Hi All,

Factoring out CONVERT_EXPR introduced a regression for (PR66726). I had to revert my previous patch due to some regressions. This is a much simplified version compared to the one I reverted.

There is a test-case (pr46309.c) in the test-suite which is valid for targets that has branch cost greater than 1.

This patch makes optimize_range_tests understand the factored out COND_EXPR. i.e., Updated the final_range_test_p to look for the new pattern. Changed the maybe_optimize_range_tests (which does the inter basic block range test optimization) accordingly.

With the patch
m68k-linux-gnu-gcc -O2 -S pr46309.c -fdump-tree-reassoc-details
grep -e "Optimizing range tests" -e into pr46309.c.*.reassoc1pr46309.c.114t.reassoc1:Optimizing range tests a_6(D) -[1, 1] and -[2, 2] and -[3, 3] and -[4, 4]
pr46309.c.114t.reassoc1: into (unsigned int) a_6(D) + 4294967295 > 3
pr46309.c.114t.reassoc1: into _10 = _13;
pr46309.c.114t.reassoc1:Optimizing range tests a_6(D) -[1, 1] and -[2, 2] and -[3, 3] and -[4, 4]
pr46309.c.114t.reassoc1: into (unsigned int) a_6(D) + 4294967295 > 3
pr46309.c.114t.reassoc1: into _10 = _13;
pr46309.c.114t.reassoc1:Optimizing range tests a_4(D) -[1, 1] and -[3, 3]
pr46309.c.114t.reassoc1: into (a_4(D) & -3) != 1
pr46309.c.114t.reassoc1: into _6 = _8;
pr46309.c.114t.reassoc1:Optimizing range tests a_4(D) -[1, 1] and -[2, 2]
pr46309.c.114t.reassoc1: into (unsigned int) a_4(D) + 4294967295 > 1
pr46309.c.114t.reassoc1: into _6 = _9;
pr46309.c.114t.reassoc1:Optimizing range tests a_5(D) -[0, 31] and -[64, 95]
pr46309.c.114t.reassoc1: into (a_5(D) & 4294967231) > 31
pr46309.c.114t.reassoc1: into _7 = _9;
pr46309.c.114t.reassoc1:Optimizing range tests a_9(D) -[0, 31] and -[64, 95]
pr46309.c.114t.reassoc1: into (a_9(D) & 4294967231) > 31
pr46309.c.114t.reassoc1:Optimizing range tests a_9(D) -[128, 159] and -[192, 223]
pr46309.c.114t.reassoc1: into (a_9(D) & 4294967231) + 4294967168 > 31
pr46309.c.114t.reassoc1: into _13 = _18 | _15;
pr46309.c.116t.reassoc1:Optimizing range tests a_2(D) -[1, 1] and -[2, 2] and -[3, 3] and -[4, 4]
pr46309.c.116t.reassoc1: into (unsigned int) a_2(D) + 4294967295 > 3
pr46309.c.116t.reassoc1:Optimizing range tests a_2(D) -[1, 1] and -[2, 2] and -[3, 3] and -[4, 4]
pr46309.c.116t.reassoc1: into (unsigned int) a_2(D) + 4294967295 > 3
pr46309.c.116t.reassoc1:Optimizing range tests a_3(D) -[0, 31] and -[64, 95]
pr46309.c.116t.reassoc1: into (a_3(D) & 4294967231) > 31
pr46309.c.116t.reassoc1:Optimizing range tests a_5(D) -[0, 31] and -[64, 95]
pr46309.c.116t.reassoc1: into (a_5(D) & 4294967231) > 31
pr46309.c.116t.reassoc1:Optimizing range tests a_5(D) -[128, 159] and -[192, 223]
pr46309.c.116t.reassoc1: into (a_5(D) & 4294967231) + 4294967168 > 31


Bootstrapped and regression testing on x86-64-linux-gnu and ppc64le-linux-gnu doesn't have any new regressions. Also did regression testing arm variants which has branch cost greater than 1

Is this OK for trunk.

Thanks,
Kugan

gcc/ChangeLog:

2016-06-01  Kugan Vivekanandarajah  <kug...@linaro.org>

        PR middle-end/66726
        * tree-ssa-reassoc.c (optimize_vec_cond_expr): Handle tcc_compare stmt
        whose result is used in PHI
        (final_range_test_p): Likewise.
        (maybe_optimize_range_tests): Likewise.
diff --git a/gcc/tree-ssa-reassoc.c b/gcc/tree-ssa-reassoc.c
index 430bcc8..851ae6d 100644
--- a/gcc/tree-ssa-reassoc.c
+++ b/gcc/tree-ssa-reassoc.c
@@ -3007,18 +3007,33 @@ optimize_vec_cond_expr (tree_code opcode, 
vec<operand_entry *> *ops)
    # _345 = PHI <_123(N), 1(...), 1(...)>
    where _234 has bool type, _123 has single use and
    bb N has a single successor M.  This is commonly used in
+   the last block of a range test.
+
+   Also Return true if STMT is tcc_compare like:
+   <bb N>:
+   ...
+   _234 = a_2(D) == 2;
+
+   <bb M>:
+   # _345 = PHI <_234(N), 1(...), 1(...)>
+   _346 = (int) _345;
+   where _234 has booltype, single use and
+   bb N has a single successor M.  This is commonly used in
    the last block of a range test.  */
 
 static bool
 final_range_test_p (gimple *stmt)
 {
-  basic_block bb, rhs_bb;
+  basic_block bb, rhs_bb, lhs_bb;
   edge e;
   tree lhs, rhs;
   use_operand_p use_p;
   gimple *use_stmt;
 
-  if (!gimple_assign_cast_p (stmt))
+  if (!gimple_assign_cast_p (stmt)
+      && (!is_gimple_assign (stmt)
+         || (TREE_CODE_CLASS (gimple_assign_rhs_code (stmt))
+             != tcc_comparison)))
     return false;
   bb = gimple_bb (stmt);
   if (!single_succ_p (bb))
@@ -3029,11 +3044,16 @@ final_range_test_p (gimple *stmt)
 
   lhs = gimple_assign_lhs (stmt);
   rhs = gimple_assign_rhs1 (stmt);
-  if (!INTEGRAL_TYPE_P (TREE_TYPE (lhs))
-      || TREE_CODE (rhs) != SSA_NAME
-      || TREE_CODE (TREE_TYPE (rhs)) != BOOLEAN_TYPE)
+  if (gimple_assign_cast_p (stmt)
+      && (!INTEGRAL_TYPE_P (TREE_TYPE (lhs))
+         || TREE_CODE (rhs) != SSA_NAME
+         || TREE_CODE (TREE_TYPE (rhs)) != BOOLEAN_TYPE))
     return false;
 
+  if (!gimple_assign_cast_p (stmt)
+      && (TREE_CODE (TREE_TYPE (lhs)) != BOOLEAN_TYPE))
+      return false;
+
   /* Test whether lhs is consumed only by a PHI in the only successor bb.  */
   if (!single_imm_use (lhs, &use_p, &use_stmt))
     return false;
@@ -3043,10 +3063,20 @@ final_range_test_p (gimple *stmt)
     return false;
 
   /* And that the rhs is defined in the same loop.  */
-  rhs_bb = gimple_bb (SSA_NAME_DEF_STMT (rhs));
-  if (rhs_bb == NULL
-      || !flow_bb_inside_loop_p (loop_containing_stmt (stmt), rhs_bb))
-    return false;
+  if (gimple_assign_cast_p (stmt))
+    {
+      if (TREE_CODE (rhs) != SSA_NAME
+         || !(rhs_bb = gimple_bb (SSA_NAME_DEF_STMT (rhs)))
+         || !flow_bb_inside_loop_p (loop_containing_stmt (stmt), rhs_bb))
+       return false;
+    }
+  else
+    {
+      if (TREE_CODE (lhs) != SSA_NAME
+         || !(lhs_bb = gimple_bb (SSA_NAME_DEF_STMT (lhs)))
+         || !flow_bb_inside_loop_p (loop_containing_stmt (stmt), lhs_bb))
+       return false;
+    }
 
   return true;
 }
@@ -3440,6 +3470,8 @@ maybe_optimize_range_tests (gimple *stmt)
 
          /* stmt is
             _123 = (int) _234;
+            OR
+            _234 = a_2(D) == 2;
 
             followed by:
             <bb M>:
@@ -3469,6 +3501,8 @@ maybe_optimize_range_tests (gimple *stmt)
             of the bitwise or resp. and, recursively.  */
          if (!get_ops (rhs, code, &ops,
                        loop_containing_stmt (stmt))
+             && (TREE_CODE_CLASS (gimple_assign_rhs_code (stmt))
+                 != tcc_comparison)
              && has_single_use (rhs))
            {
              /* Otherwise, push the _234 range test itself.  */
@@ -3481,10 +3515,36 @@ maybe_optimize_range_tests (gimple *stmt)
              oe->stmt_to_insert = NULL;
              ops.safe_push (oe);
              bb_ent.last_idx++;
+             bb_ent.op = rhs;
+           }
+         else if (is_gimple_assign (stmt)
+                  && (TREE_CODE_CLASS (gimple_assign_rhs_code (stmt))
+                      == tcc_comparison))
+           {
+             if (!get_ops (lhs, code, &ops,
+                           loop_containing_stmt (stmt))
+                 && has_single_use (rhs))
+               {
+                 operand_entry *oe = operand_entry_pool.allocate ();
+                 oe->op = lhs;
+                 oe->rank = code;
+                 oe->id = 0;
+                 oe->count = 1;
+                 ops.safe_push (oe);
+                 bb_ent.last_idx++;
+                 bb_ent.op = lhs;
+               }
+             else
+               {
+                 bb_ent.last_idx = ops.length ();
+                 bb_ent.op = rhs;
+               }
            }
          else
-           bb_ent.last_idx = ops.length ();
-         bb_ent.op = rhs;
+           {
+             bb_ent.last_idx = ops.length ();
+             bb_ent.op = rhs;
+           }
          bbinfo.safe_push (bb_ent);
          continue;
        }
@@ -3566,7 +3626,7 @@ maybe_optimize_range_tests (gimple *stmt)
                {
                  imm_use_iterator iter;
                  use_operand_p use_p;
-                 gimple *use_stmt, *cast_stmt = NULL;
+                 gimple *use_stmt, *cast_or_tcc_cmp_stmt = NULL;
 
                  FOR_EACH_IMM_USE_STMT (use_stmt, iter, bbinfo[idx].op)
                    if (is_gimple_debug (use_stmt))
@@ -3575,17 +3635,25 @@ maybe_optimize_range_tests (gimple *stmt)
                             || gimple_code (use_stmt) == GIMPLE_PHI)
                      FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
                        SET_USE (use_p, new_op);
+                   else if ((is_gimple_assign (use_stmt)
+                             && (TREE_CODE_CLASS
+                                 (gimple_assign_rhs_code (use_stmt))
+                                 == tcc_comparison)))
+                     cast_or_tcc_cmp_stmt = use_stmt;
                    else if (gimple_assign_cast_p (use_stmt))
-                     cast_stmt = use_stmt;
+                     cast_or_tcc_cmp_stmt = use_stmt;
                    else
                      gcc_unreachable ();
-                 if (cast_stmt)
+
+                 if (cast_or_tcc_cmp_stmt)
                    {
                      gcc_assert (bb == last_bb);
-                     tree lhs = gimple_assign_lhs (cast_stmt);
+                     tree lhs = gimple_assign_lhs (cast_or_tcc_cmp_stmt);
                      tree new_lhs = make_ssa_name (TREE_TYPE (lhs));
                      enum tree_code rhs_code
-                       = gimple_assign_rhs_code (cast_stmt);
+                       = gimple_assign_cast_p (cast_or_tcc_cmp_stmt)
+                       ? gimple_assign_rhs_code (cast_or_tcc_cmp_stmt)
+                       : CONVERT_EXPR;
                      gassign *g;
                      if (is_gimple_min_invariant (new_op))
                        {
@@ -3594,8 +3662,9 @@ maybe_optimize_range_tests (gimple *stmt)
                        }
                      else
                        g = gimple_build_assign (new_lhs, rhs_code, new_op);
-                     gimple_stmt_iterator gsi = gsi_for_stmt (cast_stmt);
-                     gimple_set_uid (g, gimple_uid (cast_stmt));
+                     gimple_stmt_iterator gsi
+                       = gsi_for_stmt (cast_or_tcc_cmp_stmt);
+                     gimple_set_uid (g, gimple_uid (cast_or_tcc_cmp_stmt));
                      gimple_set_visited (g, true);
                      gsi_insert_before (&gsi, g, GSI_SAME_STMT);
                      FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs)

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