From: Martin Liska <mliska@suse.cz>
Date: Thu, 4 Jul 2019 09:03:56 +0000 (+0200)
Subject: Backport r272993
X-Git-Tag: releases/gcc-9.2.0~170
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b098c7983c12e17ba872d2241173c186a3c6f4e9;p=thirdparty%2Fgcc.git

Backport r272993

2019-07-04  Martin Liska  <mliska@suse.cz>

	Backport from mainline
	2019-07-03  Martin Liska  <mliska@suse.cz>

	PR tree-optimization/90892
	* builtins.c (inline_expand_builtin_string_cmp): Handle '\0'
	in string constants.
2019-07-04  Martin Liska  <mliska@suse.cz>

	Backport from mainline
	2019-07-03  Martin Liska  <mliska@suse.cz>

	PR tree-optimization/90892
	* gcc.dg/pr90892.c: New test.

From-SVN: r273074
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ae633153aa8f..82010817b6ae 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2019-07-04  Martin Liska  <mliska@suse.cz>
+
+	Backport from mainline
+	2019-07-03  Martin Liska  <mliska@suse.cz>
+
+	PR tree-optimization/90892
+	* builtins.c (inline_expand_builtin_string_cmp): Handle '\0'
+	in string constants.
+
 2019-07-04  Martin Liska  <mliska@suse.cz>
 
 	Backport from mainline
diff --git a/gcc/builtins.c b/gcc/builtins.c
index d37d73fc4a0f..9bcb310c0150 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -7124,8 +7124,19 @@ inline_expand_builtin_string_cmp (tree exp, rtx target)
     return NULL_RTX;
 
   /* For strncmp, if the length is not a const, not qualify.  */
-  if (is_ncmp && !tree_fits_uhwi_p (len3_tree))
-    return NULL_RTX;
+  if (is_ncmp)
+    {
+      if (!tree_fits_uhwi_p (len3_tree))
+	return NULL_RTX;
+      else
+	len3 = tree_to_uhwi (len3_tree);
+    }
+
+  if (src_str1 != NULL)
+    len1 = strnlen (src_str1, len1) + 1;
+
+  if (src_str2 != NULL)
+    len2 = strnlen (src_str2, len2) + 1;
 
   int const_str_n = 0;
   if (!len1)
@@ -7140,7 +7151,7 @@ inline_expand_builtin_string_cmp (tree exp, rtx target)
   gcc_checking_assert (const_str_n > 0);
   length = (const_str_n == 1) ? len1 : len2;
 
-  if (is_ncmp && (len3 = tree_to_uhwi (len3_tree)) < length)
+  if (is_ncmp && len3 < length)
     length = len3;
 
   /* If the length of the comparision is larger than the threshold,
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 2a42f3c15b06..07b2fa79dbf5 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2019-07-04  Martin Liska  <mliska@suse.cz>
+
+	Backport from mainline
+	2019-07-03  Martin Liska  <mliska@suse.cz>
+
+	PR tree-optimization/90892
+	* gcc.dg/pr90892.c: New test.
+
 2019-07-04  Martin Liska  <mliska@suse.cz>
 
 	Backport from mainline
diff --git a/gcc/testsuite/gcc.dg/pr90892.c b/gcc/testsuite/gcc.dg/pr90892.c
new file mode 100644
index 000000000000..e4b5310807aa
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr90892.c
@@ -0,0 +1,14 @@
+/* PR tree-optimization/90892 */
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+const char *a = "A\0b";
+
+int
+main()
+{
+  if (__builtin_strncmp(a, "A\0", 2) != 0)
+    __builtin_abort ();
+
+  return 0;
+}