From: Jakub Jelinek <jakub@redhat.com>
Date: Tue, 27 Jan 2015 08:26:13 +0000 (+0100)
Subject: re PR tree-optimization/64807 (Wrong-code because of wide-int division)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=b30ea1387f8e26ad60bd4d71ba2006ea7e11a6ee;p=gcc.git

re PR tree-optimization/64807 (Wrong-code because of wide-int division)

	PR tree-optimization/64807
	* wide-int.cc (wi::divmod_internal): Clear
	b_dividend[dividend_blocks_needed].

	* gcc.dg/pr64807.c: New test.

From-SVN: r220153
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5add60716b0..05b5f74665c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2015-01-27  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/64807
+	* wide-int.cc (wi::divmod_internal): Clear
+	b_dividend[dividend_blocks_needed].
+
 2015-01-26  DJ Delorie  <dj@redhat.com>
 
 	* config/rl78/rl78.c (move_elim_pass): Don't optimize away
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 57a58b40a14..f148ca15ed1 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2015-01-27  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/64807
+	* gcc.dg/pr64807.c: New test.
+
 	PR c/64766
 	* gcc.dg/pr64766.c: New test.
 
diff --git a/gcc/testsuite/gcc.dg/pr64807.c b/gcc/testsuite/gcc.dg/pr64807.c
new file mode 100644
index 00000000000..e1bd604be00
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr64807.c
@@ -0,0 +1,19 @@
+/* PR tree-optimization/64807 */
+/* { dg-do run { target int128 } } */
+/* { dg-options "-O2" } */
+
+__uint128_t
+foo (void)
+{
+  __uint128_t a = -1;
+  __uint128_t b = -1;
+  return a / b;
+}
+
+int
+main ()
+{
+  if (foo () != 1)
+    __builtin_abort ();
+  return 0;
+}
diff --git a/gcc/wide-int.cc b/gcc/wide-int.cc
index 1143b489499..fd7cbb4c384 100644
--- a/gcc/wide-int.cc
+++ b/gcc/wide-int.cc
@@ -1819,6 +1819,7 @@ wi::divmod_internal (HOST_WIDE_INT *quotient, unsigned int *remainder_len,
 	     divisor_blocks_needed, divisor_prec, sgn);
 
   m = dividend_blocks_needed;
+  b_dividend[m] = 0;
   while (m > 1 && b_dividend[m - 1] == 0)
     m--;