1 /** @file 2 64-bit Math Worker Function. 3 The 32-bit versions of C compiler generate calls to library routines 4 to handle 64-bit math. These functions use non-standard calling conventions. 5 6 Copyright (c) 2014, Intel Corporation. All rights reserved.<BR> 7 This program and the accompanying materials 8 are licensed and made available under the terms and conditions of the BSD License 9 which accompanies this distribution. The full text of the license may be found at 10 http://opensource.org/licenses/bsd-license.php 11 12 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 13 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 14 15 **/ 16 17 18 /* 19 * Shifts a 64-bit unsigned value right by a certain number of bits. 20 */ 21 __declspec(naked) void __cdecl _aullshr (void) 22 { 23 _asm { 24 ; 25 ; Checking: Only handle 64bit shifting or more 26 ; 27 cmp cl, 64 28 jae _Exit 29 30 ; 31 ; Handle shifting between 0 and 31 bits 32 ; 33 cmp cl, 32 34 jae More32 35 shrd eax, edx, cl 36 shr edx, cl 37 ret 38 39 ; 40 ; Handle shifting of 32-63 bits 41 ; 42 More32: 43 mov eax, edx 44 xor edx, edx 45 and cl, 31 46 shr eax, cl 47 ret 48 49 ; 50 ; Invalid number (less then 32bits), return 0 51 ; 52 _Exit: 53 xor eax, eax 54 xor edx, edx 55 ret 56 } 57 } 58
