Match: Add interface match_cond_with_binary_phi for true/false arg

When matching the cond with 2 args phi node, we need to figure out
which arg of phi node comes from the true edge of cond block, as
well as the false edge.  This patch would like to add interface
to perform the action and return the true and false arg in TREE type.

The below test suites are passed for this patch.
* The rv64gcv fully regression test.
* The x86 bootstrap test.
* The x86 fully regression test.

gcc/ChangeLog:

	* gimple-match-head.cc (match_cond_with_binary_phi): Add new func
	impl to match binary phi for true and false arg.

Signed-off-by: Pan Li <pan2.li@intel.com>

1 files changed, 120 insertions, 0 deletions

diff --git a/gcc/gimple-match-head.cc b/gcc/gimple-match-head.cc
index 924d3f1..b63b66e 100644
--- a/gcc/gimple-match-head.cc
+++ b/gcc/gimple-match-head.cc
@@ -375,3 +375,123 @@ gimple_bitwise_inverted_equal_p (tree expr1, tree expr2, bool &wascmp, tree (*va
     return true;
   return false;
 }
+
+/*
+ * Return the relevant gcond * of the given phi, as well as the true
+ * and false TREE args of the phi.  Or return nullptr.
+ *
+ * If matched the gcond *, the output argument TREE true_arg and false_arg
+ * will be updated to the relevant args of phi.
+ *
+ * If failed to match, nullptr gcond * will be returned, as well as the output
+ * arguments will be set to NULL_TREE.
+ */
+
+static inline gcond *
+match_cond_with_binary_phi (gphi *phi, tree *true_arg, tree *false_arg)
+{
+  *true_arg = *false_arg = NULL_TREE;
+
+  if (gimple_phi_num_args (phi) != 2)
+    return nullptr;
+
+  basic_block pred_b0 = EDGE_PRED (gimple_bb (phi), 0)->src;
+  basic_block pred_b1 = EDGE_PRED (gimple_bb (phi), 1)->src;
+  edge edge_for_pred_0 = nullptr;
+
+  if (EDGE_COUNT (pred_b0->succs) == 2
+      && EDGE_COUNT (pred_b1->succs) == 1
+      && EDGE_COUNT (pred_b1->preds) == 1
+      && pred_b0 == EDGE_PRED (gimple_bb (phi), 0)->src)
+    /*
+     * +------+
+     * | b0:  |
+     * | def  |       +-----+
+     * | ...  |       | b1: |
+     * | cond |------>| def |
+     * +------+       | ... |
+     *    |           +-----+
+     *    #              |
+     *    |              |
+     *    v              |
+     * +-----+           |
+     * | b2: |           |
+     * | def |<----------+
+     * +-----+
+     * #: edge_for_pred_0.
+     */
+    edge_for_pred_0 = EDGE_PRED (gimple_bb (phi), 0);
+  else if (EDGE_COUNT (pred_b1->succs) == 2
+	   && EDGE_COUNT (pred_b0->succs) == 1
+	   && EDGE_COUNT (pred_b0->preds) == 1
+	   && pred_b1 == EDGE_PRED (pred_b0, 0)->src)
+    /*
+     *                +------+
+     *                | b1:  |
+     * +-----+        | def  |
+     * | b0: |        | ...  |
+     * | def |<---#---| cond |
+     * | ... |        +------+
+     * +-----+           |
+     *    |              |
+     *    |              |
+     *    |              |
+     *    v              |
+     * +-----+           |
+     * | b2: |           |
+     * | def |<----------+
+     * +-----+
+     * #: edge_for_pred_0.
+     */
+    edge_for_pred_0 = EDGE_PRED (pred_b0, 0);
+  else if (EDGE_COUNT (pred_b0->succs) == 1
+	   && EDGE_COUNT (pred_b1->succs) == 1
+	   && EDGE_COUNT (pred_b0->preds) == 1
+	   && EDGE_COUNT (pred_b1->preds) == 1
+	   && EDGE_COUNT (EDGE_PRED (pred_b0, 0)->src->succs) == 2
+	   && EDGE_PRED (pred_b0, 0)->src == EDGE_PRED (pred_b1, 0)->src)
+    /* +------+
+     * | b0:  |
+     * | ...  |       +-----+
+     * | cond |------>| b2: |
+     * +------+       | ... |
+     *    |           +-----+
+     *    #              |
+     *    |              |
+     *    v              |
+     * +-----+           |
+     * | b1: |           |
+     * | ... |           |
+     * +-----+           |
+     *    |              |
+     *    |              |
+     *    v              |
+     * +-----+           |
+     * | b3: |<----------+
+     * | ... |
+     * +-----+
+     * #: edge_for_pred_0.
+     */
+    edge_for_pred_0 = EDGE_PRED (pred_b0, 0);
+
+  if (!edge_for_pred_0)
+    return nullptr;
+
+  gcond *cond = safe_dyn_cast <gcond *> (*gsi_last_bb (edge_for_pred_0->src));
+
+  if (!cond)
+    return nullptr;
+
+  if (edge_for_pred_0->flags & EDGE_TRUE_VALUE)
+    {
+      *true_arg = gimple_phi_arg_def (phi, 0);
+      *false_arg = gimple_phi_arg_def (phi, 1);
+    }
+  else /* Aka edge_for_pred_0->flags & EDGE_FALSE_VALUE  */
+    {
+      *false_arg = gimple_phi_arg_def (phi, 0);
+      *true_arg = gimple_phi_arg_def (phi, 1);
+    }
+
+  return cond;
+}