81 lines
		
	
	
	
		
			2 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
		
		
			
		
	
	
			81 lines
		
	
	
	
		
			2 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
|   | /* | ||
|  |  * Copyright (C) 1999-2000 Hewlett-Packard Co | ||
|  |  * Copyright (C) 1999-2000 David Mosberger-Tang <davidm@hpl.hp.com>
 | ||
|  |  * | ||
|  |  * 64-bit integer division. | ||
|  |  * | ||
|  |  * This code is based on the application note entitled "Divide, Square Root | ||
|  |  * and Remainder Algorithms for the IA-64 Architecture".  This document | ||
|  |  * is available as Intel document number 248725-002 or via the web at | ||
|  |  * http://developer.intel.com/software/opensource/numerics/ | ||
|  |  * | ||
|  |  * For more details on the theory behind these algorithms, see "IA-64 | ||
|  |  * and Elementary Functions" by Peter Markstein; HP Professional Books
 | ||
|  |  * (http://www.hp.com/go/retailbooks/) | ||
|  |  */ | ||
|  | 
 | ||
|  | #include <asm/asmmacro.h> | ||
|  | 
 | ||
|  | #ifdef MODULO | ||
|  | # define OP	mod | ||
|  | #else | ||
|  | # define OP	div | ||
|  | #endif | ||
|  | 
 | ||
|  | #ifdef UNSIGNED | ||
|  | # define SGN	u | ||
|  | # define INT_TO_FP(a,b)	fcvt.xuf.s1 a=b | ||
|  | # define FP_TO_INT(a,b)	fcvt.fxu.trunc.s1 a=b | ||
|  | #else | ||
|  | # define SGN | ||
|  | # define INT_TO_FP(a,b)	fcvt.xf a=b | ||
|  | # define FP_TO_INT(a,b)	fcvt.fx.trunc.s1 a=b | ||
|  | #endif | ||
|  | 
 | ||
|  | #define PASTE1(a,b)	a##b | ||
|  | #define PASTE(a,b)	PASTE1(a,b) | ||
|  | #define NAME		PASTE(PASTE(__,SGN),PASTE(OP,di3)) | ||
|  | 
 | ||
|  | GLOBAL_ENTRY(NAME) | ||
|  | 	.regstk 2,0,0,0 | ||
|  | 	// Transfer inputs to FP registers. | ||
|  | 	setf.sig f8 = in0 | ||
|  | 	setf.sig f9 = in1 | ||
|  | 	;;
 | ||
|  | 	// Convert the inputs to FP, to avoid FP software-assist faults. | ||
|  | 	INT_TO_FP(f8, f8) | ||
|  | 	INT_TO_FP(f9, f9) | ||
|  | 	;;
 | ||
|  | 	frcpa.s1 f11, p6 = f8, f9	// y0 = frcpa(b) | ||
|  | 	;;
 | ||
|  | (p6)	fmpy.s1 f7 = f8, f11		// q0 = a*y0 | ||
|  | (p6)	fnma.s1 f6 = f9, f11, f1	// e0 = -b*y0 + 1 | ||
|  | 	;;
 | ||
|  | (p6)	fma.s1 f10 = f7, f6, f7		// q1 = q0*e0 + q0 | ||
|  | (p6)	fmpy.s1 f7 = f6, f6		// e1 = e0*e0 | ||
|  | 	;;
 | ||
|  | #ifdef MODULO | ||
|  | 	sub in1 = r0, in1		// in1 = -b | ||
|  | #endif | ||
|  | (p6)	fma.s1 f10 = f10, f7, f10	// q2 = q1*e1 + q1 | ||
|  | (p6)	fma.s1 f6 = f11, f6, f11	// y1 = y0*e0 + y0 | ||
|  | 	;;
 | ||
|  | (p6)	fma.s1 f6 = f6, f7, f6		// y2 = y1*e1 + y1 | ||
|  | (p6)	fnma.s1 f7 = f9, f10, f8	// r = -b*q2 + a | ||
|  | 	;;
 | ||
|  | #ifdef MODULO | ||
|  | 	setf.sig f8 = in0		// f8 = a | ||
|  | 	setf.sig f9 = in1		// f9 = -b | ||
|  | #endif | ||
|  | (p6)	fma.s1 f11 = f7, f6, f10	// q3 = r*y2 + q2 | ||
|  | 	;;
 | ||
|  | 	FP_TO_INT(f11, f11)		// q = trunc(q3) | ||
|  | 	;;
 | ||
|  | #ifdef MODULO | ||
|  | 	xma.l f11 = f11, f9, f8		// r = q*(-b) + a | ||
|  | 	;;
 | ||
|  | #endif | ||
|  | 	getf.sig r8 = f11		// transfer result to result register | ||
|  | 	br.ret.sptk.many rp | ||
|  | END(NAME) |