[PATCH] Handle vector COND_EXPRs in vector genericization (PR tree-optimization/65427)

[Richard Biener]

On March 16, 2015 5:21:02 PM GMT+01:00, Jakub Jelinek <jakub@redhat.com> wrote:
>Hi!
>
>On the following testcase, gimple LIM creates a vector COND_EXPR
>(scalar
>condition, vector lhs, rhs2 and rhs3), but if we don't have
>corresponding
>vector mode for it, we ICE trying to expand the BLKmode COND_EXPR, as
>it is
>unprepared for that.
>
>This patch lowers those (parallel or piecewise).
>Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

OK.  Though maybe LIM should not create these for cost reasons? I also wonder if we should lower them to control flow?

Thanks,
Richard.

>2015-03-16  Jakub Jelinek  <jakub@redhat.com>
>
>	PR tree-optimization/65427
>	* tree-vect-generic.c (do_cond, expand_vector_scalar_condition): New
>	functions.
>	(expand_vector_operations_1): Handle BLKmode vector COND_EXPR.
>
>	* gcc.c-torture/execute/pr65427.c: New test.
>
>--- gcc/tree-vect-generic.c.jj	2015-01-15 20:25:40.000000000 +0100
>+++ gcc/tree-vect-generic.c	2015-03-16 14:25:37.391932269 +0100
>@@ -1417,6 +1417,57 @@ count_type_subparts (tree type)
>   return VECTOR_TYPE_P (type) ? TYPE_VECTOR_SUBPARTS (type) : 1;
> }
> 
>+static tree
>+do_cond (gimple_stmt_iterator *gsi, tree inner_type, tree a, tree b,
>+	 tree bitpos, tree bitsize, enum tree_code code)
>+{
>+  if (TREE_CODE (TREE_TYPE (a)) == VECTOR_TYPE)
>+    a = tree_vec_extract (gsi, inner_type, a, bitsize, bitpos);
>+  if (TREE_CODE (TREE_TYPE (b)) == VECTOR_TYPE)
>+    b = tree_vec_extract (gsi, inner_type, b, bitsize, bitpos);
>+  tree cond = gimple_assign_rhs1 (gsi_stmt (*gsi));
>+  return gimplify_build3 (gsi, code, inner_type, cond, a, b);
>+}
>+
>+/* Expand a vector COND_EXPR to scalars, piecewise.  */
>+static void
>+expand_vector_scalar_condition (gimple_stmt_iterator *gsi)
>+{
>+  gassign *stmt = as_a <gassign *> (gsi_stmt (*gsi));
>+  tree type = gimple_expr_type (stmt);
>+  tree compute_type = get_compute_type (COND_EXPR, mov_optab, type);
>+  machine_mode compute_mode = TYPE_MODE (compute_type);
>+  gcc_assert (compute_mode != BLKmode);
>+  tree lhs = gimple_assign_lhs (stmt);
>+  tree rhs2 = gimple_assign_rhs2 (stmt);
>+  tree rhs3 = gimple_assign_rhs3 (stmt);
>+  tree new_rhs;
>+
>+  /* If the compute mode is not a vector mode (hence we are not
>decomposing
>+     a BLKmode vector to smaller, hardware-supported vectors), we may
>want
>+     to expand the operations in parallel.  */
>+  if (GET_MODE_CLASS (compute_mode) != MODE_VECTOR_INT
>+      && GET_MODE_CLASS (compute_mode) != MODE_VECTOR_FLOAT
>+      && GET_MODE_CLASS (compute_mode) != MODE_VECTOR_FRACT
>+      && GET_MODE_CLASS (compute_mode) != MODE_VECTOR_UFRACT
>+      && GET_MODE_CLASS (compute_mode) != MODE_VECTOR_ACCUM
>+      && GET_MODE_CLASS (compute_mode) != MODE_VECTOR_UACCUM)
>+    new_rhs = expand_vector_parallel (gsi, do_cond, type, rhs2, rhs3,
>+				      COND_EXPR);
>+  else
>+    new_rhs = expand_vector_piecewise (gsi, do_cond, type,
>compute_type,
>+				       rhs2, rhs3, COND_EXPR);
>+  if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE
>(new_rhs)))
>+    new_rhs = gimplify_build1 (gsi, VIEW_CONVERT_EXPR, TREE_TYPE
>(lhs),
>+			       new_rhs);
>+
>+  /* NOTE:  We should avoid using gimple_assign_set_rhs_from_tree. One
>+     way to do it is change expand_vector_operation and its callees to
>+     return a tree_code, RHS1 and RHS2 instead of a tree. */
>+  gimple_assign_set_rhs_from_tree (gsi, new_rhs);
>+  update_stmt (gsi_stmt (*gsi));
>+}
>+
>/* Process one statement.  If we identify a vector operation, expand
>it.  */
> 
> static void
>@@ -1449,6 +1500,14 @@ expand_vector_operations_1 (gimple_stmt_
>       return;
>     }
> 
>+  if (code == COND_EXPR
>+      && TREE_CODE (TREE_TYPE (gimple_assign_lhs (stmt))) ==
>VECTOR_TYPE
>+      && TYPE_MODE (TREE_TYPE (gimple_assign_lhs (stmt))) == BLKmode)
>+    {
>+      expand_vector_scalar_condition (gsi);
>+      return;
>+    }
>+
>   if (code == CONSTRUCTOR
>       && TREE_CODE (lhs) == SSA_NAME
>       && VECTOR_MODE_P (TYPE_MODE (TREE_TYPE (lhs)))
>--- gcc/testsuite/gcc.c-torture/execute/pr65427.c.jj	2015-03-16
>14:36:29.489254701 +0100
>+++ gcc/testsuite/gcc.c-torture/execute/pr65427.c	2015-03-16
>14:40:58.789851433 +0100
>@@ -0,0 +1,34 @@
>+/* PR tree-optimization/65427 */
>+
>+typedef int V __attribute__ ((vector_size (8 * sizeof (int))));
>+V a, b, c, d, e, f;
>+
>+__attribute__((noinline, noclone)) void
>+foo (int x, int y)
>+{
>+  do
>+    {
>+      if (x)
>+	d = a ^ c;
>+      else
>+	d = a ^ b;
>+    }
>+  while (y);
>+}
>+
>+int
>+main ()
>+{
>+  a = (V) { 1, 2, 3, 4, 5, 6, 7, 8 };
>+  b = (V) { 0x40, 0x80, 0x40, 0x80, 0x40, 0x80, 0x40, 0x80 };
>+  e = (V) { 0x41, 0x82, 0x43, 0x84, 0x45, 0x86, 0x47, 0x88 };
>+  foo (0, 0);
>+  if (__builtin_memcmp (&d, &e, sizeof (V)) != 0)
>+    __builtin_abort ();
>+  c = (V) { 0x80, 0x40, 0x80, 0x40, 0x80, 0x40, 0x80, 0x40 };
>+  f = (V) { 0x81, 0x42, 0x83, 0x44, 0x85, 0x46, 0x87, 0x48 };
>+  foo (1, 0);
>+  if (__builtin_memcmp (&d, &f, sizeof (V)) != 0)
>+    __builtin_abort ();
>+  return 0;
>+}
>
>	Jakub