diff options
Diffstat (limited to 'EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Math.c')
-rw-r--r-- | EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Math.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Math.c b/EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Math.c new file mode 100644 index 0000000000..64e683ec89 --- /dev/null +++ b/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;
+}
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