CryptoPkg: Replace BSD License with BSD+Patent License

[mirror_edk2.git] / CryptoPkg / Library / IntrinsicLib / Ia32 / MathLShiftS64.c

/** @file\r
  64-bit Math Worker Function.\r
  The 32-bit versions of C compiler generate calls to library routines\r
  to handle 64-bit math. These functions use non-standard calling conventions.\r
\r
Copyright (c) 2014, Intel Corporation. All rights reserved.<BR>\r
SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
\r
/*\r
 * Shifts a 64-bit signed value left by a particular number of bits.\r
 */\r
__declspec(naked) void __cdecl _allshl (void)\r
{\r
  _asm {\r
    ;\r
    ; Handle shifting of 64 or more bits (return 0)\r
    ;\r
    cmp     cl, 64\r
    jae     short ReturnZero\r
\r
    ;\r
    ; Handle shifting of between 0 and 31 bits\r
    ;\r
    cmp     cl, 32\r
    jae     short More32\r
    shld    edx, eax, cl\r
    shl     eax, cl\r
    ret\r
\r
    ;\r
    ; Handle shifting of between 32 and 63 bits\r
    ;\r
More32:\r
    mov     edx, eax\r
    xor     eax, eax\r
    and     cl, 31\r
    shl     edx, cl\r
    ret\r
\r
ReturnZero:\r
    xor     eax,eax\r
    xor     edx,edx\r
    ret\r
  }\r
}\r