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, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA. */
+Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA. */
/* Conditional constant propagation (CCP) is based on the SSA
propagation engine (tree-ssa-propagate.c). Constant assignments of
#include "ggc.h"
#include "basic-block.h"
#include "output.h"
-#include "errors.h"
#include "expr.h"
#include "function.h"
#include "diagnostic.h"
(i.e., a V_MAY_DEF or V_MUST_DEF), CONST_VAL[I].MEM_REF will
contain the actual memory reference used to store (i.e., the LHS of
the assignment doing the store). */
-prop_value_t *const_val;
+static prop_value_t *const_val;
/* True if we are also propagating constants in stores and loads. */
static bool do_store_ccp;
&& TREE_CODE (stmt) != SWITCH_EXPR)
return VARYING;
+ if (is_gimple_min_invariant (get_rhs (stmt)))
+ return CONSTANT;
+
found_constant = false;
FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE|SSA_OP_VUSE)
{
ccp_finalize (void)
{
/* Perform substitutions based on the known constant values. */
- substitute_and_fold (const_val);
+ substitute_and_fold (const_val, false);
free (const_val);
}
&& val2->lattice_val == CONSTANT
&& simple_cst_equal (val1->value, val2->value) == 1
&& (!do_store_ccp
- || simple_cst_equal (val1->mem_ref, val2->mem_ref) == 1))
+ || (val1->mem_ref && val2->mem_ref
+ && operand_equal_p (val1->mem_ref, val2->mem_ref, 0))))
{
/* Ci M Cj = Ci if (i == j)
Ci M Cj = VARYING if (i != j)
/* If the RHS is a memory load, see if the VUSEs associated with
it are a valid constant for that memory load. */
prop_value_t *val = get_value_loaded_by (stmt, const_val);
- if (val && simple_cst_equal (val->mem_ref, rhs) == 1)
+ if (val && val->mem_ref
+ && operand_equal_p (val->mem_ref, rhs, 0))
return val->value;
else
return NULL_TREE;
op0 = get_value (op0, true)->value;
}
- retval = fold_unary (code, TREE_TYPE (rhs), op0);
-
- /* If we folded, but did not create an invariant, then we can not
- use this expression. */
- if (retval && ! is_gimple_min_invariant (retval))
- return NULL;
-
- /* If we could not fold the expression, but the arguments are all
- constants and gimple values, then build and return the new
- expression.
-
- In some cases the new expression is still something we can
- use as a replacement for an argument. This happens with
- NOP conversions of types for example.
-
- In other cases the new expression can not be used as a
- replacement for an argument (as it would create non-gimple
- code). But the new expression can still be used to derive
- other constants. */
- if (! retval && is_gimple_min_invariant (op0))
- return build1 (code, TREE_TYPE (rhs), op0);
+ return fold_unary (code, TREE_TYPE (rhs), op0);
}
/* Binary and comparison operators. We know one or both of the
op1 = val->value;
}
- retval = fold_binary (code, TREE_TYPE (rhs), op0, op1);
-
- /* If we folded, but did not create an invariant, then we can not
- use this expression. */
- if (retval && ! is_gimple_min_invariant (retval))
- return NULL;
-
- /* If we could not fold the expression, but the arguments are all
- constants and gimple values, then build and return the new
- expression.
-
- In some cases the new expression is still something we can
- use as a replacement for an argument. This happens with
- NOP conversions of types for example.
-
- In other cases the new expression can not be used as a
- replacement for an argument (as it would create non-gimple
- code). But the new expression can still be used to derive
- other constants. */
- if (! retval
- && is_gimple_min_invariant (op0)
- && is_gimple_min_invariant (op1))
- return build (code, TREE_TYPE (rhs), op0, op1);
+ return fold_binary (code, TREE_TYPE (rhs), op0, op1);
}
/* We may be able to fold away calls to builtin functions if their
fold_const_aggregate_ref (tree t)
{
prop_value_t *value;
- tree base, ctor, idx, field, elt;
+ tree base, ctor, idx, field;
+ unsigned HOST_WIDE_INT cnt;
+ tree cfield, cval;
switch (TREE_CODE (t))
{
}
/* Whoo-hoo! I'll fold ya baby. Yeah! */
- for (elt = CONSTRUCTOR_ELTS (ctor);
- (elt && !tree_int_cst_equal (TREE_PURPOSE (elt), idx));
- elt = TREE_CHAIN (elt))
- ;
-
- if (elt)
- return TREE_VALUE (elt);
+ FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval)
+ if (tree_int_cst_equal (cfield, idx))
+ return cval;
break;
case COMPONENT_REF:
field = TREE_OPERAND (t, 1);
- for (elt = CONSTRUCTOR_ELTS (ctor); elt; elt = TREE_CHAIN (elt))
- if (TREE_PURPOSE (elt) == field
+ FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval)
+ if (cfield == field
/* FIXME: Handle bit-fields. */
- && ! DECL_BIT_FIELD (TREE_PURPOSE (elt)))
- return TREE_VALUE (elt);
+ && ! DECL_BIT_FIELD (cfield))
+ return cval;
break;
+ case REALPART_EXPR:
+ case IMAGPART_EXPR:
+ {
+ tree c = fold_const_aggregate_ref (TREE_OPERAND (t, 0));
+ if (c && TREE_CODE (c) == COMPLEX_CST)
+ return fold_build1 (TREE_CODE (t), TREE_TYPE (t), c);
+ break;
+ }
+
default:
break;
}
/* The statement produced a nonconstant value. If the statement
had UNDEFINED operands, then the result of the statement
should be UNDEFINED. Otherwise, the statement is VARYING. */
- val.lattice_val = (likelyvalue == UNDEFINED) ? UNDEFINED : VARYING;
+ if (likelyvalue == UNDEFINED || likelyvalue == UNKNOWN_VAL)
+ val.lattice_val = likelyvalue;
+ else
+ val.lattice_val = VARYING;
+
val.value = NULL_TREE;
}
we can propagate the value on the RHS. */
prop_value_t *nval = get_value_loaded_by (stmt, const_val);
- if (nval && simple_cst_equal (nval->mem_ref, rhs) == 1)
+ if (nval && nval->mem_ref
+ && operand_equal_p (nval->mem_ref, rhs, 0))
val = *nval;
else
val = evaluate_stmt (stmt);
if (TREE_CODE (orig_lhs) == VIEW_CONVERT_EXPR
&& val.lattice_val == CONSTANT)
{
- tree w = fold (build1 (VIEW_CONVERT_EXPR,
- TREE_TYPE (TREE_OPERAND (orig_lhs, 0)),
- val.value));
+ tree w = fold_build1 (VIEW_CONVERT_EXPR,
+ TREE_TYPE (TREE_OPERAND (orig_lhs, 0)),
+ val.value);
orig_lhs = TREE_OPERAND (orig_lhs, 0);
if (w && is_gimple_min_invariant (w))
for (i = 0, mask = 0; i < field_size; i++)
mask |= ((HOST_WIDE_INT) 1) << i;
- wide_val = build2 (BIT_AND_EXPR, TREE_TYPE (var), val,
- build_int_cst (TREE_TYPE (var), mask));
+ wide_val = fold_build2 (BIT_AND_EXPR, TREE_TYPE (var), val,
+ build_int_cst (TREE_TYPE (var), mask));
}
else
{
for (i = 0, mask = 0; i < (var_size - field_size); i++)
mask |= ((HOST_WIDE_INT) 1) << (var_size - i - 1);
- wide_val = build2 (BIT_IOR_EXPR, TREE_TYPE (var), val,
- build_int_cst (TREE_TYPE (var), mask));
+ wide_val = fold_build2 (BIT_IOR_EXPR, TREE_TYPE (var), val,
+ build_int_cst (TREE_TYPE (var), mask));
}
- return fold (wide_val);
+ return wide_val;
}
{
if (TYPE_UNSIGNED (TREE_TYPE (op1)))
return NULL;
- op1 = fold (build1 (NEGATE_EXPR, TREE_TYPE (op1), op1));
+ op1 = fold_build1 (NEGATE_EXPR, TREE_TYPE (op1), op1);
/* ??? In theory fold should always produce another integer. */
if (TREE_CODE (op1) != INTEGER_CST)
return NULL;
return t;
}
-
/* Subroutine of fold_stmt called via walk_tree. We perform several
simplifications of EXPR_P, mostly having to do with pointer arithmetic. */
}
break;
+ case TARGET_MEM_REF:
+ t = maybe_fold_tmr (expr);
+ break;
+
default:
return NULL_TREE;
}
}
-/* Return the string length of ARG in LENGTH. If ARG is an SSA name variable,
- follow its use-def chains. If LENGTH is not NULL and its value is not
- equal to the length we determine, or if we are unable to determine the
- length, return false. VISITED is a bitmap of visited variables. */
+/* Return the string length, maximum string length or maximum value of
+ ARG in LENGTH.
+ If ARG is an SSA name variable, follow its use-def chains. If LENGTH
+ is not NULL and, for TYPE == 0, its value is not equal to the length
+ we determine or if we are unable to determine the length or value,
+ return false. VISITED is a bitmap of visited variables.
+ TYPE is 0 if string length should be returned, 1 for maximum string
+ length and 2 for maximum value ARG can have. */
static bool
-get_strlen (tree arg, tree *length, bitmap visited)
+get_maxval_strlen (tree arg, tree *length, bitmap visited, int type)
{
tree var, def_stmt, val;
if (TREE_CODE (arg) != SSA_NAME)
{
- val = c_strlen (arg, 1);
+ if (type == 2)
+ {
+ val = arg;
+ if (TREE_CODE (val) != INTEGER_CST
+ || tree_int_cst_sgn (val) < 0)
+ return false;
+ }
+ else
+ val = c_strlen (arg, 1);
if (!val)
return false;
- if (*length && simple_cst_equal (val, *length) != 1)
- return false;
+ if (*length)
+ {
+ if (type > 0)
+ {
+ if (TREE_CODE (*length) != INTEGER_CST
+ || TREE_CODE (val) != INTEGER_CST)
+ return false;
+
+ if (tree_int_cst_lt (*length, val))
+ *length = val;
+ return true;
+ }
+ else if (simple_cst_equal (val, *length) != 1)
+ return false;
+ }
*length = val;
return true;
{
case MODIFY_EXPR:
{
- tree len, rhs;
-
+ tree rhs;
+
/* The RHS of the statement defining VAR must either have a
constant length or come from another SSA_NAME with a constant
length. */
rhs = TREE_OPERAND (def_stmt, 1);
STRIP_NOPS (rhs);
- if (TREE_CODE (rhs) == SSA_NAME)
- return get_strlen (rhs, length, visited);
-
- /* See if the RHS is a constant length. */
- len = c_strlen (rhs, 1);
- if (len)
- {
- if (*length && simple_cst_equal (len, *length) != 1)
- return false;
-
- *length = len;
- return true;
- }
-
- break;
+ return get_maxval_strlen (rhs, length, visited, type);
}
case PHI_NODE:
if (arg == PHI_RESULT (def_stmt))
continue;
- if (!get_strlen (arg, length, visited))
+ if (!get_maxval_strlen (arg, length, visited, type))
return false;
}
static tree
ccp_fold_builtin (tree stmt, tree fn)
{
- tree result, strlen_val[2];
+ tree result, val[3];
tree callee, arglist, a;
- int strlen_arg, i;
+ int arg_mask, i, type;
bitmap visited;
bool ignore;
arglist = TREE_OPERAND (fn, 1);
result = fold_builtin (callee, arglist, ignore);
if (result)
- {
- if (ignore)
- STRIP_NOPS (result);
- return result;
- }
+ {
+ if (ignore)
+ STRIP_NOPS (result);
+ return result;
+ }
/* Ignore MD builtins. */
if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_MD)
case BUILT_IN_STRLEN:
case BUILT_IN_FPUTS:
case BUILT_IN_FPUTS_UNLOCKED:
- strlen_arg = 1;
+ arg_mask = 1;
+ type = 0;
break;
case BUILT_IN_STRCPY:
case BUILT_IN_STRNCPY:
- strlen_arg = 2;
+ arg_mask = 2;
+ type = 0;
+ break;
+ case BUILT_IN_MEMCPY_CHK:
+ case BUILT_IN_MEMPCPY_CHK:
+ case BUILT_IN_MEMMOVE_CHK:
+ case BUILT_IN_MEMSET_CHK:
+ case BUILT_IN_STRNCPY_CHK:
+ arg_mask = 4;
+ type = 2;
+ break;
+ case BUILT_IN_STRCPY_CHK:
+ case BUILT_IN_STPCPY_CHK:
+ arg_mask = 2;
+ type = 1;
+ break;
+ case BUILT_IN_SNPRINTF_CHK:
+ case BUILT_IN_VSNPRINTF_CHK:
+ arg_mask = 2;
+ type = 2;
break;
default:
return NULL_TREE;
/* Try to use the dataflow information gathered by the CCP process. */
visited = BITMAP_ALLOC (NULL);
- memset (strlen_val, 0, sizeof (strlen_val));
+ memset (val, 0, sizeof (val));
for (i = 0, a = arglist;
- strlen_arg;
- i++, strlen_arg >>= 1, a = TREE_CHAIN (a))
- if (strlen_arg & 1)
+ arg_mask;
+ i++, arg_mask >>= 1, a = TREE_CHAIN (a))
+ if (arg_mask & 1)
{
bitmap_clear (visited);
- if (!get_strlen (TREE_VALUE (a), &strlen_val[i], visited))
- strlen_val[i] = NULL_TREE;
+ if (!get_maxval_strlen (TREE_VALUE (a), &val[i], visited, type))
+ val[i] = NULL_TREE;
}
BITMAP_FREE (visited);
switch (DECL_FUNCTION_CODE (callee))
{
case BUILT_IN_STRLEN:
- if (strlen_val[0])
+ if (val[0])
{
- tree new = fold_convert (TREE_TYPE (fn), strlen_val[0]);
+ tree new = fold_convert (TREE_TYPE (fn), 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. */
break;
case BUILT_IN_STRCPY:
- if (strlen_val[1] && is_gimple_val (strlen_val[1]))
- {
- tree fndecl = get_callee_fndecl (fn);
- tree arglist = TREE_OPERAND (fn, 1);
- result = fold_builtin_strcpy (fndecl, arglist, strlen_val[1]);
- }
+ if (val[1] && is_gimple_val (val[1]))
+ result = fold_builtin_strcpy (callee, arglist, val[1]);
break;
case BUILT_IN_STRNCPY:
- if (strlen_val[1] && is_gimple_val (strlen_val[1]))
- {
- tree fndecl = get_callee_fndecl (fn);
- tree arglist = TREE_OPERAND (fn, 1);
- result = fold_builtin_strncpy (fndecl, arglist, strlen_val[1]);
- }
+ if (val[1] && is_gimple_val (val[1]))
+ result = fold_builtin_strncpy (callee, arglist, val[1]);
break;
case BUILT_IN_FPUTS:
result = fold_builtin_fputs (arglist,
TREE_CODE (stmt) != MODIFY_EXPR, 0,
- strlen_val[0]);
+ val[0]);
break;
case BUILT_IN_FPUTS_UNLOCKED:
result = fold_builtin_fputs (arglist,
TREE_CODE (stmt) != MODIFY_EXPR, 1,
- strlen_val[0]);
+ val[0]);
+ break;
+
+ case BUILT_IN_MEMCPY_CHK:
+ case BUILT_IN_MEMPCPY_CHK:
+ case BUILT_IN_MEMMOVE_CHK:
+ case BUILT_IN_MEMSET_CHK:
+ if (val[2] && is_gimple_val (val[2]))
+ result = fold_builtin_memory_chk (callee, arglist, val[2], ignore,
+ DECL_FUNCTION_CODE (callee));
+ break;
+
+ case BUILT_IN_STRCPY_CHK:
+ case BUILT_IN_STPCPY_CHK:
+ if (val[1] && is_gimple_val (val[1]))
+ result = fold_builtin_stxcpy_chk (callee, arglist, val[1], ignore,
+ DECL_FUNCTION_CODE (callee));
+ break;
+
+ case BUILT_IN_STRNCPY_CHK:
+ if (val[2] && is_gimple_val (val[2]))
+ result = fold_builtin_strncpy_chk (arglist, val[2]);
+ break;
+
+ case BUILT_IN_SNPRINTF_CHK:
+ case BUILT_IN_VSNPRINTF_CHK:
+ if (val[1] && is_gimple_val (val[1]))
+ result = fold_builtin_snprintf_chk (arglist, val[1],
+ DECL_FUNCTION_CODE (callee));
break;
default:
}
-/* Fold the statement pointed by STMT_P. In some cases, this function may
+/* Fold the statement pointed to by STMT_P. In some cases, this function may
replace the whole statement with a new one. Returns true iff folding
makes any changes. */
return changed;
new_rhs = fold (rhs);
+ STRIP_USELESS_TYPE_CONVERSION (new_rhs);
if (new_rhs == rhs)
return changed;
FOR_EACH_BB (bb)
{
block_stmt_iterator i;
- for (i = bsi_start (bb); !bsi_end_p (i); bsi_next (&i))
+ for (i = bsi_start (bb); !bsi_end_p (i); )
{
tree *stmtp = bsi_stmt_ptr (i);
tree old_stmt = *stmtp;
tree call = get_rhs (*stmtp);
tree callee, result;
+ enum built_in_function fcode;
if (!call || TREE_CODE (call) != CALL_EXPR)
- continue;
+ {
+ bsi_next (&i);
+ continue;
+ }
callee = get_callee_fndecl (call);
if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL)
- continue;
+ {
+ bsi_next (&i);
+ continue;
+ }
+ fcode = DECL_FUNCTION_CODE (callee);
result = ccp_fold_builtin (*stmtp, call);
if (!result)
break;
default:
+ bsi_next (&i);
continue;
}
gcc_assert (ok);
}
}
- update_stmt (*stmtp);
+ mark_new_vars_to_rename (*stmtp);
if (maybe_clean_or_replace_eh_stmt (old_stmt, *stmtp)
&& tree_purge_dead_eh_edges (bb))
cfg_changed = true;
print_generic_stmt (dump_file, *stmtp, dump_flags);
fprintf (dump_file, "\n");
}
+
+ /* Retry the same statement if it changed into another
+ builtin, there might be new opportunities now. */
+ call = get_rhs (*stmtp);
+ if (!call || TREE_CODE (call) != CALL_EXPR)
+ {
+ bsi_next (&i);
+ continue;
+ }
+ callee = get_callee_fndecl (call);
+ if (!callee
+ || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL
+ || DECL_FUNCTION_CODE (callee) == fcode)
+ bsi_next (&i);
}
}
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