[PATCH] Fix PR tree-optimization/72810

[Patrick Palka]

Sometimes the case labels of a switch have a different type than the
switch operand, e.g. in the test case below, the case labels have type t
and the switch operand has type int. Because the verifier expects that
case labels of a switch each have the exact same type, it's important to
avoid changing their types when truncating their range.

Does this patch look OK to commit after bootstrap + regtesting?

gcc/ChangeLog:

	PR tree-optimization/72810
	* tree-vrp.c (simplify_switch_using_ranges): Avoid changing
	the types of the case labels when truncating.

gcc/testsuite/ChangeLog:

	PR tree-optimization/72810
	* tree-ssa/vrp110.c: New test.
---
 gcc/testsuite/gcc.dg/tree-ssa/vrp110.c | 24 +++++++++++++++++++
 gcc/tree-vrp.c                         | 43 +++++++++++++++++++---------------
 2 files changed, 48 insertions(+), 19 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/vrp110.c

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp110.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp110.c
new file mode 100644
index 0000000..34d7eb4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp110.c
@@ -0,0 +1,24 @@
+/* { dg-options "-O2" }  */
+
+extern void foo (void);
+extern void bar (void);
+
+void
+test (int i)
+{
+  if (i == 1)
+    return;
+
+  typedef int t;
+  t j = i;
+  switch (j)
+    {
+    case 1:
+    case 2:
+      foo ();
+      break;
+    case 7:
+      bar ();
+      break;
+    }
+}
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 7e3b513..2c166db 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -9643,61 +9643,66 @@ simplify_switch_using_ranges (gswitch *stmt)
       tree min_label = gimple_switch_label (stmt, min_idx);
       tree max_label = gimple_switch_label (stmt, max_idx);
 
+      /* Avoid changing the types of the case labels when truncating.  */
+      tree case_label_type = TREE_TYPE (CASE_LOW (min_label));
+      tree vr_min = fold_convert (case_label_type, vr->min);
+      tree vr_max = fold_convert (case_label_type, vr->max);
+
       if (vr->type == VR_RANGE)
 	{
 	  /* If OP's value range is [2,8] and the low label range is
 	     0 ... 3, truncate the label's range to 2 .. 3.  */
-	  if (tree_int_cst_compare (CASE_LOW (min_label), vr->min) < 0
+	  if (tree_int_cst_compare (CASE_LOW (min_label), vr_min) < 0
 	      && CASE_HIGH (min_label) != NULL_TREE
-	      && tree_int_cst_compare (CASE_HIGH (min_label), vr->min) >= 0)
-	    CASE_LOW (min_label) = vr->min;
+	      && tree_int_cst_compare (CASE_HIGH (min_label), vr_min) >= 0)
+	    CASE_LOW (min_label) = vr_min;
 
 	  /* If OP's value range is [2,8] and the high label range is
 	     7 ... 10, truncate the label's range to 7 .. 8.  */
-	  if (tree_int_cst_compare (CASE_LOW (max_label), vr->max) <= 0
+	  if (tree_int_cst_compare (CASE_LOW (max_label), vr_max) <= 0
 	      && CASE_HIGH (max_label) != NULL_TREE
-	      && tree_int_cst_compare (CASE_HIGH (max_label), vr->max) > 0)
-	    CASE_HIGH (max_label) = vr->max;
+	      && tree_int_cst_compare (CASE_HIGH (max_label), vr_max) > 0)
+	    CASE_HIGH (max_label) = vr_max;
 	}
       else if (vr->type == VR_ANTI_RANGE)
 	{
-	  tree one_cst = build_one_cst (TREE_TYPE (op));
+	  tree one_cst = build_one_cst (case_label_type);
 
 	  if (min_label == max_label)
 	    {
 	      /* If OP's value range is ~[7,8] and the label's range is
 		 7 ... 10, truncate the label's range to 9 ... 10.  */
-	      if (tree_int_cst_compare (CASE_LOW (min_label), vr->min) == 0
+	      if (tree_int_cst_compare (CASE_LOW (min_label), vr_min) == 0
 		  && CASE_HIGH (min_label) != NULL_TREE
-		  && tree_int_cst_compare (CASE_HIGH (min_label), vr->max) > 0)
+		  && tree_int_cst_compare (CASE_HIGH (min_label), vr_max) > 0)
 		CASE_LOW (min_label)
-		  = int_const_binop (PLUS_EXPR, vr->max, one_cst);
+		  = int_const_binop (PLUS_EXPR, vr_max, one_cst);
 
 	      /* If OP's value range is ~[7,8] and the label's range is
 		 5 ... 8, truncate the label's range to 5 ... 6.  */
-	      if (tree_int_cst_compare (CASE_LOW (min_label), vr->min) < 0
+	      if (tree_int_cst_compare (CASE_LOW (min_label), vr_min) < 0
 		  && CASE_HIGH (min_label) != NULL_TREE
-		  && tree_int_cst_compare (CASE_HIGH (min_label), vr->max) == 0)
+		  && tree_int_cst_compare (CASE_HIGH (min_label), vr_max) == 0)
 		CASE_HIGH (min_label)
-		  = int_const_binop (MINUS_EXPR, vr->min, one_cst);
+		  = int_const_binop (MINUS_EXPR, vr_min, one_cst);
 	    }
 	  else
 	    {
 	      /* If OP's value range is ~[2,8] and the low label range is
 		 0 ... 3, truncate the label's range to 0 ... 1.  */
-	      if (tree_int_cst_compare (CASE_LOW (min_label), vr->min) < 0
+	      if (tree_int_cst_compare (CASE_LOW (min_label), vr_min) < 0
 		  && CASE_HIGH (min_label) != NULL_TREE
-		  && tree_int_cst_compare (CASE_HIGH (min_label), vr->min) >= 0)
+		  && tree_int_cst_compare (CASE_HIGH (min_label), vr_min) >= 0)
 		CASE_HIGH (min_label)
-		  = int_const_binop (MINUS_EXPR, vr->min, one_cst);
+		  = int_const_binop (MINUS_EXPR, vr_min, one_cst);
 
 	      /* If OP's value range is ~[2,8] and the high label range is
 		 7 ... 10, truncate the label's range to 9 ... 10.  */
-	      if (tree_int_cst_compare (CASE_LOW (max_label), vr->max) <= 0
+	      if (tree_int_cst_compare (CASE_LOW (max_label), vr_max) <= 0
 		  && CASE_HIGH (max_label) != NULL_TREE
-		  && tree_int_cst_compare (CASE_HIGH (max_label), vr->max) > 0)
+		  && tree_int_cst_compare (CASE_HIGH (max_label), vr_max) > 0)
 		CASE_LOW (max_label)
-		  = int_const_binop (PLUS_EXPR, vr->max, one_cst);
+		  = int_const_binop (PLUS_EXPR, vr_max, one_cst);
 	    }
 	}
 
-- 
2.9.2.614.g990027a