From 395848255cfa88f6f0f33a9b14c79e584a05d6fc Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Wed, 10 Nov 2021 16:23:12 -0500 Subject: [PATCH] c-family: don't cache large vecs Patrick observed recently that an element of the vector cache could be arbitrarily large. Let's only cache relatively small vecs. gcc/c-family/ChangeLog: * c-common.c (release_tree_vector): Only cache vecs smaller than 16 elements. --- gcc/c-family/c-common.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c index 436df45..90e8ec8 100644 --- a/gcc/c-family/c-common.c +++ b/gcc/c-family/c-common.c @@ -8213,8 +8213,16 @@ release_tree_vector (vec *vec) { if (vec != NULL) { - vec->truncate (0); - vec_safe_push (tree_vector_cache, vec); + if (vec->allocated () >= 16) + /* Don't cache vecs that have expanded more than once. On a p64 + target, vecs double in alloc size with each power of 2 elements, e.g + at 16 elements the alloc increases from 128 to 256 bytes. */ + vec_free (vec); + else + { + vec->truncate (0); + vec_safe_push (tree_vector_cache, vec); + } } } -- 2.7.4