[gcc r13-5064] tree-optimization/101912 - testcase for fixed uninit case

[Richard Biener <rguenth@gcc.gnu.org>]

https://gcc.gnu.org/g:7afecddf1ecbb93ee44517ad6d3e9c1c0d68e722

commit r13-5064-g7afecddf1ecbb93ee44517ad6d3e9c1c0d68e722
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Jan 9 11:00:43 2023 +0100

    tree-optimization/101912 - testcase for fixed uninit case
    
    We now properly optimize this testcase and no longer diagnose
    a bogus uninit use.
    
            PR tree-optimization/101912
            * gcc.dg/uninit-pr101912.c: New testcase.

Diff:
---
 gcc/testsuite/gcc.dg/uninit-pr101912.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/gcc/testsuite/gcc.dg/uninit-pr101912.c b/gcc/testsuite/gcc.dg/uninit-pr101912.c
new file mode 100644
index 00000000000..1550c03436d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/uninit-pr101912.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -Wuninitialized" } */
+
+int getint (void);
+int
+tzloadbody (void)
+{
+  int n = getint ();
+  int prevcorr;
+  int leapcnt = 0;
+  for (int i = 0; i < n; i++)
+    {
+      int corr = getint ();
+      if (corr < 1 || (corr == 1 && !(leapcnt == 0 || (prevcorr < corr ? corr == prevcorr + 1 : (corr == prevcorr || corr == prevcorr - 1))))) /* { dg-bogus "uninitialized" } */
+	return -1;
+
+      prevcorr = corr;
+      leapcnt++;
+    }
+  return leapcnt;
+}