Revert r201806. Allow out-of-range start bits in shifted_mask.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/wide-int@204325 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 5 insertions, 7 deletions

diff --git a/gcc/wide-int.cc b/gcc/wide-int.cc
index 5b08d1092b4..f22b348797b 100644
--- a/gcc/wide-int.cc
+++ b/gcc/wide-int.cc
@@ -748,18 +748,16 @@ unsigned int
 wi::shifted_mask (HOST_WIDE_INT *val, unsigned int start, unsigned int width,
 		  bool negate, unsigned int prec)
 {
-  gcc_assert (start < 4 * MAX_BITSIZE_MODE_ANY_INT);
-
-  if (start + width > prec)
-    width = prec - start;
-  unsigned int end = start + width;
-
-  if (width == 0)
+  if (start >= prec || width == 0)
     {
       val[0] = negate ? -1 : 0;
       return 1;
     }
 
+  if (width > prec - start)
+    width = prec - start;
+  unsigned int end = start + width;
+
   unsigned int i = 0;
   while (i < start / HOST_BITS_PER_WIDE_INT)
     val[i++] = negate ? -1 : 0;