diff options
Diffstat (limited to 'src/VBox/Devices/EFI/Firmware/CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.c')
-rw-r--r-- | src/VBox/Devices/EFI/Firmware/CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/src/VBox/Devices/EFI/Firmware/CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.c b/src/VBox/Devices/EFI/Firmware/CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.c new file mode 100644 index 00000000..29497692 --- /dev/null +++ b/src/VBox/Devices/EFI/Firmware/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 + } +} |