From: Richard Biener <rguenther@suse.de>
Date: Tue, 6 Sep 2022 08:42:50 +0000 (+0200)
Subject: tree-optimization/106844 - fix ICE in init_use_preds
X-Git-Tag: basepoints/gcc-14~4714
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1a4e1425f8498580994e32ceb3c50bd52616a82d;p=thirdparty%2Fgcc.git

tree-optimization/106844 - fix ICE in init_use_preds

The following fixes an oversight in the last change to
compute_control_dep_chain where we have to return whether we found
a chain.

	PR tree-optimization/106844
	* gimple-predicate-analysis.cc (compute_control_dep_chain):
	Return whether we found a chain.

	* gcc.dg/pr106844.c: New testcase.
---

diff --git a/gcc/gimple-predicate-analysis.cc b/gcc/gimple-predicate-analysis.cc
index 681047deee77..ef2906ebc51a 100644
--- a/gcc/gimple-predicate-analysis.cc
+++ b/gcc/gimple-predicate-analysis.cc
@@ -1077,7 +1077,7 @@ compute_control_dep_chain (basic_block dom_bb, const_basic_block dep_bb,
 	      if (dump_file)
 		fprintf (dump_file, "param_uninit_control_dep_attempts "
 			 "exceeded: %u\n", *num_calls);
-	      return false;
+	      break;
 	    }
 	  ++*num_calls;
 
diff --git a/gcc/testsuite/gcc.dg/pr106844.c b/gcc/testsuite/gcc.dg/pr106844.c
new file mode 100644
index 000000000000..df68d76f2572
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr106844.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O -Wuninitialized --param uninit-control-dep-attempts=1" } */
+
+struct {
+  int count;
+  int array[8];
+} fde_merge_v1;
+
+void
+fde_merge_i2() {
+  unsigned i1;
+  do
+    while (i1 && fde_merge_v1.array[i1 - 1]) /* { dg-warning "uninitialized" } */
+      i1--;
+  while (fde_merge_i2);
+}