[gcc r14-5449] Use case label type to create case range.

[Andrew Macleod <amacleod@gcc.gnu.org>]

https://gcc.gnu.org/g:8f331be42991aa4d58ac770faf993accfcce882b

commit r14-5449-g8f331be42991aa4d58ac770faf993accfcce882b
Author: Andrew MacLeod <amacleod@redhat.com>
Date:   Mon Nov 13 09:58:10 2023 -0500

    Use case label type to create case range.
    
    Create a range from the label type, and cast it to the required type.
    
            PR tree-optimization/112509
            gcc/
            * tree-vrp.cc (find_case_label_range): Create range from case labels.
    
            gcc/testsuite/
            * gcc.dg/pr112509.c: New.

Diff:
---
 gcc/testsuite/gcc.dg/pr112509.c | 22 ++++++++++++++++++++++
 gcc/tree-vrp.cc                 |  6 +-----
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/gcc/testsuite/gcc.dg/pr112509.c b/gcc/testsuite/gcc.dg/pr112509.c
new file mode 100644
index 00000000000..b733780bdc7
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr112509.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-tree-vrp -fno-tree-fre -fno-tree-forwprop" } */
+
+struct S {
+  unsigned j : 3;
+};
+int k, l, m_1 = {0};
+void f(int l, struct S x) {
+  unsigned int k_1;
+  while (m_1 % 8) switch (x.j) {
+    case 1:
+    case 3:
+    case 4:
+    case 6:
+    case 2:
+    case 5: l = m_1;
+    case 7:
+    case 0: k_1 = 0;
+    default: break;
+    }
+}
+void foo(struct S x) { f(l, x); }
diff --git a/gcc/tree-vrp.cc b/gcc/tree-vrp.cc
index 19d8f995d70..917fa873714 100644
--- a/gcc/tree-vrp.cc
+++ b/gcc/tree-vrp.cc
@@ -886,8 +886,6 @@ find_case_label_range (gswitch *switch_stmt, const irange *range_of_op)
   size_t i, j;
   tree op = gimple_switch_index (switch_stmt);
   tree type = TREE_TYPE (op);
-  unsigned prec = TYPE_PRECISION (type);
-  signop sign = TYPE_SIGN (type);
   tree tmin = wide_int_to_tree (type, range_of_op->lower_bound ());
   tree tmax = wide_int_to_tree (type, range_of_op->upper_bound ());
   find_case_label_range (switch_stmt, tmin, tmax, &i, &j);
@@ -900,9 +898,7 @@ find_case_label_range (gswitch *switch_stmt, const irange *range_of_op)
 	= CASE_HIGH (label) ? CASE_HIGH (label) : CASE_LOW (label);
       wide_int wlow = wi::to_wide (CASE_LOW (label));
       wide_int whigh = wi::to_wide (case_high);
-      int_range_max label_range (type,
-				 wide_int::from (wlow, prec, sign),
-				 wide_int::from (whigh, prec, sign));
+      int_range_max label_range (TREE_TYPE (case_high), wlow, whigh);
       if (!types_compatible_p (label_range.type (), range_of_op->type ()))
 	range_cast (label_range, range_of_op->type ());
       label_range.intersect (*range_of_op);