1 ;------------------------------------------------------------------------------ 2 ; 3 ; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR> 4 ; This program and the accompanying materials 5 ; are licensed and made available under the terms and conditions of the BSD License 6 ; which accompanies this distribution. The full text of the license may be found at 7 ; http://opensource.org/licenses/bsd-license.php. 8 ; 9 ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 10 ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 11 ; 12 ; Module Name: 13 ; 14 ; DivU64x64Remainder.asm 15 ; 16 ; Abstract: 17 ; 18 ; Calculate the quotient of a 64-bit integer by a 64-bit integer and returns 19 ; both the quotient and the remainder 20 ; 21 ;------------------------------------------------------------------------------ 22 23 .386 24 .model flat,C 25 .code 26 27 EXTERN InternalMathDivRemU64x32:PROC 28 29 ;------------------------------------------------------------------------------ 30 ; UINT64 31 ; EFIAPI 32 ; InternalMathDivRemU64x64 ( 33 ; IN UINT64 Dividend, 34 ; IN UINT64 Divisor, 35 ; OUT UINT64 *Remainder OPTIONAL 36 ; ); 37 ;------------------------------------------------------------------------------ 38 InternalMathDivRemU64x64 PROC 39 mov ecx, [esp + 16] ; ecx <- divisor[32..63] 40 test ecx, ecx 41 jnz _@DivRemU64x64 ; call _@DivRemU64x64 if Divisor > 2^32 42 mov ecx, [esp + 20] 43 jecxz @F 44 and dword ptr [ecx + 4], 0 ; zero high dword of remainder 45 mov [esp + 16], ecx ; set up stack frame to match DivRemU64x32 46 @@: 47 jmp InternalMathDivRemU64x32 48 InternalMathDivRemU64x64 ENDP 49 50 _@DivRemU64x64 PROC PRIVATE USES ebx esi edi 51 mov edx, dword ptr [esp + 20] 52 mov eax, dword ptr [esp + 16] ; edx:eax <- dividend 53 mov edi, edx 54 mov esi, eax ; edi:esi <- dividend 55 mov ebx, dword ptr [esp + 24] ; ecx:ebx <- divisor 56 @@: 57 shr edx, 1 58 rcr eax, 1 59 shrd ebx, ecx, 1 60 shr ecx, 1 61 jnz @B 62 div ebx 63 mov ebx, eax ; ebx <- quotient 64 mov ecx, [esp + 28] ; ecx <- high dword of divisor 65 mul dword ptr [esp + 24] ; edx:eax <- quotient * divisor[0..31] 66 imul ecx, ebx ; ecx <- quotient * divisor[32..63] 67 add edx, ecx ; edx <- (quotient * divisor)[32..63] 68 mov ecx, dword ptr [esp + 32] ; ecx <- addr for Remainder 69 jc @TooLarge ; product > 2^64 70 cmp edi, edx ; compare high 32 bits 71 ja @Correct 72 jb @TooLarge ; product > dividend 73 cmp esi, eax 74 jae @Correct ; product <= dividend 75 @TooLarge: 76 dec ebx ; adjust quotient by -1 77 jecxz @Return ; return if Remainder == NULL 78 sub eax, dword ptr [esp + 24] 79 sbb edx, dword ptr [esp + 28] ; edx:eax <- (quotient - 1) * divisor 80 @Correct: 81 jecxz @Return 82 sub esi, eax 83 sbb edi, edx ; edi:esi <- remainder 84 mov [ecx], esi 85 mov [ecx + 4], edi 86 @Return: 87 mov eax, ebx ; eax <- quotient 88 xor edx, edx ; quotient is 32 bits long 89 ret 90 _@DivRemU64x64 ENDP 91 92 END 93
