Merge remote-tracking branch 'bonzini/iommu-for-anthony' into staging

# By Paolo Bonzini (50) and others
# Via Paolo Bonzini
* bonzini/iommu-for-anthony: (66 commits)
  exec: change some APIs to take AddressSpaceDispatch
  exec: remove cur_map
  exec: put memory map in AddressSpaceDispatch
  exec: separate current radix tree from the one being built
  exec: move listener from AddressSpaceDispatch to AddressSpace
  memory: move MemoryListener declaration earlier
  exec: separate current memory map from the one being built
  exec: change well-known physical sections to macros
  qom: Use atomics for object refcounting
  memory: add reference counting to FlatView
  memory: use a new FlatView pointer on every topology update
  memory: access FlatView from a local variable
  add a header file for atomic operations
  hw/[u-x]*: pass owner to memory_region_init* functions
  hw/t*: pass owner to memory_region_init* functions
  hw/s*: pass owner to memory_region_init* functions
  hw/p*: pass owner to memory_region_init* functions
  hw/n*: pass owner to memory_region_init* functions
  hw/m*: pass owner to memory_region_init* functions
  hw/i*: pass owner to memory_region_init* functions
  ...

Message-id: 1372950842-32422-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 17 insertions, 8 deletions

diff --git a/include/qemu/int128.h b/include/qemu/int128.h
index bfe7678a04..9ed47aafd3 100644
--- a/include/qemu/int128.h
+++ b/include/qemu/int128.h
@@ -1,6 +1,10 @@
 #ifndef INT128_H
 #define INT128_H
 
+#include <assert.h>
+#include <stdint.h>
+#include <stdbool.h>
+
 typedef struct Int128 Int128;
 
 struct Int128 {
@@ -55,21 +59,26 @@ static inline Int128 int128_rshift(Int128 a, int n)
 
 static inline Int128 int128_add(Int128 a, Int128 b)
 {
-    Int128 r = { a.lo + b.lo, a.hi + b.hi };
-    r.hi += (r.lo < a.lo) || (r.lo < b.lo);
-    return r;
+    uint64_t lo = a.lo + b.lo;
+
+    /* a.lo <= a.lo + b.lo < a.lo + k (k is the base, 2^64).  Hence,
+     * a.lo + b.lo >= k implies 0 <= lo = a.lo + b.lo - k < a.lo.
+     * Similarly, a.lo + b.lo < k implies a.lo <= lo = a.lo + b.lo < k.
+     *
+     * So the carry is lo < a.lo.
+     */
+    return (Int128) { lo, (uint64_t)a.hi + b.hi + (lo < a.lo) };
 }
 
 static inline Int128 int128_neg(Int128 a)
 {
-    a.lo = ~a.lo;
-    a.hi = ~a.hi;
-    return int128_add(a, int128_one());
+    uint64_t lo = -a.lo;
+    return (Int128) { lo, ~(uint64_t)a.hi + !lo };
 }
 
 static inline Int128 int128_sub(Int128 a, Int128 b)
 {
-    return int128_add(a, int128_neg(b));
+    return (Int128){ a.lo - b.lo, a.hi - b.hi - (a.lo < b.lo) };
 }
 
 static inline bool int128_nonneg(Int128 a)
@@ -89,7 +98,7 @@ static inline bool int128_ne(Int128 a, Int128 b)
 
 static inline bool int128_ge(Int128 a, Int128 b)
 {
-    return int128_nonneg(int128_sub(a, b));
+    return a.hi > b.hi || (a.hi == b.hi && a.lo >= b.lo);
 }
 
 static inline bool int128_lt(Int128 a, Int128 b)