Changeset 745 in vbox

Timestamp:

Feb 7, 2007 12:37:08 PM (18 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

18397

Message:

Use ASMBitFirstSet for check if data block is zero.

File:

• trunk/src/VBox/Devices/Storage/VBoxHDD.cpp (modified) (3 diffs)

trunk/src/VBox/Devices/Storage/VBoxHDD.cpp

@@ -36 +36 @@
 #include <iprt/file.h>
 #include <iprt/string.h>
+#include <iprt/asm.h>
 
 #include "Builtins.h"
@@ -1601 +1602 @@
              * means that it's a zero block. Don't need to write anything to this
              * block if the data consists of just zeroes. */
-            bool fBlockZeroed = true; /* Block is zeroed flag. */
-            for (unsigned i = 0; i < (cbToWrite >> 2); i++)
-                if (((uint32_t *)pvBuf)[i] != 0)
-                {
-                    /* Block is not zeroed! */
-                    fBlockZeroed = false;
-                    break;
-                }
-
-            if (fBlockZeroed)
+            Assert(cbToWrite % 4 == 0);
+            if (ASMBitFirstSet((volatile void *)pvBuf, cbToWrite * 8) == -1)
             {
                 pImage->paBlocks[uBlock] = VDI_IMAGE_BLOCK_ZERO;
@@ -2638 +2631 @@
 
                 /* Check block for data. */
-                bool fBlockZeroed = true;    /* Block is zeroed flag. */
-                for (unsigned i = 0; i < (cbBlock >> 2); i++)
-                    if (((uint32_t *)pvBuf)[i] != 0)
-                    {
-                        /* Block is not zeroed! */
-                        fBlockZeroed = false;
-                        break;
-                    }
-
-                if (!fBlockZeroed)
+                Assert(cbBlock % 4 == 0);
+                if (ASMBitFirstSet(pvBuf, cbBlock * 8) != -1)
                 {
                     /* Block has a data, may be it must be moved. */