(simplify_shift_count, case LSHIFTRT): Don't merge shifts of different

modes if first is any right shift.

From-SVN: r9674

diff --git a/gcc/combine.c b/gcc/combine.c
index 68e91f973c741e3a515bd43d6c5e8baaeff166fe..3b58b34b8544d51b5d694d89fb7ab79d2b6f5124 100644 (file)
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -7898,7 +7898,7 @@ simplify_shift_const (x, code, result_mode, varop, count)
                 ASHIFTRT.
 
                 If the mode of this shift is not the mode of the outer shift,
-                we can't do this if either shift is ASHIFTRT or ROTATE.
+                we can't do this if either shift is a right shift or ROTATE.
 
                 Finally, we can't do any of these if the mode is too wide
                 unless the codes are the same.
@@ -7909,7 +7909,8 @@ simplify_shift_const (x, code, result_mode, varop, count)
              if (code == first_code)
                {
                  if (GET_MODE (varop) != result_mode
-                     && (code == ASHIFTRT || code == ROTATE))
+                     && (code == ASHIFTRT || code == LSHIFTRT
+                         || code == ROTATE))
                    break;
 
                  count += first_count;
@@ -7921,7 +7922,8 @@ simplify_shift_const (x, code, result_mode, varop, count)
                  || (code == ROTATE && first_code == ASHIFTRT)
                  || GET_MODE_BITSIZE (mode) > HOST_BITS_PER_WIDE_INT
                  || (GET_MODE (varop) != result_mode
-                     && (first_code == ASHIFTRT || first_code == ROTATE
+                     && (first_code == ASHIFTRT || first_code == LSHIFTRT
+                         || first_code == ROTATE
                          || code == ROTATE)))
                break;