>From 596e7164df0d84748dc6bf6a3cf39e5f85ab8331 Mon Sep 17 00:00:00 2001
From: qing zhao <qing.zhao@oracle.com>
Date: Tue, 7 Aug 2018 09:52:14 -0700
Subject: [PATCH] fix PR86519

---
 gcc/builtins.c                     | 7 ++++++-
 gcc/testsuite/gcc.dg/strcmpopt_6.c | 6 +++---
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/gcc/builtins.c b/gcc/builtins.c
index 39611de..d1d49f5 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -4480,11 +4480,16 @@ expand_builtin_memcmp (tree exp, rtx target, bool result_eq)
 				  /*objsize=*/NULL_TREE);
     }
 
+  /* If the specified length exceeds the size of either object, 
+     call the function.  */
+  if (!no_overflow)
+    return NULL_RTX;
+
   /* Due to the performance benefit, always inline the calls first
      when result_eq is false.  */
   rtx result = NULL_RTX;
 
-  if (!result_eq && fcode != BUILT_IN_BCMP && no_overflow)
+  if (!result_eq && fcode != BUILT_IN_BCMP)
     {
       result = inline_expand_builtin_string_cmp (exp, target);
       if (result)
diff --git a/gcc/testsuite/gcc.dg/strcmpopt_6.c b/gcc/testsuite/gcc.dg/strcmpopt_6.c
index 964b9e4..4c6de02 100644
--- a/gcc/testsuite/gcc.dg/strcmpopt_6.c
+++ b/gcc/testsuite/gcc.dg/strcmpopt_6.c
@@ -1,7 +1,7 @@
 /* When the specified length exceeds one of the arguments of the call to memcmp, 
    the call to memcmp should NOT be inlined.  */
-/* { dg-do run } */
-/* { dg-options "-O2 -fdump-rtl-expand -Wno-stringop-overflow" } */
+/* { dg-do compile } */
+/* { dg-options "-O2 -Wno-stringop-overflow" } */
 
 typedef struct { char s[8]; int x; } S;
 
@@ -33,4 +33,4 @@ int main (void)
 
 }
 
-/* { dg-final { scan-rtl-dump-times "__builtin_memcmp" 6 "expand" } } */
+/* { dg-final { scan-assembler-times "memcmp" 2 } } */
-- 
1.9.1