allow constructing a auto_vec with a preallocation, and a possibly larger actual allocation size

This allows us to set the capacity of the vector when we construct it,
and still use a stack buffer when the size is small enough.

gcc/ChangeLog:

2017-05-13  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>

	* genrecog.c (int_set::int_set): Explicitly construct our
	auto_vec base class.
	* vec.h (auto_vec::auto_vec): New constructor.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@248019 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 5 insertions, 3 deletions

diff --git a/gcc/genrecog.c b/gcc/genrecog.c
index 6a9e610e7a0..b69043f0d02 100644
--- a/gcc/genrecog.c
+++ b/gcc/genrecog.c
@@ -1407,14 +1407,16 @@ struct int_set : public auto_vec <uint64_t, 1>
   iterator end ();
 };
 
-int_set::int_set () {}
+int_set::int_set () : auto_vec<uint64_t, 1> () {}
 
-int_set::int_set (uint64_t label)
+int_set::int_set (uint64_t label) :
+  auto_vec<uint64_t, 1> ()
 {
   safe_push (label);
 }
 
-int_set::int_set (const int_set &other)
+int_set::int_set (const int_set &other) :
+  auto_vec<uint64_t, 1> ()
 {
   safe_splice (other);
 }