#include "tm.h"
#include "tree.h"
#include "flags.h"
-#include "rtl.h"
-#include "tm_p.h"
-#include "ggc.h"
-#include "basic-block.h"
-#include "output.h"
-#include "expr.h"
#include "function.h"
-#include "diagnostic.h"
-#include "timevar.h"
#include "tree-dump.h"
#include "tree-flow.h"
#include "tree-pass.h"
#include "tree-ssa-propagate.h"
-#include "value-prof.h"
-#include "langhooks.h"
#include "target.h"
+/* Return true when DECL can be referenced from current unit.
+ We can get declarations that are not possible to reference for
+ various reasons:
+
+ 1) When analyzing C++ virtual tables.
+ C++ virtual tables do have known constructors even
+ when they are keyed to other compilation unit.
+ Those tables can contain pointers to methods and vars
+ in other units. Those methods have both STATIC and EXTERNAL
+ set.
+ 2) In WHOPR mode devirtualization might lead to reference
+ to method that was partitioned elsehwere.
+ In this case we have static VAR_DECL or FUNCTION_DECL
+ that has no corresponding callgraph/varpool node
+ declaring the body.
+ 3) COMDAT functions referred by external vtables that
+ we devirtualize only during final copmilation stage.
+ At this time we already decided that we will not output
+ the function body and thus we can't reference the symbol
+ directly. */
+
+static bool
+can_refer_decl_in_current_unit_p (tree decl)
+{
+ struct varpool_node *vnode;
+ struct cgraph_node *node;
+
+ if (!TREE_STATIC (decl) && !DECL_EXTERNAL (decl))
+ return true;
+ /* External flag is set, so we deal with C++ reference
+ to static object from other file. */
+ if (DECL_EXTERNAL (decl) && TREE_STATIC (decl)
+ && TREE_CODE (decl) == VAR_DECL)
+ {
+ /* Just be sure it is not big in frontend setting
+ flags incorrectly. Those variables should never
+ be finalized. */
+ gcc_checking_assert (!(vnode = varpool_get_node (decl))
+ || !vnode->finalized);
+ return false;
+ }
+ /* When function is public, we always can introduce new reference.
+ Exception are the COMDAT functions where introducing a direct
+ reference imply need to include function body in the curren tunit. */
+ if (TREE_PUBLIC (decl) && !DECL_COMDAT (decl))
+ return true;
+ /* We are not at ltrans stage; so don't worry about WHOPR.
+ Also when still gimplifying all referred comdat functions will be
+ produced. */
+ if (!flag_ltrans && (!DECL_COMDAT (decl) || !cgraph_function_flags_ready))
+ return true;
+ /* If we already output the function body, we are safe. */
+ if (TREE_ASM_WRITTEN (decl))
+ return true;
+ if (TREE_CODE (decl) == FUNCTION_DECL)
+ {
+ node = cgraph_get_node (decl);
+ /* Check that we still have function body and that we didn't took
+ the decision to eliminate offline copy of the function yet.
+ The second is important when devirtualization happens during final
+ compilation stage when making a new reference no longer makes callee
+ to be compiled. */
+ if (!node || !node->analyzed || node->global.inlined_to)
+ return false;
+ }
+ else if (TREE_CODE (decl) == VAR_DECL)
+ {
+ vnode = varpool_get_node (decl);
+ if (!vnode || !vnode->finalized)
+ return false;
+ }
+ return true;
+}
+
+/* CVAL is value taken from DECL_INITIAL of variable. Try to transorm it into
+ acceptable form for is_gimple_min_invariant. */
+
+tree
+canonicalize_constructor_val (tree cval)
+{
+ STRIP_NOPS (cval);
+ if (TREE_CODE (cval) == POINTER_PLUS_EXPR)
+ {
+ tree t = maybe_fold_offset_to_address (EXPR_LOCATION (cval),
+ TREE_OPERAND (cval, 0),
+ TREE_OPERAND (cval, 1),
+ TREE_TYPE (cval));
+ if (t)
+ cval = t;
+ }
+ if (TREE_CODE (cval) == ADDR_EXPR)
+ {
+ tree base = get_base_address (TREE_OPERAND (cval, 0));
+
+ if (base
+ && (TREE_CODE (base) == VAR_DECL
+ || TREE_CODE (base) == FUNCTION_DECL)
+ && !can_refer_decl_in_current_unit_p (base))
+ return NULL_TREE;
+ if (base && TREE_CODE (base) == VAR_DECL)
+ add_referenced_var (base);
+ }
+ return cval;
+}
/* If SYM is a constant variable with known value, return the value.
NULL_TREE is returned otherwise. */
tree
get_symbol_constant_value (tree sym)
{
- if (TREE_STATIC (sym)
- && (TREE_READONLY (sym)
- || TREE_CODE (sym) == CONST_DECL))
+ if (const_value_known_p (sym))
{
tree val = DECL_INITIAL (sym);
if (val)
{
- STRIP_NOPS (val);
- if (is_gimple_min_invariant (val))
- {
- if (TREE_CODE (val) == ADDR_EXPR)
- {
- tree base = get_base_address (TREE_OPERAND (val, 0));
- if (base && TREE_CODE (base) == VAR_DECL)
- {
- TREE_ADDRESSABLE (base) = 1;
- if (gimple_referenced_vars (cfun))
- add_referenced_var (base);
- }
- }
- return val;
- }
+ val = canonicalize_constructor_val (val);
+ if (val && is_gimple_min_invariant (val))
+ return val;
+ else
+ return NULL_TREE;
}
/* Variables declared 'const' without an initializer
have zero as the initializer if they may not be
overridden at link or run time. */
if (!val
- && !DECL_EXTERNAL (sym)
- && targetm.binds_local_p (sym)
&& (INTEGRAL_TYPE_P (TREE_TYPE (sym))
|| SCALAR_FLOAT_TYPE_P (TREE_TYPE (sym))))
- return fold_convert (TREE_TYPE (sym), integer_zero_node);
+ return build_zero_cst (TREE_TYPE (sym));
}
return NULL_TREE;
bool
may_propagate_address_into_dereference (tree addr, tree deref)
{
- gcc_assert (INDIRECT_REF_P (deref)
+ gcc_assert (TREE_CODE (deref) == MEM_REF
&& TREE_CODE (addr) == ADDR_EXPR);
/* Don't propagate if ADDR's operand has incomplete type. */
/* A subroutine of fold_stmt. Attempts to fold *(A+O) to A[X].
- BASE is an array type. OFFSET is a byte displacement. ORIG_TYPE
- is the desired result type.
+ BASE is an array type. OFFSET is a byte displacement.
LOC is the location of the original expression. */
static tree
-maybe_fold_offset_to_array_ref (location_t loc, tree base, tree offset,
- tree orig_type,
- bool allow_negative_idx)
+maybe_fold_offset_to_array_ref (location_t loc, tree base, tree offset)
{
tree min_idx, idx, idx_type, elt_offset = integer_zero_node;
tree array_type, elt_type, elt_size;
if (TREE_CODE (array_type) != ARRAY_TYPE)
return NULL_TREE;
elt_type = TREE_TYPE (array_type);
- if (!useless_type_conversion_p (orig_type, elt_type))
- return NULL_TREE;
/* Use signed size type for intermediate computation on the index. */
idx_type = ssizetype;
char *(c[4]);
c[3][2];
should not be simplified into (*c)[14] or tree-vrp will
- give false warnings. The same is true for
- struct A { long x; char d[0]; } *a;
- (char *)a - 4;
- which should be not folded to &a->d[-8]. */
- if (domain_type
- && TYPE_MAX_VALUE (domain_type)
- && TREE_CODE (TYPE_MAX_VALUE (domain_type)) == INTEGER_CST)
+ give false warnings.
+ This is only an issue for multi-dimensional arrays. */
+ if (TREE_CODE (elt_type) == ARRAY_TYPE
+ && domain_type)
{
- tree up_bound = TYPE_MAX_VALUE (domain_type);
-
- if (tree_int_cst_lt (up_bound, idx)
- /* Accesses after the end of arrays of size 0 (gcc
- extension) and 1 are likely intentional ("struct
- hack"). */
- && compare_tree_int (up_bound, 1) > 0)
+ if (TYPE_MAX_VALUE (domain_type)
+ && TREE_CODE (TYPE_MAX_VALUE (domain_type)) == INTEGER_CST
+ && tree_int_cst_lt (TYPE_MAX_VALUE (domain_type), idx))
return NULL_TREE;
- }
- if (domain_type
- && TYPE_MIN_VALUE (domain_type))
- {
- if (!allow_negative_idx
- && TREE_CODE (TYPE_MIN_VALUE (domain_type)) == INTEGER_CST
- && tree_int_cst_lt (idx, TYPE_MIN_VALUE (domain_type)))
+ else if (TYPE_MIN_VALUE (domain_type)
+ && TREE_CODE (TYPE_MIN_VALUE (domain_type)) == INTEGER_CST
+ && tree_int_cst_lt (idx, TYPE_MIN_VALUE (domain_type)))
+ return NULL_TREE;
+ else if (compare_tree_int (idx, 0) < 0)
return NULL_TREE;
}
- else if (!allow_negative_idx
- && compare_tree_int (idx, 0) < 0)
- return NULL_TREE;
{
tree t = build4 (ARRAY_REF, elt_type, base, idx, NULL_TREE, NULL_TREE);
}
-/* Attempt to fold *(S+O) to S.X.
- BASE is a record type. OFFSET is a byte displacement. ORIG_TYPE
- is the desired result type.
-
- LOC is the location of the original expression. */
-
-static tree
-maybe_fold_offset_to_component_ref (location_t loc, tree record_type,
- tree base, tree offset, tree orig_type)
-{
- tree f, t, field_type, tail_array_field, field_offset;
- tree ret;
- tree new_base;
-
- if (TREE_CODE (record_type) != RECORD_TYPE
- && TREE_CODE (record_type) != UNION_TYPE
- && TREE_CODE (record_type) != QUAL_UNION_TYPE)
- return NULL_TREE;
-
- /* Short-circuit silly cases. */
- if (useless_type_conversion_p (record_type, orig_type))
- return NULL_TREE;
-
- tail_array_field = NULL_TREE;
- for (f = TYPE_FIELDS (record_type); f ; f = TREE_CHAIN (f))
- {
- int cmp;
-
- if (TREE_CODE (f) != FIELD_DECL)
- continue;
- if (DECL_BIT_FIELD (f))
- continue;
-
- if (!DECL_FIELD_OFFSET (f))
- continue;
- field_offset = byte_position (f);
- if (TREE_CODE (field_offset) != INTEGER_CST)
- continue;
-
- /* ??? Java creates "interesting" fields for representing base classes.
- They have no name, and have no context. With no context, we get into
- trouble with nonoverlapping_component_refs_p. Skip them. */
- if (!DECL_FIELD_CONTEXT (f))
- continue;
-
- /* The previous array field isn't at the end. */
- tail_array_field = NULL_TREE;
-
- /* Check to see if this offset overlaps with the field. */
- cmp = tree_int_cst_compare (field_offset, offset);
- if (cmp > 0)
- continue;
-
- field_type = TREE_TYPE (f);
-
- /* Here we exactly match the offset being checked. If the types match,
- then we can return that field. */
- if (cmp == 0
- && useless_type_conversion_p (orig_type, field_type))
- {
- t = fold_build3 (COMPONENT_REF, field_type, base, f, NULL_TREE);
- return t;
- }
-
- /* Don't care about offsets into the middle of scalars. */
- if (!AGGREGATE_TYPE_P (field_type))
- continue;
-
- /* Check for array at the end of the struct. This is often
- used as for flexible array members. We should be able to
- turn this into an array access anyway. */
- if (TREE_CODE (field_type) == ARRAY_TYPE)
- tail_array_field = f;
-
- /* Check the end of the field against the offset. */
- if (!DECL_SIZE_UNIT (f)
- || TREE_CODE (DECL_SIZE_UNIT (f)) != INTEGER_CST)
- continue;
- t = int_const_binop (MINUS_EXPR, offset, field_offset, 1);
- if (!tree_int_cst_lt (t, DECL_SIZE_UNIT (f)))
- continue;
-
- /* If we matched, then set offset to the displacement into
- this field. */
- new_base = fold_build3 (COMPONENT_REF, field_type, base, f, NULL_TREE);
- SET_EXPR_LOCATION (new_base, loc);
-
- /* Recurse to possibly find the match. */
- ret = maybe_fold_offset_to_array_ref (loc, new_base, t, orig_type,
- f == TYPE_FIELDS (record_type));
- if (ret)
- return ret;
- ret = maybe_fold_offset_to_component_ref (loc, field_type, new_base, t,
- orig_type);
- if (ret)
- return ret;
- }
-
- if (!tail_array_field)
- return NULL_TREE;
-
- f = tail_array_field;
- field_type = TREE_TYPE (f);
- offset = int_const_binop (MINUS_EXPR, offset, byte_position (f), 1);
-
- /* If we get here, we've got an aggregate field, and a possibly
- nonzero offset into them. Recurse and hope for a valid match. */
- base = fold_build3 (COMPONENT_REF, field_type, base, f, NULL_TREE);
- SET_EXPR_LOCATION (base, loc);
-
- t = maybe_fold_offset_to_array_ref (loc, base, offset, orig_type,
- f == TYPE_FIELDS (record_type));
- if (t)
- return t;
- return maybe_fold_offset_to_component_ref (loc, field_type, base, offset,
- orig_type);
-}
-
-/* Attempt to express (ORIG_TYPE)BASE+OFFSET as BASE->field_of_orig_type
- or BASE[index] or by combination of those.
-
+/* Attempt to express (ORIG_TYPE)BASE+OFFSET as BASE[index].
LOC is the location of original expression.
- Before attempting the conversion strip off existing ADDR_EXPRs and
- handled component refs. */
+ Before attempting the conversion strip off existing ADDR_EXPRs. */
tree
maybe_fold_offset_to_reference (location_t loc, tree base, tree offset,
tree orig_type)
{
tree ret;
- tree type;
STRIP_NOPS (base);
if (TREE_CODE (base) != ADDR_EXPR)
return NULL_TREE;
base = TREE_OPERAND (base, 0);
-
- /* Handle case where existing COMPONENT_REF pick e.g. wrong field of union,
- so it needs to be removed and new COMPONENT_REF constructed.
- The wrong COMPONENT_REF are often constructed by folding the
- (type *)&object within the expression (type *)&object+offset */
- if (handled_component_p (base))
- {
- HOST_WIDE_INT sub_offset, size, maxsize;
- tree newbase;
- newbase = get_ref_base_and_extent (base, &sub_offset,
- &size, &maxsize);
- gcc_assert (newbase);
- if (size == maxsize
- && size != -1
- && !(sub_offset & (BITS_PER_UNIT - 1)))
- {
- base = newbase;
- if (sub_offset)
- offset = int_const_binop (PLUS_EXPR, offset,
- build_int_cst (TREE_TYPE (offset),
- sub_offset / BITS_PER_UNIT), 1);
- }
- }
- if (useless_type_conversion_p (orig_type, TREE_TYPE (base))
+ if (types_compatible_p (orig_type, TREE_TYPE (base))
&& integer_zerop (offset))
return base;
- type = TREE_TYPE (base);
-
- ret = maybe_fold_offset_to_component_ref (loc, type, base, offset, orig_type);
- if (!ret)
- ret = maybe_fold_offset_to_array_ref (loc, base, offset, orig_type, true);
- return ret;
+ ret = maybe_fold_offset_to_array_ref (loc, base, offset);
+ if (ret && types_compatible_p (orig_type, TREE_TYPE (ret)))
+ return ret;
+ return NULL_TREE;
}
-/* Attempt to express (ORIG_TYPE)&BASE+OFFSET as &BASE->field_of_orig_type
- or &BASE[index] or by combination of those.
-
- LOC is the location of the original expression.
-
- Before attempting the conversion strip off existing component refs. */
+/* Attempt to express (ORIG_TYPE)ADDR+OFFSET as (*ADDR)[index].
+ LOC is the location of the original expression. */
tree
maybe_fold_offset_to_address (location_t loc, tree addr, tree offset,
tree orig_type)
{
- tree t;
-
- gcc_assert (POINTER_TYPE_P (TREE_TYPE (addr))
- && POINTER_TYPE_P (orig_type));
-
- t = maybe_fold_offset_to_reference (loc, addr, offset,
- TREE_TYPE (orig_type));
- if (t != NULL_TREE)
- {
- tree orig = addr;
- tree ptr_type;
-
- /* For __builtin_object_size to function correctly we need to
- make sure not to fold address arithmetic so that we change
- reference from one array to another. This would happen for
- example for
-
- struct X { char s1[10]; char s2[10] } s;
- char *foo (void) { return &s.s2[-4]; }
-
- where we need to avoid generating &s.s1[6]. As the C and
- C++ frontends create different initial trees
- (char *) &s.s1 + -4 vs. &s.s1[-4] we have to do some
- sophisticated comparisons here. Note that checking for the
- condition after the fact is easier than trying to avoid doing
- the folding. */
- STRIP_NOPS (orig);
- if (TREE_CODE (orig) == ADDR_EXPR)
- orig = TREE_OPERAND (orig, 0);
- if ((TREE_CODE (orig) == ARRAY_REF
- || (TREE_CODE (orig) == COMPONENT_REF
- && TREE_CODE (TREE_TYPE (TREE_OPERAND (orig, 1))) == ARRAY_TYPE))
- && (TREE_CODE (t) == ARRAY_REF
- || TREE_CODE (t) == COMPONENT_REF)
- && !operand_equal_p (TREE_CODE (orig) == ARRAY_REF
- ? TREE_OPERAND (orig, 0) : orig,
- TREE_CODE (t) == ARRAY_REF
- ? TREE_OPERAND (t, 0) : t, 0))
- return NULL_TREE;
+ tree base, ret;
- ptr_type = build_pointer_type (TREE_TYPE (t));
- if (!useless_type_conversion_p (orig_type, ptr_type))
- return NULL_TREE;
- return build_fold_addr_expr_with_type_loc (loc, t, ptr_type);
- }
-
- return NULL_TREE;
-}
-
-/* A subroutine of fold_stmt. Attempt to simplify *(BASE+OFFSET).
- Return the simplified expression, or NULL if nothing could be done. */
-
-static tree
-maybe_fold_stmt_indirect (tree expr, tree base, tree offset)
-{
- tree t;
- bool volatile_p = TREE_THIS_VOLATILE (expr);
- location_t loc = EXPR_LOCATION (expr);
-
- /* We may well have constructed a double-nested PLUS_EXPR via multiple
- substitutions. Fold that down to one. Remove NON_LVALUE_EXPRs that
- are sometimes added. */
- base = fold (base);
- STRIP_TYPE_NOPS (base);
- TREE_OPERAND (expr, 0) = base;
-
- /* One possibility is that the address reduces to a string constant. */
- t = fold_read_from_constant_string (expr);
- if (t)
- return t;
-
- /* Add in any offset from a POINTER_PLUS_EXPR. */
- if (TREE_CODE (base) == POINTER_PLUS_EXPR)
+ STRIP_NOPS (addr);
+ if (TREE_CODE (addr) != ADDR_EXPR)
+ return NULL_TREE;
+ base = TREE_OPERAND (addr, 0);
+ ret = maybe_fold_offset_to_array_ref (loc, base, offset);
+ if (ret)
{
- tree offset2;
-
- offset2 = TREE_OPERAND (base, 1);
- if (TREE_CODE (offset2) != INTEGER_CST)
+ ret = build_fold_addr_expr (ret);
+ if (!useless_type_conversion_p (orig_type, TREE_TYPE (ret)))
return NULL_TREE;
- base = TREE_OPERAND (base, 0);
-
- offset = fold_convert (sizetype,
- int_const_binop (PLUS_EXPR, offset, offset2, 1));
- }
-
- if (TREE_CODE (base) == ADDR_EXPR)
- {
- tree base_addr = base;
-
- /* Strip the ADDR_EXPR. */
- base = TREE_OPERAND (base, 0);
-
- /* Fold away CONST_DECL to its value, if the type is scalar. */
- if (TREE_CODE (base) == CONST_DECL
- && is_gimple_min_invariant (DECL_INITIAL (base)))
- return DECL_INITIAL (base);
-
- /* If there is no offset involved simply return the folded base. */
- if (integer_zerop (offset))
- return base;
-
- /* Try folding *(&B+O) to B.X. */
- t = maybe_fold_offset_to_reference (loc, base_addr, offset,
- TREE_TYPE (expr));
- if (t)
- {
- /* Preserve volatileness of the original expression.
- We can end up with a plain decl here which is shared
- and we shouldn't mess with its flags. */
- if (!SSA_VAR_P (t))
- TREE_THIS_VOLATILE (t) = volatile_p;
- return t;
- }
+ SET_EXPR_LOCATION (ret, loc);
}
- else
- {
- /* We can get here for out-of-range string constant accesses,
- such as "_"[3]. Bail out of the entire substitution search
- and arrange for the entire statement to be replaced by a
- call to __builtin_trap. In all likelihood this will all be
- constant-folded away, but in the meantime we can't leave with
- something that get_expr_operands can't understand. */
-
- t = base;
- STRIP_NOPS (t);
- if (TREE_CODE (t) == ADDR_EXPR
- && TREE_CODE (TREE_OPERAND (t, 0)) == STRING_CST)
- {
- /* FIXME: Except that this causes problems elsewhere with dead
- code not being deleted, and we die in the rtl expanders
- because we failed to remove some ssa_name. In the meantime,
- just return zero. */
- /* FIXME2: This condition should be signaled by
- fold_read_from_constant_string directly, rather than
- re-checking for it here. */
- return integer_zero_node;
- }
- /* Try folding *(B+O) to B->X. Still an improvement. */
- if (POINTER_TYPE_P (TREE_TYPE (base)))
- {
- t = maybe_fold_offset_to_reference (loc, base, offset,
- TREE_TYPE (expr));
- if (t)
- return t;
- }
- }
-
- /* Otherwise we had an offset that we could not simplify. */
- return NULL_TREE;
+ return ret;
}
/* Or op0 should now be A[0] and the non-constant offset defined
via a multiplication by the array element size. */
if (TREE_CODE (op0) == ARRAY_REF
+ /* As we will end up creating a variable index array access
+ in the outermost array dimension make sure there isn't
+ a more inner array that the index could overflow to. */
+ && TREE_CODE (TREE_OPERAND (op0, 0)) != ARRAY_REF
&& integer_zerop (TREE_OPERAND (op0, 1))
- && TREE_CODE (op1) == SSA_NAME
- && host_integerp (TYPE_SIZE_UNIT (TREE_TYPE (op0)), 1))
+ && TREE_CODE (op1) == SSA_NAME)
{
gimple offset_def = SSA_NAME_DEF_STMT (op1);
- if (!is_gimple_assign (offset_def))
+ tree elsz = TYPE_SIZE_UNIT (TREE_TYPE (op0));
+ if (!host_integerp (elsz, 1)
+ || !is_gimple_assign (offset_def))
+ return NULL_TREE;
+
+ /* Do not build array references of something that we can't
+ see the true number of array dimensions for. */
+ if (!DECL_P (TREE_OPERAND (op0, 0))
+ && !handled_component_p (TREE_OPERAND (op0, 0)))
return NULL_TREE;
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),
- TYPE_SIZE_UNIT (TREE_TYPE (op0))))
+ && tree_int_cst_equal (gimple_assign_rhs2 (offset_def), elsz))
return build_fold_addr_expr
(build4 (ARRAY_REF, TREE_TYPE (op0),
TREE_OPERAND (op0, 0),
gimple_assign_rhs1 (offset_def),
TREE_OPERAND (op0, 2),
TREE_OPERAND (op0, 3)));
- else if (integer_onep (TYPE_SIZE_UNIT (TREE_TYPE (op0)))
+ else if (integer_onep (elsz)
&& gimple_assign_rhs_code (offset_def) != MULT_EXPR)
return build_fold_addr_expr
(build4 (ARRAY_REF, TREE_TYPE (op0),
TREE_OPERAND (op0, 2),
TREE_OPERAND (op0, 3)));
}
+ else if (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE
+ /* Dto. */
+ && TREE_CODE (TREE_TYPE (TREE_TYPE (op0))) != ARRAY_TYPE
+ && TREE_CODE (op1) == SSA_NAME)
+ {
+ gimple offset_def = SSA_NAME_DEF_STMT (op1);
+ tree elsz = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (op0)));
+ if (!host_integerp (elsz, 1)
+ || !is_gimple_assign (offset_def))
+ return NULL_TREE;
+
+ /* Do not build array references of something that we can't
+ see the true number of array dimensions for. */
+ if (!DECL_P (op0)
+ && !handled_component_p (op0))
+ return NULL_TREE;
+
+ 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), elsz))
+ return build_fold_addr_expr
+ (build4 (ARRAY_REF, TREE_TYPE (TREE_TYPE (op0)),
+ op0, gimple_assign_rhs1 (offset_def),
+ integer_zero_node, NULL_TREE));
+ else if (integer_onep (elsz)
+ && gimple_assign_rhs_code (offset_def) != MULT_EXPR)
+ return build_fold_addr_expr
+ (build4 (ARRAY_REF, TREE_TYPE (TREE_TYPE (op0)),
+ op0, op1,
+ integer_zero_node, NULL_TREE));
+ }
+
return NULL_TREE;
}
ptd_type = TREE_TYPE (TREE_TYPE (op0));
/* At which point we can try some of the same things as for indirects. */
- t = maybe_fold_offset_to_array_ref (loc, op0, op1, ptd_type, true);
- if (!t)
- t = maybe_fold_offset_to_component_ref (loc, TREE_TYPE (op0), op0, op1,
- ptd_type);
+ t = maybe_fold_offset_to_array_ref (loc, op0, op1);
if (t)
{
- t = build1 (ADDR_EXPR, res_type, t);
+ t = build_fold_addr_expr (t);
+ if (!useless_type_conversion_p (res_type, TREE_TYPE (t)))
+ return NULL_TREE;
SET_EXPR_LOCATION (t, loc);
}
maybe_fold_reference (tree expr, bool is_lhs)
{
tree *t = &expr;
+ tree result;
- if (TREE_CODE (expr) == ARRAY_REF
- && !is_lhs)
- {
- tree tem = fold_read_from_constant_string (expr);
- if (tem)
- return tem;
- }
+ if (!is_lhs
+ && (result = fold_const_aggregate_ref (expr))
+ && is_gimple_min_invariant (result))
+ return result;
/* ??? We might want to open-code the relevant remaining cases
to avoid using the generic fold. */
while (handled_component_p (*t))
t = &TREE_OPERAND (*t, 0);
- if (TREE_CODE (*t) == INDIRECT_REF)
+ /* Fold back MEM_REFs to reference trees. */
+ if (TREE_CODE (*t) == MEM_REF
+ && TREE_CODE (TREE_OPERAND (*t, 0)) == ADDR_EXPR
+ && integer_zerop (TREE_OPERAND (*t, 1))
+ && (TREE_THIS_VOLATILE (*t)
+ == TREE_THIS_VOLATILE (TREE_OPERAND (TREE_OPERAND (*t, 0), 0)))
+ && !TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (*t, 1)))
+ && (TYPE_MAIN_VARIANT (TREE_TYPE (*t))
+ == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (TREE_OPERAND (*t, 1)))))
+ /* We have to look out here to not drop a required conversion
+ from the rhs to the lhs if is_lhs, but we don't have the
+ rhs here to verify that. Thus require strict type
+ compatibility. */
+ && types_compatible_p (TREE_TYPE (*t),
+ TREE_TYPE (TREE_OPERAND
+ (TREE_OPERAND (*t, 0), 0))))
{
- tree tem = maybe_fold_stmt_indirect (*t, TREE_OPERAND (*t, 0),
- integer_zero_node);
- /* Avoid folding *"abc" = 5 into 'a' = 5. */
- if (is_lhs && tem && CONSTANT_CLASS_P (tem))
- tem = NULL_TREE;
- if (!tem
- && TREE_CODE (TREE_OPERAND (*t, 0)) == ADDR_EXPR)
- /* If we had a good reason for propagating the address here,
- make sure we end up with valid gimple. See PR34989. */
- tem = TREE_OPERAND (TREE_OPERAND (*t, 0), 0);
-
+ tree tem;
+ *t = TREE_OPERAND (TREE_OPERAND (*t, 0), 0);
+ tem = maybe_fold_reference (expr, is_lhs);
+ if (tem)
+ return tem;
+ return expr;
+ }
+ /* Canonicalize MEM_REFs invariant address operand. */
+ else if (TREE_CODE (*t) == MEM_REF
+ && !is_gimple_mem_ref_addr (TREE_OPERAND (*t, 0)))
+ {
+ bool volatile_p = TREE_THIS_VOLATILE (*t);
+ tree tem = fold_binary (MEM_REF, TREE_TYPE (*t),
+ TREE_OPERAND (*t, 0),
+ TREE_OPERAND (*t, 1));
+ if (tem)
+ {
+ TREE_THIS_VOLATILE (tem) = volatile_p;
+ *t = tem;
+ tem = maybe_fold_reference (expr, is_lhs);
+ if (tem)
+ return tem;
+ return expr;
+ }
+ }
+ else if (TREE_CODE (*t) == TARGET_MEM_REF)
+ {
+ tree tem = maybe_fold_tmr (*t);
if (tem)
{
*t = tem;
COND_EXPR_THEN (rhs), COND_EXPR_ELSE (rhs));
}
- else if (TREE_CODE (rhs) == TARGET_MEM_REF)
- return maybe_fold_tmr (rhs);
-
else if (REFERENCE_CLASS_P (rhs))
return maybe_fold_reference (rhs, false);
else if (TREE_CODE (rhs) == ADDR_EXPR)
{
- tree tem = maybe_fold_reference (TREE_OPERAND (rhs, 0), true);
- if (tem)
+ tree ref = TREE_OPERAND (rhs, 0);
+ tree tem = maybe_fold_reference (ref, true);
+ if (tem
+ && TREE_CODE (tem) == MEM_REF
+ && integer_zerop (TREE_OPERAND (tem, 1)))
+ result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (tem, 0));
+ else if (tem)
result = fold_convert (TREE_TYPE (rhs),
build_fold_addr_expr_loc (loc, tem));
+ else if (TREE_CODE (ref) == MEM_REF
+ && integer_zerop (TREE_OPERAND (ref, 1)))
+ result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (ref, 0));
}
else if (TREE_CODE (rhs) == CONSTRUCTOR
}
break;
+ case GIMPLE_TERNARY_RHS:
+ result = fold_ternary_loc (loc, subcode,
+ TREE_TYPE (gimple_assign_lhs (stmt)),
+ gimple_assign_rhs1 (stmt),
+ gimple_assign_rhs2 (stmt),
+ gimple_assign_rhs3 (stmt));
+
+ if (result)
+ {
+ STRIP_USELESS_TYPE_CONVERSION (result);
+ if (valid_gimple_rhs_p (result))
+ return result;
+
+ /* Fold might have produced non-GIMPLE, so if we trust it blindly
+ we lose canonicalization opportunities. Do not go again
+ through fold here though, or the same non-GIMPLE will be
+ produced. */
+ if (commutative_ternary_tree_code (subcode)
+ && tree_swap_operands_p (gimple_assign_rhs1 (stmt),
+ gimple_assign_rhs2 (stmt), false))
+ return build3 (subcode, TREE_TYPE (gimple_assign_lhs (stmt)),
+ gimple_assign_rhs2 (stmt),
+ gimple_assign_rhs1 (stmt),
+ gimple_assign_rhs3 (stmt));
+ }
+ break;
+
case GIMPLE_INVALID_RHS:
gcc_unreachable ();
}
is replaced. If the call is expected to produces a result, then it
is replaced by an assignment of the new RHS to the result variable.
If the result is to be ignored, then the call is replaced by a
- GIMPLE_NOP. */
+ GIMPLE_NOP. A proper VDEF chain is retained by making the first
+ VUSE and the last VDEF of the whole sequence be the same as the replaced
+ statement and using new SSA names for stores in between. */
void
gimplify_and_update_call_from_tree (gimple_stmt_iterator *si_p, tree expr)
gimple_seq stmts = gimple_seq_alloc();
struct gimplify_ctx gctx;
gimple last = NULL;
+ gimple laststore = NULL;
+ tree reaching_vuse;
stmt = gsi_stmt (*si_p);
gcc_assert (is_gimple_call (stmt));
lhs = gimple_call_lhs (stmt);
+ reaching_vuse = gimple_vuse (stmt);
push_gimplify_context (&gctx);
if (lhs == NULL_TREE)
- gimplify_and_add (expr, &stmts);
+ {
+ gimplify_and_add (expr, &stmts);
+ /* We can end up with folding a memcpy of an empty class assignment
+ which gets optimized away by C++ gimplification. */
+ if (gimple_seq_empty_p (stmts))
+ {
+ if (gimple_in_ssa_p (cfun))
+ {
+ unlink_stmt_vdef (stmt);
+ release_defs (stmt);
+ }
+ gsi_remove (si_p, true);
+ return;
+ }
+ }
else
tmp = get_initialized_tmp_var (expr, &stmts, NULL);
gsi_next (si_p);
}
new_stmt = gsi_stmt (i);
- find_new_referenced_vars (new_stmt);
- mark_symbols_for_renaming (new_stmt);
+ if (gimple_in_ssa_p (cfun))
+ {
+ find_new_referenced_vars (new_stmt);
+ mark_symbols_for_renaming (new_stmt);
+ }
+ /* If the new statement has a VUSE, update it with exact SSA name we
+ know will reach this one. */
+ if (gimple_vuse (new_stmt))
+ {
+ /* If we've also seen a previous store create a new VDEF for
+ the latter one, and make that the new reaching VUSE. */
+ if (laststore)
+ {
+ reaching_vuse = make_ssa_name (gimple_vop (cfun), laststore);
+ gimple_set_vdef (laststore, reaching_vuse);
+ update_stmt (laststore);
+ laststore = NULL;
+ }
+ gimple_set_vuse (new_stmt, reaching_vuse);
+ gimple_set_modified (new_stmt, true);
+ }
+ if (gimple_assign_single_p (new_stmt)
+ && !is_gimple_reg (gimple_assign_lhs (new_stmt)))
+ {
+ laststore = new_stmt;
+ }
last = new_stmt;
}
if (lhs == NULL_TREE)
{
- unlink_stmt_vdef (stmt);
- release_defs (stmt);
+ /* If we replace a call without LHS that has a VDEF and our new
+ sequence ends with a store we must make that store have the same
+ vdef in order not to break the sequencing. This can happen
+ for instance when folding memcpy calls into assignments. */
+ if (gimple_vdef (stmt) && laststore)
+ {
+ gimple_set_vdef (laststore, gimple_vdef (stmt));
+ if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME)
+ SSA_NAME_DEF_STMT (gimple_vdef (stmt)) = laststore;
+ update_stmt (laststore);
+ }
+ else if (gimple_in_ssa_p (cfun))
+ {
+ unlink_stmt_vdef (stmt);
+ release_defs (stmt);
+ }
new_stmt = last;
}
else
gsi_insert_before (si_p, last, GSI_NEW_STMT);
gsi_next (si_p);
}
+ if (laststore && is_gimple_reg (lhs))
+ {
+ gimple_set_vdef (laststore, gimple_vdef (stmt));
+ update_stmt (laststore);
+ if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME)
+ SSA_NAME_DEF_STMT (gimple_vdef (stmt)) = laststore;
+ laststore = NULL;
+ }
+ else if (laststore)
+ {
+ reaching_vuse = make_ssa_name (gimple_vop (cfun), laststore);
+ gimple_set_vdef (laststore, reaching_vuse);
+ update_stmt (laststore);
+ laststore = NULL;
+ }
new_stmt = gimple_build_assign (lhs, tmp);
- gimple_set_vuse (new_stmt, gimple_vuse (stmt));
- gimple_set_vdef (new_stmt, gimple_vdef (stmt));
- move_ssa_defining_stmt_for_defs (new_stmt, stmt);
+ if (!is_gimple_reg (tmp))
+ gimple_set_vuse (new_stmt, reaching_vuse);
+ if (!is_gimple_reg (lhs))
+ {
+ gimple_set_vdef (new_stmt, gimple_vdef (stmt));
+ if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME)
+ SSA_NAME_DEF_STMT (gimple_vdef (stmt)) = new_stmt;
+ }
+ else if (reaching_vuse == gimple_vuse (stmt))
+ unlink_stmt_vdef (stmt);
}
gimple_set_location (new_stmt, gimple_location (stmt));
}
/* If we were already here, break the infinite cycle. */
- if (bitmap_bit_p (visited, SSA_NAME_VERSION (arg)))
+ if (!bitmap_set_bit (visited, SSA_NAME_VERSION (arg)))
return true;
- bitmap_set_bit (visited, SSA_NAME_VERSION (arg));
var = arg;
def_stmt = SSA_NAME_DEF_STMT (var);
fold_convert (TREE_TYPE (gimple_call_lhs (stmt)), val[0]);
/* If the result is not a valid gimple value, or not a cast
- of a valid gimple value, then we can not use the result. */
+ of a valid gimple value, then we cannot use the result. */
if (is_gimple_val (new_val)
- || (is_gimple_cast (new_val)
+ || (CONVERT_EXPR_P (new_val)
&& is_gimple_val (TREE_OPERAND (new_val, 0))))
return new_val;
}
if (TREE_CODE (ref) == COMPONENT_REF)
{
tree par_type;
- tree binfo, base_binfo;
+ tree binfo;
tree field = TREE_OPERAND (ref, 1);
if (!DECL_ARTIFICIAL (field))
|| BINFO_N_BASE_BINFOS (binfo) == 0)
return NULL_TREE;
- base_binfo = BINFO_BASE_BINFO (binfo, 0);
- if (BINFO_TYPE (base_binfo) != TREE_TYPE (field))
+ /* Offset 0 indicates the primary base, whose vtable contents are
+ represented in the binfo for the derived class. */
+ if (int_bit_position (field) != 0)
{
tree d_binfo;
+ /* Get descendant binfo. */
d_binfo = gimple_get_relevant_ref_binfo (TREE_OPERAND (ref, 0),
known_binfo);
- /* Get descendant binfo. */
if (!d_binfo)
return NULL_TREE;
return get_base_binfo_for_type (d_binfo, TREE_TYPE (field));
return TYPE_BINFO (TREE_TYPE (ref));
else if (known_binfo
&& (TREE_CODE (ref) == SSA_NAME
- || TREE_CODE (ref) == INDIRECT_REF))
+ || TREE_CODE (ref) == MEM_REF))
return known_binfo;
else
return NULL_TREE;
gimple_fold_obj_type_ref_known_binfo (HOST_WIDE_INT token, tree known_binfo)
{
HOST_WIDE_INT i;
- tree v, fndecl;
+ tree v, fndecl, delta;
v = BINFO_VIRTUALS (known_binfo);
i = 0;
}
fndecl = TREE_VALUE (v);
+ delta = TREE_PURPOSE (v);
+ gcc_assert (host_integerp (delta, 0));
+
+ if (integer_nonzerop (delta))
+ {
+ struct cgraph_node *node = cgraph_get_node (fndecl);
+ HOST_WIDE_INT off = tree_low_cst (delta, 0);
+
+ if (!node)
+ return NULL;
+ for (node = node->same_body; node; node = node->next)
+ if (node->thunk.thunk_p && off == node->thunk.fixed_offset)
+ break;
+ if (node)
+ fndecl = node->decl;
+ else
+ return NULL;
+ }
+
+ /* When cgraph node is missing and function is not public, we cannot
+ devirtualize. This can happen in WHOPR when the actual method
+ ends up in other partition, because we found devirtualization
+ possibility too late. */
+ if (!can_refer_decl_in_current_unit_p (fndecl))
+ return NULL;
return build_fold_addr_expr (fndecl);
}
if (binfo)
{
HOST_WIDE_INT token = tree_low_cst (OBJ_TYPE_REF_TOKEN (ref), 1);
+ /* If there is no virtual methods leave the OBJ_TYPE_REF alone. */
+ if (!BINFO_VIRTUALS (binfo))
+ return NULL_TREE;
return gimple_fold_obj_type_ref_known_binfo (token, binfo);
}
else
It is assumed that the operands have been previously folded. */
static bool
-fold_gimple_call (gimple_stmt_iterator *gsi)
+fold_gimple_call (gimple_stmt_iterator *gsi, bool inplace)
{
gimple stmt = gsi_stmt (*gsi);
/* Check for builtins that CCP can handle using information not
available in the generic fold routines. */
- if (callee && DECL_BUILT_IN (callee))
+ if (!inplace && callee && DECL_BUILT_IN (callee))
{
tree result = gimple_fold_builtin (stmt);
there requires that we create a new CALL_EXPR, and that requires
copying EH region info to the new node. Easier to just do it
here where we can just smash the call operand. */
- /* ??? Is there a good reason not to do this in fold_stmt_inplace? */
callee = gimple_call_fn (stmt);
if (TREE_CODE (callee) == OBJ_TYPE_REF
&& TREE_CODE (OBJ_TYPE_REF_OBJECT (callee)) == ADDR_EXPR)
changed = true;
}
}
- /* The entire statement may be replaced in this case. */
- if (!inplace)
- changed |= fold_gimple_call (gsi);
+ changed |= fold_gimple_call (gsi, inplace);
break;
case GIMPLE_ASM:
}
break;
+ case GIMPLE_DEBUG:
+ if (gimple_debug_bind_p (stmt))
+ {
+ tree val = gimple_debug_bind_get_value (stmt);
+ if (val
+ && REFERENCE_CLASS_P (val))
+ {
+ tree tem = maybe_fold_reference (val, false);
+ if (tem)
+ {
+ gimple_debug_bind_set_value (stmt, tem);
+ changed = true;
+ }
+ }
+ }
+ break;
+
default:;
}
return changed;
}
+/* Canonicalize and possibly invert the boolean EXPR; return NULL_TREE
+ if EXPR is null or we don't know how.
+ If non-null, the result always has boolean type. */
+
+static tree
+canonicalize_bool (tree expr, bool invert)
+{
+ if (!expr)
+ return NULL_TREE;
+ else if (invert)
+ {
+ if (integer_nonzerop (expr))
+ return boolean_false_node;
+ else if (integer_zerop (expr))
+ return boolean_true_node;
+ else if (TREE_CODE (expr) == SSA_NAME)
+ return fold_build2 (EQ_EXPR, boolean_type_node, expr,
+ build_int_cst (TREE_TYPE (expr), 0));
+ else if (TREE_CODE_CLASS (TREE_CODE (expr)) == tcc_comparison)
+ return fold_build2 (invert_tree_comparison (TREE_CODE (expr), false),
+ boolean_type_node,
+ TREE_OPERAND (expr, 0),
+ TREE_OPERAND (expr, 1));
+ else
+ return NULL_TREE;
+ }
+ else
+ {
+ if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE)
+ return expr;
+ if (integer_nonzerop (expr))
+ return boolean_true_node;
+ else if (integer_zerop (expr))
+ return boolean_false_node;
+ else if (TREE_CODE (expr) == SSA_NAME)
+ return fold_build2 (NE_EXPR, boolean_type_node, expr,
+ build_int_cst (TREE_TYPE (expr), 0));
+ else if (TREE_CODE_CLASS (TREE_CODE (expr)) == tcc_comparison)
+ return fold_build2 (TREE_CODE (expr),
+ boolean_type_node,
+ TREE_OPERAND (expr, 0),
+ TREE_OPERAND (expr, 1));
+ else
+ return NULL_TREE;
+ }
+}
+
+/* Check to see if a boolean expression EXPR is logically equivalent to the
+ comparison (OP1 CODE OP2). Check for various identities involving
+ SSA_NAMEs. */
+
+static bool
+same_bool_comparison_p (const_tree expr, enum tree_code code,
+ const_tree op1, const_tree op2)
+{
+ gimple s;
+
+ /* The obvious case. */
+ if (TREE_CODE (expr) == code
+ && operand_equal_p (TREE_OPERAND (expr, 0), op1, 0)
+ && operand_equal_p (TREE_OPERAND (expr, 1), op2, 0))
+ return true;
+
+ /* Check for comparing (name, name != 0) and the case where expr
+ is an SSA_NAME with a definition matching the comparison. */
+ if (TREE_CODE (expr) == SSA_NAME
+ && TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE)
+ {
+ if (operand_equal_p (expr, op1, 0))
+ return ((code == NE_EXPR && integer_zerop (op2))
+ || (code == EQ_EXPR && integer_nonzerop (op2)));
+ s = SSA_NAME_DEF_STMT (expr);
+ if (is_gimple_assign (s)
+ && gimple_assign_rhs_code (s) == code
+ && operand_equal_p (gimple_assign_rhs1 (s), op1, 0)
+ && operand_equal_p (gimple_assign_rhs2 (s), op2, 0))
+ return true;
+ }
+
+ /* If op1 is of the form (name != 0) or (name == 0), and the definition
+ of name is a comparison, recurse. */
+ if (TREE_CODE (op1) == SSA_NAME
+ && TREE_CODE (TREE_TYPE (op1)) == BOOLEAN_TYPE)
+ {
+ s = SSA_NAME_DEF_STMT (op1);
+ if (is_gimple_assign (s)
+ && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison)
+ {
+ enum tree_code c = gimple_assign_rhs_code (s);
+ if ((c == NE_EXPR && integer_zerop (op2))
+ || (c == EQ_EXPR && integer_nonzerop (op2)))
+ return same_bool_comparison_p (expr, c,
+ gimple_assign_rhs1 (s),
+ gimple_assign_rhs2 (s));
+ if ((c == EQ_EXPR && integer_zerop (op2))
+ || (c == NE_EXPR && integer_nonzerop (op2)))
+ return same_bool_comparison_p (expr,
+ invert_tree_comparison (c, false),
+ gimple_assign_rhs1 (s),
+ gimple_assign_rhs2 (s));
+ }
+ }
+ return false;
+}
+
+/* Check to see if two boolean expressions OP1 and OP2 are logically
+ equivalent. */
+
+static bool
+same_bool_result_p (const_tree op1, const_tree op2)
+{
+ /* Simple cases first. */
+ if (operand_equal_p (op1, op2, 0))
+ return true;
+
+ /* Check the cases where at least one of the operands is a comparison.
+ These are a bit smarter than operand_equal_p in that they apply some
+ identifies on SSA_NAMEs. */
+ if (TREE_CODE_CLASS (TREE_CODE (op2)) == tcc_comparison
+ && same_bool_comparison_p (op1, TREE_CODE (op2),
+ TREE_OPERAND (op2, 0),
+ TREE_OPERAND (op2, 1)))
+ return true;
+ if (TREE_CODE_CLASS (TREE_CODE (op1)) == tcc_comparison
+ && same_bool_comparison_p (op2, TREE_CODE (op1),
+ TREE_OPERAND (op1, 0),
+ TREE_OPERAND (op1, 1)))
+ return true;
+
+ /* Default case. */
+ return false;
+}
+
+/* Forward declarations for some mutually recursive functions. */
+
+static tree
+and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b,
+ enum tree_code code2, tree op2a, tree op2b);
+static tree
+and_var_with_comparison (tree var, bool invert,
+ enum tree_code code2, tree op2a, tree op2b);
+static tree
+and_var_with_comparison_1 (gimple stmt,
+ enum tree_code code2, tree op2a, tree op2b);
+static tree
+or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b,
+ enum tree_code code2, tree op2a, tree op2b);
+static tree
+or_var_with_comparison (tree var, bool invert,
+ enum tree_code code2, tree op2a, tree op2b);
+static tree
+or_var_with_comparison_1 (gimple stmt,
+ enum tree_code code2, tree op2a, tree op2b);
+
+/* Helper function for and_comparisons_1: try to simplify the AND of the
+ ssa variable VAR with the comparison specified by (OP2A CODE2 OP2B).
+ If INVERT is true, invert the value of the VAR before doing the AND.
+ Return NULL_EXPR if we can't simplify this to a single expression. */
+
+static tree
+and_var_with_comparison (tree var, bool invert,
+ enum tree_code code2, tree op2a, tree op2b)
+{
+ tree t;
+ gimple stmt = SSA_NAME_DEF_STMT (var);
+
+ /* We can only deal with variables whose definitions are assignments. */
+ if (!is_gimple_assign (stmt))
+ return NULL_TREE;
+
+ /* If we have an inverted comparison, apply DeMorgan's law and rewrite
+ !var AND (op2a code2 op2b) => !(var OR !(op2a code2 op2b))
+ Then we only have to consider the simpler non-inverted cases. */
+ if (invert)
+ t = or_var_with_comparison_1 (stmt,
+ invert_tree_comparison (code2, false),
+ op2a, op2b);
+ else
+ t = and_var_with_comparison_1 (stmt, code2, op2a, op2b);
+ return canonicalize_bool (t, invert);
+}
+
+/* Try to simplify the AND of the ssa variable defined by the assignment
+ STMT with the comparison specified by (OP2A CODE2 OP2B).
+ Return NULL_EXPR if we can't simplify this to a single expression. */
+
+static tree
+and_var_with_comparison_1 (gimple stmt,
+ enum tree_code code2, tree op2a, tree op2b)
+{
+ tree var = gimple_assign_lhs (stmt);
+ tree true_test_var = NULL_TREE;
+ tree false_test_var = NULL_TREE;
+ enum tree_code innercode = gimple_assign_rhs_code (stmt);
+
+ /* Check for identities like (var AND (var == 0)) => false. */
+ if (TREE_CODE (op2a) == SSA_NAME
+ && TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE)
+ {
+ if ((code2 == NE_EXPR && integer_zerop (op2b))
+ || (code2 == EQ_EXPR && integer_nonzerop (op2b)))
+ {
+ true_test_var = op2a;
+ if (var == true_test_var)
+ return var;
+ }
+ else if ((code2 == EQ_EXPR && integer_zerop (op2b))
+ || (code2 == NE_EXPR && integer_nonzerop (op2b)))
+ {
+ false_test_var = op2a;
+ if (var == false_test_var)
+ return boolean_false_node;
+ }
+ }
+
+ /* If the definition is a comparison, recurse on it. */
+ if (TREE_CODE_CLASS (innercode) == tcc_comparison)
+ {
+ tree t = and_comparisons_1 (innercode,
+ gimple_assign_rhs1 (stmt),
+ gimple_assign_rhs2 (stmt),
+ code2,
+ op2a,
+ op2b);
+ if (t)
+ return t;
+ }
+
+ /* If the definition is an AND or OR expression, we may be able to
+ simplify by reassociating. */
+ if (innercode == TRUTH_AND_EXPR
+ || innercode == TRUTH_OR_EXPR
+ || (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE
+ && (innercode == BIT_AND_EXPR || innercode == BIT_IOR_EXPR)))
+ {
+ tree inner1 = gimple_assign_rhs1 (stmt);
+ tree inner2 = gimple_assign_rhs2 (stmt);
+ gimple s;
+ tree t;
+ tree partial = NULL_TREE;
+ bool is_and = (innercode == TRUTH_AND_EXPR || innercode == BIT_AND_EXPR);
+
+ /* Check for boolean identities that don't require recursive examination
+ of inner1/inner2:
+ inner1 AND (inner1 AND inner2) => inner1 AND inner2 => var
+ inner1 AND (inner1 OR inner2) => inner1
+ !inner1 AND (inner1 AND inner2) => false
+ !inner1 AND (inner1 OR inner2) => !inner1 AND inner2
+ Likewise for similar cases involving inner2. */
+ if (inner1 == true_test_var)
+ return (is_and ? var : inner1);
+ else if (inner2 == true_test_var)
+ return (is_and ? var : inner2);
+ else if (inner1 == false_test_var)
+ return (is_and
+ ? boolean_false_node
+ : and_var_with_comparison (inner2, false, code2, op2a, op2b));
+ else if (inner2 == false_test_var)
+ return (is_and
+ ? boolean_false_node
+ : and_var_with_comparison (inner1, false, code2, op2a, op2b));
+
+ /* Next, redistribute/reassociate the AND across the inner tests.
+ Compute the first partial result, (inner1 AND (op2a code op2b)) */
+ if (TREE_CODE (inner1) == SSA_NAME
+ && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner1))
+ && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison
+ && (t = maybe_fold_and_comparisons (gimple_assign_rhs_code (s),
+ gimple_assign_rhs1 (s),
+ gimple_assign_rhs2 (s),
+ code2, op2a, op2b)))
+ {
+ /* Handle the AND case, where we are reassociating:
+ (inner1 AND inner2) AND (op2a code2 op2b)
+ => (t AND inner2)
+ If the partial result t is a constant, we win. Otherwise
+ continue on to try reassociating with the other inner test. */
+ if (is_and)
+ {
+ if (integer_onep (t))
+ return inner2;
+ else if (integer_zerop (t))
+ return boolean_false_node;
+ }
+
+ /* Handle the OR case, where we are redistributing:
+ (inner1 OR inner2) AND (op2a code2 op2b)
+ => (t OR (inner2 AND (op2a code2 op2b))) */
+ else
+ {
+ if (integer_onep (t))
+ return boolean_true_node;
+ else
+ /* Save partial result for later. */
+ partial = t;
+ }
+ }
+
+ /* Compute the second partial result, (inner2 AND (op2a code op2b)) */
+ if (TREE_CODE (inner2) == SSA_NAME
+ && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner2))
+ && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison
+ && (t = maybe_fold_and_comparisons (gimple_assign_rhs_code (s),
+ gimple_assign_rhs1 (s),
+ gimple_assign_rhs2 (s),
+ code2, op2a, op2b)))
+ {
+ /* Handle the AND case, where we are reassociating:
+ (inner1 AND inner2) AND (op2a code2 op2b)
+ => (inner1 AND t) */
+ if (is_and)
+ {
+ if (integer_onep (t))
+ return inner1;
+ else if (integer_zerop (t))
+ return boolean_false_node;
+ }
+
+ /* Handle the OR case. where we are redistributing:
+ (inner1 OR inner2) AND (op2a code2 op2b)
+ => (t OR (inner1 AND (op2a code2 op2b)))
+ => (t OR partial) */
+ else
+ {
+ if (integer_onep (t))
+ return boolean_true_node;
+ else if (partial)
+ {
+ /* We already got a simplification for the other
+ operand to the redistributed OR expression. The
+ interesting case is when at least one is false.
+ Or, if both are the same, we can apply the identity
+ (x OR x) == x. */
+ if (integer_zerop (partial))
+ return t;
+ else if (integer_zerop (t))
+ return partial;
+ else if (same_bool_result_p (t, partial))
+ return t;
+ }
+ }
+ }
+ }
+ return NULL_TREE;
+}
+
+/* Try to simplify the AND of two comparisons defined by
+ (OP1A CODE1 OP1B) and (OP2A CODE2 OP2B), respectively.
+ If this can be done without constructing an intermediate value,
+ return the resulting tree; otherwise NULL_TREE is returned.
+ This function is deliberately asymmetric as it recurses on SSA_DEFs
+ in the first comparison but not the second. */
+
+static tree
+and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b,
+ enum tree_code code2, tree op2a, tree op2b)
+{
+ /* First check for ((x CODE1 y) AND (x CODE2 y)). */
+ if (operand_equal_p (op1a, op2a, 0)
+ && operand_equal_p (op1b, op2b, 0))
+ {
+ tree t = combine_comparisons (UNKNOWN_LOCATION,
+ TRUTH_ANDIF_EXPR, code1, code2,
+ boolean_type_node, op1a, op1b);
+ if (t)
+ return t;
+ }
+
+ /* Likewise the swapped case of the above. */
+ if (operand_equal_p (op1a, op2b, 0)
+ && operand_equal_p (op1b, op2a, 0))
+ {
+ tree t = combine_comparisons (UNKNOWN_LOCATION,
+ TRUTH_ANDIF_EXPR, code1,
+ swap_tree_comparison (code2),
+ boolean_type_node, op1a, op1b);
+ if (t)
+ return t;
+ }
+
+ /* If both comparisons are of the same value against constants, we might
+ be able to merge them. */
+ if (operand_equal_p (op1a, op2a, 0)
+ && TREE_CODE (op1b) == INTEGER_CST
+ && TREE_CODE (op2b) == INTEGER_CST)
+ {
+ int cmp = tree_int_cst_compare (op1b, op2b);
+
+ /* If we have (op1a == op1b), we should either be able to
+ return that or FALSE, depending on whether the constant op1b
+ also satisfies the other comparison against op2b. */
+ if (code1 == EQ_EXPR)
+ {
+ bool done = true;
+ bool val;
+ switch (code2)
+ {
+ case EQ_EXPR: val = (cmp == 0); break;
+ case NE_EXPR: val = (cmp != 0); break;
+ case LT_EXPR: val = (cmp < 0); break;
+ case GT_EXPR: val = (cmp > 0); break;
+ case LE_EXPR: val = (cmp <= 0); break;
+ case GE_EXPR: val = (cmp >= 0); break;
+ default: done = false;
+ }
+ if (done)
+ {
+ if (val)
+ return fold_build2 (code1, boolean_type_node, op1a, op1b);
+ else
+ return boolean_false_node;
+ }
+ }
+ /* Likewise if the second comparison is an == comparison. */
+ else if (code2 == EQ_EXPR)
+ {
+ bool done = true;
+ bool val;
+ switch (code1)
+ {
+ case EQ_EXPR: val = (cmp == 0); break;
+ case NE_EXPR: val = (cmp != 0); break;
+ case LT_EXPR: val = (cmp > 0); break;
+ case GT_EXPR: val = (cmp < 0); break;
+ case LE_EXPR: val = (cmp >= 0); break;
+ case GE_EXPR: val = (cmp <= 0); break;
+ default: done = false;
+ }
+ if (done)
+ {
+ if (val)
+ return fold_build2 (code2, boolean_type_node, op2a, op2b);
+ else
+ return boolean_false_node;
+ }
+ }
+
+ /* Same business with inequality tests. */
+ else if (code1 == NE_EXPR)
+ {
+ bool val;
+ switch (code2)
+ {
+ case EQ_EXPR: val = (cmp != 0); break;
+ case NE_EXPR: val = (cmp == 0); break;
+ case LT_EXPR: val = (cmp >= 0); break;
+ case GT_EXPR: val = (cmp <= 0); break;
+ case LE_EXPR: val = (cmp > 0); break;
+ case GE_EXPR: val = (cmp < 0); break;
+ default:
+ val = false;
+ }
+ if (val)
+ return fold_build2 (code2, boolean_type_node, op2a, op2b);
+ }
+ else if (code2 == NE_EXPR)
+ {
+ bool val;
+ switch (code1)
+ {
+ case EQ_EXPR: val = (cmp == 0); break;
+ case NE_EXPR: val = (cmp != 0); break;
+ case LT_EXPR: val = (cmp <= 0); break;
+ case GT_EXPR: val = (cmp >= 0); break;
+ case LE_EXPR: val = (cmp < 0); break;
+ case GE_EXPR: val = (cmp > 0); break;
+ default:
+ val = false;
+ }
+ if (val)
+ return fold_build2 (code1, boolean_type_node, op1a, op1b);
+ }
+
+ /* Chose the more restrictive of two < or <= comparisons. */
+ else if ((code1 == LT_EXPR || code1 == LE_EXPR)
+ && (code2 == LT_EXPR || code2 == LE_EXPR))
+ {
+ if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR))
+ return fold_build2 (code1, boolean_type_node, op1a, op1b);
+ else
+ return fold_build2 (code2, boolean_type_node, op2a, op2b);
+ }
+
+ /* Likewise chose the more restrictive of two > or >= comparisons. */
+ else if ((code1 == GT_EXPR || code1 == GE_EXPR)
+ && (code2 == GT_EXPR || code2 == GE_EXPR))
+ {
+ if ((cmp > 0) || (cmp == 0 && code1 == GT_EXPR))
+ return fold_build2 (code1, boolean_type_node, op1a, op1b);
+ else
+ return fold_build2 (code2, boolean_type_node, op2a, op2b);
+ }
+
+ /* Check for singleton ranges. */
+ else if (cmp == 0
+ && ((code1 == LE_EXPR && code2 == GE_EXPR)
+ || (code1 == GE_EXPR && code2 == LE_EXPR)))
+ return fold_build2 (EQ_EXPR, boolean_type_node, op1a, op2b);
+
+ /* Check for disjoint ranges. */
+ else if (cmp <= 0
+ && (code1 == LT_EXPR || code1 == LE_EXPR)
+ && (code2 == GT_EXPR || code2 == GE_EXPR))
+ return boolean_false_node;
+ else if (cmp >= 0
+ && (code1 == GT_EXPR || code1 == GE_EXPR)
+ && (code2 == LT_EXPR || code2 == LE_EXPR))
+ return boolean_false_node;
+ }
+
+ /* Perhaps the first comparison is (NAME != 0) or (NAME == 1) where
+ NAME's definition is a truth value. See if there are any simplifications
+ that can be done against the NAME's definition. */
+ if (TREE_CODE (op1a) == SSA_NAME
+ && (code1 == NE_EXPR || code1 == EQ_EXPR)
+ && (integer_zerop (op1b) || integer_onep (op1b)))
+ {
+ bool invert = ((code1 == EQ_EXPR && integer_zerop (op1b))
+ || (code1 == NE_EXPR && integer_onep (op1b)));
+ gimple stmt = SSA_NAME_DEF_STMT (op1a);
+ switch (gimple_code (stmt))
+ {
+ case GIMPLE_ASSIGN:
+ /* Try to simplify by copy-propagating the definition. */
+ return and_var_with_comparison (op1a, invert, code2, op2a, op2b);
+
+ case GIMPLE_PHI:
+ /* If every argument to the PHI produces the same result when
+ ANDed with the second comparison, we win.
+ Do not do this unless the type is bool since we need a bool
+ result here anyway. */
+ if (TREE_CODE (TREE_TYPE (op1a)) == BOOLEAN_TYPE)
+ {
+ tree result = NULL_TREE;
+ unsigned i;
+ for (i = 0; i < gimple_phi_num_args (stmt); i++)
+ {
+ tree arg = gimple_phi_arg_def (stmt, i);
+
+ /* If this PHI has itself as an argument, ignore it.
+ If all the other args produce the same result,
+ we're still OK. */
+ if (arg == gimple_phi_result (stmt))
+ continue;
+ else if (TREE_CODE (arg) == INTEGER_CST)
+ {
+ if (invert ? integer_nonzerop (arg) : integer_zerop (arg))
+ {
+ if (!result)
+ result = boolean_false_node;
+ else if (!integer_zerop (result))
+ return NULL_TREE;
+ }
+ else if (!result)
+ result = fold_build2 (code2, boolean_type_node,
+ op2a, op2b);
+ else if (!same_bool_comparison_p (result,
+ code2, op2a, op2b))
+ return NULL_TREE;
+ }
+ else if (TREE_CODE (arg) == SSA_NAME)
+ {
+ tree temp = and_var_with_comparison (arg, invert,
+ code2, op2a, op2b);
+ if (!temp)
+ return NULL_TREE;
+ else if (!result)
+ result = temp;
+ else if (!same_bool_result_p (result, temp))
+ return NULL_TREE;
+ }
+ else
+ return NULL_TREE;
+ }
+ return result;
+ }
+
+ default:
+ break;
+ }
+ }
+ return NULL_TREE;
+}
+
+/* Try to simplify the AND of two comparisons, specified by
+ (OP1A CODE1 OP1B) and (OP2B CODE2 OP2B), respectively.
+ If this can be simplified to a single expression (without requiring
+ introducing more SSA variables to hold intermediate values),
+ return the resulting tree. Otherwise return NULL_TREE.
+ If the result expression is non-null, it has boolean type. */
+
+tree
+maybe_fold_and_comparisons (enum tree_code code1, tree op1a, tree op1b,
+ enum tree_code code2, tree op2a, tree op2b)
+{
+ tree t = and_comparisons_1 (code1, op1a, op1b, code2, op2a, op2b);
+ if (t)
+ return t;
+ else
+ return and_comparisons_1 (code2, op2a, op2b, code1, op1a, op1b);
+}
+
+/* Helper function for or_comparisons_1: try to simplify the OR of the
+ ssa variable VAR with the comparison specified by (OP2A CODE2 OP2B).
+ If INVERT is true, invert the value of VAR before doing the OR.
+ Return NULL_EXPR if we can't simplify this to a single expression. */
+
+static tree
+or_var_with_comparison (tree var, bool invert,
+ enum tree_code code2, tree op2a, tree op2b)
+{
+ tree t;
+ gimple stmt = SSA_NAME_DEF_STMT (var);
+
+ /* We can only deal with variables whose definitions are assignments. */
+ if (!is_gimple_assign (stmt))
+ return NULL_TREE;
+
+ /* If we have an inverted comparison, apply DeMorgan's law and rewrite
+ !var OR (op2a code2 op2b) => !(var AND !(op2a code2 op2b))
+ Then we only have to consider the simpler non-inverted cases. */
+ if (invert)
+ t = and_var_with_comparison_1 (stmt,
+ invert_tree_comparison (code2, false),
+ op2a, op2b);
+ else
+ t = or_var_with_comparison_1 (stmt, code2, op2a, op2b);
+ return canonicalize_bool (t, invert);
+}
+
+/* Try to simplify the OR of the ssa variable defined by the assignment
+ STMT with the comparison specified by (OP2A CODE2 OP2B).
+ Return NULL_EXPR if we can't simplify this to a single expression. */
+
+static tree
+or_var_with_comparison_1 (gimple stmt,
+ enum tree_code code2, tree op2a, tree op2b)
+{
+ tree var = gimple_assign_lhs (stmt);
+ tree true_test_var = NULL_TREE;
+ tree false_test_var = NULL_TREE;
+ enum tree_code innercode = gimple_assign_rhs_code (stmt);
+
+ /* Check for identities like (var OR (var != 0)) => true . */
+ if (TREE_CODE (op2a) == SSA_NAME
+ && TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE)
+ {
+ if ((code2 == NE_EXPR && integer_zerop (op2b))
+ || (code2 == EQ_EXPR && integer_nonzerop (op2b)))
+ {
+ true_test_var = op2a;
+ if (var == true_test_var)
+ return var;
+ }
+ else if ((code2 == EQ_EXPR && integer_zerop (op2b))
+ || (code2 == NE_EXPR && integer_nonzerop (op2b)))
+ {
+ false_test_var = op2a;
+ if (var == false_test_var)
+ return boolean_true_node;
+ }
+ }
+
+ /* If the definition is a comparison, recurse on it. */
+ if (TREE_CODE_CLASS (innercode) == tcc_comparison)
+ {
+ tree t = or_comparisons_1 (innercode,
+ gimple_assign_rhs1 (stmt),
+ gimple_assign_rhs2 (stmt),
+ code2,
+ op2a,
+ op2b);
+ if (t)
+ return t;
+ }
+
+ /* If the definition is an AND or OR expression, we may be able to
+ simplify by reassociating. */
+ if (innercode == TRUTH_AND_EXPR
+ || innercode == TRUTH_OR_EXPR
+ || (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE
+ && (innercode == BIT_AND_EXPR || innercode == BIT_IOR_EXPR)))
+ {
+ tree inner1 = gimple_assign_rhs1 (stmt);
+ tree inner2 = gimple_assign_rhs2 (stmt);
+ gimple s;
+ tree t;
+ tree partial = NULL_TREE;
+ bool is_or = (innercode == TRUTH_OR_EXPR || innercode == BIT_IOR_EXPR);
+
+ /* Check for boolean identities that don't require recursive examination
+ of inner1/inner2:
+ inner1 OR (inner1 OR inner2) => inner1 OR inner2 => var
+ inner1 OR (inner1 AND inner2) => inner1
+ !inner1 OR (inner1 OR inner2) => true
+ !inner1 OR (inner1 AND inner2) => !inner1 OR inner2
+ */
+ if (inner1 == true_test_var)
+ return (is_or ? var : inner1);
+ else if (inner2 == true_test_var)
+ return (is_or ? var : inner2);
+ else if (inner1 == false_test_var)
+ return (is_or
+ ? boolean_true_node
+ : or_var_with_comparison (inner2, false, code2, op2a, op2b));
+ else if (inner2 == false_test_var)
+ return (is_or
+ ? boolean_true_node
+ : or_var_with_comparison (inner1, false, code2, op2a, op2b));
+
+ /* Next, redistribute/reassociate the OR across the inner tests.
+ Compute the first partial result, (inner1 OR (op2a code op2b)) */
+ if (TREE_CODE (inner1) == SSA_NAME
+ && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner1))
+ && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison
+ && (t = maybe_fold_or_comparisons (gimple_assign_rhs_code (s),
+ gimple_assign_rhs1 (s),
+ gimple_assign_rhs2 (s),
+ code2, op2a, op2b)))
+ {
+ /* Handle the OR case, where we are reassociating:
+ (inner1 OR inner2) OR (op2a code2 op2b)
+ => (t OR inner2)
+ If the partial result t is a constant, we win. Otherwise
+ continue on to try reassociating with the other inner test. */
+ if (innercode == TRUTH_OR_EXPR)
+ {
+ if (integer_onep (t))
+ return boolean_true_node;
+ else if (integer_zerop (t))
+ return inner2;
+ }
+
+ /* Handle the AND case, where we are redistributing:
+ (inner1 AND inner2) OR (op2a code2 op2b)
+ => (t AND (inner2 OR (op2a code op2b))) */
+ else
+ {
+ if (integer_zerop (t))
+ return boolean_false_node;
+ else
+ /* Save partial result for later. */
+ partial = t;
+ }
+ }
+
+ /* Compute the second partial result, (inner2 OR (op2a code op2b)) */
+ if (TREE_CODE (inner2) == SSA_NAME
+ && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner2))
+ && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison
+ && (t = maybe_fold_or_comparisons (gimple_assign_rhs_code (s),
+ gimple_assign_rhs1 (s),
+ gimple_assign_rhs2 (s),
+ code2, op2a, op2b)))
+ {
+ /* Handle the OR case, where we are reassociating:
+ (inner1 OR inner2) OR (op2a code2 op2b)
+ => (inner1 OR t) */
+ if (innercode == TRUTH_OR_EXPR)
+ {
+ if (integer_zerop (t))
+ return inner1;
+ else if (integer_onep (t))
+ return boolean_true_node;
+ }
+
+ /* Handle the AND case, where we are redistributing:
+ (inner1 AND inner2) OR (op2a code2 op2b)
+ => (t AND (inner1 OR (op2a code2 op2b)))
+ => (t AND partial) */
+ else
+ {
+ if (integer_zerop (t))
+ return boolean_false_node;
+ else if (partial)
+ {
+ /* We already got a simplification for the other
+ operand to the redistributed AND expression. The
+ interesting case is when at least one is true.
+ Or, if both are the same, we can apply the identity
+ (x AND x) == true. */
+ if (integer_onep (partial))
+ return t;
+ else if (integer_onep (t))
+ return partial;
+ else if (same_bool_result_p (t, partial))
+ return boolean_true_node;
+ }
+ }
+ }
+ }
+ return NULL_TREE;
+}
+
+/* Try to simplify the OR of two comparisons defined by
+ (OP1A CODE1 OP1B) and (OP2A CODE2 OP2B), respectively.
+ If this can be done without constructing an intermediate value,
+ return the resulting tree; otherwise NULL_TREE is returned.
+ This function is deliberately asymmetric as it recurses on SSA_DEFs
+ in the first comparison but not the second. */
+
+static tree
+or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b,
+ enum tree_code code2, tree op2a, tree op2b)
+{
+ /* First check for ((x CODE1 y) OR (x CODE2 y)). */
+ if (operand_equal_p (op1a, op2a, 0)
+ && operand_equal_p (op1b, op2b, 0))
+ {
+ tree t = combine_comparisons (UNKNOWN_LOCATION,
+ TRUTH_ORIF_EXPR, code1, code2,
+ boolean_type_node, op1a, op1b);
+ if (t)
+ return t;
+ }
+
+ /* Likewise the swapped case of the above. */
+ if (operand_equal_p (op1a, op2b, 0)
+ && operand_equal_p (op1b, op2a, 0))
+ {
+ tree t = combine_comparisons (UNKNOWN_LOCATION,
+ TRUTH_ORIF_EXPR, code1,
+ swap_tree_comparison (code2),
+ boolean_type_node, op1a, op1b);
+ if (t)
+ return t;
+ }
+
+ /* If both comparisons are of the same value against constants, we might
+ be able to merge them. */
+ if (operand_equal_p (op1a, op2a, 0)
+ && TREE_CODE (op1b) == INTEGER_CST
+ && TREE_CODE (op2b) == INTEGER_CST)
+ {
+ int cmp = tree_int_cst_compare (op1b, op2b);
+
+ /* If we have (op1a != op1b), we should either be able to
+ return that or TRUE, depending on whether the constant op1b
+ also satisfies the other comparison against op2b. */
+ if (code1 == NE_EXPR)
+ {
+ bool done = true;
+ bool val;
+ switch (code2)
+ {
+ case EQ_EXPR: val = (cmp == 0); break;
+ case NE_EXPR: val = (cmp != 0); break;
+ case LT_EXPR: val = (cmp < 0); break;
+ case GT_EXPR: val = (cmp > 0); break;
+ case LE_EXPR: val = (cmp <= 0); break;
+ case GE_EXPR: val = (cmp >= 0); break;
+ default: done = false;
+ }
+ if (done)
+ {
+ if (val)
+ return boolean_true_node;
+ else
+ return fold_build2 (code1, boolean_type_node, op1a, op1b);
+ }
+ }
+ /* Likewise if the second comparison is a != comparison. */
+ else if (code2 == NE_EXPR)
+ {
+ bool done = true;
+ bool val;
+ switch (code1)
+ {
+ case EQ_EXPR: val = (cmp == 0); break;
+ case NE_EXPR: val = (cmp != 0); break;
+ case LT_EXPR: val = (cmp > 0); break;
+ case GT_EXPR: val = (cmp < 0); break;
+ case LE_EXPR: val = (cmp >= 0); break;
+ case GE_EXPR: val = (cmp <= 0); break;
+ default: done = false;
+ }
+ if (done)
+ {
+ if (val)
+ return boolean_true_node;
+ else
+ return fold_build2 (code2, boolean_type_node, op2a, op2b);
+ }
+ }
+
+ /* See if an equality test is redundant with the other comparison. */
+ else if (code1 == EQ_EXPR)
+ {
+ bool val;
+ switch (code2)
+ {
+ case EQ_EXPR: val = (cmp == 0); break;
+ case NE_EXPR: val = (cmp != 0); break;
+ case LT_EXPR: val = (cmp < 0); break;
+ case GT_EXPR: val = (cmp > 0); break;
+ case LE_EXPR: val = (cmp <= 0); break;
+ case GE_EXPR: val = (cmp >= 0); break;
+ default:
+ val = false;
+ }
+ if (val)
+ return fold_build2 (code2, boolean_type_node, op2a, op2b);
+ }
+ else if (code2 == EQ_EXPR)
+ {
+ bool val;
+ switch (code1)
+ {
+ case EQ_EXPR: val = (cmp == 0); break;
+ case NE_EXPR: val = (cmp != 0); break;
+ case LT_EXPR: val = (cmp > 0); break;
+ case GT_EXPR: val = (cmp < 0); break;
+ case LE_EXPR: val = (cmp >= 0); break;
+ case GE_EXPR: val = (cmp <= 0); break;
+ default:
+ val = false;
+ }
+ if (val)
+ return fold_build2 (code1, boolean_type_node, op1a, op1b);
+ }
+
+ /* Chose the less restrictive of two < or <= comparisons. */
+ else if ((code1 == LT_EXPR || code1 == LE_EXPR)
+ && (code2 == LT_EXPR || code2 == LE_EXPR))
+ {
+ if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR))
+ return fold_build2 (code2, boolean_type_node, op2a, op2b);
+ else
+ return fold_build2 (code1, boolean_type_node, op1a, op1b);
+ }
+
+ /* Likewise chose the less restrictive of two > or >= comparisons. */
+ else if ((code1 == GT_EXPR || code1 == GE_EXPR)
+ && (code2 == GT_EXPR || code2 == GE_EXPR))
+ {
+ if ((cmp > 0) || (cmp == 0 && code1 == GT_EXPR))
+ return fold_build2 (code2, boolean_type_node, op2a, op2b);
+ else
+ return fold_build2 (code1, boolean_type_node, op1a, op1b);
+ }
+
+ /* Check for singleton ranges. */
+ else if (cmp == 0
+ && ((code1 == LT_EXPR && code2 == GT_EXPR)
+ || (code1 == GT_EXPR && code2 == LT_EXPR)))
+ return fold_build2 (NE_EXPR, boolean_type_node, op1a, op2b);
+
+ /* Check for less/greater pairs that don't restrict the range at all. */
+ else if (cmp >= 0
+ && (code1 == LT_EXPR || code1 == LE_EXPR)
+ && (code2 == GT_EXPR || code2 == GE_EXPR))
+ return boolean_true_node;
+ else if (cmp <= 0
+ && (code1 == GT_EXPR || code1 == GE_EXPR)
+ && (code2 == LT_EXPR || code2 == LE_EXPR))
+ return boolean_true_node;
+ }
+
+ /* Perhaps the first comparison is (NAME != 0) or (NAME == 1) where
+ NAME's definition is a truth value. See if there are any simplifications
+ that can be done against the NAME's definition. */
+ if (TREE_CODE (op1a) == SSA_NAME
+ && (code1 == NE_EXPR || code1 == EQ_EXPR)
+ && (integer_zerop (op1b) || integer_onep (op1b)))
+ {
+ bool invert = ((code1 == EQ_EXPR && integer_zerop (op1b))
+ || (code1 == NE_EXPR && integer_onep (op1b)));
+ gimple stmt = SSA_NAME_DEF_STMT (op1a);
+ switch (gimple_code (stmt))
+ {
+ case GIMPLE_ASSIGN:
+ /* Try to simplify by copy-propagating the definition. */
+ return or_var_with_comparison (op1a, invert, code2, op2a, op2b);
+
+ case GIMPLE_PHI:
+ /* If every argument to the PHI produces the same result when
+ ORed with the second comparison, we win.
+ Do not do this unless the type is bool since we need a bool
+ result here anyway. */
+ if (TREE_CODE (TREE_TYPE (op1a)) == BOOLEAN_TYPE)
+ {
+ tree result = NULL_TREE;
+ unsigned i;
+ for (i = 0; i < gimple_phi_num_args (stmt); i++)
+ {
+ tree arg = gimple_phi_arg_def (stmt, i);
+
+ /* If this PHI has itself as an argument, ignore it.
+ If all the other args produce the same result,
+ we're still OK. */
+ if (arg == gimple_phi_result (stmt))
+ continue;
+ else if (TREE_CODE (arg) == INTEGER_CST)
+ {
+ if (invert ? integer_zerop (arg) : integer_nonzerop (arg))
+ {
+ if (!result)
+ result = boolean_true_node;
+ else if (!integer_onep (result))
+ return NULL_TREE;
+ }
+ else if (!result)
+ result = fold_build2 (code2, boolean_type_node,
+ op2a, op2b);
+ else if (!same_bool_comparison_p (result,
+ code2, op2a, op2b))
+ return NULL_TREE;
+ }
+ else if (TREE_CODE (arg) == SSA_NAME)
+ {
+ tree temp = or_var_with_comparison (arg, invert,
+ code2, op2a, op2b);
+ if (!temp)
+ return NULL_TREE;
+ else if (!result)
+ result = temp;
+ else if (!same_bool_result_p (result, temp))
+ return NULL_TREE;
+ }
+ else
+ return NULL_TREE;
+ }
+ return result;
+ }
+
+ default:
+ break;
+ }
+ }
+ return NULL_TREE;
+}
+
+/* Try to simplify the OR of two comparisons, specified by
+ (OP1A CODE1 OP1B) and (OP2B CODE2 OP2B), respectively.
+ If this can be simplified to a single expression (without requiring
+ introducing more SSA variables to hold intermediate values),
+ return the resulting tree. Otherwise return NULL_TREE.
+ If the result expression is non-null, it has boolean type. */
+
+tree
+maybe_fold_or_comparisons (enum tree_code code1, tree op1a, tree op1b,
+ enum tree_code code2, tree op2a, tree op2b)
+{
+ tree t = or_comparisons_1 (code1, op1a, op1b, code2, op2a, op2b);
+ if (t)
+ return t;
+ else
+ return or_comparisons_1 (code2, op2a, op2b, code1, op1a, op1b);
+}
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