re PR c/19606 (wrong code for arith.expr: (((unsigned int)(signed int) a ) / 2LL) with signed char a=-4)

gcc/
	PR c/19606.
	* c-typeck.c (build_binary_op): Perform implicit casts of
	operands before shortening them.

gcc/testsuite/
	PR c/19606.
	* gcc.c-torture/execute/pr19606.c: New.

From-SVN: r110321

2 files changed, 39 insertions, 0 deletions

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 50cc323..2f2f8c6 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2006-01-28  Kazu Hirata  <kazu@codesourcery.com>
+
+	PR c/19606.
+	* gcc.c-torture/execute/pr19606.c: New.
+
 2006-01-27  Carlos O'Donell  <carlos@codesourcery.com>
 
 	* gcc.dg/pragma-re-4.c: New test.
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr19606.c b/gcc/testsuite/gcc.c-torture/execute/pr19606.c
new file mode 100644
index 0000000..d1e836f
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr19606.c
@@ -0,0 +1,34 @@
+/* PR c/19606
+   The C front end used to shorten the type of a division to a type
+   that does not preserve the semantics of the original computation.
+   Make sure that won't happen.  */
+
+signed char a = -4;
+
+int
+foo (void)
+{
+  return ((unsigned int) (signed int) a) / 2LL;
+}
+
+int
+bar (void)
+{
+  return ((unsigned int) (signed int) a) % 5LL;
+}
+
+int
+main (void)
+{
+  int r;
+
+  r = foo ();
+  if (r != ((unsigned int) (signed int) (signed char) -4) / 2LL)
+    abort ();
+
+  r = bar ();
+  if (r != ((unsigned int) (signed int) (signed char) -4) % 5LL)
+    abort ();
+
+  exit (0);
+}