Changeset 21572 in vbox for trunk/src/VBox/VMM

Timestamp:

Jul 14, 2009 10:53:43 AM (16 years ago)

Author:

vboxsync

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

50055

Message:

Put back relevant comment

File:

• trunk/src/VBox/VMM/VMMR0/HWACCMR0A.asm (modified) (1 diff)

trunk/src/VBox/VMM/VMMR0/HWACCMR0A.asm

@@ -949 +949 @@
     mov     ecx, esi
  %else
+    ; from http://www.cs.cmu.edu/~fp/courses/15213-s06/misc/asm64-handout.pdf:
+    ; ``Perhaps unexpectedly, instructions that move or generate 32-bit register
+    ;   values also set the upper 32 bits of the register to zero. Consequently
+    ;   there is no need for an instruction movzlq.''
     mov     eax, ecx
     mov     ecx, edx