- Implement remaining functions in rtl/i386/math_asm.S - Fix some more build issues. Modified: trunk/reactos/lib/rtl/i386/math_asm.S Modified: trunk/reactos/lib/rtl/rtl.h Modified: trunk/reactos/lib/rtl/rtl.xml Modified: trunk/reactos/lib/string/mbstowcs.c Modified: trunk/reactos/lib/string/sscanf.c Modified: trunk/reactos/lib/string/string.xml Modified: trunk/reactos/lib/string/wcstombs.c _____
Modified: trunk/reactos/lib/rtl/i386/math_asm.S --- trunk/reactos/lib/rtl/i386/math_asm.S 2005-11-30 08:01:56 UTC (rev 19772) +++ trunk/reactos/lib/rtl/i386/math_asm.S 2005-11-30 08:15:13 UTC (rev 19773) @@ -69,190 +69,891 @@
__fltused: .long 0x9875
+.intel_syntax noprefix + /* FUNCTIONS ***************************************************************/
-/* - * long long - * __alldiv(long long Dividend, long long Divisor)// - * - * Parameters: - * [ESP+04h] - long long Dividend - * [ESP+0Ch] - long long Divisor - * Registers: - * Unknown - * Returns: - * EDX:EAX - long long quotient (Dividend/Divisor) - * Notes: - * Routine removes the arguments from the stack. - */ +// +// lldiv - signed long divide +// +// Purpose: +// Does a signed long divide of the arguments. Arguments are +// not changed. +// +// Entry: +// Arguments are passed on the stack: +// 1st pushed: divisor (QWORD) +// 2nd pushed: dividend (QWORD) +// +// Exit: +// EDX:EAX contains the quotient (dividend/divisor) +// NOTE: this routine removes the parameters from the stack. +// +// Uses: +// ECX +// + __alldiv: - call ___divdi3 - ret $0x10
-/* - * long long - * __allmul(long long Multiplier, long long Multiplicand)// - * - * Parameters: - * [ESP+04h] - long long Multiplier - * [ESP+0Ch] - long long Multiplicand - * Registers: - * Unknown - * Returns: - * EDX:EAX - long long product (Multiplier*Multiplicand) - * Notes: - * Routine removes the arguments from the stack. - */ + push edi + push esi + push ebx + +// Set up the local stack and save the index registers. When this is done +// the stack frame will look as follows (assuming that the expression a/b will +// generate a call to lldiv(a, b)): +// +// ----------------- +// | | +// |---------------| +// | | +// |--divisor (b)--| +// | | +// |---------------| +// | | +// |--dividend (a)-| +// | | +// |---------------| +// | return addr** | +// |---------------| +// | EDI | +// |---------------| +// | ESI | +// |---------------| +// ESP---->| EBX | +// ----------------- +// + +#define DVNDLO [esp + 16] // stack address of dividend (a) +#define DVNDHI [esp + 20] // stack address of dividend (a) +#define DVSRLO [esp + 24] // stack address of divisor (b) +#define DVSRHI [esp + 28] // stack address of divisor (b) + +// Determine sign of the result (edi = 0 if result is positive, non-zero +// otherwise) and make operands positive. + + xor edi,edi // result sign assumed positive + + mov eax,DVNDHI // hi word of a + or eax,eax // test to see if signed + jge short L1 // skip rest if a is already positive + inc edi // complement result sign flag + mov edx,DVNDLO // lo word of a + neg eax // make a positive + neg edx + sbb eax,0 + mov DVNDHI,eax // save positive value + mov DVNDLO,edx +L1: + mov eax,DVSRHI // hi word of b + or eax,eax // test to see if signed + jge short L2 // skip rest if b is already positive + inc edi // complement the result sign flag + mov edx,DVSRLO // lo word of a + neg eax // make b positive + neg edx + sbb eax,0 + mov DVSRHI,eax // save positive value + mov DVSRLO,edx +L2: + +// +// Now do the divide. First look to see if the divisor is less than 4194304K. +// If so, then we can use a simple algorithm with word divides, otherwise +// things get a little more complex. +// +// NOTE - eax currently contains the high order word of DVSR +// + + or eax,eax // check to see if divisor < 4194304K + jnz short L3 // nope, gotta do this the hard way + mov ecx,DVSRLO // load divisor + mov eax,DVNDHI // load high word of dividend + xor edx,edx + div ecx // eax <- high order bits of quotient + mov ebx,eax // save high bits of quotient + mov eax,DVNDLO // edx:eax <- remainder:lo word of dividend + div ecx // eax <- low order bits of quotient + mov edx,ebx // edx:eax <- quotient + jmp short L4 // set sign, restore stack and return + +// +// Here we do it the hard way. Remember, eax contains the high word of DVSR +// + +L3: + mov ebx,eax // ebx:ecx <- divisor + mov ecx,DVSRLO + mov edx,DVNDHI // edx:eax <- dividend + mov eax,DVNDLO +L5: + shr ebx,1 // shift divisor right one bit + rcr ecx,1 + shr edx,1 // shift dividend right one bit + rcr eax,1 + or ebx,ebx + jnz short L5 // loop until divisor < 4194304K + div ecx // now divide, ignore remainder + mov esi,eax // save quotient + +// +// We may be off by one, so to check, we will multiply the quotient +// by the divisor and check the result against the orignal dividend +// Note that we must also check for overflow, which can occur if the +// dividend is close to 2**64 and the quotient is off by 1. +// + + mul dword ptr DVSRHI // QUOT * DVSRHI + mov ecx,eax + mov eax,DVSRLO + mul esi // QUOT * DVSRLO + add edx,ecx // EDX:EAX = QUOT * DVSR + jc short L6 // carry means Quotient is off by 1 + +// +// do long compare here between original dividend and the result of the +// multiply in edx:eax. If original is larger or equal, we are ok, otherwise +// subtract one (1) from the quotient. +// + + cmp edx,DVNDHI // compare hi words of result and original + ja short L6 // if result > original, do subtract + jb short L7 // if result < original, we are ok + cmp eax,DVNDLO // hi words are equal, compare lo words + jbe short L7 // if less or equal we are ok, else subtract +L6: + dec esi // subtract 1 from quotient +L7: + xor edx,edx // edx:eax <- quotient + mov eax,esi + +// +// Just the cleanup left to do. edx:eax contains the quotient. Set the sign +// according to the save value, cleanup the stack, and return. +// + +L4: + dec edi // check to see if result is negative + jnz short L8 // if EDI == 0, result should be negative + neg edx // otherwise, negate the result + neg eax + sbb edx,0 + +// +// Restore the saved registers and return. +// + +L8: + pop ebx + pop esi + pop edi + + ret 16 + +// +// llmul - long multiply routine +// +// Purpose: +// Does a long multiply (same for signed/unsigned) +// Parameters are not changed. +// +// Entry: +// Parameters are passed on the stack: +// 1st pushed: multiplier (QWORD) +// 2nd pushed: multiplicand (QWORD) +// +// Exit: +// EDX:EAX - product of multiplier and multiplicand +// NOTE: parameters are removed from the stack +// +// Uses: +// ECX +// + __allmul: - pushl %ebp - movl %esp, %ebp - pushl %edi - pushl %esi - pushl %ebx - subl $12, %esp - movl 16(%ebp), %ebx - movl 8(%ebp), %eax - mull %ebx - movl 20(%ebp), %ecx - movl %eax, -24(%ebp) - movl 8(%ebp), %eax - movl %edx, %esi - imull %ecx, %eax - addl %eax, %esi - movl 12(%ebp), %eax - imull %eax, %ebx - leal (%ebx,%esi), %eax - movl %eax, -20(%ebp) - movl -24(%ebp), %eax - movl -20(%ebp), %edx - addl $12, %esp - popl %ebx - popl %esi - popl %edi - popl %ebp - ret $0x10
-/* - * unsigned long long - * __aullrem(unsigned long long Dividend, unsigned long long Divisor)// - * - * Parameters: - * [ESP+04h] - unsigned long long Dividend - * [ESP+0Ch] - unsigned long long Divisor - * Registers: - * Unknown - * Returns: - * EDX:EAX - unsigned long long remainder (Dividend%Divisor) - * Notes: - * Routine removes the arguments from the stack. - */ -__aullrem: - call ___umoddi3 - ret $16 +#define ALO [esp + 4] // stack address of a +#define AHI [esp + 8] // stack address of a +#define BLO [esp + 12] // stack address of b +#define BHI [esp + 16] // stack address of b
-/* - * long long - * __allshl(long long Value, unsigned char Shift)// - * - * Parameters: - * EDX:EAX - signed long long value to be shifted left - * CL - number of bits to shift by - * Registers: - * Destroys CL - * Returns: - * EDX:EAX - shifted value - */ +// +// AHI, BHI : upper 32 bits of A and B +// ALO, BLO : lower 32 bits of A and B +// +// ALO * BLO +// ALO * BHI +// + BLO * AHI +// --------------------- +// + + mov eax,AHI + mov ecx,BHI + or ecx,eax //test for both hiwords zero. + mov ecx,BLO + jnz short hard //both are zero, just mult ALO and BLO + + mov eax,AHI + mul ecx + + ret 16 // callee restores the stack + +hard: + push ebx + +// must redefine A and B since esp has been altered + +#define A2LO [esp + 4] // stack address of a +#define A2HI [esp + 8] // stack address of a +#define B2LO [esp + 12] // stack address of b +#define B2HI [esp + 16] // stack address of b + + mul ecx //eax has AHI, ecx has BLO, so AHI * BLO + mov ebx,eax //save result + + mov eax,A2LO + mul dword ptr B2HI //ALO * BHI + add ebx,eax //ebx = ((ALO * BHI) + (AHI * BLO)) + + mov eax,A2LO //ecx = BLO + mul ecx //so edx:eax = ALO*BLO + add edx,ebx //now edx has all the LO*HI stuff + + pop ebx + + ret 16 // callee restores the stack + +// +// llrem - signed long remainder +// +// Purpose: +// Does a signed long remainder of the arguments. Arguments are +// not changed. +// +// Entry: +// Arguments are passed on the stack: +// 1st pushed: divisor (QWORD) +// 2nd pushed: dividend (QWORD) +// +// Exit: +// EDX:EAX contains the remainder (dividend%divisor) +// NOTE: this routine removes the parameters from the stack. +// +// Uses: +// ECX +// + +__allrem : + + push ebx + push edi + +// Set up the local stack and save the index registers. When this is done +// the stack frame will look as follows (assuming that the expression a%b will +// generate a call to lrem(a, b)): +// +// ----------------- +// | | +// |---------------| +// | | +// |--divisor (b)--| +// | | +// |---------------| +// | | +// |--dividend (a)-| +// | | +// |---------------| +// | return addr** | +// |---------------| +// | EBX | +// |---------------| +// ESP---->| EDI | +// ----------------- +// + +#undef DVNDLO +#undef DVNDHI +#undef DVSRLO +#undef DVSRHI +#define DVNDLO [esp + 12] // stack address of dividend (a) +#define DVNDHI [esp + 16] // stack address of dividend (a) +#define DVSRLO [esp + 20] // stack address of divisor (b) +#define DVSRHI [esp + 24] // stack address of divisor (b) + +// Determine sign of the result (edi = 0 if result is positive, non-zero +// otherwise) and make operands positive. + + xor edi,edi // result sign assumed positive + + mov eax,DVNDHI // hi word of a + or eax,eax // test to see if signed + jge short .L1 // skip rest if a is already positive + inc edi // complement result sign flag bit + mov edx,DVNDLO // lo word of a + neg eax // make a positive + neg edx + sbb eax,0 + mov DVNDHI,eax // save positive value + mov DVNDLO,edx +.L1: + mov eax,DVSRHI // hi word of b + or eax,eax // test to see if signed + jge short .L2 // skip rest if b is already positive + mov edx,DVSRLO // lo word of b + neg eax // make b positive + neg edx + sbb eax,0 + mov DVSRHI,eax // save positive value + mov DVSRLO,edx +.L2: + +// +// Now do the divide. First look to see if the divisor is less than 4194304K. +// If so, then we can use a simple algorithm with word divides, otherwise +// things get a little more complex. +// +// NOTE - eax currently contains the high order word of DVSR +// + + or eax,eax // check to see if divisor < 4194304K + jnz short .L3 // nope, gotta do this the hard way + mov ecx,DVSRLO // load divisor + mov eax,DVNDHI // load high word of dividend + xor edx,edx + div ecx // edx <- remainder + mov eax,DVNDLO // edx:eax <- remainder:lo word of dividend + div ecx // edx <- final remainder + mov eax,edx // edx:eax <- remainder + xor edx,edx + dec edi // check result sign flag + jns short .L4 // negate result, restore stack and return + jmp short .L8 // result sign ok, restore stack and return + +// +// Here we do it the hard way. Remember, eax contains the high word of DVSR +// + +.L3: + mov ebx,eax // ebx:ecx <- divisor + mov ecx,DVSRLO + mov edx,DVNDHI // edx:eax <- dividend + mov eax,DVNDLO +.L5: + shr ebx,1 // shift divisor right one bit + rcr ecx,1 + shr edx,1 // shift dividend right one bit + rcr eax,1 + or ebx,ebx + jnz short .L5 // loop until divisor < 4194304K + div ecx // now divide, ignore remainder + +// +// We may be off by one, so to check, we will multiply the quotient +// by the divisor and check the result against the orignal dividend +// Note that we must also check for overflow, which can occur if the +// dividend is close to 2**64 and the quotient is off by 1. +// + + mov ecx,eax // save a copy of quotient in ECX + mul dword ptr DVSRHI + xchg ecx,eax // save product, get quotient in EAX + mul dword ptr DVSRLO + add edx,ecx // EDX:EAX = QUOT * DVSR + jc short .L6 // carry means Quotient is off by 1 + +// +// do long compare here between original dividend and the result of the +// multiply in edx:eax. If original is larger or equal, we are ok, otherwise +// subtract the original divisor from the result. +// + + cmp edx,DVNDHI // compare hi words of result and original + ja short .L6 // if result > original, do subtract + jb short .L7 // if result < original, we are ok + cmp eax,DVNDLO // hi words are equal, compare lo words + jbe short .L7 // if less or equal we are ok, else subtract +.L6: + sub eax,DVSRLO // subtract divisor from result + sbb edx,DVSRHI +.L7: + +// +// Calculate remainder by subtracting the result from the original dividend. +// Since the result is already in a register, we will do the subtract in the +// opposite direction and negate the result if necessary. +// + + sub eax,DVNDLO // subtract dividend from result + sbb edx,DVNDHI + +// +// Now check the result sign flag to see if the result is supposed to be positive +// or negative. It is currently negated (because we subtracted in the 'wrong' +// direction), so if the sign flag is set we are done, otherwise we must negate +// the result to make it positive again. +// + + dec edi // check result sign flag + jns short .L8 // result is ok, restore stack and return +.L4: + neg edx // otherwise, negate the result + neg eax + sbb edx,0 + +// +// Just the cleanup left to do. edx:eax contains the quotient. +// Restore the saved registers and return. +// + +.L8: + pop edi + pop ebx + + ret 16 + +// +// llshl - long shift left +// +// Purpose: +// Does a Long Shift Left (signed and unsigned are identical) +// Shifts a long left any number of bits. +// +// Entry: +// EDX:EAX - long value to be shifted +// CL - number of bits to shift by +// +// Exit: +// EDX:EAX - shifted value +// +// Uses: +// CL is destroyed. +// + __allshl: - shldl %cl, %eax, %edx - sall %cl, %eax - andl $32, %ecx - je 1f - movl %eax, %edx - xorl %eax, %eax -1: - ret
-/* - * long long - * __allshr(long long Value, unsigned char Shift)// - * - * Parameters: - * EDX:EAX - signed long long value to be shifted right - * CL - number of bits to shift by - * Registers: - * Destroys CL - * Returns: - * EDX:EAX - shifted value - */ +// +// Handle shifts of 64 or more bits (all get 0) +// + cmp cl, 64 + jae short RETZERO + +// +// Handle shifts of between 0 and 31 bits +// + cmp cl, 32 + jae short MORE32 + shld edx,eax,cl + shl eax,cl + ret + +// +// Handle shifts of between 32 and 63 bits +// +MORE32: + mov edx,eax + xor eax,eax + and cl,31 + shl edx,cl + ret + +// +// return 0 in edx:eax +// +RETZERO: + xor eax,eax + xor edx,edx + ret + +// +// llshr - long shift right +// +// Purpose: +// Does a signed Long Shift Right +// Shifts a long right any number of bits. +// +// Entry: +// EDX:EAX - long value to be shifted +// CL - number of bits to shift by +// +// Exit: +// EDX:EAX - shifted value +// +// Uses: +// CL is destroyed. +// + __allshr: - shrdl %cl, %edx, %eax - sarl %cl, %edx - andl $32, %ecx - je 1f - movl %edx, %eax - sarl $31, %edx -1: - ret
-/* - * unsigned long long - * __aulldiv(unsigned long long Dividend, unsigned long long Divisor)// - * - * Parameters: - * [ESP+04h] - unsigned long long Dividend - * [ESP+0Ch] - unsigned long long Divisor - * Registers: - * Unknown - * Returns: - * EDX:EAX - unsigned long long quotient (Dividend/Divisor) - * Notes: - * Routine removes the arguments from the stack. - */ +// +// Handle shifts of 64 bits or more (if shifting 64 bits or more, the result +// depends only on the high order bit of edx). +// + cmp cl,64 + jae short .RETSIGN + +// +// Handle shifts of between 0 and 31 bits +// + cmp cl, 32 + jae short .MORE32 + shrd eax,edx,cl + sar edx,cl + ret + +// +// Handle shifts of between 32 and 63 bits +// +.MORE32: + mov eax,edx + sar edx,31 + and cl,31 + sar eax,cl + ret + +// +// Return double precision 0 or -1, depending on the sign of edx +// +.RETSIGN: + sar edx,31 + mov eax,edx + ret + +// +// ulldiv - unsigned long divide +// +// Purpose: +// Does a unsigned long divide of the arguments. Arguments are +// not changed. +// +// Entry: +// Arguments are passed on the stack: +// 1st pushed: divisor (QWORD) +// 2nd pushed: dividend (QWORD) +// +// Exit: +// EDX:EAX contains the quotient (dividend/divisor) +// NOTE: this routine removes the parameters from the stack. +// +// Uses: +// ECX +// + __aulldiv: - call ___udivdi3 - ret $16
-/* - * unsigned long long - * __aullshr(unsigned long long Value, unsigned char Shift)// - * - * Parameters: - * EDX:EAX - unsigned long long value to be shifted right - * CL - number of bits to shift by - * Registers: - * Destroys CL - * Returns: - * EDX:EAX - shifted value - */ + push ebx + push esi + +// Set up the local stack and save the index registers. When this is done +// the stack frame will look as follows (assuming that the expression a/b will +// generate a call to uldiv(a, b)): +// +// ----------------- +// | | +// |---------------| +// | | +// |--divisor (b)--| +// | | +// |---------------| +// | | +// |--dividend (a)-| +// | | +// |---------------| +// | return addr** | +// |---------------| +// | EBX | +// |---------------| +// ESP---->| ESI | +// ----------------- +// + +#undef DVNDLO +#undef DVNDHI +#undef DVSRLO +#undef DVSRHI +#define DVNDLO [esp + 12] // stack address of dividend (a) +#define DVNDHI [esp + 16] // stack address of dividend (a) +#define DVSRLO [esp + 20] // stack address of divisor (b) +#define DVSRHI [esp + 24] // stack address of divisor (b) + +// +// Now do the divide. First look to see if the divisor is less than 4194304K. +// If so, then we can use a simple algorithm with word divides, otherwise +// things get a little more complex. +// + + mov eax,DVSRHI // check to see if divisor < 4194304K + or eax,eax + jnz short ..L1 // nope, gotta do this the hard way + mov ecx,DVSRLO // load divisor + mov eax,DVNDHI // load high word of dividend + xor edx,edx + div ecx // get high order bits of quotient + mov ebx,eax // save high bits of quotient + mov eax,DVNDLO // edx:eax <- remainder:lo word of dividend + div ecx // get low order bits of quotient + mov edx,ebx // edx:eax <- quotient hi:quotient lo + jmp short ..L2 // restore stack and return + +// +// Here we do it the hard way. Remember, eax contains DVSRHI +// + +..L1: + mov ecx,eax // ecx:ebx <- divisor + mov ebx,DVSRLO + mov edx,DVNDHI // edx:eax <- dividend + mov eax,DVNDLO +..L3: + shr ecx,1 // shift divisor right one bit// hi bit <- 0 + rcr ebx,1 + shr edx,1 // shift dividend right one bit// hi bit <- 0 + rcr eax,1 + or ecx,ecx + jnz short ..L3 // loop until divisor < 4194304K + div ebx // now divide, ignore remainder + mov esi,eax // save quotient + +// +// We may be off by one, so to check, we will multiply the quotient +// by the divisor and check the result against the orignal dividend +// Note that we must also check for overflow, which can occur if the +// dividend is close to 2**64 and the quotient is off by 1. +// + + mul dword ptr DVSRHI // QUOT * DVSRHI + mov ecx,eax + mov eax,DVSRLO + mul esi // QUOT * DVSRLO + add edx,ecx // EDX:EAX = QUOT * DVSR + jc short ..L4 // carry means Quotient is off by 1 + +// +// do long compare here between original dividend and the result of the +// multiply in edx:eax. If original is larger or equal, we are ok, otherwise +// subtract one (1) from the quotient. +// + + cmp edx,DVNDHI // compare hi words of result and original + ja short ..L4 // if result > original, do subtract + jb short ..L5 // if result < original, we are ok + cmp eax,DVNDLO // hi words are equal, compare lo words + jbe short ..L5 // if less or equal we are ok, else subtract +..L4: + dec esi // subtract 1 from quotient +..L5: + xor edx,edx // edx:eax <- quotient + mov eax,esi + +// +// Just the cleanup left to do. edx:eax contains the quotient. +// Restore the saved registers and return. +// + +..L2: + + pop esi + pop ebx + + ret 16 + +// +// ullshr - long shift right +// +// Purpose: +// Does a unsigned Long Shift Right +// Shifts a long right any number of bits. +// +// Entry: +// EDX:EAX - long value to be shifted +// CL - number of bits to shift by +// +// Exit: +// EDX:EAX - shifted value +// +// Uses: +// CL is destroyed. +// + __aullshr: - shrdl %cl, %edx, %eax - shrl %cl, %edx - andl $32, %ecx - je 1f - movl %edx, %eax -1: - ret - -/* - * long long - * __allrem(long long Dividend, long long Divisor)// - * - * Parameters: - * [ESP+04h] - long long Dividend - * [ESP+0Ch] - long long Divisor - * Registers: - * Unknown - * Returns: - * EDX:EAX - long long remainder (Dividend/Divisor) - * Notes: - * Routine removes the arguments from the stack. - */ -__allrem: - call ___moddi3 - ret $16 - -.intel_syntax noprefix
+// +// Handle shifts of 64 bits or more (if shifting 64 bits or more, the result +// depends only on the high order bit of edx). +// + cmp cl,64 + jae short ..RETZERO + +// +// Handle shifts of between 0 and 31 bits +// + cmp cl, 32 + jae short ..MORE32 + shrd eax,edx,cl + shr edx,cl + ret + +// +// Handle shifts of between 32 and 63 bits +// +..MORE32: + mov eax,edx + xor edx,edx + and cl,31 + shr eax,cl + ret + +// +// return 0 in edx:eax +// +..RETZERO: + xor eax,eax + xor edx,edx + ret + +// +// ullrem - unsigned long remainder +// +// Purpose: +// Does a unsigned long remainder of the arguments. Arguments are +// not changed. +// +// Entry: +// Arguments are passed on the stack: +// 1st pushed: divisor (QWORD) +// 2nd pushed: dividend (QWORD) +// +// Exit: +// EDX:EAX contains the remainder (dividend%divisor) +// NOTE: this routine removes the parameters from the stack. +// +// Uses: +// ECX +// + +__aullrem: + + push ebx + +// Set up the local stack and save the index registers. When this is done +// the stack frame will look as follows (assuming that the expression a%b will +// generate a call to ullrem(a, b)): +// +// ----------------- +// | | +// |---------------| +// | | +// |--divisor (b)--| +// | | +// |---------------| +// | | +// |--dividend (a)-| +// | | +// |---------------| +// | return addr** | +// |---------------| +// ESP---->| EBX | +// ----------------- +// + +#undef DVNDLO +#undef DVNDHI +#undef DVSRLO +#undef DVSRHI +#define DVNDLO [esp + 8] // stack address of dividend (a) +#define DVNDHI [esp + 8] // stack address of dividend (a) +#define DVSRLO [esp + 16] // stack address of divisor (b) +#define DVSRHI [esp + 20] // stack address of divisor (b) + +// Now do the divide. First look to see if the divisor is less than 4194304K. +// If so, then we can use a simple algorithm with word divides, otherwise +// things get a little more complex. +// + + mov eax,DVSRHI // check to see if divisor < 4194304K + or eax,eax + jnz short ...L1 // nope, gotta do this the hard way + mov ecx,DVSRLO // load divisor + mov eax,DVNDHI // load high word of dividend + xor edx,edx + div ecx // edx <- remainder, eax <- quotient + mov eax,DVNDLO // edx:eax <- remainder:lo word of dividend + div ecx // edx <- final remainder + mov eax,edx // edx:eax <- remainder + xor edx,edx + jmp short ...L2 // restore stack and return + +// +// Here we do it the hard way. Remember, eax contains DVSRHI +// + +...L1: + mov ecx,eax // ecx:ebx <- divisor + mov ebx,DVSRLO + mov edx,DVNDHI // edx:eax <- dividend + mov eax,DVNDLO +...L3: [truncated at 1000 lines; 365 more skipped]
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