diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4007a660c21..0347c24ae88 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2009-07-08  Adam Nemet  <anemet@caviumnetworks.com>
+
+	* simplify-rtx.c (simplify_binary_operation_1) <AND>: Transform (and
+        (truncate)) into (truncate (and)).
+
 2009-07-08  Adam Nemet  <anemet@caviumnetworks.com>
 
 	* combine.c (make_extraction): Check TRULY_NOOP_TRUNCATION before
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 782d7172091..ff690684ee6 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -2336,6 +2336,18 @@ simplify_binary_operation_1 (enum rtx_code code, enum machine_mode mode,
 	  return simplify_gen_unary (ZERO_EXTEND, mode, tem, imode);
 	}
 
+      /* Transform (and (truncate X) C) into (truncate (and X C)).  This way
+	 we might be able to further simplify the AND with X and potentially
+	 remove the truncation altogether.  */
+      if (GET_CODE (op0) == TRUNCATE && CONST_INT_P (trueop1))
+	{
+	  rtx x = XEXP (op0, 0);
+	  enum machine_mode xmode = GET_MODE (x);
+	  tem = simplify_gen_binary (AND, xmode, x,
+				     gen_int_mode (INTVAL (trueop1), xmode));
+	  return simplify_gen_unary (TRUNCATE, mode, tem, xmode);
+	}
+
       /* Canonicalize (A | C1) & C2 as (A & C2) | (C1 & C2).  */
       if (GET_CODE (op0) == IOR
 	  && CONST_INT_P (trueop1)
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 72585073651..3dcfad3fe3a 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,9 +1,13 @@
+2009-07-08  Adam Nemet  <anemet@caviumnetworks.com>
+
+	* gcc.target/mips/truncate-5.c: New test.
+
 2009-07-08  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
 
 	PR libfortran/40330
 	PR libfortran/40662
 	* gfortran.dg/fmt_cache_1.f: New test.
-	
+
 2009-07-08  Tobias Burnus  <burnus@net-b.de>
 
 	PR fortran/40675
@@ -24,7 +28,7 @@
 	* gfortran.dg/proc_ptr_21.f90: New test.
 
 2009-07-08  Manuel López-Ibáñez  <manu@gcc.gnu.org>
-	
+
 	PR c++/31246
 	* g++.dg/warn/pr31246.C: New.
 	* g++.dg/warn/pr31246-2.C: New.
diff --git a/gcc/testsuite/gcc.target/mips/truncate-5.c b/gcc/testsuite/gcc.target/mips/truncate-5.c
new file mode 100644
index 00000000000..046ef80c453
--- /dev/null
+++ b/gcc/testsuite/gcc.target/mips/truncate-5.c
@@ -0,0 +1,14 @@
+/* If we AND in DI mode (i.e. replace the order of TRUNCATE and AND) then we
+   can remove the TRUNCATE.  */
+/* { dg-options "-O -mgp64" } */
+/* { dg-final { scan-assembler-not "\tsll\t\[^\n\]*,0" } } */
+
+struct s
+{
+  unsigned a:5;
+};
+
+f (struct s *s, unsigned long long a)
+{
+  s->a = a & 0x3;
+}