (TREE_CODE (def_rhs) == ADDR_EXPR);
+
+ lhs = gimple_assign_lhs (use_stmt);
+ rhs_code = gimple_assign_rhs_code (use_stmt);
+ rhs = gimple_assign_rhs1 (use_stmt);
+
+ /* Trivial cases. The use statement could be a trivial copy or a
+ useless conversion. Recurse to the uses of the lhs as copyprop does
+ not copy through different variant pointers and FRE does not catch
+ all useless conversions. Treat the case of a single-use name and
+ a conversion to def_rhs type separate, though. */
+ if (TREE_CODE (lhs) == SSA_NAME
+ && ((rhs_code == SSA_NAME && rhs == name)
+ || CONVERT_EXPR_CODE_P (rhs_code)))
+ {
+ /* Only recurse if we don't deal with a single use or we cannot
+ do the propagation to the current statement. In particular
+ we can end up with a conversion needed for a non-invariant
+ address which we cannot do in a single statement. */
+ if (!single_use_p
+ || (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (def_rhs))
+ && (!is_gimple_min_invariant (def_rhs)
+ || (INTEGRAL_TYPE_P (TREE_TYPE (lhs))
+ && POINTER_TYPE_P (TREE_TYPE (def_rhs))
+ && (TYPE_PRECISION (TREE_TYPE (lhs))
+ > TYPE_PRECISION (TREE_TYPE (def_rhs)))))))
+ return forward_propagate_addr_expr (lhs, def_rhs);
+
+ gimple_assign_set_rhs1 (use_stmt, unshare_expr (def_rhs));
+ if (useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (def_rhs)))
+ gimple_assign_set_rhs_code (use_stmt, TREE_CODE (def_rhs));
+ else
+ gimple_assign_set_rhs_code (use_stmt, NOP_EXPR);
+ return true;
+ }
- /* Strip away any outer COMPONENT_REF/ARRAY_REF nodes from the LHS.
+ /* Propagate through constant pointer adjustments. */
+ if (TREE_CODE (lhs) == SSA_NAME
+ && rhs_code == POINTER_PLUS_EXPR
+ && rhs == name
+ && TREE_CODE (gimple_assign_rhs2 (use_stmt)) == INTEGER_CST)
+ {
+ tree new_def_rhs;
+ /* As we come here with non-invariant addresses in def_rhs we need
+ to make sure we can build a valid constant offsetted address
+ for further propagation. Simply rely on fold building that
+ and check after the fact. */
+ new_def_rhs = fold_build2 (MEM_REF, TREE_TYPE (TREE_TYPE (rhs)),
+ def_rhs,
+ fold_convert (ptr_type_node,
+ gimple_assign_rhs2 (use_stmt)));
+ if (TREE_CODE (new_def_rhs) == MEM_REF
+ && !is_gimple_mem_ref_addr (TREE_OPERAND (new_def_rhs, 0)))
+ return false;
+ new_def_rhs = build_fold_addr_expr_with_type (new_def_rhs,
+ TREE_TYPE (rhs));
+
+ /* Recurse. If we could propagate into all uses of lhs do not
+ bother to replace into the current use but just pretend we did. */
+ if (TREE_CODE (new_def_rhs) == ADDR_EXPR
+ && forward_propagate_addr_expr (lhs, new_def_rhs))
+ return true;
+
+ if (useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (new_def_rhs)))
+ gimple_assign_set_rhs_with_ops (use_stmt_gsi, TREE_CODE (new_def_rhs),
+ new_def_rhs, NULL_TREE);
+ else if (is_gimple_min_invariant (new_def_rhs))
+ gimple_assign_set_rhs_with_ops (use_stmt_gsi, NOP_EXPR,
+ new_def_rhs, NULL_TREE);
+ else
+ return false;
+ gcc_assert (gsi_stmt (*use_stmt_gsi) == use_stmt);
+ update_stmt (use_stmt);
+ return true;
+ }
+
+ /* Now strip away any outer COMPONENT_REF/ARRAY_REF nodes from the LHS.
ADDR_EXPR will not appear on the LHS. */
- lhs = GIMPLE_STMT_OPERAND (use_stmt, 0);
- while (TREE_CODE (lhs) == COMPONENT_REF || TREE_CODE (lhs) == ARRAY_REF)
+ lhs = gimple_assign_lhs (use_stmt);
+ while (handled_component_p (lhs))
lhs = TREE_OPERAND (lhs, 0);
- rhs = GIMPLE_STMT_OPERAND (use_stmt, 1);
-
- /* Now see if the LHS node is an INDIRECT_REF using NAME. If so,
+ /* Now see if the LHS node is a MEM_REF using NAME. If so,
propagate the ADDR_EXPR into the use of NAME and fold the result. */
- if (TREE_CODE (lhs) == INDIRECT_REF && TREE_OPERAND (lhs, 0) == name)
+ if (TREE_CODE (lhs) == MEM_REF
+ && TREE_OPERAND (lhs, 0) == name)
{
- /* This should always succeed in creating gimple, so there is
- no need to save enough state to undo this propagation. */
- TREE_OPERAND (lhs, 0) = unshare_expr (def_rhs);
- fold_stmt_inplace (use_stmt);
- tidy_after_forward_propagate_addr (use_stmt);
-
- /* The only case we did not replace all uses this way is if the
- use statement is of the form *name = name. */
- return rhs != name;
+ tree def_rhs_base;
+ HOST_WIDE_INT def_rhs_offset;
+ /* If the address is invariant we can always fold it. */
+ if ((def_rhs_base = get_addr_base_and_unit_offset (TREE_OPERAND (def_rhs, 0),
+ &def_rhs_offset)))
+ {
+ double_int off = mem_ref_offset (lhs);
+ tree new_ptr;
+ off = double_int_add (off,
+ shwi_to_double_int (def_rhs_offset));
+ if (TREE_CODE (def_rhs_base) == MEM_REF)
+ {
+ off = double_int_add (off, mem_ref_offset (def_rhs_base));
+ new_ptr = TREE_OPERAND (def_rhs_base, 0);
+ }
+ else
+ new_ptr = build_fold_addr_expr (def_rhs_base);
+ TREE_OPERAND (lhs, 0) = new_ptr;
+ TREE_OPERAND (lhs, 1)
+ = double_int_to_tree (TREE_TYPE (TREE_OPERAND (lhs, 1)), off);
+ tidy_after_forward_propagate_addr (use_stmt);
+ /* Continue propagating into the RHS if this was not the only use. */
+ if (single_use_p)
+ return true;
+ }
+ /* If the LHS is a plain dereference and the value type is the same as
+ that of the pointed-to type of the address we can put the
+ dereferenced address on the LHS preserving the original alias-type. */
+ else if (gimple_assign_lhs (use_stmt) == lhs
+ && useless_type_conversion_p
+ (TREE_TYPE (TREE_OPERAND (def_rhs, 0)),
+ TREE_TYPE (gimple_assign_rhs1 (use_stmt))))
+ {
+ tree *def_rhs_basep = &TREE_OPERAND (def_rhs, 0);
+ tree new_offset, new_base, saved;
+ while (handled_component_p (*def_rhs_basep))
+ def_rhs_basep = &TREE_OPERAND (*def_rhs_basep, 0);
+ saved = *def_rhs_basep;
+ if (TREE_CODE (*def_rhs_basep) == MEM_REF)
+ {
+ new_base = TREE_OPERAND (*def_rhs_basep, 0);
+ new_offset
+ = int_const_binop (PLUS_EXPR, TREE_OPERAND (lhs, 1),
+ TREE_OPERAND (*def_rhs_basep, 1));
+ }
+ else
+ {
+ new_base = build_fold_addr_expr (*def_rhs_basep);
+ new_offset = TREE_OPERAND (lhs, 1);
+ }
+ *def_rhs_basep = build2 (MEM_REF, TREE_TYPE (*def_rhs_basep),
+ new_base, new_offset);
+ gimple_assign_set_lhs (use_stmt,
+ unshare_expr (TREE_OPERAND (def_rhs, 0)));
+ *def_rhs_basep = saved;
+ tidy_after_forward_propagate_addr (use_stmt);
+ /* Continue propagating into the RHS if this was not the
+ only use. */
+ if (single_use_p)
+ return true;
+ }
+ else
+ /* We can have a struct assignment dereferencing our name twice.
+ Note that we didn't propagate into the lhs to not falsely
+ claim we did when propagating into the rhs. */
+ res = false;
}
- /* Trivial case. The use statement could be a trivial copy or a
- useless conversion. Recurse to the uses of the lhs as copyprop does
- not copy through differen variant pointers and FRE does not catch
- all useless conversions. */
- else if ((TREE_CODE (lhs) == SSA_NAME
- && rhs == name)
- || ((TREE_CODE (rhs) == NOP_EXPR
- || TREE_CODE (rhs) == CONVERT_EXPR)
- && tree_ssa_useless_type_conversion_1 (TREE_TYPE (rhs),
- TREE_TYPE (def_rhs))))
- return forward_propagate_addr_expr (lhs, def_rhs);
-
/* Strip away any outer COMPONENT_REF, ARRAY_REF or ADDR_EXPR
nodes from the RHS. */
- while (TREE_CODE (rhs) == COMPONENT_REF
- || TREE_CODE (rhs) == ARRAY_REF
- || TREE_CODE (rhs) == ADDR_EXPR)
+ rhs = gimple_assign_rhs1 (use_stmt);
+ if (TREE_CODE (rhs) == ADDR_EXPR)
+ rhs = TREE_OPERAND (rhs, 0);
+ while (handled_component_p (rhs))
rhs = TREE_OPERAND (rhs, 0);
- /* Now see if the RHS node is an INDIRECT_REF using NAME. If so,
+ /* Now see if the RHS node is a MEM_REF using NAME. If so,
propagate the ADDR_EXPR into the use of NAME and fold the result. */
- if (TREE_CODE (rhs) == INDIRECT_REF && TREE_OPERAND (rhs, 0) == name)
+ if (TREE_CODE (rhs) == MEM_REF
+ && TREE_OPERAND (rhs, 0) == name)
{
- /* This should always succeed in creating gimple, so there is
- no need to save enough state to undo this propagation. */
- TREE_OPERAND (rhs, 0) = unshare_expr (def_rhs);
- fold_stmt_inplace (use_stmt);
- tidy_after_forward_propagate_addr (use_stmt);
- return true;
+ tree def_rhs_base;
+ HOST_WIDE_INT def_rhs_offset;
+ if ((def_rhs_base = get_addr_base_and_unit_offset (TREE_OPERAND (def_rhs, 0),
+ &def_rhs_offset)))
+ {
+ double_int off = mem_ref_offset (rhs);
+ tree new_ptr;
+ off = double_int_add (off,
+ shwi_to_double_int (def_rhs_offset));
+ if (TREE_CODE (def_rhs_base) == MEM_REF)
+ {
+ off = double_int_add (off, mem_ref_offset (def_rhs_base));
+ new_ptr = TREE_OPERAND (def_rhs_base, 0);
+ }
+ else
+ new_ptr = build_fold_addr_expr (def_rhs_base);
+ TREE_OPERAND (rhs, 0) = new_ptr;
+ TREE_OPERAND (rhs, 1)
+ = double_int_to_tree (TREE_TYPE (TREE_OPERAND (rhs, 1)), off);
+ fold_stmt_inplace (use_stmt);
+ tidy_after_forward_propagate_addr (use_stmt);
+ return res;
+ }
+ /* If the LHS is a plain dereference and the value type is the same as
+ that of the pointed-to type of the address we can put the
+ dereferenced address on the LHS preserving the original alias-type. */
+ else if (gimple_assign_rhs1 (use_stmt) == rhs
+ && useless_type_conversion_p
+ (TREE_TYPE (gimple_assign_lhs (use_stmt)),
+ TREE_TYPE (TREE_OPERAND (def_rhs, 0))))
+ {
+ tree *def_rhs_basep = &TREE_OPERAND (def_rhs, 0);
+ tree new_offset, new_base, saved;
+ while (handled_component_p (*def_rhs_basep))
+ def_rhs_basep = &TREE_OPERAND (*def_rhs_basep, 0);
+ saved = *def_rhs_basep;
+ if (TREE_CODE (*def_rhs_basep) == MEM_REF)
+ {
+ new_base = TREE_OPERAND (*def_rhs_basep, 0);
+ new_offset
+ = int_const_binop (PLUS_EXPR, TREE_OPERAND (rhs, 1),
+ TREE_OPERAND (*def_rhs_basep, 1));
+ }
+ else
+ {
+ new_base = build_fold_addr_expr (*def_rhs_basep);
+ new_offset = TREE_OPERAND (rhs, 1);
+ }
+ *def_rhs_basep = build2 (MEM_REF, TREE_TYPE (*def_rhs_basep),
+ new_base, new_offset);
+ gimple_assign_set_rhs1 (use_stmt,
+ unshare_expr (TREE_OPERAND (def_rhs, 0)));
+ *def_rhs_basep = saved;
+ fold_stmt_inplace (use_stmt);
+ tidy_after_forward_propagate_addr (use_stmt);
+ return res;
+ }
}
+ /* If the use of the ADDR_EXPR is not a POINTER_PLUS_EXPR, there
+ is nothing to do. */
+ if (gimple_assign_rhs_code (use_stmt) != POINTER_PLUS_EXPR
+ || gimple_assign_rhs1 (use_stmt) != name)
+ return false;
+
/* The remaining cases are all for turning pointer arithmetic into
array indexing. They only apply when we have the address of
element zero in an array. If that is not the case then there
is nothing to do. */
array_ref = TREE_OPERAND (def_rhs, 0);
- if (TREE_CODE (array_ref) != ARRAY_REF
- || TREE_CODE (TREE_TYPE (TREE_OPERAND (array_ref, 0))) != ARRAY_TYPE
- || !integer_zerop (TREE_OPERAND (array_ref, 1)))
- return false;
-
- /* If the use of the ADDR_EXPR must be a PLUS_EXPR, or else there
- is nothing to do. */
- if (TREE_CODE (rhs) != PLUS_EXPR)
+ if ((TREE_CODE (array_ref) != ARRAY_REF
+ || TREE_CODE (TREE_TYPE (TREE_OPERAND (array_ref, 0))) != ARRAY_TYPE
+ || TREE_CODE (TREE_OPERAND (array_ref, 1)) != INTEGER_CST)
+ && TREE_CODE (TREE_TYPE (array_ref)) != ARRAY_TYPE)
return false;
- /* Try to optimize &x[0] + C where C is a multiple of the size
- of the elements in X into &x[C/element size]. */
- if (TREE_OPERAND (rhs, 0) == name
- && TREE_CODE (TREE_OPERAND (rhs, 1)) == INTEGER_CST)
+ rhs2 = gimple_assign_rhs2 (use_stmt);
+ /* Try to optimize &x[C1] p+ C2 where C2 is a multiple of the size
+ of the elements in X into &x[C1 + C2/element size]. */
+ if (TREE_CODE (rhs2) == INTEGER_CST)
{
- tree orig = unshare_expr (rhs);
- TREE_OPERAND (rhs, 0) = unshare_expr (def_rhs);
-
- /* If folding succeeds, then we have just exposed new variables
- in USE_STMT which will need to be renamed. If folding fails,
- then we need to put everything back the way it was. */
- if (fold_stmt_inplace (use_stmt))
+ tree new_rhs = maybe_fold_stmt_addition (gimple_location (use_stmt),
+ TREE_TYPE (def_rhs),
+ def_rhs, rhs2);
+ if (new_rhs)
{
+ tree type = TREE_TYPE (gimple_assign_lhs (use_stmt));
+ new_rhs = unshare_expr (new_rhs);
+ if (!useless_type_conversion_p (type, TREE_TYPE (new_rhs)))
+ {
+ if (!is_gimple_min_invariant (new_rhs))
+ new_rhs = force_gimple_operand_gsi (use_stmt_gsi, new_rhs,
+ true, NULL_TREE,
+ true, GSI_SAME_STMT);
+ new_rhs = fold_convert (type, new_rhs);
+ }
+ gimple_assign_set_rhs_from_tree (use_stmt_gsi, new_rhs);
+ use_stmt = gsi_stmt (*use_stmt_gsi);
+ update_stmt (use_stmt);
tidy_after_forward_propagate_addr (use_stmt);
return true;
}
- else
- {
- GIMPLE_STMT_OPERAND (use_stmt, 1) = orig;
- update_stmt (use_stmt);
- return false;
- }
}
- /* Try to optimize &x[0] + OFFSET where OFFSET is defined by
+ /* Try to optimize &x[0] p+ OFFSET where OFFSET is defined by
converting a multiplication of an index by the size of the
array elements, then the result is converted into the proper
type for the arithmetic. */
- if (TREE_OPERAND (rhs, 0) == name
- && TREE_CODE (TREE_OPERAND (rhs, 1)) == SSA_NAME
- /* Avoid problems with IVopts creating PLUS_EXPRs with a
- different type than their operands. */
- && lang_hooks.types_compatible_p (TREE_TYPE (name), TREE_TYPE (rhs)))
- {
- bool res;
- tree offset_stmt = SSA_NAME_DEF_STMT (TREE_OPERAND (rhs, 1));
-
- res = forward_propagate_addr_into_variable_array_index (offset_stmt, lhs,
- def_rhs, use_stmt);
- return res;
- }
-
- /* Same as the previous case, except the operands of the PLUS_EXPR
- were reversed. */
- if (TREE_OPERAND (rhs, 1) == name
- && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME
+ if (TREE_CODE (rhs2) == SSA_NAME
+ && (TREE_CODE (array_ref) != ARRAY_REF
+ || integer_zerop (TREE_OPERAND (array_ref, 1)))
+ && useless_type_conversion_p (TREE_TYPE (name), TREE_TYPE (def_rhs))
/* Avoid problems with IVopts creating PLUS_EXPRs with a
different type than their operands. */
- && lang_hooks.types_compatible_p (TREE_TYPE (name), TREE_TYPE (rhs)))
- {
- bool res;
- tree offset_stmt = SSA_NAME_DEF_STMT (TREE_OPERAND (rhs, 0));
- res = forward_propagate_addr_into_variable_array_index (offset_stmt, lhs,
- def_rhs, use_stmt);
- return res;
- }
+ && useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (def_rhs)))
+ return forward_propagate_addr_into_variable_array_index (rhs2, def_rhs,
+ use_stmt_gsi);
return false;
}
static bool
forward_propagate_addr_expr (tree name, tree rhs)
{
- int stmt_loop_depth = bb_for_stmt (SSA_NAME_DEF_STMT (name))->loop_depth;
+ int stmt_loop_depth = gimple_bb (SSA_NAME_DEF_STMT (name))->loop_depth;
imm_use_iterator iter;
- tree use_stmt;
+ gimple use_stmt;
bool all = true;
+ bool single_use_p = has_single_use (name);
FOR_EACH_IMM_USE_STMT (use_stmt, iter, name)
{
bool result;
+ tree use_rhs;
/* If the use is not in a simple assignment statement, then
there is nothing we can do. */
- if (TREE_CODE (use_stmt) != GIMPLE_MODIFY_STMT)
+ if (gimple_code (use_stmt) != GIMPLE_ASSIGN)
{
- all = false;
+ if (!is_gimple_debug (use_stmt))
+ all = false;
continue;
}
- /* If the use is in a deeper loop nest, then we do not want
- to propagate the ADDR_EXPR into the loop as that is likely
- adding expression evaluations into the loop. */
- if (bb_for_stmt (use_stmt)->loop_depth > stmt_loop_depth)
+ /* If the use is in a deeper loop nest, then we do not want
+ to propagate non-invariant ADDR_EXPRs into the loop as that
+ is likely adding expression evaluations into the loop. */
+ if (gimple_bb (use_stmt)->loop_depth > stmt_loop_depth
+ && !is_gimple_min_invariant (rhs))
{
all = false;
continue;
}
-
- push_stmt_changes (&use_stmt);
- result = forward_propagate_addr_expr_1 (name, rhs, use_stmt);
+ {
+ gimple_stmt_iterator gsi = gsi_for_stmt (use_stmt);
+ result = forward_propagate_addr_expr_1 (name, rhs, &gsi,
+ single_use_p);
+ /* If the use has moved to a different statement adjust
+ the update machinery for the old statement too. */
+ if (use_stmt != gsi_stmt (gsi))
+ {
+ update_stmt (use_stmt);
+ use_stmt = gsi_stmt (gsi);
+ }
+
+ update_stmt (use_stmt);
+ }
all &= result;
- pop_stmt_changes (&use_stmt);
-
/* Remove intermediate now unused copy and conversion chains. */
+ use_rhs = gimple_assign_rhs1 (use_stmt);
if (result
- && TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 0)) == SSA_NAME
- && (TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 1)) == SSA_NAME
- || TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 1)) == NOP_EXPR
- || TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 1)) == CONVERT_EXPR))
+ && TREE_CODE (gimple_assign_lhs (use_stmt)) == SSA_NAME
+ && TREE_CODE (use_rhs) == SSA_NAME
+ && has_zero_uses (gimple_assign_lhs (use_stmt)))
{
- block_stmt_iterator bsi = bsi_for_stmt (use_stmt);
+ gimple_stmt_iterator gsi = gsi_for_stmt (use_stmt);
release_defs (use_stmt);
- bsi_remove (&bsi, true);
+ gsi_remove (&gsi, true);
}
}
- return all;
+ return all && has_zero_uses (name);
}
+
+/* Forward propagate the comparison defined in STMT like
+ cond_1 = x CMP y to uses of the form
+ a_1 = (T')cond_1
+ a_1 = !cond_1
+ a_1 = cond_1 != 0
+ Returns true if stmt is now unused. */
+
+static bool
+forward_propagate_comparison (gimple stmt)
+{
+ tree name = gimple_assign_lhs (stmt);
+ gimple use_stmt;
+ tree tmp = NULL_TREE;
+
+ /* Don't propagate ssa names that occur in abnormal phis. */
+ if ((TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
+ && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_assign_rhs1 (stmt)))
+ || (TREE_CODE (gimple_assign_rhs2 (stmt)) == SSA_NAME
+ && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_assign_rhs2 (stmt))))
+ return false;
+
+ /* Do not un-cse comparisons. But propagate through copies. */
+ use_stmt = get_prop_dest_stmt (name, &name);
+ if (!use_stmt)
+ return false;
+
+ /* Conversion of the condition result to another integral type. */
+ if (is_gimple_assign (use_stmt)
+ && (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (use_stmt))
+ || TREE_CODE_CLASS (gimple_assign_rhs_code (use_stmt))
+ == tcc_comparison
+ || gimple_assign_rhs_code (use_stmt) == TRUTH_NOT_EXPR)
+ && INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_lhs (use_stmt))))
+ {
+ tree lhs = gimple_assign_lhs (use_stmt);
+
+ /* We can propagate the condition into a conversion. */
+ if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (use_stmt)))
+ {
+ /* Avoid using fold here as that may create a COND_EXPR with
+ non-boolean condition as canonical form. */
+ tmp = build2 (gimple_assign_rhs_code (stmt), TREE_TYPE (lhs),
+ gimple_assign_rhs1 (stmt), gimple_assign_rhs2 (stmt));
+ }
+ /* We can propagate the condition into X op CST where op
+ is EQ_EXPR or NE_EXPR and CST is either one or zero. */
+ else if (TREE_CODE_CLASS (gimple_assign_rhs_code (use_stmt))
+ == tcc_comparison
+ && TREE_CODE (gimple_assign_rhs1 (use_stmt)) == SSA_NAME
+ && TREE_CODE (gimple_assign_rhs2 (use_stmt)) == INTEGER_CST)
+ {
+ enum tree_code code = gimple_assign_rhs_code (use_stmt);
+ tree cst = gimple_assign_rhs2 (use_stmt);
+ tree cond;
+
+ cond = build2 (gimple_assign_rhs_code (stmt),
+ TREE_TYPE (cst),
+ gimple_assign_rhs1 (stmt),
+ gimple_assign_rhs2 (stmt));
+
+ tmp = combine_cond_expr_cond (gimple_location (use_stmt),
+ code, TREE_TYPE (lhs),
+ cond, cst, false);
+ if (tmp == NULL_TREE)
+ return false;
+ }
+ /* We can propagate the condition into a statement that
+ computes the logical negation of the comparison result. */
+ else if (gimple_assign_rhs_code (use_stmt) == TRUTH_NOT_EXPR)
+ {
+ tree type = TREE_TYPE (gimple_assign_rhs1 (stmt));
+ bool nans = HONOR_NANS (TYPE_MODE (type));
+ enum tree_code code;
+ code = invert_tree_comparison (gimple_assign_rhs_code (stmt), nans);
+ if (code == ERROR_MARK)
+ return false;
+
+ tmp = build2 (code, TREE_TYPE (lhs), gimple_assign_rhs1 (stmt),
+ gimple_assign_rhs2 (stmt));
+ }
+ else
+ return false;
+
+ {
+ gimple_stmt_iterator gsi = gsi_for_stmt (use_stmt);
+ gimple_assign_set_rhs_from_tree (&gsi, unshare_expr (tmp));
+ use_stmt = gsi_stmt (gsi);
+ update_stmt (use_stmt);
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ tree old_rhs = rhs_to_tree (TREE_TYPE (gimple_assign_lhs (stmt)),
+ stmt);
+ fprintf (dump_file, " Replaced '");
+ print_generic_expr (dump_file, old_rhs, dump_flags);
+ fprintf (dump_file, "' with '");
+ print_generic_expr (dump_file, tmp, dump_flags);
+ fprintf (dump_file, "'\n");
+ }
+
+ /* Remove defining statements. */
+ return remove_prop_source_from_use (name);
+ }
+
+ return false;
+}
+
+
/* If we have lhs = ~x (STMT), look and see if earlier we had x = ~y.
If so, we can change STMT into lhs = y which can later be copy
- propagated. Similarly for negation.
+ propagated. Similarly for negation.
- This could trivially be formulated as a forward propagation
+ This could trivially be formulated as a forward propagation
to immediate uses. However, we already had an implementation
from DOM which used backward propagation via the use-def links.
there's less work to do for each NOT/NEG expression we find.
Backwards propagation needs to look at the statement in a single
backlink. Forward propagation needs to look at potentially more
- than one forward link. */
+ than one forward link.
-static void
-simplify_not_neg_expr (tree stmt)
+ Returns true when the statement was changed. */
+
+static bool
+simplify_not_neg_expr (gimple_stmt_iterator *gsi_p)
{
- tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
- tree rhs_def_stmt = SSA_NAME_DEF_STMT (TREE_OPERAND (rhs, 0));
+ gimple stmt = gsi_stmt (*gsi_p);
+ tree rhs = gimple_assign_rhs1 (stmt);
+ gimple rhs_def_stmt = SSA_NAME_DEF_STMT (rhs);
/* See if the RHS_DEF_STMT has the same form as our statement. */
- if (TREE_CODE (rhs_def_stmt) == GIMPLE_MODIFY_STMT
- && TREE_CODE (GIMPLE_STMT_OPERAND (rhs_def_stmt, 1)) == TREE_CODE (rhs))
+ if (is_gimple_assign (rhs_def_stmt)
+ && gimple_assign_rhs_code (rhs_def_stmt) == gimple_assign_rhs_code (stmt))
{
- tree rhs_def_operand =
- TREE_OPERAND (GIMPLE_STMT_OPERAND (rhs_def_stmt, 1), 0);
+ tree rhs_def_operand = gimple_assign_rhs1 (rhs_def_stmt);
/* Verify that RHS_DEF_OPERAND is a suitable SSA_NAME. */
if (TREE_CODE (rhs_def_operand) == SSA_NAME
&& ! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs_def_operand))
{
- GIMPLE_STMT_OPERAND (stmt, 1) = rhs_def_operand;
+ gimple_assign_set_rhs_from_tree (gsi_p, rhs_def_operand);
+ stmt = gsi_stmt (*gsi_p);
update_stmt (stmt);
+ return true;
}
}
+
+ return false;
}
/* STMT is a SWITCH_EXPR for which we attempt to find equivalent forms of
the condition which we may be able to optimize better. */
-static void
-simplify_switch_expr (tree stmt)
+static bool
+simplify_gimple_switch (gimple stmt)
{
- tree cond = SWITCH_COND (stmt);
+ tree cond = gimple_switch_index (stmt);
tree def, to, ti;
+ gimple def_stmt;
/* The optimization that we really care about is removing unnecessary
casts. That will let us do much better in propagating the inferred
constant at the switch target. */
if (TREE_CODE (cond) == SSA_NAME)
{
- def = SSA_NAME_DEF_STMT (cond);
- if (TREE_CODE (def) == GIMPLE_MODIFY_STMT)
+ def_stmt = SSA_NAME_DEF_STMT (cond);
+ if (is_gimple_assign (def_stmt))
{
- def = GIMPLE_STMT_OPERAND (def, 1);
- if (TREE_CODE (def) == NOP_EXPR)
+ if (gimple_assign_rhs_code (def_stmt) == NOP_EXPR)
{
int need_precision;
bool fail;
- def = TREE_OPERAND (def, 0);
+ def = gimple_assign_rhs1 (def_stmt);
-#ifdef ENABLE_CHECKING
/* ??? Why was Jeff testing this? We are gimple... */
- gcc_assert (is_gimple_val (def));
-#endif
+ gcc_checking_assert (is_gimple_val (def));
to = TREE_TYPE (cond);
ti = TREE_TYPE (def);
if (!fail)
{
- SWITCH_COND (stmt) = def;
+ gimple_switch_set_index (stmt, def);
update_stmt (stmt);
+ return true;
+ }
+ }
+ }
+ }
+
+ return false;
+}
+
+/* For pointers p2 and p1 return p2 - p1 if the
+ difference is known and constant, otherwise return NULL. */
+
+static tree
+constant_pointer_difference (tree p1, tree p2)
+{
+ int i, j;
+#define CPD_ITERATIONS 5
+ tree exps[2][CPD_ITERATIONS];
+ tree offs[2][CPD_ITERATIONS];
+ int cnt[2];
+
+ for (i = 0; i < 2; i++)
+ {
+ tree p = i ? p1 : p2;
+ tree off = size_zero_node;
+ gimple stmt;
+ enum tree_code code;
+
+ /* For each of p1 and p2 we need to iterate at least
+ twice, to handle ADDR_EXPR directly in p1/p2,
+ SSA_NAME with ADDR_EXPR or POINTER_PLUS_EXPR etc.
+ on definition's stmt RHS. Iterate a few extra times. */
+ j = 0;
+ do
+ {
+ if (!POINTER_TYPE_P (TREE_TYPE (p)))
+ break;
+ if (TREE_CODE (p) == ADDR_EXPR)
+ {
+ tree q = TREE_OPERAND (p, 0);
+ HOST_WIDE_INT offset;
+ tree base = get_addr_base_and_unit_offset (q, &offset);
+ if (base)
+ {
+ q = base;
+ if (offset)
+ off = size_binop (PLUS_EXPR, off, size_int (offset));
}
+ if (TREE_CODE (q) == MEM_REF
+ && TREE_CODE (TREE_OPERAND (q, 0)) == SSA_NAME)
+ {
+ p = TREE_OPERAND (q, 0);
+ off = size_binop (PLUS_EXPR, off,
+ double_int_to_tree (sizetype,
+ mem_ref_offset (q)));
+ }
+ else
+ {
+ exps[i][j] = q;
+ offs[i][j++] = off;
+ break;
+ }
+ }
+ if (TREE_CODE (p) != SSA_NAME)
+ break;
+ exps[i][j] = p;
+ offs[i][j++] = off;
+ if (j == CPD_ITERATIONS)
+ break;
+ stmt = SSA_NAME_DEF_STMT (p);
+ if (!is_gimple_assign (stmt) || gimple_assign_lhs (stmt) != p)
+ break;
+ code = gimple_assign_rhs_code (stmt);
+ if (code == POINTER_PLUS_EXPR)
+ {
+ if (TREE_CODE (gimple_assign_rhs2 (stmt)) != INTEGER_CST)
+ break;
+ off = size_binop (PLUS_EXPR, off, gimple_assign_rhs2 (stmt));
+ p = gimple_assign_rhs1 (stmt);
+ }
+ else if (code == ADDR_EXPR || code == NOP_EXPR)
+ p = gimple_assign_rhs1 (stmt);
+ else
+ break;
+ }
+ while (1);
+ cnt[i] = j;
+ }
+
+ for (i = 0; i < cnt[0]; i++)
+ for (j = 0; j < cnt[1]; j++)
+ if (exps[0][i] == exps[1][j])
+ return size_binop (MINUS_EXPR, offs[0][i], offs[1][j]);
+
+ return NULL_TREE;
+}
+
+/* *GSI_P is a GIMPLE_CALL to a builtin function.
+ Optimize
+ memcpy (p, "abcd", 4);
+ memset (p + 4, ' ', 3);
+ into
+ memcpy (p, "abcd ", 7);
+ call if the latter can be stored by pieces during expansion. */
+
+static bool
+simplify_builtin_call (gimple_stmt_iterator *gsi_p, tree callee2)
+{
+ gimple stmt1, stmt2 = gsi_stmt (*gsi_p);
+ tree vuse = gimple_vuse (stmt2);
+ if (vuse == NULL)
+ return false;
+ stmt1 = SSA_NAME_DEF_STMT (vuse);
+
+ switch (DECL_FUNCTION_CODE (callee2))
+ {
+ case BUILT_IN_MEMSET:
+ if (gimple_call_num_args (stmt2) != 3
+ || gimple_call_lhs (stmt2)
+ || CHAR_BIT != 8
+ || BITS_PER_UNIT != 8)
+ break;
+ else
+ {
+ tree callee1;
+ tree ptr1, src1, str1, off1, len1, lhs1;
+ tree ptr2 = gimple_call_arg (stmt2, 0);
+ tree val2 = gimple_call_arg (stmt2, 1);
+ tree len2 = gimple_call_arg (stmt2, 2);
+ tree diff, vdef, new_str_cst;
+ gimple use_stmt;
+ unsigned int ptr1_align;
+ unsigned HOST_WIDE_INT src_len;
+ char *src_buf;
+ use_operand_p use_p;
+
+ if (!host_integerp (val2, 0)
+ || !host_integerp (len2, 1))
+ break;
+ if (is_gimple_call (stmt1))
+ {
+ /* If first stmt is a call, it needs to be memcpy
+ or mempcpy, with string literal as second argument and
+ constant length. */
+ callee1 = gimple_call_fndecl (stmt1);
+ if (callee1 == NULL_TREE
+ || DECL_BUILT_IN_CLASS (callee1) != BUILT_IN_NORMAL
+ || gimple_call_num_args (stmt1) != 3)
+ break;
+ if (DECL_FUNCTION_CODE (callee1) != BUILT_IN_MEMCPY
+ && DECL_FUNCTION_CODE (callee1) != BUILT_IN_MEMPCPY)
+ break;
+ ptr1 = gimple_call_arg (stmt1, 0);
+ src1 = gimple_call_arg (stmt1, 1);
+ len1 = gimple_call_arg (stmt1, 2);
+ lhs1 = gimple_call_lhs (stmt1);
+ if (!host_integerp (len1, 1))
+ break;
+ str1 = string_constant (src1, &off1);
+ if (str1 == NULL_TREE)
+ break;
+ if (!host_integerp (off1, 1)
+ || compare_tree_int (off1, TREE_STRING_LENGTH (str1) - 1) > 0
+ || compare_tree_int (len1, TREE_STRING_LENGTH (str1)
+ - tree_low_cst (off1, 1)) > 0
+ || TREE_CODE (TREE_TYPE (str1)) != ARRAY_TYPE
+ || TYPE_MODE (TREE_TYPE (TREE_TYPE (str1)))
+ != TYPE_MODE (char_type_node))
+ break;
+ }
+ else if (gimple_assign_single_p (stmt1))
+ {
+ /* Otherwise look for length 1 memcpy optimized into
+ assignment. */
+ ptr1 = gimple_assign_lhs (stmt1);
+ src1 = gimple_assign_rhs1 (stmt1);
+ if (TREE_CODE (ptr1) != MEM_REF
+ || TYPE_MODE (TREE_TYPE (ptr1)) != TYPE_MODE (char_type_node)
+ || !host_integerp (src1, 0))
+ break;
+ ptr1 = build_fold_addr_expr (ptr1);
+ callee1 = NULL_TREE;
+ len1 = size_one_node;
+ lhs1 = NULL_TREE;
+ off1 = size_zero_node;
+ str1 = NULL_TREE;
+ }
+ else
+ break;
+
+ diff = constant_pointer_difference (ptr1, ptr2);
+ if (diff == NULL && lhs1 != NULL)
+ {
+ diff = constant_pointer_difference (lhs1, ptr2);
+ if (DECL_FUNCTION_CODE (callee1) == BUILT_IN_MEMPCPY
+ && diff != NULL)
+ diff = size_binop (PLUS_EXPR, diff,
+ fold_convert (sizetype, len1));
+ }
+ /* If the difference between the second and first destination pointer
+ is not constant, or is bigger than memcpy length, bail out. */
+ if (diff == NULL
+ || !host_integerp (diff, 1)
+ || tree_int_cst_lt (len1, diff))
+ break;
+
+ /* Use maximum of difference plus memset length and memcpy length
+ as the new memcpy length, if it is too big, bail out. */
+ src_len = tree_low_cst (diff, 1);
+ src_len += tree_low_cst (len2, 1);
+ if (src_len < (unsigned HOST_WIDE_INT) tree_low_cst (len1, 1))
+ src_len = tree_low_cst (len1, 1);
+ if (src_len > 1024)
+ break;
+
+ /* If mempcpy value is used elsewhere, bail out, as mempcpy
+ with bigger length will return different result. */
+ if (lhs1 != NULL_TREE
+ && DECL_FUNCTION_CODE (callee1) == BUILT_IN_MEMPCPY
+ && (TREE_CODE (lhs1) != SSA_NAME
+ || !single_imm_use (lhs1, &use_p, &use_stmt)
+ || use_stmt != stmt2))
+ break;
+
+ /* If anything reads memory in between memcpy and memset
+ call, the modified memcpy call might change it. */
+ vdef = gimple_vdef (stmt1);
+ if (vdef != NULL
+ && (!single_imm_use (vdef, &use_p, &use_stmt)
+ || use_stmt != stmt2))
+ break;
+
+ ptr1_align = get_pointer_alignment (ptr1, BIGGEST_ALIGNMENT);
+ /* Construct the new source string literal. */
+ src_buf = XALLOCAVEC (char, src_len + 1);
+ if (callee1)
+ memcpy (src_buf,
+ TREE_STRING_POINTER (str1) + tree_low_cst (off1, 1),
+ tree_low_cst (len1, 1));
+ else
+ src_buf[0] = tree_low_cst (src1, 0);
+ memset (src_buf + tree_low_cst (diff, 1),
+ tree_low_cst (val2, 1), tree_low_cst (len2, 1));
+ src_buf[src_len] = '\0';
+ /* Neither builtin_strncpy_read_str nor builtin_memcpy_read_str
+ handle embedded '\0's. */
+ if (strlen (src_buf) != src_len)
+ break;
+ rtl_profile_for_bb (gimple_bb (stmt2));
+ /* If the new memcpy wouldn't be emitted by storing the literal
+ by pieces, this optimization might enlarge .rodata too much,
+ as commonly used string literals couldn't be shared any
+ longer. */
+ if (!can_store_by_pieces (src_len,
+ builtin_strncpy_read_str,
+ src_buf, ptr1_align, false))
+ break;
+
+ new_str_cst = build_string_literal (src_len, src_buf);
+ if (callee1)
+ {
+ /* If STMT1 is a mem{,p}cpy call, adjust it and remove
+ memset call. */
+ if (lhs1 && DECL_FUNCTION_CODE (callee1) == BUILT_IN_MEMPCPY)
+ gimple_call_set_lhs (stmt1, NULL_TREE);
+ gimple_call_set_arg (stmt1, 1, new_str_cst);
+ gimple_call_set_arg (stmt1, 2,
+ build_int_cst (TREE_TYPE (len1), src_len));
+ update_stmt (stmt1);
+ unlink_stmt_vdef (stmt2);
+ gsi_remove (gsi_p, true);
+ release_defs (stmt2);
+ if (lhs1 && DECL_FUNCTION_CODE (callee1) == BUILT_IN_MEMPCPY)
+ release_ssa_name (lhs1);
+ return true;
}
+ else
+ {
+ /* Otherwise, if STMT1 is length 1 memcpy optimized into
+ assignment, remove STMT1 and change memset call into
+ memcpy call. */
+ gimple_stmt_iterator gsi = gsi_for_stmt (stmt1);
+
+ if (!is_gimple_val (ptr1))
+ ptr1 = force_gimple_operand_gsi (gsi_p, ptr1, true, NULL_TREE,
+ true, GSI_SAME_STMT);
+ gimple_call_set_fndecl (stmt2, built_in_decls [BUILT_IN_MEMCPY]);
+ gimple_call_set_arg (stmt2, 0, ptr1);
+ gimple_call_set_arg (stmt2, 1, new_str_cst);
+ gimple_call_set_arg (stmt2, 2,
+ build_int_cst (TREE_TYPE (len2), src_len));
+ unlink_stmt_vdef (stmt1);
+ gsi_remove (&gsi, true);
+ release_defs (stmt1);
+ update_stmt (stmt2);
+ return false;
+ }
+ }
+ break;
+ default:
+ break;
+ }
+ return false;
+}
+
+/* Simplify bitwise binary operations.
+ Return true if a transformation applied, otherwise return false. */
+
+static bool
+simplify_bitwise_binary (gimple_stmt_iterator *gsi)
+{
+ gimple stmt = gsi_stmt (*gsi);
+ tree arg1 = gimple_assign_rhs1 (stmt);
+ tree arg2 = gimple_assign_rhs2 (stmt);
+ enum tree_code code = gimple_assign_rhs_code (stmt);
+ tree res;
+ gimple def1 = NULL, def2 = NULL;
+ tree def1_arg1, def2_arg1;
+ enum tree_code def1_code, def2_code;
+
+ /* If the first argument is an SSA name that is itself a result of a
+ typecast of an ADDR_EXPR to an integer, feed the ADDR_EXPR to the
+ folder rather than the ssa name. */
+ if (code == BIT_AND_EXPR
+ && TREE_CODE (arg2) == INTEGER_CST
+ && TREE_CODE (arg1) == SSA_NAME)
+ {
+ gimple def = SSA_NAME_DEF_STMT (arg1);
+ tree op = arg1;
+
+ /* ??? This looks bogus - the conversion could be truncating. */
+ if (is_gimple_assign (def)
+ && CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def))
+ && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
+ {
+ tree opp = gimple_assign_rhs1 (def);
+ if (TREE_CODE (opp) == ADDR_EXPR)
+ op = opp;
+ }
+
+ res = fold_binary_loc (gimple_location (stmt),
+ BIT_AND_EXPR, TREE_TYPE (gimple_assign_lhs (stmt)),
+ op, arg2);
+ if (res && is_gimple_min_invariant (res))
+ {
+ gimple_assign_set_rhs_from_tree (gsi, res);
+ update_stmt (stmt);
+ return true;
+ }
+ }
+
+ def1_code = TREE_CODE (arg1);
+ def1_arg1 = arg1;
+ if (TREE_CODE (arg1) == SSA_NAME)
+ {
+ def1 = SSA_NAME_DEF_STMT (arg1);
+ if (is_gimple_assign (def1))
+ {
+ def1_code = gimple_assign_rhs_code (def1);
+ def1_arg1 = gimple_assign_rhs1 (def1);
+ }
+ }
+
+ def2_code = TREE_CODE (arg2);
+ def2_arg1 = arg2;
+ if (TREE_CODE (arg2) == SSA_NAME)
+ {
+ def2 = SSA_NAME_DEF_STMT (arg2);
+ if (is_gimple_assign (def2))
+ {
+ def2_code = gimple_assign_rhs_code (def2);
+ def2_arg1 = gimple_assign_rhs1 (def2);
}
}
+
+ /* For bitwise binary operations apply operand conversions to the
+ binary operation result instead of to the operands. This allows
+ to combine successive conversions and bitwise binary operations. */
+ if (CONVERT_EXPR_CODE_P (def1_code)
+ && CONVERT_EXPR_CODE_P (def2_code)
+ && types_compatible_p (TREE_TYPE (def1_arg1), TREE_TYPE (def2_arg1))
+ /* Make sure that the conversion widens the operands or that it
+ changes the operation to a bitfield precision. */
+ && ((TYPE_PRECISION (TREE_TYPE (def1_arg1))
+ < TYPE_PRECISION (TREE_TYPE (arg1)))
+ || (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (arg1)))
+ != MODE_INT)
+ || (TYPE_PRECISION (TREE_TYPE (arg1))
+ != GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (arg1))))))
+ {
+ gimple newop;
+ tree tem = create_tmp_reg (TREE_TYPE (def1_arg1),
+ NULL);
+ newop = gimple_build_assign_with_ops (code, tem, def1_arg1, def2_arg1);
+ tem = make_ssa_name (tem, newop);
+ gimple_assign_set_lhs (newop, tem);
+ gsi_insert_before (gsi, newop, GSI_SAME_STMT);
+ gimple_assign_set_rhs_with_ops_1 (gsi, NOP_EXPR,
+ tem, NULL_TREE, NULL_TREE);
+ update_stmt (gsi_stmt (*gsi));
+ return true;
+ }
+
+ /* (a | CST1) & CST2 -> (a & CST2) | (CST1 & CST2). */
+ if (code == BIT_AND_EXPR
+ && def1_code == BIT_IOR_EXPR
+ && TREE_CODE (arg2) == INTEGER_CST
+ && TREE_CODE (gimple_assign_rhs2 (def1)) == INTEGER_CST)
+ {
+ tree cst = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg2),
+ arg2, gimple_assign_rhs2 (def1));
+ tree tem;
+ gimple newop;
+ if (integer_zerop (cst))
+ {
+ gimple_assign_set_rhs1 (stmt, def1_arg1);
+ update_stmt (stmt);
+ return true;
+ }
+ tem = create_tmp_reg (TREE_TYPE (arg2), NULL);
+ newop = gimple_build_assign_with_ops (BIT_AND_EXPR,
+ tem, def1_arg1, arg2);
+ tem = make_ssa_name (tem, newop);
+ gimple_assign_set_lhs (newop, tem);
+ /* Make sure to re-process the new stmt as it's walking upwards. */
+ gsi_insert_before (gsi, newop, GSI_NEW_STMT);
+ gimple_assign_set_rhs1 (stmt, tem);
+ gimple_assign_set_rhs2 (stmt, cst);
+ gimple_assign_set_rhs_code (stmt, BIT_IOR_EXPR);
+ update_stmt (stmt);
+ return true;
+ }
+
+ /* Combine successive equal operations with constants. */
+ if ((code == BIT_AND_EXPR
+ || code == BIT_IOR_EXPR
+ || code == BIT_XOR_EXPR)
+ && def1_code == code
+ && TREE_CODE (arg2) == INTEGER_CST
+ && TREE_CODE (gimple_assign_rhs2 (def1)) == INTEGER_CST)
+ {
+ tree cst = fold_build2 (code, TREE_TYPE (arg2),
+ arg2, gimple_assign_rhs2 (def1));
+ gimple_assign_set_rhs1 (stmt, def1_arg1);
+ gimple_assign_set_rhs2 (stmt, cst);
+ update_stmt (stmt);
+ return true;
+ }
+
+ return false;
}
-/* Main entry point for the forward propagation optimizer. */
+
+/* Perform re-associations of the plus or minus statement STMT that are
+ always permitted. Returns true if the CFG was changed. */
+
+static bool
+associate_plusminus (gimple stmt)
+{
+ tree rhs1 = gimple_assign_rhs1 (stmt);
+ tree rhs2 = gimple_assign_rhs2 (stmt);
+ enum tree_code code = gimple_assign_rhs_code (stmt);
+ gimple_stmt_iterator gsi;
+ bool changed;
+
+ /* We can't reassociate at all for saturating types. */
+ if (TYPE_SATURATING (TREE_TYPE (rhs1)))
+ return false;
+
+ /* First contract negates. */
+ do
+ {
+ changed = false;
+
+ /* A +- (-B) -> A -+ B. */
+ if (TREE_CODE (rhs2) == SSA_NAME)
+ {
+ gimple def_stmt = SSA_NAME_DEF_STMT (rhs2);
+ if (is_gimple_assign (def_stmt)
+ && gimple_assign_rhs_code (def_stmt) == NEGATE_EXPR)
+ {
+ code = (code == MINUS_EXPR) ? PLUS_EXPR : MINUS_EXPR;
+ gimple_assign_set_rhs_code (stmt, code);
+ rhs2 = gimple_assign_rhs1 (def_stmt);
+ gimple_assign_set_rhs2 (stmt, rhs2);
+ gimple_set_modified (stmt, true);
+ changed = true;
+ }
+ }
+
+ /* (-A) + B -> B - A. */
+ if (TREE_CODE (rhs1) == SSA_NAME
+ && code == PLUS_EXPR)
+ {
+ gimple def_stmt = SSA_NAME_DEF_STMT (rhs1);
+ if (is_gimple_assign (def_stmt)
+ && gimple_assign_rhs_code (def_stmt) == NEGATE_EXPR)
+ {
+ code = MINUS_EXPR;
+ gimple_assign_set_rhs_code (stmt, code);
+ rhs1 = rhs2;
+ gimple_assign_set_rhs1 (stmt, rhs1);
+ rhs2 = gimple_assign_rhs1 (def_stmt);
+ gimple_assign_set_rhs2 (stmt, rhs2);
+ gimple_set_modified (stmt, true);
+ changed = true;
+ }
+ }
+ }
+ while (changed);
+
+ /* We can't reassociate floating-point or fixed-point plus or minus
+ because of saturation to +-Inf. */
+ if (FLOAT_TYPE_P (TREE_TYPE (rhs1))
+ || FIXED_POINT_TYPE_P (TREE_TYPE (rhs1)))
+ goto out;
+
+ /* Second match patterns that allow contracting a plus-minus pair
+ irrespective of overflow issues.
+
+ (A +- B) - A -> +- B
+ (A +- B) -+ B -> A
+ (CST +- A) +- CST -> CST +- A
+ (A + CST) +- CST -> A + CST
+ ~A + A -> -1
+ ~A + 1 -> -A
+ A - (A +- B) -> -+ B
+ A +- (B +- A) -> +- B
+ CST +- (CST +- A) -> CST +- A
+ CST +- (A +- CST) -> CST +- A
+ A + ~A -> -1
+
+ via commutating the addition and contracting operations to zero
+ by reassociation. */
+
+ gsi = gsi_for_stmt (stmt);
+ if (TREE_CODE (rhs1) == SSA_NAME)
+ {
+ gimple def_stmt = SSA_NAME_DEF_STMT (rhs1);
+ if (is_gimple_assign (def_stmt))
+ {
+ enum tree_code def_code = gimple_assign_rhs_code (def_stmt);
+ if (def_code == PLUS_EXPR
+ || def_code == MINUS_EXPR)
+ {
+ tree def_rhs1 = gimple_assign_rhs1 (def_stmt);
+ tree def_rhs2 = gimple_assign_rhs2 (def_stmt);
+ if (operand_equal_p (def_rhs1, rhs2, 0)
+ && code == MINUS_EXPR)
+ {
+ /* (A +- B) - A -> +- B. */
+ code = ((def_code == PLUS_EXPR)
+ ? TREE_CODE (def_rhs2) : NEGATE_EXPR);
+ rhs1 = def_rhs2;
+ rhs2 = NULL_TREE;
+ gimple_assign_set_rhs_with_ops (&gsi, code, rhs1, NULL_TREE);
+ gcc_assert (gsi_stmt (gsi) == stmt);
+ gimple_set_modified (stmt, true);
+ }
+ else if (operand_equal_p (def_rhs2, rhs2, 0)
+ && code != def_code)
+ {
+ /* (A +- B) -+ B -> A. */
+ code = TREE_CODE (def_rhs1);
+ rhs1 = def_rhs1;
+ rhs2 = NULL_TREE;
+ gimple_assign_set_rhs_with_ops (&gsi, code, rhs1, NULL_TREE);
+ gcc_assert (gsi_stmt (gsi) == stmt);
+ gimple_set_modified (stmt, true);
+ }
+ else if (TREE_CODE (rhs2) == INTEGER_CST
+ && TREE_CODE (def_rhs1) == INTEGER_CST)
+ {
+ /* (CST +- A) +- CST -> CST +- A. */
+ tree cst = fold_binary (code, TREE_TYPE (rhs1),
+ def_rhs1, rhs2);
+ if (cst && !TREE_OVERFLOW (cst))
+ {
+ code = def_code;
+ gimple_assign_set_rhs_code (stmt, code);
+ rhs1 = cst;
+ gimple_assign_set_rhs1 (stmt, rhs1);
+ rhs2 = def_rhs2;
+ gimple_assign_set_rhs2 (stmt, rhs2);
+ gimple_set_modified (stmt, true);
+ }
+ }
+ else if (TREE_CODE (rhs2) == INTEGER_CST
+ && TREE_CODE (def_rhs2) == INTEGER_CST
+ && def_code == PLUS_EXPR)
+ {
+ /* (A + CST) +- CST -> A + CST. */
+ tree cst = fold_binary (code, TREE_TYPE (rhs1),
+ def_rhs2, rhs2);
+ if (cst && !TREE_OVERFLOW (cst))
+ {
+ code = PLUS_EXPR;
+ gimple_assign_set_rhs_code (stmt, code);
+ rhs1 = def_rhs1;
+ gimple_assign_set_rhs1 (stmt, rhs1);
+ rhs2 = cst;
+ gimple_assign_set_rhs2 (stmt, rhs2);
+ gimple_set_modified (stmt, true);
+ }
+ }
+ }
+ else if (def_code == BIT_NOT_EXPR
+ && INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
+ {
+ tree def_rhs1 = gimple_assign_rhs1 (def_stmt);
+ if (code == PLUS_EXPR
+ && operand_equal_p (def_rhs1, rhs2, 0))
+ {
+ /* ~A + A -> -1. */
+ code = INTEGER_CST;
+ rhs1 = build_int_cst_type (TREE_TYPE (rhs2), -1);
+ rhs2 = NULL_TREE;
+ gimple_assign_set_rhs_with_ops (&gsi, code, rhs1, NULL_TREE);
+ gcc_assert (gsi_stmt (gsi) == stmt);
+ gimple_set_modified (stmt, true);
+ }
+ else if (code == PLUS_EXPR
+ && integer_onep (rhs1))
+ {
+ /* ~A + 1 -> -A. */
+ code = NEGATE_EXPR;
+ rhs1 = def_rhs1;
+ rhs2 = NULL_TREE;
+ gimple_assign_set_rhs_with_ops (&gsi, code, rhs1, NULL_TREE);
+ gcc_assert (gsi_stmt (gsi) == stmt);
+ gimple_set_modified (stmt, true);
+ }
+ }
+ }
+ }
+
+ if (rhs2 && TREE_CODE (rhs2) == SSA_NAME)
+ {
+ gimple def_stmt = SSA_NAME_DEF_STMT (rhs2);
+ if (is_gimple_assign (def_stmt))
+ {
+ enum tree_code def_code = gimple_assign_rhs_code (def_stmt);
+ if (def_code == PLUS_EXPR
+ || def_code == MINUS_EXPR)
+ {
+ tree def_rhs1 = gimple_assign_rhs1 (def_stmt);
+ tree def_rhs2 = gimple_assign_rhs2 (def_stmt);
+ if (operand_equal_p (def_rhs1, rhs1, 0)
+ && code == MINUS_EXPR)
+ {
+ /* A - (A +- B) -> -+ B. */
+ code = ((def_code == PLUS_EXPR)
+ ? NEGATE_EXPR : TREE_CODE (def_rhs2));
+ rhs1 = def_rhs2;
+ rhs2 = NULL_TREE;
+ gimple_assign_set_rhs_with_ops (&gsi, code, rhs1, NULL_TREE);
+ gcc_assert (gsi_stmt (gsi) == stmt);
+ gimple_set_modified (stmt, true);
+ }
+ else if (operand_equal_p (def_rhs2, rhs1, 0)
+ && code != def_code)
+ {
+ /* A +- (B +- A) -> +- B. */
+ code = ((code == PLUS_EXPR)
+ ? TREE_CODE (def_rhs1) : NEGATE_EXPR);
+ rhs1 = def_rhs1;
+ rhs2 = NULL_TREE;
+ gimple_assign_set_rhs_with_ops (&gsi, code, rhs1, NULL_TREE);
+ gcc_assert (gsi_stmt (gsi) == stmt);
+ gimple_set_modified (stmt, true);
+ }
+ else if (TREE_CODE (rhs1) == INTEGER_CST
+ && TREE_CODE (def_rhs1) == INTEGER_CST)
+ {
+ /* CST +- (CST +- A) -> CST +- A. */
+ tree cst = fold_binary (code, TREE_TYPE (rhs2),
+ rhs1, def_rhs1);
+ if (cst && !TREE_OVERFLOW (cst))
+ {
+ code = (code == def_code ? PLUS_EXPR : MINUS_EXPR);
+ gimple_assign_set_rhs_code (stmt, code);
+ rhs1 = cst;
+ gimple_assign_set_rhs1 (stmt, rhs1);
+ rhs2 = def_rhs2;
+ gimple_assign_set_rhs2 (stmt, rhs2);
+ gimple_set_modified (stmt, true);
+ }
+ }
+ else if (TREE_CODE (rhs1) == INTEGER_CST
+ && TREE_CODE (def_rhs2) == INTEGER_CST)
+ {
+ /* CST +- (A +- CST) -> CST +- A. */
+ tree cst = fold_binary (def_code == code
+ ? PLUS_EXPR : MINUS_EXPR,
+ TREE_TYPE (rhs2),
+ rhs1, def_rhs2);
+ if (cst && !TREE_OVERFLOW (cst))
+ {
+ rhs1 = cst;
+ gimple_assign_set_rhs1 (stmt, rhs1);
+ rhs2 = def_rhs1;
+ gimple_assign_set_rhs2 (stmt, rhs2);
+ gimple_set_modified (stmt, true);
+ }
+ }
+ }
+ else if (def_code == BIT_NOT_EXPR
+ && INTEGRAL_TYPE_P (TREE_TYPE (rhs2)))
+ {
+ tree def_rhs1 = gimple_assign_rhs1 (def_stmt);
+ if (code == PLUS_EXPR
+ && operand_equal_p (def_rhs1, rhs1, 0))
+ {
+ /* A + ~A -> -1. */
+ code = INTEGER_CST;
+ rhs1 = build_int_cst_type (TREE_TYPE (rhs1), -1);
+ rhs2 = NULL_TREE;
+ gimple_assign_set_rhs_with_ops (&gsi, code, rhs1, NULL_TREE);
+ gcc_assert (gsi_stmt (gsi) == stmt);
+ gimple_set_modified (stmt, true);
+ }
+ }
+ }
+ }
+
+out:
+ if (gimple_modified_p (stmt))
+ {
+ fold_stmt_inplace (stmt);
+ update_stmt (stmt);
+ if (maybe_clean_or_replace_eh_stmt (stmt, stmt)
+ && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
+ return true;
+ }
+
+ return false;
+}
+
+/* Combine two conversions in a row for the second conversion at *GSI.
+ Returns true if there were any changes made. */
+
+static bool
+combine_conversions (gimple_stmt_iterator *gsi)
+{
+ gimple stmt = gsi_stmt (*gsi);
+ gimple def_stmt;
+ tree op0, lhs;
+ enum tree_code code = gimple_assign_rhs_code (stmt);
+
+ gcc_checking_assert (CONVERT_EXPR_CODE_P (code)
+ || code == FLOAT_EXPR
+ || code == FIX_TRUNC_EXPR);
+
+ lhs = gimple_assign_lhs (stmt);
+ op0 = gimple_assign_rhs1 (stmt);
+ if (useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (op0)))
+ {
+ gimple_assign_set_rhs_code (stmt, TREE_CODE (op0));
+ return true;
+ }
+
+ if (TREE_CODE (op0) != SSA_NAME)
+ return false;
+
+ def_stmt = SSA_NAME_DEF_STMT (op0);
+ if (!is_gimple_assign (def_stmt))
+ return false;
+
+ if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt)))
+ {
+ tree defop0 = gimple_assign_rhs1 (def_stmt);
+ tree type = TREE_TYPE (lhs);
+ tree inside_type = TREE_TYPE (defop0);
+ tree inter_type = TREE_TYPE (op0);
+ int inside_int = INTEGRAL_TYPE_P (inside_type);
+ int inside_ptr = POINTER_TYPE_P (inside_type);
+ int inside_float = FLOAT_TYPE_P (inside_type);
+ int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
+ unsigned int inside_prec = TYPE_PRECISION (inside_type);
+ int inside_unsignedp = TYPE_UNSIGNED (inside_type);
+ int inter_int = INTEGRAL_TYPE_P (inter_type);
+ int inter_ptr = POINTER_TYPE_P (inter_type);
+ int inter_float = FLOAT_TYPE_P (inter_type);
+ int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
+ unsigned int inter_prec = TYPE_PRECISION (inter_type);
+ int inter_unsignedp = TYPE_UNSIGNED (inter_type);
+ int final_int = INTEGRAL_TYPE_P (type);
+ int final_ptr = POINTER_TYPE_P (type);
+ int final_float = FLOAT_TYPE_P (type);
+ int final_vec = TREE_CODE (type) == VECTOR_TYPE;
+ unsigned int final_prec = TYPE_PRECISION (type);
+ int final_unsignedp = TYPE_UNSIGNED (type);
+
+ /* In addition to the cases of two conversions in a row
+ handled below, if we are converting something to its own
+ type via an object of identical or wider precision, neither
+ conversion is needed. */
+ if (useless_type_conversion_p (type, inside_type)
+ && (((inter_int || inter_ptr) && final_int)
+ || (inter_float && final_float))
+ && inter_prec >= final_prec)
+ {
+ gimple_assign_set_rhs1 (stmt, unshare_expr (defop0));
+ gimple_assign_set_rhs_code (stmt, TREE_CODE (defop0));
+ update_stmt (stmt);
+ return true;
+ }
+
+ /* Likewise, if the intermediate and initial types are either both
+ float or both integer, we don't need the middle conversion if the
+ former is wider than the latter and doesn't change the signedness
+ (for integers). Avoid this if the final type is a pointer since
+ then we sometimes need the middle conversion. Likewise if the
+ final type has a precision not equal to the size of its mode. */
+ if (((inter_int && inside_int)
+ || (inter_float && inside_float)
+ || (inter_vec && inside_vec))
+ && inter_prec >= inside_prec
+ && (inter_float || inter_vec
+ || inter_unsignedp == inside_unsignedp)
+ && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
+ && TYPE_MODE (type) == TYPE_MODE (inter_type))
+ && ! final_ptr
+ && (! final_vec || inter_prec == inside_prec))
+ {
+ gimple_assign_set_rhs1 (stmt, defop0);
+ update_stmt (stmt);
+ return true;
+ }
+
+ /* If we have a sign-extension of a zero-extended value, we can
+ replace that by a single zero-extension. */
+ if (inside_int && inter_int && final_int
+ && inside_prec < inter_prec && inter_prec < final_prec
+ && inside_unsignedp && !inter_unsignedp)
+ {
+ gimple_assign_set_rhs1 (stmt, defop0);
+ update_stmt (stmt);
+ return true;
+ }
+
+ /* Two conversions in a row are not needed unless:
+ - some conversion is floating-point (overstrict for now), or
+ - some conversion is a vector (overstrict for now), or
+ - the intermediate type is narrower than both initial and
+ final, or
+ - the intermediate type and innermost type differ in signedness,
+ and the outermost type is wider than the intermediate, or
+ - the initial type is a pointer type and the precisions of the
+ intermediate and final types differ, or
+ - the final type is a pointer type and the precisions of the
+ initial and intermediate types differ. */
+ if (! inside_float && ! inter_float && ! final_float
+ && ! inside_vec && ! inter_vec && ! final_vec
+ && (inter_prec >= inside_prec || inter_prec >= final_prec)
+ && ! (inside_int && inter_int
+ && inter_unsignedp != inside_unsignedp
+ && inter_prec < final_prec)
+ && ((inter_unsignedp && inter_prec > inside_prec)
+ == (final_unsignedp && final_prec > inter_prec))
+ && ! (inside_ptr && inter_prec != final_prec)
+ && ! (final_ptr && inside_prec != inter_prec)
+ && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
+ && TYPE_MODE (type) == TYPE_MODE (inter_type)))
+ {
+ gimple_assign_set_rhs1 (stmt, defop0);
+ update_stmt (stmt);
+ return true;
+ }
+
+ /* A truncation to an unsigned type should be canonicalized as
+ bitwise and of a mask. */
+ if (final_int && inter_int && inside_int
+ && final_prec == inside_prec
+ && final_prec > inter_prec
+ && inter_unsignedp)
+ {
+ tree tem;
+ tem = fold_build2 (BIT_AND_EXPR, inside_type,
+ defop0,
+ double_int_to_tree
+ (inside_type, double_int_mask (inter_prec)));
+ if (!useless_type_conversion_p (type, inside_type))
+ {
+ tem = force_gimple_operand_gsi (gsi, tem, true, NULL_TREE, true,
+ GSI_SAME_STMT);
+ gimple_assign_set_rhs1 (stmt, tem);
+ }
+ else
+ gimple_assign_set_rhs_from_tree (gsi, tem);
+ update_stmt (gsi_stmt (*gsi));
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/* Main entry point for the forward propagation and statement combine
+ optimizer. */
static unsigned int
-tree_ssa_forward_propagate_single_use_vars (void)
+ssa_forward_propagate_and_combine (void)
{
basic_block bb;
unsigned int todoflags = 0;
FOR_EACH_BB (bb)
{
- block_stmt_iterator bsi;
+ gimple_stmt_iterator gsi;
- /* Note we update BSI within the loop as necessary. */
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); )
+ /* Apply forward propagation to all stmts in the basic-block.
+ Note we update GSI within the loop as necessary. */
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); )
{
- tree stmt = bsi_stmt (bsi);
+ gimple stmt = gsi_stmt (gsi);
+ tree lhs, rhs;
+ enum tree_code code;
- /* If this statement sets an SSA_NAME to an address,
- try to propagate the address into the uses of the SSA_NAME. */
- if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT)
+ if (!is_gimple_assign (stmt))
{
- tree lhs = GIMPLE_STMT_OPERAND (stmt, 0);
- tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
+ gsi_next (&gsi);
+ continue;
+ }
+ lhs = gimple_assign_lhs (stmt);
+ rhs = gimple_assign_rhs1 (stmt);
+ code = gimple_assign_rhs_code (stmt);
+ if (TREE_CODE (lhs) != SSA_NAME
+ || has_zero_uses (lhs))
+ {
+ gsi_next (&gsi);
+ continue;
+ }
- if (TREE_CODE (lhs) != SSA_NAME)
+ /* If this statement sets an SSA_NAME to an address,
+ try to propagate the address into the uses of the SSA_NAME. */
+ if (code == ADDR_EXPR
+ /* Handle pointer conversions on invariant addresses
+ as well, as this is valid gimple. */
+ || (CONVERT_EXPR_CODE_P (code)
+ && TREE_CODE (rhs) == ADDR_EXPR
+ && POINTER_TYPE_P (TREE_TYPE (lhs))))
+ {
+ tree base = get_base_address (TREE_OPERAND (rhs, 0));
+ if ((!base
+ || !DECL_P (base)
+ || decl_address_invariant_p (base))
+ && !stmt_references_abnormal_ssa_name (stmt)
+ && forward_propagate_addr_expr (lhs, rhs))
{
- bsi_next (&bsi);
- continue;
+ release_defs (stmt);
+ todoflags |= TODO_remove_unused_locals;
+ gsi_remove (&gsi, true);
}
-
- if (TREE_CODE (rhs) == ADDR_EXPR)
+ else
+ gsi_next (&gsi);
+ }
+ else if (code == POINTER_PLUS_EXPR
+ && can_propagate_from (stmt))
+ {
+ if (TREE_CODE (gimple_assign_rhs2 (stmt)) == INTEGER_CST
+ /* ??? Better adjust the interface to that function
+ instead of building new trees here. */
+ && forward_propagate_addr_expr
+ (lhs,
+ build1 (ADDR_EXPR,
+ TREE_TYPE (rhs),
+ fold_build2 (MEM_REF,
+ TREE_TYPE (TREE_TYPE (rhs)),
+ rhs,
+ fold_convert
+ (ptr_type_node,
+ gimple_assign_rhs2 (stmt))))))
{
- if (forward_propagate_addr_expr (lhs, rhs))
- {
- release_defs (stmt);
- todoflags |= TODO_remove_unused_locals;
- bsi_remove (&bsi, true);
- }
- else
- bsi_next (&bsi);
+ release_defs (stmt);
+ todoflags |= TODO_remove_unused_locals;
+ gsi_remove (&gsi, true);
}
- else if ((TREE_CODE (rhs) == BIT_NOT_EXPR
- || TREE_CODE (rhs) == NEGATE_EXPR)
- && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME)
+ else if (is_gimple_min_invariant (rhs))
{
- simplify_not_neg_expr (stmt);
- bsi_next (&bsi);
+ /* Make sure to fold &a[0] + off_1 here. */
+ fold_stmt_inplace (stmt);
+ update_stmt (stmt);
+ if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR)
+ gsi_next (&gsi);
}
- else if (TREE_CODE (rhs) == COND_EXPR)
- {
- forward_propagate_into_cond (rhs, stmt);
- bsi_next (&bsi);
- }
else
- bsi_next (&bsi);
+ gsi_next (&gsi);
}
- else if (TREE_CODE (stmt) == SWITCH_EXPR)
+ else if (TREE_CODE_CLASS (code) == tcc_comparison)
{
- simplify_switch_expr (stmt);
- bsi_next (&bsi);
+ forward_propagate_comparison (stmt);
+ gsi_next (&gsi);
}
- else if (TREE_CODE (stmt) == COND_EXPR)
+ else
+ gsi_next (&gsi);
+ }
+
+ /* Combine stmts with the stmts defining their operands.
+ Note we update GSI within the loop as necessary. */
+ for (gsi = gsi_last_bb (bb); !gsi_end_p (gsi);)
+ {
+ gimple stmt = gsi_stmt (gsi);
+ bool changed = false;
+
+ switch (gimple_code (stmt))
{
- forward_propagate_into_cond (stmt, stmt);
- bsi_next (&bsi);
+ case GIMPLE_ASSIGN:
+ {
+ tree rhs1 = gimple_assign_rhs1 (stmt);
+ enum tree_code code = gimple_assign_rhs_code (stmt);
+
+ if ((code == BIT_NOT_EXPR
+ || code == NEGATE_EXPR)
+ && TREE_CODE (rhs1) == SSA_NAME)
+ changed = simplify_not_neg_expr (&gsi);
+ else if (code == COND_EXPR)
+ {
+ /* In this case the entire COND_EXPR is in rhs1. */
+ int did_something;
+ fold_defer_overflow_warnings ();
+ did_something = forward_propagate_into_cond (&gsi);
+ stmt = gsi_stmt (gsi);
+ if (did_something == 2)
+ cfg_changed = true;
+ fold_undefer_overflow_warnings
+ (!TREE_NO_WARNING (rhs1) && did_something, stmt,
+ WARN_STRICT_OVERFLOW_CONDITIONAL);
+ changed = did_something != 0;
+ }
+ else if (TREE_CODE_CLASS (code) == tcc_comparison)
+ {
+ bool no_warning = gimple_no_warning_p (stmt);
+ fold_defer_overflow_warnings ();
+ changed = forward_propagate_into_comparison (&gsi);
+ fold_undefer_overflow_warnings
+ (!no_warning && changed,
+ stmt, WARN_STRICT_OVERFLOW_CONDITIONAL);
+ }
+ else if (code == BIT_AND_EXPR
+ || code == BIT_IOR_EXPR
+ || code == BIT_XOR_EXPR)
+ changed = simplify_bitwise_binary (&gsi);
+ else if (code == PLUS_EXPR
+ || code == MINUS_EXPR)
+ changed = associate_plusminus (stmt);
+ else if (CONVERT_EXPR_CODE_P (code)
+ || code == FLOAT_EXPR
+ || code == FIX_TRUNC_EXPR)
+ changed = combine_conversions (&gsi);
+ break;
+ }
+
+ case GIMPLE_SWITCH:
+ changed = simplify_gimple_switch (stmt);
+ break;
+
+ case GIMPLE_COND:
+ {
+ int did_something;
+ fold_defer_overflow_warnings ();
+ did_something = forward_propagate_into_gimple_cond (stmt);
+ if (did_something == 2)
+ cfg_changed = true;
+ fold_undefer_overflow_warnings
+ (did_something, stmt, WARN_STRICT_OVERFLOW_CONDITIONAL);
+ changed = did_something != 0;
+ break;
+ }
+
+ case GIMPLE_CALL:
+ {
+ tree callee = gimple_call_fndecl (stmt);
+ if (callee != NULL_TREE
+ && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL)
+ changed = simplify_builtin_call (&gsi, callee);
+ break;
+ }
+
+ default:;
}
- else
- bsi_next (&bsi);
+
+ /* If the stmt changed try combining it again. */
+ if (!changed)
+ gsi_prev (&gsi);
}
}
if (cfg_changed)
todoflags |= TODO_cleanup_cfg;
+
return todoflags;
}
static bool
gate_forwprop (void)
{
- return 1;
+ return flag_tree_forwprop;
}
-struct tree_opt_pass pass_forwprop = {
+struct gimple_opt_pass pass_forwprop =
+{
+ {
+ GIMPLE_PASS,
"forwprop", /* name */
gate_forwprop, /* gate */
- tree_ssa_forward_propagate_single_use_vars, /* execute */
+ ssa_forward_propagate_and_combine, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
TODO_dump_func
| TODO_ggc_collect
| TODO_update_ssa
- | TODO_verify_ssa, /* todo_flags_finish */
- 0 /* letter */
+ | TODO_verify_ssa /* todo_flags_finish */
+ }
};
+
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