From: Jørgen Kvalsvik <j@lambda.is>
Date: Wed, 28 Jan 2026 19:33:21 +0000 (+0100)
Subject: Permit const counters in flush_on_edges [PR123855]
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=340c45dc16a0a75a477192a2baaf28235be7f520;p=thirdparty%2Fgcc.git

Permit const counters in flush_on_edges [PR123855]

Relax the (accidental) requirement and permit that function-local
counters don't have SSA names.  We really only look up the def
statement to check if it is a phi node, in which case we need to
resolve the counter from there.  This obviously doesn't apply when it
is a constant.

	PR gcov-profile/123855

gcc/ChangeLog:

	* path-coverage.cc (flush_on_edges): Only look up SSA name def
	stmt when counter is non-const.

gcc/testsuite/ChangeLog:

	* gcc.misc-tests/gcov-pr123855.c: New test.
---

diff --git a/gcc/path-coverage.cc b/gcc/path-coverage.cc
index 7ce662ce007..68a30d5a8ee 100644
--- a/gcc/path-coverage.cc
+++ b/gcc/path-coverage.cc
@@ -379,8 +379,8 @@ void
 flush_on_edges (basic_block bb, size_t bucket, tree local, tree mask,
 		tree atomic_ior, tree gcov_type_node)
 {
-  gimple *def = SSA_NAME_DEF_STMT (local);
-  gphi *phi = dyn_cast <gphi *> (def);
+  gimple *def = !constant_p (local) ? SSA_NAME_DEF_STMT (local) : NULL;
+  gphi *phi = safe_dyn_cast <gphi *> (def);
 
   tree relaxed = nullptr;
   if (atomic_ior)
diff --git a/gcc/testsuite/gcc.misc-tests/gcov-pr123855.c b/gcc/testsuite/gcc.misc-tests/gcov-pr123855.c
new file mode 100644
index 00000000000..16fc27a850f
--- /dev/null
+++ b/gcc/testsuite/gcc.misc-tests/gcov-pr123855.c
@@ -0,0 +1,13 @@
+/* { dg-options "--coverage -fpath-coverage" } */
+
+__attribute__((__returns_twice__)) void
+foo ()
+{
+  foo ();
+  for (;;)
+    ;
+}
+
+int main () {}
+
+/* { dg-final { run-gcov prime-paths gcov-pr123855.c } } */