[PATCH] Fix reassoc range opt related ICE (PR tree-optimization/81003)

[Jakub Jelinek]

Hi!

force_gimple_operand_gsi called by update_range_test can using match.pd
simplifications sometimes return INTEGER_CST (especially when cunroll
unrolled code isn't really optimized by forwprop/ccp and similar passes
before reassoc2), but that is something not acceptable to the rest of
the optimize_range* code, because it needs to know not just the value,
but also some gimple_stmt_iterator to insert related code etc.

This patch makes sure we have a SSA_NAME even in that case.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2017-06-08  Jakub Jelinek  <ja...@redhat.com>

        PR tree-optimization/81003
        * tree-ssa-reassoc.c (force_into_ssa_name): New function.
        (update_range_test): Use it instead of force_gimple_operand_gsi.

        * gcc.c-torture/compile/pr81003.c: New test.

--- gcc/tree-ssa-reassoc.c.jj   2017-06-05 11:58:14.000000000 +0200
+++ gcc/tree-ssa-reassoc.c      2017-06-08 12:20:47.619790903 +0200
@@ -2282,6 +2282,26 @@ range_entry_cmp (const void *a, const vo
     }
 }
 
+/* Helper function for update_range_test.  Force EXPR into an SSA_NAME,
+   insert needed statements BEFORE or after GSI.  */
+
+static tree
+force_into_ssa_name (gimple_stmt_iterator *gsi, tree expr, bool before)
+{
+  enum gsi_iterator_update m = before ? GSI_SAME_STMT : GSI_CONTINUE_LINKING;
+  tree ret = force_gimple_operand_gsi (gsi, expr, true, NULL_TREE, before, m);
+  if (TREE_CODE (ret) != SSA_NAME)
+    {
+      gimple *g = gimple_build_assign (make_ssa_name (TREE_TYPE (ret)), ret);
+      if (before)
+       gsi_insert_before (gsi, g, GSI_SAME_STMT);
+      else
+       gsi_insert_after (gsi, g, GSI_CONTINUE_LINKING);
+      ret = gimple_assign_lhs (g);
+    }
+  return ret;
+}
+
 /* Helper routine of optimize_range_test.
    [EXP, IN_P, LOW, HIGH, STRICT_OVERFLOW_P] is a merged range for
    RANGE and OTHERRANGE through OTHERRANGE + COUNT - 1 ranges,
@@ -2393,15 +2413,13 @@ update_range_test (struct range_entry *r
   else if (op != range->exp)
     {
       gsi_insert_seq_before (&gsi, seq, GSI_SAME_STMT);
-      tem = force_gimple_operand_gsi (&gsi, tem, true, NULL_TREE, true,
-                                     GSI_SAME_STMT);
+      tem = force_into_ssa_name (&gsi, tem, true);
       gsi_prev (&gsi);
     }
   else if (gimple_code (stmt) != GIMPLE_PHI)
     {
       gsi_insert_seq_after (&gsi, seq, GSI_CONTINUE_LINKING);
-      tem = force_gimple_operand_gsi (&gsi, tem, true, NULL_TREE, false,
-                                     GSI_CONTINUE_LINKING);
+      tem = force_into_ssa_name (&gsi, tem, false);
     }
   else
     {
@@ -2419,8 +2437,7 @@ update_range_test (struct range_entry *r
            }
        }
       gsi_insert_seq_before (&gsi, seq, GSI_SAME_STMT);
-      tem = force_gimple_operand_gsi (&gsi, tem, true, NULL_TREE, true,
-                                     GSI_SAME_STMT);
+      tem = force_into_ssa_name (&gsi, tem, true);
       if (gsi_end_p (gsi))
        gsi = gsi_last_bb (gimple_bb (stmt));
       else
--- gcc/testsuite/gcc.c-torture/compile/pr81003.c.jj    2017-06-08 
12:16:20.284127013 +0200
+++ gcc/testsuite/gcc.c-torture/compile/pr81003.c       2017-06-08 
12:16:07.000000000 +0200
@@ -0,0 +1,10 @@
+/* PR tree-optimization/81003 */
+
+unsigned int a, b;
+
+void
+foo (void)
+{
+  for (b = 0; b < 13; b += 2)
+    a &= !!b;
+}

        Jakub