| From 5a3112e24aa41c50703739ccf419bad6136eb797 Mon Sep 17 00:00:00 2001 |
| From: Markus Armbruster <armbru@redhat.com> |
| Date: Wed, 22 Jan 2014 12:13:55 +0100 |
| Subject: [PATCH 4/4] qdev: Use clz in print_size |
| |
| RH-Author: Markus Armbruster <armbru@redhat.com> |
| Message-id: <1390392835-21809-3-git-send-email-armbru@redhat.com> |
| Patchwork-id: 56888 |
| O-Subject: [PATCH 7.0 qemu-kvm 2/2] qdev: Use clz in print_size |
| Bugzilla: 1034876 |
| RH-Acked-by: Marcel Apfelbaum <marcel.a@redhat.com> |
| RH-Acked-by: Orit Wasserman <owasserm@redhat.com> |
| RH-Acked-by: Dr. David Alan Gilbert (git) <dgilbert@redhat.com> |
| RH-Acked-by: Michael S. Tsirkin <mst@redhat.com> |
| |
| From: Richard Henderson <rth@twiddle.net> |
| |
| We can compute a floor log2 value with clz rather than a division loop. |
| |
| Signed-off-by: Richard Henderson <rth@twiddle.net> |
| Message-id: 1375208443-17288-3-git-send-email-rth@twiddle.net |
| Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> |
| (cherry picked from commit 1197cbb9eda1dc82e2fa1815ca62bc3de158353e) |
| Signed-off-by: Markus Armbruster <armbru@redhat.com> |
| |
| hw/core/qdev-properties.c | 20 +++++++++++++------- |
| 1 file changed, 13 insertions(+), 7 deletions(-) |
| |
| Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> |
| |
| hw/core/qdev-properties.c | 20 +++++++++++++------- |
| 1 files changed, 13 insertions(+), 7 deletions(-) |
| |
| diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c |
| index d6d10c9..dc8ae69 100644 |
| |
| |
| @@ -1172,15 +1172,21 @@ static int parse_size(DeviceState *dev, Property *prop, const char *str) |
| |
| static int print_size(DeviceState *dev, Property *prop, char *dest, size_t len) |
| { |
| - uint64_t *ptr = qdev_get_prop_ptr(dev, prop); |
| - char suffixes[] = {'T', 'G', 'M', 'K', 'B'}; |
| - int i = 0; |
| - uint64_t div; |
| + static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T' }; |
| + uint64_t div, val = *(uint64_t *)qdev_get_prop_ptr(dev, prop); |
| + int i; |
| |
| - for (div = 1ULL << 40; !(*ptr / div) ; div >>= 10) { |
| - i++; |
| + /* Compute floor(log2(val)). */ |
| + i = 64 - clz64(val); |
| + |
| + /* Find the power of 1024 that we'll display as the units. */ |
| + i /= 10; |
| + if (i >= ARRAY_SIZE(suffixes)) { |
| + i = ARRAY_SIZE(suffixes) - 1; |
| } |
| - return snprintf(dest, len, "%0.03f%c", (double)*ptr/div, suffixes[i]); |
| + div = 1ULL << (i * 10); |
| + |
| + return snprintf(dest, len, "%0.03f%c", (double)val/div, suffixes[i]); |
| } |
| |
| PropertyInfo qdev_prop_size = { |
| -- |
| 1.7.1 |
| |