re PR middle-end/67338 (fold-const sanitizer runtime error in roundup_loc)

	PR c/67338
	* fold-const.c (round_up_loc): Negate divisor in unsigned type to
	avoid UB.

	* gcc.dg/pr67338.c: New test.

From-SVN: r246305

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index afb4a52..59be61f 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2017-03-21  Jakub Jelinek  <jakub@redhat.com>
+
+       PR c/67338
+       * fold-const.c (round_up_loc): Negate divisor in unsigned type to
+       avoid UB.
+
 2017-03-20  Segher Boessenkool  <segher@kernel.crashing.org>
 
        PR rtl-optimization/79910

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 12445aa..1a9a264 100644 (file)
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -14250,7 +14250,7 @@ round_up_loc (location_t loc, tree value, unsigned int divisor)
 
          overflow_p = TREE_OVERFLOW (value);
          val += divisor - 1;
-         val &= - (int) divisor;
+         val &= (int) -divisor;
          if (val == 0)
            overflow_p = true;
 

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index c2dc55a..69cf112 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2017-03-21  Jakub Jelinek  <jakub@redhat.com>
 
+       PR c/67338
+       * gcc.dg/pr67338.c: New test.
+
        PR c++/35878
        * g++.dg/init/pr35878_1.C: Rewrite directives to scan optimized
        dump instead of assembler.

diff --git a/gcc/testsuite/gcc.dg/pr67338.c b/gcc/testsuite/gcc.dg/pr67338.c
new file mode 100644 (file)
index 0000000..0fdc302
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr67338.c
@@ -0,0 +1,4 @@
+/* PR c/67338 */
+/* { dg-do compile { target *-*-linux* *-*-gnu* } } */
+
+struct S { __attribute__((aligned (1 << 28))) double a; };