middle-end/106027 - fix types in needle folding

The fold_to_nonsharp_ineq_using_bound folding ends up creating invalid
typed IL which confuses later foldings.  The following fixes that.

2022-06-20  Richard Biener  <rguenther@suse.de>

	PR middle-end/106027
	* fold-const.cc (fold_to_nonsharp_ineq_using_bound): Use the
	type of the prevailing comparison for the new comparison type.
	(fold_binary_loc): Use proper types for the A < X && A + 1 > Y
	to A < X && A >= Y folding.

	* gcc.dg/pr106027.c: New testcase.

(cherry picked from commit 713f2fd923442b1be620a44240ddf786ae0ab476)

diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc
index 8c423c8..948e13a 100644 (file)
--- a/gcc/fold-const.cc
+++ b/gcc/fold-const.cc
@@ -7529,7 +7529,7 @@ tree_swap_operands_p (const_tree arg0, const_tree arg1)
 static tree
 fold_to_nonsharp_ineq_using_bound (location_t loc, tree ineq, tree bound)
 {
-  tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
+  tree a, typea, type = TREE_TYPE (bound), a1, diff, y;
 
   if (TREE_CODE (bound) == LT_EXPR)
     a = TREE_OPERAND (bound, 0);
@@ -12036,11 +12036,15 @@ fold_binary_loc (location_t loc, enum tree_code code, tree type,
        {
          tem = fold_to_nonsharp_ineq_using_bound (loc, arg0, arg1);
          if (tem && !operand_equal_p (tem, arg0, 0))
-           return fold_build2_loc (loc, code, type, tem, arg1);
+           return fold_convert (type,
+                                fold_build2_loc (loc, code, TREE_TYPE (arg1),
+                                                 tem, arg1));
 
          tem = fold_to_nonsharp_ineq_using_bound (loc, arg1, arg0);
          if (tem && !operand_equal_p (tem, arg1, 0))
-           return fold_build2_loc (loc, code, type, arg0, tem);
+           return fold_convert (type,
+                                fold_build2_loc (loc, code, TREE_TYPE (arg0),
+                                                 arg0, tem));
        }
 
       if ((tem = fold_truth_andor (loc, code, type, arg0, arg1, op0, op1))

diff --git a/gcc/testsuite/gcc.dg/pr106027.c b/gcc/testsuite/gcc.dg/pr106027.c
new file mode 100644 (file)
index 0000000..735205f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr106027.c
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+int
+foo (unsigned int x, int y)
+{
+  return x <= (((y != y) < 0) ? y < 1 : 0);
+}