diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0eacd1e7b8b..bf326de9eea 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2006-11-12  Michael Matz  <matz@suse.de>
+	    Roger Sayle  <roger@eyesopen.com>
+
+	PR rtl-optimization/29797
+	* ifcvt.c (noce_try_bitop): Correct calculation of bitnum on
+	BITS_BIG_ENDIAN targets.
+
 2006-11-12  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
 	* builtins.c (fold_builtin_cosh): New.
diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c
index 4d7341cec88..f2226c402aa 100644
--- a/gcc/ifcvt.c
+++ b/gcc/ifcvt.c
@@ -1943,7 +1943,9 @@ noce_try_bitop (struct noce_if_info *if_info)
 	return FALSE;
       bitnum = INTVAL (XEXP (cond, 2));
       mode = GET_MODE (x);
-      if (bitnum >= HOST_BITS_PER_WIDE_INT)
+      if (BITS_BIG_ENDIAN)
+	bitnum = GET_MODE_BITSIZE (mode) - 1 - bitnum;
+      if (bitnum < 0 || bitnum >= HOST_BITS_PER_WIDE_INT)
 	return FALSE;
     }
   else
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 7237d4f2b7d..4566f8855b4 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2006-11-12  Roger Sayle  <roger@eyesopen.com>
+
+	PR rtl-optimization/29797
+	* gcc.c-torture/execute/pr29797-1.c: New test case.
+
 2006-11-12  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
 	* gcc.dg/torture/builtin-symmetric-1.c: Add more cases.
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr29797-1.c b/gcc/testsuite/gcc.c-torture/execute/pr29797-1.c
new file mode 100644
index 00000000000..9bcc2a9c59b
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr29797-1.c
@@ -0,0 +1,14 @@
+extern void abort(void);
+
+unsigned int bar(void) { return 32768; }
+
+int main()
+{
+  unsigned int nStyle = bar ();
+  if (nStyle & 32768)
+    nStyle |= 65536;
+  if (nStyle != (32768 | 65536))
+    abort ();
+  return 0;
+}
+