diff options
| author |   Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
|---|---|---|
| committer | Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
| commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
| tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/edk2/MdePkg/Library/BaseLib/HighBitSet64.c | |
| parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) | |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/edk2/MdePkg/Library/BaseLib/HighBitSet64.c')
| -rw-r--r-- | roms/edk2/MdePkg/Library/BaseLib/HighBitSet64.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/roms/edk2/MdePkg/Library/BaseLib/HighBitSet64.c b/roms/edk2/MdePkg/Library/BaseLib/HighBitSet64.c new file mode 100644 index 000000000..4f06dfc88 --- /dev/null +++ b/roms/edk2/MdePkg/Library/BaseLib/HighBitSet64.c @@ -0,0 +1,49 @@ +/** @file
+ Math worker functions.
+
+ Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+
+
+
+#include "BaseLibInternals.h"
+
+/**
+ Returns the bit position of the highest bit set in a 64-bit value. Equivalent
+ to log2(x).
+
+ This function computes the bit position of the highest bit set in the 64-bit
+ value specified by Operand. If Operand is zero, then -1 is returned.
+ Otherwise, a value between 0 and 63 is returned.
+
+ @param Operand The 64-bit operand to evaluate.
+
+ @retval 0..63 Position of the highest bit set in Operand if found.
+ @retval -1 Operand is zero.
+
+**/
+INTN
+EFIAPI
+HighBitSet64 (
+ IN UINT64 Operand
+ )
+{
+ if (Operand == (UINT32)Operand) {
+ //
+ // Operand is just a 32-bit integer
+ //
+ return HighBitSet32 ((UINT32)Operand);
+ }
+
+ //
+ // Operand is really a 64-bit integer
+ //
+ if (sizeof (UINTN) == sizeof (UINT32)) {
+ return HighBitSet32 (((UINT32*)&Operand)[1]) + 32;
+ } else {
+ return HighBitSet32 ((UINT32)RShiftU64 (Operand, 32)) + 32;
+ }
+}
|