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/CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.c | |
| parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) | |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/edk2/CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.c')
| -rw-r--r-- | roms/edk2/CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/roms/edk2/CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.c b/roms/edk2/CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.c new file mode 100644 index 000000000..efa38983a --- /dev/null +++ b/roms/edk2/CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.c @@ -0,0 +1,51 @@ +/** @file
+ 64-bit Math Worker Function.
+ The 32-bit versions of C compiler generate calls to library routines
+ to handle 64-bit math. These functions use non-standard calling conventions.
+
+Copyright (c) 2014, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+
+/*
+ * Shifts a 64-bit unsigned value right by a certain number of bits.
+ */
+__declspec(naked) void __cdecl _aullshr (void)
+{
+ _asm {
+ ;
+ ; Checking: Only handle 64bit shifting or more
+ ;
+ cmp cl, 64
+ jae _Exit
+
+ ;
+ ; Handle shifting between 0 and 31 bits
+ ;
+ cmp cl, 32
+ jae More32
+ shrd eax, edx, cl
+ shr edx, cl
+ ret
+
+ ;
+ ; Handle shifting of 32-63 bits
+ ;
+More32:
+ mov eax, edx
+ xor edx, edx
+ and cl, 31
+ shr eax, cl
+ ret
+
+ ;
+ ; Invalid number (less then 32bits), return 0
+ ;
+_Exit:
+ xor eax, eax
+ xor edx, edx
+ ret
+ }
+}
|