//==========================================================================; // // THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY // KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE // IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR // PURPOSE. // // Copyright (c) 1992-1994 Microsoft Corporation // //--------------------------------------------------------------------------; // // muldiv32.h // // Description: // math routines for 32 bit signed and unsiged numbers. // // MulDiv32(a,b,c) = (a * b) / c (round down, signed) // // MulDivRD(a,b,c) = (a * b) / c (round down, unsigned) // MulDivRN(a,b,c) = (a * b + c/2) / c (round nearest, unsigned) // MulDivRU(a,b,c) = (a * b + c-1) / c (round up, unsigned) // //==========================================================================; #ifndef _INC_MULDIV32 #define _INC_MULDIV32 #ifndef INLINE #define INLINE __inline #endif #ifdef WIN32 //----------------------------------------------------------------------; // // Win 32 // //----------------------------------------------------------------------; #ifdef _X86_ // // Use 32-bit x86 assembly. // #pragma warning(disable:4035 4704) INLINE LONG MulDiv32(LONG a,LONG b,LONG c) { _asm mov eax,dword ptr a // mov eax, a _asm mov ebx,dword ptr b // mov ebx, b _asm mov ecx,dword ptr c // mov ecx, c _asm imul ebx // imul ebx _asm idiv ecx // idiv ecx _asm shld edx, eax, 16 // shld edx, eax, 16 } // MulDiv32() INLINE DWORD MulDivRN(DWORD a,DWORD b,DWORD c) { _asm mov eax,dword ptr a // mov eax, a _asm mov ebx,dword ptr b // mov ebx, b _asm mov ecx,dword ptr c // mov ecx, c _asm mul ebx // mul ebx _asm mov ebx,ecx // mov ebx,ecx _asm shr ebx,1 // sar ebx,1 _asm add eax,ebx // add eax,ebx _asm adc edx,0 // adc edx,0 _asm div ecx // div ecx _asm shld edx, eax, 16 // shld edx, eax, 16 } // MulDiv32() INLINE DWORD MulDivRU(DWORD a,DWORD b,DWORD c) { _asm mov eax,dword ptr a // mov eax, a _asm mov ebx,dword ptr b // mov ebx, b _asm mov ecx,dword ptr c // mov ecx, c _asm mul ebx // mul ebx _asm mov ebx,ecx // mov ebx,ecx _asm dec ebx // dec ebx _asm add eax,ebx // add eax,ebx _asm adc edx,0 // adc edx,0 _asm div ecx // div ecx _asm shld edx, eax, 16 // shld edx, eax, 16 } // MulDivRU32() INLINE DWORD MulDivRD(DWORD a,DWORD b,DWORD c) { _asm mov eax,dword ptr a // mov eax, a _asm mov ebx,dword ptr b // mov ebx, b _asm mov ecx,dword ptr c // mov ecx, c _asm mul ebx // mul ebx _asm div ecx // div ecx _asm shld edx, eax, 16 // shld edx, eax, 16 } // MulDivRD32() #pragma warning(default:4035 4704) #else // // Use C9 __int64 support for Daytona RISC platforms. // INLINE LONG MulDiv32( LONG a, LONG b, LONG c ) { return (LONG)( Int32x32To64(a,b) / c ); } INLINE DWORD MulDivRD( DWORD a, DWORD b, DWORD c ) { return (DWORD)( UInt32x32To64(a,b) / c ); } INLINE DWORD MulDivRN( DWORD a, DWORD b, DWORD c ) { return (DWORD)( (UInt32x32To64(a,b)+c/2) / c ); } INLINE DWORD MulDivRU( DWORD a, DWORD b, DWORD c ) { return (DWORD)( (UInt32x32To64(a,b)+c-1) / c ); } #endif #else //----------------------------------------------------------------------; // // Win 16 // //----------------------------------------------------------------------; #pragma warning(disable:4035 4704) // // Compile for 16-bit - we can use x86 with proper opcode prefixes // to get 32-bit instructions. // INLINE LONG MulDiv32(LONG a,LONG b,LONG c) { _asm _emit 0x66 _asm mov ax,word ptr a // mov eax, a _asm _emit 0x66 _asm mov bx,word ptr b // mov ebx, b _asm _emit 0x66 _asm mov cx,word ptr c // mov ecx, c _asm _emit 0x66 _asm imul bx // imul ebx _asm _emit 0x66 _asm idiv cx // idiv ecx _asm _emit 0x66 // shld edx, eax, 16 _asm _emit 0x0F _asm _emit 0xA4 _asm _emit 0xC2 _asm _emit 0x10 } // MulDiv32() INLINE DWORD MulDivRN(DWORD a,DWORD b,DWORD c) { _asm _emit 0x66 _asm mov ax,word ptr a // mov eax, a _asm _emit 0x66 _asm mov bx,word ptr b // mov ebx, b _asm _emit 0x66 _asm mov cx,word ptr c // mov ecx, c _asm _emit 0x66 _asm mul bx // mul ebx _asm _emit 0x66 _asm mov bx,cx // mov ebx,ecx _asm _emit 0x66 _asm shr bx,1 // sar ebx,1 _asm _emit 0x66 _asm add ax,bx // add eax,ebx _asm _emit 0x66 _asm adc dx,0 // adc edx,0 _asm _emit 0x66 _asm div cx // div ecx _asm _emit 0x66 // shld edx, eax, 16 _asm _emit 0x0F _asm _emit 0xA4 _asm _emit 0xC2 _asm _emit 0x10 } // MulDiv32() INLINE DWORD MulDivRU(DWORD a,DWORD b,DWORD c) { _asm _emit 0x66 _asm mov ax,word ptr a // mov eax, a _asm _emit 0x66 _asm mov bx,word ptr b // mov ebx, b _asm _emit 0x66 _asm mov cx,word ptr c // mov ecx, c _asm _emit 0x66 _asm mul bx // mul ebx _asm _emit 0x66 _asm mov bx,cx // mov ebx,ecx _asm _emit 0x66 _asm dec bx // dec ebx _asm _emit 0x66 _asm add ax,bx // add eax,ebx _asm _emit 0x66 _asm adc dx,0 // adc edx,0 _asm _emit 0x66 _asm div cx // div ecx _asm _emit 0x66 // shld edx, eax, 16 _asm _emit 0x0F _asm _emit 0xA4 _asm _emit 0xC2 _asm _emit 0x10 } // MulDivRU32() INLINE DWORD MulDivRD(DWORD a,DWORD b,DWORD c) { _asm _emit 0x66 _asm mov ax,word ptr a // mov eax, a _asm _emit 0x66 _asm mov bx,word ptr b // mov ebx, b _asm _emit 0x66 _asm mov cx,word ptr c // mov ecx, c _asm _emit 0x66 _asm mul bx // mul ebx _asm _emit 0x66 _asm div cx // div ecx _asm _emit 0x66 // shld edx, eax, 16 _asm _emit 0x0F _asm _emit 0xA4 _asm _emit 0xC2 _asm _emit 0x10 } // MulDivRD32() #pragma warning(default:4035 4704) #endif // // some code references these by other names. // #define muldiv32 MulDivRN #define muldivrd32 MulDivRD #define muldivru32 MulDivRU #endif // _INC_MULDIV32