Changeset 59747 in vbox for trunk/src/VBox/Runtime/common/misc

Timestamp:

Feb 19, 2016 11:18:18 PM (9 years ago)

Author:

vboxsync

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

105617

Message:

iprt/asm.h: Cleaned up the ASMMemIsAll8/U32 mess and implmeneted the former in assembly. (Found inverted usage due to bad naming in copyUtf8Block, but it is fortunately an unused method.) Replaces the complicated ASMBitFirstSet based scanning in RTSgBufIsZero with a simple call to the new ASMMemIsZero function.

File:

• trunk/src/VBox/Runtime/common/misc/sg.cpp (modified) (2 diffs)

trunk/src/VBox/Runtime/common/misc/sg.cpp

@@ -407 +407 @@
 }
 
+
 RTDECL(bool) RTSgBufIsZero(PRTSGBUF pSgBuf, size_t cbCheck)
 {
@@ -420 +421 @@
         if (!cbThisCheck)
             break;
-
-/** @todo fix this after asm.h gets updated.    */
-        /* Use optimized inline assembler if possible. */
-        if (   !(cbThisCheck % 4)
-            && cbThisCheck * 8 <= UINT32_MAX)
-        {
-            if (ASMBitFirstSet((volatile void *)pvBuf, (uint32_t)cbThisCheck * 8) != -1)
-            {
-                fIsZero = false;
-                break;
-            }
-        }
-        else
-        {
-            for (size_t i = 0; i < cbThisCheck; i++)
-            {
-                char *pbBuf = (char *)pvBuf;
-                if (*pbBuf)
-                {
-                    fIsZero = false;
-                    break;
-                }
-                pvBuf = pbBuf + 1;
-            }
-
-            if (!fIsZero)
-                break;
-        }
-
+        fIsZero = ASMMemIsZero(pvBuf, cbThisCheck);
+        if (!fIsZero)
+            break;
         cbLeft -= cbThisCheck;
     }