diff mbox series

[PULL,06/29] exec.c: add a check between constants to see whether we could skip

Message ID 1568644929-9124-7-git-send-email-pbonzini@redhat.com
State New
Headers show
Series [PULL,01/29] i386/kvm: support guest access CORE cstate | expand

Commit Message

Paolo Bonzini Sept. 16, 2019, 2:41 p.m. UTC 
From: Wei Yang <richardw.yang@linux.intel.com>

The maximum level is defined as P_L2_LEVELS and skip is defined with 6
bits, which means if P_L2_LEVELS < (1 << 6), skip never exceeds the
boundary.

Since this check is between two constants, which leverages compiler
to optimize the code based on different configuration.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20190321082555.21118-7-richardw.yang@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 exec.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/exec.c b/exec.c
index d1969bb..b9511be 100644
--- a/exec.c
+++ b/exec.c
@@ -324,7 +324,8 @@  static void phys_page_compact(PhysPageEntry *lp, Node *nodes)
     assert(valid_ptr < P_L2_SIZE);
 
     /* Don't compress if it won't fit in the # of bits we have. */
-    if (lp->skip + p[valid_ptr].skip >= (1 << 6)) {
+    if (P_L2_LEVELS >= (1 << 6) &&
+        lp->skip + p[valid_ptr].skip >= (1 << 6)) {
         return;
     }