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. */
/* This file implements operations on chains of recurrences. Chains
of recurrences are used for modeling evolution functions of scalar
#include "tm.h"
#include "ggc.h"
#include "tree.h"
+#include "real.h"
#include "diagnostic.h"
#include "varray.h"
+#include "cfgloop.h"
+#include "tree-flow.h"
#include "tree-chrec.h"
#include "tree-pass.h"
#include "params.h"
+#include "tree-scalar-evolution.h"
\f
(CHREC_VARIABLE (poly1),
chrec_fold_minus (type, poly0, CHREC_LEFT (poly1)),
chrec_fold_multiply (type, CHREC_RIGHT (poly1),
- build_int_cst_type (type, -1)));
+ SCALAR_FLOAT_TYPE_P (type)
+ ? build_real (type, dconstm1)
+ : build_int_cst_type (type, -1)));
}
if (CHREC_VARIABLE (poly0) > CHREC_VARIABLE (poly1))
tree poly0,
tree poly1)
{
+ tree t0, t1, t2;
+ int var;
+
gcc_assert (poly0);
gcc_assert (poly1);
gcc_assert (TREE_CODE (poly0) == POLYNOMIAL_CHREC);
/* poly0 and poly1 are two polynomials in the same variable,
{a, +, b}_x * {c, +, d}_x -> {a*c, +, a*d + b*c + b*d, +, 2*b*d}_x. */
- return
- build_polynomial_chrec
- (CHREC_VARIABLE (poly0),
- build_polynomial_chrec
- (CHREC_VARIABLE (poly0),
-
- /* "a*c". */
- chrec_fold_multiply (type, CHREC_LEFT (poly0), CHREC_LEFT (poly1)),
- /* "a*d + b*c + b*d". */
- chrec_fold_plus
- (type, chrec_fold_multiply (type, CHREC_LEFT (poly0), CHREC_RIGHT (poly1)),
-
- chrec_fold_plus
- (type,
- chrec_fold_multiply (type, CHREC_RIGHT (poly0), CHREC_LEFT (poly1)),
- chrec_fold_multiply (type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1))))),
-
- /* "2*b*d". */
- chrec_fold_multiply
- (type, build_int_cst (NULL_TREE, 2),
- chrec_fold_multiply (type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1))));
+ /* "a*c". */
+ t0 = chrec_fold_multiply (type, CHREC_LEFT (poly0), CHREC_LEFT (poly1));
+
+ /* "a*d + b*c + b*d". */
+ t1 = chrec_fold_multiply (type, CHREC_LEFT (poly0), CHREC_RIGHT (poly1));
+ t1 = chrec_fold_plus (type, t1, chrec_fold_multiply (type,
+ CHREC_RIGHT (poly0),
+ CHREC_LEFT (poly1)));
+ t1 = chrec_fold_plus (type, t1, chrec_fold_multiply (type,
+ CHREC_RIGHT (poly0),
+ CHREC_RIGHT (poly1)));
+ /* "2*b*d". */
+ t2 = chrec_fold_multiply (type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1));
+ t2 = chrec_fold_multiply (type, SCALAR_FLOAT_TYPE_P (type)
+ ? build_real (type, dconst2)
+ : build_int_cst_type (type, 2), t2);
+
+ var = CHREC_VARIABLE (poly0);
+ return build_polynomial_chrec (var, t0,
+ build_polynomial_chrec (var, t1, t2));
}
/* When the operands are automatically_generated_chrec_p, the fold has
return build_polynomial_chrec
(CHREC_VARIABLE (op1),
chrec_fold_minus (type, op0, CHREC_LEFT (op1)),
- chrec_fold_multiply (type, CHREC_RIGHT (op1),
- build_int_cst_type (type, -1)));
+ chrec_fold_multiply (type, CHREC_RIGHT (op1),
+ SCALAR_FLOAT_TYPE_P (type)
+ ? build_real (type, dconstm1)
+ : build_int_cst_type (type, -1)));
default:
{
&& size < PARAM_VALUE (PARAM_SCEV_MAX_EXPR_SIZE))
return build2 (code, type, op0, op1);
else if (size < PARAM_VALUE (PARAM_SCEV_MAX_EXPR_SIZE))
- return fold_build2 (code, type, op0, op1);
+ return fold_build2 (code, type,
+ fold_convert (type, op0),
+ fold_convert (type, op1));
else
return chrec_dont_know;
}
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "(chrec_apply \n");
+ if (TREE_CODE (x) == INTEGER_CST && SCALAR_FLOAT_TYPE_P (type))
+ x = build_real_from_int_cst (type, x);
+
if (evolution_function_is_affine_p (chrec))
{
/* "{a, +, b} (x)" -> "a + b*x". */
{
if (TREE_CODE (chrec) == POLYNOMIAL_CHREC
&& CHREC_VARIABLE (chrec) > loop_num)
- return build2
- (TREE_CODE (chrec),
- build_int_cst (NULL_TREE, CHREC_VARIABLE (chrec)),
- reset_evolution_in_loop (loop_num, CHREC_LEFT (chrec), new_evol),
- reset_evolution_in_loop (loop_num, CHREC_RIGHT (chrec), new_evol));
-
+ {
+ tree left = reset_evolution_in_loop (loop_num, CHREC_LEFT (chrec),
+ new_evol);
+ tree right = reset_evolution_in_loop (loop_num, CHREC_RIGHT (chrec),
+ new_evol);
+ return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left),
+ build_int_cst (NULL_TREE, CHREC_VARIABLE (chrec)),
+ left, right);
+ }
+
while (TREE_CODE (chrec) == POLYNOMIAL_CHREC
&& CHREC_VARIABLE (chrec) == loop_num)
chrec = CHREC_LEFT (chrec);
}
}
+/* Recursive helper function. */
+
+static bool
+evolution_function_is_invariant_rec_p (tree chrec, int loopnum)
+{
+ if (evolution_function_is_constant_p (chrec))
+ return true;
+
+ if (TREE_CODE (chrec) == SSA_NAME
+ && expr_invariant_in_loop_p (current_loops->parray[loopnum],
+ chrec))
+ return true;
+
+ if (TREE_CODE (chrec) == POLYNOMIAL_CHREC)
+ {
+ if (CHREC_VARIABLE (chrec) == (unsigned) loopnum
+ || !evolution_function_is_invariant_rec_p (CHREC_RIGHT (chrec),
+ loopnum)
+ || !evolution_function_is_invariant_rec_p (CHREC_LEFT (chrec),
+ loopnum))
+ return false;
+ return true;
+ }
+
+ switch (TREE_CODE_LENGTH (TREE_CODE (chrec)))
+ {
+ case 2:
+ if (!evolution_function_is_invariant_rec_p (TREE_OPERAND (chrec, 1),
+ loopnum))
+ return false;
+
+ case 1:
+ if (!evolution_function_is_invariant_rec_p (TREE_OPERAND (chrec, 0),
+ loopnum))
+ return false;
+ return true;
+
+ default:
+ return false;
+ }
+
+ return false;
+}
+
+/* Return true if CHREC is invariant in loop LOOPNUM, false otherwise. */
+
+bool
+evolution_function_is_invariant_p (tree chrec, int loopnum)
+{
+ if (evolution_function_is_constant_p (chrec))
+ return true;
+
+ if (current_loops != NULL)
+ return evolution_function_is_invariant_rec_p (chrec, loopnum);
+
+ return false;
+}
+
/* Determine whether the given tree is an affine multivariate
evolution. */
\f
-/* Convert CHREC to TYPE. The following is rule is always true:
- TREE_TYPE (chrec) == TREE_TYPE (CHREC_LEFT (chrec)) == TREE_TYPE
- (CHREC_RIGHT (chrec)). An example of what could happen when adding
- two chrecs and the type of the CHREC_RIGHT is different than
- CHREC_LEFT is:
+/* Convert CHREC to TYPE. When the analyzer knows the context in
+ which the CHREC is built, it sets AT_STMT to the statement that
+ contains the definition of the analyzed variable, otherwise the
+ conversion is less accurate: the information is used for
+ determining a more accurate estimation of the number of iterations.
+ By default AT_STMT could be safely set to NULL_TREE.
+
+ The following rule is always true: TREE_TYPE (chrec) ==
+ TREE_TYPE (CHREC_LEFT (chrec)) == TREE_TYPE (CHREC_RIGHT (chrec)).
+ An example of what could happen when adding two chrecs and the type
+ of the CHREC_RIGHT is different than CHREC_LEFT is:
{(uint) 0, +, (uchar) 10} +
{(uint) 0, +, (uchar) 250}
*/
tree
-chrec_convert (tree type,
- tree chrec)
+chrec_convert (tree type, tree chrec, tree at_stmt)
{
- tree ct;
-
+ tree ct, res;
+
if (automatically_generated_chrec_p (chrec))
return chrec;
if (ct == type)
return chrec;
- if (TYPE_PRECISION (ct) < TYPE_PRECISION (type))
- return count_ev_in_wider_type (type, chrec);
-
- switch (TREE_CODE (chrec))
+ if (evolution_function_is_affine_p (chrec))
{
- case POLYNOMIAL_CHREC:
+ tree base, step;
+ bool dummy;
+ struct loop *loop = current_loops->parray[CHREC_VARIABLE (chrec)];
+
+ base = instantiate_parameters (loop, CHREC_LEFT (chrec));
+ step = instantiate_parameters (loop, CHREC_RIGHT (chrec));
+
+ /* Avoid conversion of (signed char) {(uchar)1, +, (uchar)1}_x
+ when it is not possible to prove that the scev does not wrap.
+ See PR22236, where a sequence 1, 2, ..., 255 has to be
+ converted to signed char, but this would wrap:
+ 1, 2, ..., 127, -128, ... The result should not be
+ {(schar)1, +, (schar)1}_x, but instead, we should keep the
+ conversion: (schar) {(uchar)1, +, (uchar)1}_x. */
+ if (scev_probably_wraps_p (type, base, step, at_stmt, loop,
+ &dummy, &dummy))
+ goto failed_to_convert;
+
+ step = convert_step (loop, type, base, step, at_stmt);
+ if (!step)
+ {
+ failed_to_convert:;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "(failed conversion:");
+ fprintf (dump_file, "\n type: ");
+ print_generic_expr (dump_file, type, 0);
+ fprintf (dump_file, "\n base: ");
+ print_generic_expr (dump_file, base, 0);
+ fprintf (dump_file, "\n step: ");
+ print_generic_expr (dump_file, step, 0);
+ fprintf (dump_file, "\n estimated_nb_iterations: ");
+ print_generic_expr (dump_file, loop->estimated_nb_iterations, 0);
+ fprintf (dump_file, "\n)\n");
+ }
+
+ return fold_convert (type, chrec);
+ }
+
return build_polynomial_chrec (CHREC_VARIABLE (chrec),
- chrec_convert (type,
- CHREC_LEFT (chrec)),
- chrec_convert (type,
- CHREC_RIGHT (chrec)));
+ chrec_convert (type, CHREC_LEFT (chrec),
+ at_stmt),
+ step);
+ }
- default:
- {
- tree res = fold_convert (type, chrec);
+ if (TREE_CODE (chrec) == POLYNOMIAL_CHREC)
+ return chrec_dont_know;
- /* Don't propagate overflows. */
- if (CONSTANT_CLASS_P (res))
- {
- TREE_CONSTANT_OVERFLOW (res) = 0;
- TREE_OVERFLOW (res) = 0;
- }
+ res = fold_convert (type, chrec);
- /* But reject constants that don't fit in their type after conversion.
- This can happen if TYPE_MIN_VALUE or TYPE_MAX_VALUE are not the
- natural values associated with TYPE_PRECISION and TYPE_UNSIGNED,
- and can cause problems later when computing niters of loops. Note
- that we don't do the check before converting because we don't want
- to reject conversions of negative chrecs to unsigned types. */
- if (TREE_CODE (res) == INTEGER_CST
- && TREE_CODE (type) == INTEGER_TYPE
- && !int_fits_type_p (res, type))
- res = chrec_dont_know;
-
- return res;
- }
+ /* Don't propagate overflows. */
+ if (CONSTANT_CLASS_P (res))
+ {
+ TREE_CONSTANT_OVERFLOW (res) = 0;
+ TREE_OVERFLOW (res) = 0;
}
+
+ /* But reject constants that don't fit in their type after conversion.
+ This can happen if TYPE_MIN_VALUE or TYPE_MAX_VALUE are not the
+ natural values associated with TYPE_PRECISION and TYPE_UNSIGNED,
+ and can cause problems later when computing niters of loops. Note
+ that we don't do the check before converting because we don't want
+ to reject conversions of negative chrecs to unsigned types. */
+ if (TREE_CODE (res) == INTEGER_CST
+ && TREE_CODE (type) == INTEGER_TYPE
+ && !int_fits_type_p (res, type))
+ res = chrec_dont_know;
+
+ return res;
+}
+
+/* Convert CHREC to TYPE, without regard to signed overflows. Returns the new
+ chrec if something else than what chrec_convert would do happens, NULL_TREE
+ otherwise. */
+
+tree
+chrec_convert_aggressive (tree type, tree chrec)
+{
+ tree inner_type, left, right, lc, rc;
+
+ if (automatically_generated_chrec_p (chrec)
+ || TREE_CODE (chrec) != POLYNOMIAL_CHREC)
+ return NULL_TREE;
+
+ inner_type = TREE_TYPE (chrec);
+ if (TYPE_PRECISION (type) > TYPE_PRECISION (inner_type))
+ return NULL_TREE;
+
+ left = CHREC_LEFT (chrec);
+ right = CHREC_RIGHT (chrec);
+ lc = chrec_convert_aggressive (type, left);
+ if (!lc)
+ lc = chrec_convert (type, left, NULL_TREE);
+ rc = chrec_convert_aggressive (type, right);
+ if (!rc)
+ rc = chrec_convert (type, right, NULL_TREE);
+
+ return build_polynomial_chrec (CHREC_VARIABLE (chrec), lc, rc);
}
/* Returns the type of the chrec. */
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