Re: [tree-ssa-ccp] modify extend_mask to extend bits based on signop

[Prathamesh Kulkarni]

Ah, the mail failed to be delivered to gcc-patches, sorry for the double-post.
On 5 August 2016 at 01:26, Prathamesh Kulkarni
<prathamesh.kulka...@linaro.org> wrote:
> Hi,
> Is the attached patch OK ?
> Since we want to extend based on signop, I removed ORing with wi::mask().
> Bootstrap+test passes on x86_64-unknown-linux-gnu.
> Cross-test in progress on arm*-*-* and aarch64*-*-*.
> Ok for trunk ?
>
> Thanks,
> Prathamesh

2016-08-04  Prathamesh Kulkarni  <prathamesh.kulka...@linaro.org>

        * tree-ssa-ccp.c (extend_mask): New param sgn.
        Remove ORing with wi::mask.
        (get_default_value): Adjust call to extend_mask to pass sign.
        (evaluate_stmt): Likewise.

diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index ae120a8..06e2905 100644
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -234,10 +234,9 @@ debug_lattice_value (ccp_prop_value_t val)
 /* Extend NONZERO_BITS to a full mask, with the upper bits being set.  */
 
 static widest_int
-extend_mask (const wide_int &nonzero_bits)
+extend_mask (const wide_int &nonzero_bits, signop sgn)
 {
-  return (wi::mask <widest_int> (wi::get_precision (nonzero_bits), true)
-         | widest_int::from (nonzero_bits, UNSIGNED));
+  return widest_int::from (nonzero_bits, sgn); 
 }
 
 /* Compute a default value for variable VAR and store it in the
@@ -287,7 +286,7 @@ get_default_value (tree var)
                {
                  val.lattice_val = CONSTANT;
                  val.value = build_zero_cst (TREE_TYPE (var));
-                 val.mask = extend_mask (nonzero_bits);
+                 val.mask = extend_mask (nonzero_bits, TYPE_SIGN (TREE_TYPE 
(var)));
                }
            }
        }
@@ -1937,7 +1936,7 @@ evaluate_stmt (gimple *stmt)
            {
              val.lattice_val = CONSTANT;
              val.value = build_zero_cst (TREE_TYPE (lhs));
-             val.mask = extend_mask (nonzero_bits);
+             val.mask = extend_mask (nonzero_bits, TYPE_SIGN (TREE_TYPE 
(lhs)));
              is_constant = true;
            }
          else
@@ -1948,7 +1947,8 @@ evaluate_stmt (gimple *stmt)
              if (nonzero_bits == 0)
                val.mask = 0;
              else
-               val.mask = val.mask & extend_mask (nonzero_bits);
+               val.mask = val.mask & extend_mask (nonzero_bits,
+                                                  TYPE_SIGN (TREE_TYPE (lhs)));
            }
        }
     }