Hello,

I have been experimenting with generating VEC_COND_EXPR from the front-end, and these are just a couple things I noticed.

1) optabs.c requires that the first argument of vec_cond_expr be a comparison, but verify_gimple_assign_ternary only checks is_gimple_condexpr, like for COND_EXPR. In the long term, it seems better to also allow ssa_name and vector_cst (thus match the is_gimple_condexpr condition), but for now I just want to know early if I created an invalid vec_cond_expr.

2) a little refactoring of the code to find a suitable vector type for comparison results, and one more place where it should be used (no testcase yet because I don't know if that path can be taken without front-end changes first). I did wonder, for tree-ssa-forwprop, about using directly TREE_TYPE (cond) without truth_type_for.

Hmm, now I am wondering whether I should have waited until I had front-end vec_cond_expr support to submit everything at once...

2012-09-27  Marc Glisse  <marc.gli...@inria.fr>

        * tree-cfg.c (verify_gimple_assign_ternary): Stricter check on
        first argument of VEC_COND_EXPR.
        * tree.c (truth_type_for): New function.
        * tree.h (truth_type_for): Declare.
        * gimple-fold.c (and_comparisons_1): Call it.
        (or_comparisons_1): Likewise.
        * tree-ssa-forwprop.c (forward_propagate_into_cond): Likewise.

--
Marc Glisse
Index: gcc/tree-ssa-forwprop.c
===================================================================
--- gcc/tree-ssa-forwprop.c     (revision 191810)
+++ gcc/tree-ssa-forwprop.c     (working copy)
@@ -549,21 +549,22 @@ static bool
 forward_propagate_into_cond (gimple_stmt_iterator *gsi_p)
 {
   gimple stmt = gsi_stmt (*gsi_p);
   tree tmp = NULL_TREE;
   tree cond = gimple_assign_rhs1 (stmt);
   bool swap = false;
 
   /* We can do tree combining on SSA_NAME and comparison expressions.  */
   if (COMPARISON_CLASS_P (cond))
     tmp = forward_propagate_into_comparison_1 (stmt, TREE_CODE (cond),
-                                              boolean_type_node,
+                                              truth_type_for
+                                                (TREE_TYPE (cond)),
                                               TREE_OPERAND (cond, 0),
                                               TREE_OPERAND (cond, 1));
   else if (TREE_CODE (cond) == SSA_NAME)
     {
       enum tree_code code;
       tree name = cond;
       gimple def_stmt = get_prop_source_stmt (name, true, NULL);
       if (!def_stmt || !can_propagate_from (def_stmt))
        return 0;
 
Index: gcc/tree-cfg.c
===================================================================
--- gcc/tree-cfg.c      (revision 191810)
+++ gcc/tree-cfg.c      (working copy)
@@ -3758,22 +3758,24 @@ verify_gimple_assign_ternary (gimple stm
   tree rhs2_type = TREE_TYPE (rhs2);
   tree rhs3 = gimple_assign_rhs3 (stmt);
   tree rhs3_type = TREE_TYPE (rhs3);
 
   if (!is_gimple_reg (lhs))
     {
       error ("non-register as LHS of ternary operation");
       return true;
     }
 
-  if (((rhs_code == VEC_COND_EXPR || rhs_code == COND_EXPR)
-       ? !is_gimple_condexpr (rhs1) : !is_gimple_val (rhs1))
+  if (((rhs_code == COND_EXPR) ? !is_gimple_condexpr (rhs1)
+       : (rhs_code == VEC_COND_EXPR) ? (!is_gimple_condexpr (rhs1)
+                                       || is_gimple_val (rhs1))
+       : !is_gimple_val (rhs1))
       || !is_gimple_val (rhs2)
       || !is_gimple_val (rhs3))
     {
       error ("invalid operands in ternary operation");
       return true;
     }
 
   /* First handle operations that involve different types.  */
   switch (rhs_code)
     {
Index: gcc/gimple-fold.c
===================================================================
--- gcc/gimple-fold.c   (revision 191810)
+++ gcc/gimple-fold.c   (working copy)
@@ -23,21 +23,20 @@ along with GCC; see the file COPYING3.
 #include "coretypes.h"
 #include "tm.h"
 #include "tree.h"
 #include "flags.h"
 #include "function.h"
 #include "dumpfile.h"
 #include "tree-flow.h"
 #include "tree-ssa-propagate.h"
 #include "target.h"
 #include "gimple-fold.h"
-#include "langhooks.h"
 
 /* Return true when DECL can be referenced from current unit.
    FROM_DECL (if non-null) specify constructor of variable DECL was taken from.
    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
@@ -1686,29 +1685,21 @@ and_var_with_comparison_1 (gimple stmt,
    (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)
 {
-  tree truth_type = boolean_type_node;
-  if (TREE_CODE (TREE_TYPE (op1a)) == VECTOR_TYPE)
-    {
-      tree vec_type = TREE_TYPE (op1a);
-      tree elem = lang_hooks.types.type_for_size
-       (GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (vec_type))), 0);
-      truth_type = build_opaque_vector_type (elem,
-                                            TYPE_VECTOR_SUBPARTS (vec_type));
-    }
+  tree truth_type = truth_type_for (TREE_TYPE (op1a));
 
   /* First check for ((x CODE1 y) AND (x CODE2 y)).  */
   if (operand_equal_p (op1a, op2a, 0)
       && operand_equal_p (op1b, op2b, 0))
     {
       /* Result will be either NULL_TREE, or a combined comparison.  */
       tree t = combine_comparisons (UNKNOWN_LOCATION,
                                    TRUTH_ANDIF_EXPR, code1, code2,
                                    truth_type, op1a, op1b);
       if (t)
@@ -2158,29 +2149,21 @@ or_var_with_comparison_1 (gimple stmt,
    (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)
 {
-  tree truth_type = boolean_type_node;
-  if (TREE_CODE (TREE_TYPE (op1a)) == VECTOR_TYPE)
-    {
-      tree vec_type = TREE_TYPE (op1a);
-      tree elem = lang_hooks.types.type_for_size
-       (GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (vec_type))), 0);
-      truth_type = build_opaque_vector_type (elem,
-                                            TYPE_VECTOR_SUBPARTS (vec_type));
-    }
+  tree truth_type = truth_type_for (TREE_TYPE (op1a));
 
   /* First check for ((x CODE1 y) OR (x CODE2 y)).  */
   if (operand_equal_p (op1a, op2a, 0)
       && operand_equal_p (op1b, op2b, 0))
     {
       /* Result will be either NULL_TREE, or a combined comparison.  */
       tree t = combine_comparisons (UNKNOWN_LOCATION,
                                    TRUTH_ORIF_EXPR, code1, code2,
                                    truth_type, op1a, op1b);
       if (t)
Index: gcc/tree.c
===================================================================
--- gcc/tree.c  (revision 191810)
+++ gcc/tree.c  (working copy)
@@ -10243,20 +10243,36 @@ unsigned_type_for (tree type)
 /* If TYPE is an integral or pointer type, return an integer type with
    the same precision which is signed, or itself if TYPE is already a
    signed integer type.  */
 
 tree
 signed_type_for (tree type)
 {
   return signed_or_unsigned_type_for (0, type);
 }
 
+/* If TYPE is a vector type, return a signed integer vector type with the
+   same width and number of subparts. Otherwise return boolean_type_node.  */
+
+tree
+truth_type_for (tree type)
+{
+  if (TREE_CODE (type) == VECTOR_TYPE)
+    {
+      tree elem = lang_hooks.types.type_for_size
+        (GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (type))), 0);
+      return build_opaque_vector_type (elem, TYPE_VECTOR_SUBPARTS (type));
+    }
+  else
+    return boolean_type_node;
+}
+
 /* Returns the largest value obtainable by casting something in INNER type to
    OUTER type.  */
 
 tree
 upper_bound_in_type (tree outer, tree inner)
 {
   double_int high;
   unsigned int det = 0;
   unsigned oprec = TYPE_PRECISION (outer);
   unsigned iprec = TYPE_PRECISION (inner);
Index: gcc/tree.h
===================================================================
--- gcc/tree.h  (revision 191810)
+++ gcc/tree.h  (working copy)
@@ -4762,20 +4762,21 @@ extern tree build_call_valist (tree, tre
 extern tree build_call_array_loc (location_t, tree, tree, int, const tree *);
 extern tree build_call_vec (tree, tree, VEC(tree,gc) *);
 
 /* Construct various nodes representing data types.  */
 
 extern tree make_signed_type (int);
 extern tree make_unsigned_type (int);
 extern tree signed_or_unsigned_type_for (int, tree);
 extern tree signed_type_for (tree);
 extern tree unsigned_type_for (tree);
+extern tree truth_type_for (tree);
 extern void initialize_sizetypes (void);
 extern void fixup_unsigned_type (tree);
 extern tree build_pointer_type_for_mode (tree, enum machine_mode, bool);
 extern tree build_pointer_type (tree);
 extern tree build_reference_type_for_mode (tree, enum machine_mode, bool);
 extern tree build_reference_type (tree);
 extern tree build_vector_type_for_mode (tree, enum machine_mode);
 extern tree build_vector_type (tree innertype, int nunits);
 extern tree build_opaque_vector_type (tree innertype, int nunits);
 extern tree build_type_no_quals (tree);

Reply via email to