tree-ssa-forwprop.c (forward_propagate_into_cond): Handle vectors.

2012-10-23  Marc Glisse  <marc.glisse@inria.fr>

gcc/
	* tree-ssa-forwprop.c (forward_propagate_into_cond): Handle vectors.
	* fold-const.c (fold_relational_const): Handle VECTOR_CST.
	* doc/generic.texi (VEC_COND_EXPR): Document current policy.

gcc/testsuite/
	* gcc.dg/tree-ssa/foldconst-6.c: New testcase.

From-SVN: r192711

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 815c582..24839c4 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2012-10-23  Marc Glisse  <marc.glisse@inria.fr>
+
+       * tree-ssa-forwprop.c (forward_propagate_into_cond): Handle vectors.
+       * fold-const.c (fold_relational_const): Handle VECTOR_CST.
+       * doc/generic.texi (VEC_COND_EXPR): Document current policy.
+
 2012-10-23  Jan Hubicka  <jh@suse.cz>
 
        PR middle-end/54937

diff --git a/gcc/doc/generic.texi b/gcc/doc/generic.texi
index 082a528..c739731 100644 (file)
--- a/gcc/doc/generic.texi
+++ b/gcc/doc/generic.texi
@@ -1780,8 +1780,9 @@ operand is of signed integral vector type.  If an element of the first
 operand evaluates to a zero value, the corresponding element of the
 result is taken from the third operand. If it evaluates to a minus one
 value, it is taken from the second operand. It should never evaluate to
-any other value. In contrast with a @code{COND_EXPR}, all operands are
-always evaluated.
+any other value currently, but optimizations should not rely on that
+property. In contrast with a @code{COND_EXPR}, all operands are always
+evaluated.
 @end table
 
 

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 053b3f5..e3e4151 100644 (file)
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -16130,6 +16130,31 @@ fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
        return NULL_TREE;
     }
 
+  if (TREE_CODE (op0) == VECTOR_CST && TREE_CODE (op1) == VECTOR_CST)
+    {
+      unsigned count = VECTOR_CST_NELTS (op0);
+      tree *elts =  XALLOCAVEC (tree, count);
+      gcc_assert (VECTOR_CST_NELTS (op1) == count
+                 && TYPE_VECTOR_SUBPARTS (type) == count);
+
+      for (unsigned i = 0; i < count; i++)
+       {
+         tree elem_type = TREE_TYPE (type);
+         tree elem0 = VECTOR_CST_ELT (op0, i);
+         tree elem1 = VECTOR_CST_ELT (op1, i);
+
+         tree tem = fold_relational_const (code, elem_type,
+                                           elem0, elem1);
+
+         if (tem == NULL_TREE)
+           return NULL_TREE;
+
+         elts[i] = build_int_cst (elem_type, integer_zerop (tem) ? 0 : -1);
+       }
+
+      return build_vector (type, elts);
+    }
+
   /* From here on we only handle LT, LE, GT, GE, EQ and NE.
 
      To compute GT, swap the arguments and do LT.

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 7a6d258..7c7ce7c 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2012-10-23  Marc Glisse  <marc.glisse@inria.fr>
+
+       * gcc.dg/tree-ssa/foldconst-6.c: New testcase.
+
 2012-10-23  Jan Hubicka  <jh@suse.cz>
 
        PR middle-end/54937

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/foldconst-6.c b/gcc/testsuite/gcc.dg/tree-ssa/foldconst-6.c
new file mode 100644 (file)
index 0000000..0c08f8f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/foldconst-6.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-ccp1" } */
+
+typedef long vec __attribute__ ((vector_size (2 * sizeof(long))));
+
+void f (vec *r)
+{
+  vec a = { -2, 666 };
+  vec b = { 3, 2 };
+  *r = a < b;
+}
+
+/* { dg-final { scan-tree-dump-not "666" "ccp1"} } */
+/* { dg-final { cleanup-tree-dump "ccp1" } } */

diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
index b6c5654..f193fa9 100644 (file)
--- a/gcc/tree-ssa-forwprop.c
+++ b/gcc/tree-ssa-forwprop.c
@@ -551,6 +551,7 @@ 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);
+  enum tree_code code = gimple_assign_rhs_code (stmt);
   bool swap = false;
 
   /* We can do tree combining on SSA_NAME and comparison expressions.  */
@@ -561,23 +562,24 @@ forward_propagate_into_cond (gimple_stmt_iterator *gsi_p)
                                               TREE_OPERAND (cond, 1));
   else if (TREE_CODE (cond) == SSA_NAME)
     {
-      enum tree_code code;
+      enum tree_code def_code;
       tree name = cond;
       gimple def_stmt = get_prop_source_stmt (name, true, NULL);
       if (!def_stmt || !can_propagate_from (def_stmt))
        return 0;
 
-      code = gimple_assign_rhs_code (def_stmt);
-      if (TREE_CODE_CLASS (code) == tcc_comparison)
+      def_code = gimple_assign_rhs_code (def_stmt);
+      if (TREE_CODE_CLASS (def_code) == tcc_comparison)
        tmp = fold_build2_loc (gimple_location (def_stmt),
-                              code,
+                              def_code,
                               TREE_TYPE (cond),
                               gimple_assign_rhs1 (def_stmt),
                               gimple_assign_rhs2 (def_stmt));
-      else if ((code == BIT_NOT_EXPR
-               && TYPE_PRECISION (TREE_TYPE (cond)) == 1)
-              || (code == BIT_XOR_EXPR
-                  && integer_onep (gimple_assign_rhs2 (def_stmt))))
+      else if (code == COND_EXPR
+              && ((def_code == BIT_NOT_EXPR
+                   && TYPE_PRECISION (TREE_TYPE (cond)) == 1)
+                  || (def_code == BIT_XOR_EXPR
+                      && integer_onep (gimple_assign_rhs2 (def_stmt)))))
        {
          tmp = gimple_assign_rhs1 (def_stmt);
          swap = true;
@@ -596,7 +598,8 @@ forward_propagate_into_cond (gimple_stmt_iterator *gsi_p)
          fprintf (dump_file, "'\n");
        }
 
-      if (integer_onep (tmp))
+      if ((code == VEC_COND_EXPR) ? integer_all_onesp (tmp)
+                                 : integer_onep (tmp))
        gimple_assign_set_rhs_from_tree (gsi_p, gimple_assign_rhs2 (stmt));
       else if (integer_zerop (tmp))
        gimple_assign_set_rhs_from_tree (gsi_p, gimple_assign_rhs3 (stmt));