Add in the 1st version of ECP.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@2832 6f19259b-4bc3-4df7-8a09-765794883524

EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Math.c

@@ -0,0 +1,216 @@
+/*++
+
+Copyright (c) 2004, Intel Corporation                                                         
+All rights reserved. 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.             
+
+Module Name:
+
+  Math.c
+
+Abstract:
+
+  Math worker functions. 
+
+--*/
+
+#include "Tiano.h"
+
+UINT64
+LShiftU64 (
+  IN UINT64   Operand,
+  IN UINTN    Count
+  )
+/*++
+
+Routine Description:
+
+  This routine allows a 64 bit value to be left shifted by 32 bits and 
+  returns the shifted value.
+  Count is valid up 63. (Only Bits 0-5 is valid for Count)
+
+Arguments:
+
+  Operand - Value to be shifted
+  Count   - Number of times to shift left.
+ 
+Returns:
+
+  Value shifted left identified by the Count.
+
+--*/
+{
+  return Operand << Count;
+}
+
+UINT64
+MultU64x32 (
+  IN UINT64   Multiplicand,
+  IN UINTN    Multiplier
+  )
+/*++  
+  
+Routine Description:
+
+  This routine allows a 64 bit value to be multiplied with a 32 bit 
+  value returns 64bit result.
+  No checking if the result is greater than 64bits
+
+Arguments:
+
+  Multiplicand  - multiplicand
+  Multiplier    - multiplier
+
+Returns:
+
+  Multiplicand * Multiplier
+  
+--*/
+{
+  return Multiplicand * Multiplier;
+}
+
+UINT64
+RShiftU64 (
+  IN UINT64   Operand,
+  IN UINTN    Count
+  )
+/*++
+
+Routine Description:
+
+  This routine allows a 64 bit value to be right shifted by 32 bits and returns the 
+  shifted value.
+  Count is valid up 63. (Only Bits 0-5 is valid for Count)
+
+Arguments:
+
+  Operand - Value to be shifted
+  Count   - Number of times to shift right.
+ 
+Returns:
+
+  Value shifted right identified by the Count.
+
+--*/
+{
+  return Operand >> Count;
+}
+
+UINT64
+DivU64x32 (
+  IN UINT64   Dividend,
+  IN UINTN    Divisor,
+  OUT UINTN   *Remainder OPTIONAL
+  )
+/*++
+
+Routine Description:
+
+  This routine allows a 64 bit value to be divided with a 32 bit value returns 
+  64bit result and the Remainder.
+
+Arguments:
+
+  Dividend  - dividend
+  Divisor   - divisor
+  Remainder - buffer for remainder
+ 
+Returns:
+
+  Dividend  / Divisor
+  Remainder = Dividend mod Divisor
+
+--*/
+{
+  if (Remainder != NULL) {
+    *Remainder = Dividend % Divisor;
+  }
+
+  return Dividend / Divisor;
+}
+
+UINT8
+Log2 (
+  IN UINT64   Operand
+  )
+/*++
+
+Routine Description:
+
+  This function computes rounded down log2 of the Operand.  This is an equivalent
+  of the position of the highest bit set in the Operand treated as a mask.
+  E.g., Log2 (0x0001) == 0, Log2 (0x0002) == 1, Log2 (0x0003) == 1, Log2 (0x0005) == 2
+  Log2 (0x4000) == 14, Log2 (0x8000) == 15, Log2 (0xC000) == 15, Log2 (0xFFFF) == 15, etc.
+
+Arguments:
+  Operand - value of which the Log2 is to be computed.
+
+Returns:
+  Rounded down log2 of the Operand or 0xFF if zero passed in.
+
+--*/
+{
+  UINT8 Bitpos;
+  Bitpos = 0;
+
+  if (Operand == 0) {
+    return (0xff);
+  }
+
+  while (Operand != 0) {
+    Operand >>= 1;
+    Bitpos++;
+  }
+  return (Bitpos - 1);
+
+}
+
+UINT64
+GetPowerOfTwo (
+  IN UINT64 Operand
+  )
+/*++
+
+Routine Description:
+
+  Calculates the largest integer that is both 
+  a power of two and less than Input
+
+Arguments:
+
+  Operand  - value to calculate power of two
+
+Returns:
+
+  the largest integer that is both  a power of 
+  two and less than Input
+
+--*/
+{
+  UINT8 Bitpos;
+  Bitpos = 0;
+
+  if (Operand == 0) {
+    return 0;
+  }
+
+  while (Operand != 0) {
+    Operand >>= 1;
+    Bitpos++;
+  }
+
+  Operand = 1;
+  Bitpos--;
+  while (Bitpos != 0) {
+    Operand <<= 1;
+    Bitpos--;
+  }
+
+  return Operand;
+}