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-rw-r--r--MdePkg/Library/BaseLib/Ia32/ReadMm4.c42
1 files changed, 42 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseLib/Ia32/ReadMm4.c b/MdePkg/Library/BaseLib/Ia32/ReadMm4.c
new file mode 100644
index 000000000000..ecc3896cfc07
--- /dev/null
+++ b/MdePkg/Library/BaseLib/Ia32/ReadMm4.c
@@ -0,0 +1,42 @@
+/** @file
+ AsmReadMm4 function
+
+ Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
+ This program and the accompanying materials
+ are licensed and made available under the terms and conditions of the BSD License
+ which accompanies this distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php.
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+
+
+
+/**
+ Reads the current value of 64-bit MMX Register #4 (MM4).
+
+ Reads and returns the current value of MM4. This function is only available
+ on IA-32 and x64.
+
+ @return The current value of MM4.
+
+**/
+UINT64
+EFIAPI
+AsmReadMm4 (
+ VOID
+ )
+{
+ _asm {
+ push eax
+ push eax
+ movq [esp], mm4
+ pop eax
+ pop edx
+ emms
+ }
+}
+