diff options
| author | Andi Kleen <ak@linux.intel.com> | 2011-10-29 01:02:35 +0000 |
|---|---|---|
| committer | Andi Kleen <ak@gcc.gnu.org> | 2011-10-29 01:02:35 +0000 |
| commit | 3bc50163311275e8da17365a68e10a765a134867 (patch) | |
| tree | 8f9e002586202119430d4bd8c63fee062dce5c6a /gcc/ggc-page.c | |
| parent | 25f0ea8135b221a7d560e9062d30d14be33c5582 (diff) | |
| download | gcc-3bc50163311275e8da17365a68e10a765a134867.tar.gz | |
Use more efficient alignment in ggc
Jakub had some concerns about the performance of page alignments in
ggc-page, which use a hardware division instructions currently.
This patch changes them all to use a new PAGE_ALIGN macro, which
exploits that pages are a power of two.
gcc/:
2011-10-21 Andi Kleen <ak@linux.intel.com>
* ggc-page (PAGE_ALIGN): Add.
(alloc_page, ggc_pch_total_size, ggc_pch_this_base, ggc_pch_read):
Replace ROUND_UP with PAGE_ALIGN.
From-SVN: r180650
Diffstat (limited to 'gcc/ggc-page.c')
| -rw-r--r-- | gcc/ggc-page.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/gcc/ggc-page.c b/gcc/ggc-page.c index c796160316b..ee796cbb7e9 100644 --- a/gcc/ggc-page.c +++ b/gcc/ggc-page.c @@ -221,6 +221,10 @@ static const size_t extra_order_size_table[] = { #define ROUND_UP(x, f) (CEIL (x, f) * (f)) +/* Round X to next multiple of the page size */ + +#define PAGE_ALIGN(x) (((x) + G.pagesize - 1) & ~(G.pagesize - 1)) + /* The Ith entry is the number of objects on a page or order I. */ static unsigned objects_per_page_table[NUM_ORDERS]; @@ -739,7 +743,7 @@ alloc_page (unsigned order) entry_size = num_objects * OBJECT_SIZE (order); if (entry_size < G.pagesize) entry_size = G.pagesize; - entry_size = ROUND_UP (entry_size, G.pagesize); + entry_size = PAGE_ALIGN (entry_size); entry = NULL; page = NULL; @@ -2236,7 +2240,7 @@ ggc_pch_total_size (struct ggc_pch_data *d) unsigned i; for (i = 0; i < NUM_ORDERS; i++) - a += ROUND_UP (d->d.totals[i] * OBJECT_SIZE (i), G.pagesize); + a += PAGE_ALIGN (d->d.totals[i] * OBJECT_SIZE (i)); return a; } @@ -2249,7 +2253,7 @@ ggc_pch_this_base (struct ggc_pch_data *d, void *base) for (i = 0; i < NUM_ORDERS; i++) { d->base[i] = a; - a += ROUND_UP (d->d.totals[i] * OBJECT_SIZE (i), G.pagesize); + a += PAGE_ALIGN (d->d.totals[i] * OBJECT_SIZE (i)); } } @@ -2442,7 +2446,7 @@ ggc_pch_read (FILE *f, void *addr) if (d.totals[i] == 0) continue; - bytes = ROUND_UP (d.totals[i] * OBJECT_SIZE (i), G.pagesize); + bytes = PAGE_ALIGN (d.totals[i] * OBJECT_SIZE (i)); num_objs = bytes / OBJECT_SIZE (i); entry = XCNEWVAR (struct page_entry, (sizeof (struct page_entry) - sizeof (long) |