[wide-int] Fix LTO regression that I'd introduced

[Richard Sandiford]

It turns out that gcc20's version of binutils is too old for the LTO plugin,
so the tests I'd been running hadn't exercised it.  This patch fixes a
regression that Kenny pointed out.

The problem was that build_int_cst and build_int_cst_type were using
the signedness of the type to decide how the HWI should be extended,
whereas they're supposed to use sign extension regardless.

Tested on x86_64-linux-gnu, this time with trunk binutils.  OK for wide-int?

Thanks,
Richard


gcc/
        * tree.h (wi::hwi): Delete.
        * tree.c (build_int_cst, build_int_cst_type): Use wi::shwi.
        (build_int_cstu): Use wi::uhwi.

Index: gcc/tree.h
===================================================================
--- gcc/tree.h  (revision 202746)
+++ gcc/tree.h  (working copy)
@@ -5206,8 +5206,6 @@
 
 namespace wi
 {
-  hwi_with_prec hwi (HOST_WIDE_INT, const_tree);
-
   template <typename T>
   bool fits_to_tree_p (const T &x, const_tree);
 
@@ -5216,12 +5214,6 @@
   wide_int from_mpz (const_tree, mpz_t, bool);
 }
 
-inline wi::hwi_with_prec
-wi::hwi (HOST_WIDE_INT val, const_tree type)
-{
-  return hwi_with_prec (val, TYPE_PRECISION (type), TYPE_SIGN (type));
-}
-
 template <typename T>
 bool
 wi::fits_to_tree_p (const T &x, const_tree type)
Index: gcc/tree.c
===================================================================
--- gcc/tree.c  (revision 202746)
+++ gcc/tree.c  (working copy)
@@ -1056,13 +1056,13 @@
   if (!type)
     type = integer_type_node;
 
-  return wide_int_to_tree (type, wi::hwi (low, type));
+  return wide_int_to_tree (type, wi::shwi (low, TYPE_PRECISION (type)));
 }
 
 tree
 build_int_cstu (tree type, unsigned HOST_WIDE_INT cst)
 {
-  return wide_int_to_tree (type, wi::hwi (cst, type));
+  return wide_int_to_tree (type, wi::uhwi (cst, TYPE_PRECISION (type)));
 }
 
 /* Create an INT_CST node with a LOW value sign extended to TYPE.  */
@@ -1071,7 +1071,7 @@
 build_int_cst_type (tree type, HOST_WIDE_INT low)
 {
   gcc_assert (type);
-  return wide_int_to_tree (type, wi::hwi (low, type));
+  return wide_int_to_tree (type, wi::shwi (low, TYPE_PRECISION (type)));
 }
 
 /* Constructs tree in type TYPE from with value given by CST.  Signedness