diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5b6fd01d85f..fa4d4ba0b4e 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2012-10-31  Richard Sandiford  <rdsandiford@googlemail.com>
+
+	* combine.c (simplify_comparison): If BITS_BIG_ENDIAN, always assume
+	that zero_extracts of const_ints are doing word-sized extractions.
+
 2012-10-31  Richard Sandiford  <rdsandiford@googlemail.com>
 
 	* combine.c (make_extraction): Remove dead wanted_inner_mode-
diff --git a/gcc/combine.c b/gcc/combine.c
index e9d0a45d633..5bbf0bde937 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -11154,17 +11154,7 @@ simplify_comparison (enum rtx_code code, rtx *pop0, rtx *pop1)
 	      && (i = exact_log2 (UINTVAL (XEXP (op0, 0)))) >= 0)
 	    {
 	      if (BITS_BIG_ENDIAN)
-		{
-		  enum machine_mode new_mode
-		    = mode_for_extraction (EP_extzv, 1);
-		  if (new_mode == MAX_MACHINE_MODE)
-		    i = BITS_PER_WORD - 1 - i;
-		  else
-		    {
-		      mode = new_mode;
-		      i = (GET_MODE_PRECISION (mode) - 1 - i);
-		    }
-		}
+		i = BITS_PER_WORD - 1 - i;
 
 	      op0 = XEXP (op0, 2);
 	      op1 = GEN_INT (i);