* tree-ssa-loop-niter.c (implies_nonnegative_p): New function.

	(derive_constant_upper_bound): Derive more precise upper bound in
	common cases.  Return type changed to double_int.
	(record_estimate): Reflect the changed return type of
	derive_constant_upper_bound.
	* double-int.c (double_int_zext, double_int_sext): Fix.

	* gcc.dg/tree-ssa/loop-18.c: New test.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@114674 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 6 insertions, 6 deletions

diff --git a/gcc/double-int.c b/gcc/double-int.c
index ab1975f09a9..5a7b51dbe31 100644
--- a/gcc/double-int.c
+++ b/gcc/double-int.c
@@ -72,8 +72,8 @@ double_int_zext (double_int cst, unsigned prec)
   double_int mask = double_int_mask (prec);
   double_int r;
 
-  r.low = cst.low & ~mask.low;
-  r.high = cst.high & ~mask.high;
+  r.low = cst.low & mask.low;
+  r.high = cst.high & mask.high;
 
   return r;
 }
@@ -96,13 +96,13 @@ double_int_sext (double_int cst, unsigned prec)
     }
   if (((snum >> (prec - 1)) & 1) == 1)
     {
-      r.low = cst.low | mask.low;
-      r.high = cst.high | mask.high;
+      r.low = cst.low | ~mask.low;
+      r.high = cst.high | ~mask.high;
     }
   else
     {
-      r.low = cst.low & ~mask.low;
-      r.high = cst.high & ~mask.high;
+      r.low = cst.low & mask.low;
+      r.high = cst.high & mask.high;
     } 
 
   return r;