diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 60de22da4e9..bc469656054 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2003-01-28  Richard Sandiford  <rsandifo@redhat.com>
+
+	* combine.c (nonzero_bits): Fix check for negative divide operands.
+
 2003-01-28  Richard Henderson  <rth@redhat.com>
 
 	* config/ia64/ia64.c (ia64_rwreloc_section_type_flags): New.
diff --git a/gcc/combine.c b/gcc/combine.c
index 4f03d008e7e..90c4482e33a 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -8369,14 +8369,15 @@ nonzero_bits (x, mode)
       {
 	unsigned HOST_WIDE_INT nz0 = nonzero_bits (XEXP (x, 0), mode);
 	unsigned HOST_WIDE_INT nz1 = nonzero_bits (XEXP (x, 1), mode);
+	int sign_index = GET_MODE_BITSIZE (GET_MODE (x)) - 1;
 	int width0 = floor_log2 (nz0) + 1;
 	int width1 = floor_log2 (nz1) + 1;
 	int low0 = floor_log2 (nz0 & -nz0);
 	int low1 = floor_log2 (nz1 & -nz1);
 	HOST_WIDE_INT op0_maybe_minusp
-	  = (nz0 & ((HOST_WIDE_INT) 1 << (mode_width - 1)));
+	  = (nz0 & ((HOST_WIDE_INT) 1 << sign_index));
 	HOST_WIDE_INT op1_maybe_minusp
-	  = (nz1 & ((HOST_WIDE_INT) 1 << (mode_width - 1)));
+	  = (nz1 & ((HOST_WIDE_INT) 1 << sign_index));
 	unsigned int result_width = mode_width;
 	int result_low = 0;
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index c2f60e6ede7..9e5ea48f89e 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2003-01-28  Richard Sandiford  <rsandifo@redhat.com>
+
+	* gcc.c-torture/execute/20030128-1.c: New test.
+
 2003-01-28  Jeffrey D. Oldham  <oldham@codesourcery.com>
 
 	* g++.dg/lookup/nested1.C: Test moved from ...
diff --git a/gcc/testsuite/gcc.c-torture/execute/20030128-1.c b/gcc/testsuite/gcc.c-torture/execute/20030128-1.c
new file mode 100644
index 00000000000..ceca322ccaf
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/20030128-1.c
@@ -0,0 +1,10 @@
+unsigned char x = 50;
+volatile short y = -5;
+
+int main ()
+{
+  x /= y;
+  if (x != (unsigned char) -10)
+    abort ();
+  exit (0);
+}