From e41103081bfa341bdb1037e94d6b8f7a0af39067 Mon Sep 17 00:00:00 2001
From: Jan Hubicka <jh@suse.cz>
Date: Thu, 10 Aug 2023 18:35:13 +0200
Subject: [PATCH] Fix undefined behaviour in profile_count::differs_from_p
This patch avoid overflow in profile_count::differs_from_p and also makes it to
return false from one of the values is undefined while other is defined.
gcc/ChangeLog:
* profile-count.cc (profile_count::differs_from_p): Fix overflow and
handling of undefined values.
---
gcc/profile-count.cc | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/gcc/profile-count.cc b/gcc/profile-count.cc
index e63c9432388b..a14f379db8fa 100644
--- a/gcc/profile-count.cc
+++ b/gcc/profile-count.cc
@@ -128,13 +128,14 @@ profile_count::differs_from_p (profile_count other) const
{
gcc_checking_assert (compatible_p (other));
if (!initialized_p () || !other.initialized_p ())
- return false;
+ return initialized_p () != other.initialized_p ();
if ((uint64_t)m_val - (uint64_t)other.m_val < 100
|| (uint64_t)other.m_val - (uint64_t)m_val < 100)
return false;
if (!other.m_val)
return true;
- int64_t ratio = (int64_t)m_val * 100 / other.m_val;
+ uint64_t ratio;
+ safe_scale_64bit (m_val, 100, other.m_val, &ratio);
return ratio < 99 || ratio > 101;
}
--
GitLab