From 25adbb382535de2c981755df211295249a93c4e2 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Mon, 21 Nov 2022 12:47:53 -0700
Subject: [PATCH] [algs] Use __builtin_mul_overflow

Compiles to smaller binary.
---
 src/hb-algs.hh | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/hb-algs.hh b/src/hb-algs.hh
index bcd7ad059..9659d6330 100644
--- a/src/hb-algs.hh
+++ b/src/hb-algs.hh
@@ -853,10 +853,14 @@ hb_in_ranges (T u, T lo1, T hi1, Ts... ds)
  * Overflow checking.
  */
 
-/* Consider __builtin_mul_overflow use here also */
 static inline bool
 hb_unsigned_mul_overflows (unsigned int count, unsigned int size)
 {
+#if (defined(__GNUC__) && (__GNUC__ >= 4)) || defined(__clang__)
+  unsigned result;
+  return __builtin_mul_overflow (count, size, &result);
+#endif
+
   return (size > 0) && (count >= ((unsigned int) -1) / size);
 }