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authorTom Tromey <tromey@redhat.com>2011-10-17 10:00:07 +0000
committerDodji Seketeli <dodji@gcc.gnu.org>2011-10-17 12:00:07 +0200
commitb9bd6f743843a53de1396c43d1e308e51d40c5c4 (patch)
tree0b0e309c095d0459230339edc0343cafe8f0c4c8 /libcpp/include
parent64a1a422dba4b0c09ad38310e32a223f2e16ed9d (diff)
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Reduce memory waste due to non-power-of-2 allocs
This patch basically arranges for the allocation size of line_map buffers to be as close as possible to a power of two. This *significantly* decreases peak memory consumption as (macro) maps are numerous and stay live during all the compilation. The patch adds a new ggc_round_alloc_size interface to the ggc allocator. In each of the two main allocator implementations ('page' and 'zone') the function has been extracted from the main allocation function code and returns the actual size of the allocated memory region, thus giving a chance to the caller to maximize the amount of memory it actually uses from the allocated memory region. In the 'none' allocator implementation (that uses xmalloc) the ggc_round_alloc_size just returns the requested allocation size. Co-Authored-By: Dodji Seketeli <dodji@redhat.com> From-SVN: r180086
Diffstat (limited to 'libcpp/include')
-rw-r--r--libcpp/include/line-map.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/libcpp/include/line-map.h b/libcpp/include/line-map.h
index 572e330..1e2a148 100644
--- a/libcpp/include/line-map.h
+++ b/libcpp/include/line-map.h
@@ -53,6 +53,10 @@ typedef unsigned int source_location;
/* Memory allocation function typedef. Works like xrealloc. */
typedef void *(*line_map_realloc) (void *, size_t);
+/* Memory allocator function that returns the actual allocated size,
+ for a given requested allocation. */
+typedef size_t (*line_map_round_alloc_size_func) (size_t);
+
/* An ordinary line map encodes physical source locations. Those
physical source locations are called "spelling locations".
@@ -281,6 +285,10 @@ struct GTY(()) line_maps {
/* If non-null, the allocator to use when resizing 'maps'. If null,
xrealloc is used. */
line_map_realloc reallocator;
+
+ /* The allocators' function used to know the actual size it
+ allocated, for a certain allocation size requested. */
+ line_map_round_alloc_size_func round_alloc_size;
};
/* Returns the pointer to the memory region where information about