PageRenderTime 17ms CodeModel.GetById 5ms app.highlight 10ms RepoModel.GetById 1ms app.codeStats 0ms

/arch/ia64/lib/idiv64.S

https://bitbucket.org/evzijst/gittest
Assembly | 80 lines | 65 code | 5 blank | 10 comment | 1 complexity | 5b888df8cb00efa37367a9e9f5a8ad6d MD5 | raw file
 1/*
 2 * Copyright (C) 1999-2000 Hewlett-Packard Co
 3 * Copyright (C) 1999-2000 David Mosberger-Tang <davidm@hpl.hp.com>
 4 *
 5 * 64-bit integer division.
 6 *
 7 * This code is based on the application note entitled "Divide, Square Root
 8 * and Remainder Algorithms for the IA-64 Architecture".  This document
 9 * is available as Intel document number 248725-002 or via the web at
10 * http://developer.intel.com/software/opensource/numerics/
11 *
12 * For more details on the theory behind these algorithms, see "IA-64
13 * and Elementary Functions" by Peter Markstein; HP Professional Books
14 * (http://www.hp.com/go/retailbooks/)
15 */
16
17#include <asm/asmmacro.h>
18
19#ifdef MODULO
20# define OP	mod
21#else
22# define OP	div
23#endif
24
25#ifdef UNSIGNED
26# define SGN	u
27# define INT_TO_FP(a,b)	fcvt.xuf.s1 a=b
28# define FP_TO_INT(a,b)	fcvt.fxu.trunc.s1 a=b
29#else
30# define SGN
31# define INT_TO_FP(a,b)	fcvt.xf a=b
32# define FP_TO_INT(a,b)	fcvt.fx.trunc.s1 a=b
33#endif
34
35#define PASTE1(a,b)	a##b
36#define PASTE(a,b)	PASTE1(a,b)
37#define NAME		PASTE(PASTE(__,SGN),PASTE(OP,di3))
38
39GLOBAL_ENTRY(NAME)
40	.regstk 2,0,0,0
41	// Transfer inputs to FP registers.
42	setf.sig f8 = in0
43	setf.sig f9 = in1
44	;;
45	// Convert the inputs to FP, to avoid FP software-assist faults.
46	INT_TO_FP(f8, f8)
47	INT_TO_FP(f9, f9)
48	;;
49	frcpa.s1 f11, p6 = f8, f9	// y0 = frcpa(b)
50	;;
51(p6)	fmpy.s1 f7 = f8, f11		// q0 = a*y0
52(p6)	fnma.s1 f6 = f9, f11, f1	// e0 = -b*y0 + 1
53	;;
54(p6)	fma.s1 f10 = f7, f6, f7		// q1 = q0*e0 + q0
55(p6)	fmpy.s1 f7 = f6, f6		// e1 = e0*e0
56	;;
57#ifdef MODULO
58	sub in1 = r0, in1		// in1 = -b
59#endif
60(p6)	fma.s1 f10 = f10, f7, f10	// q2 = q1*e1 + q1
61(p6)	fma.s1 f6 = f11, f6, f11	// y1 = y0*e0 + y0
62	;;
63(p6)	fma.s1 f6 = f6, f7, f6		// y2 = y1*e1 + y1
64(p6)	fnma.s1 f7 = f9, f10, f8	// r = -b*q2 + a
65	;;
66#ifdef MODULO
67	setf.sig f8 = in0		// f8 = a
68	setf.sig f9 = in1		// f9 = -b
69#endif
70(p6)	fma.s1 f11 = f7, f6, f10	// q3 = r*y2 + q2
71	;;
72	FP_TO_INT(f11, f11)		// q = trunc(q3)
73	;;
74#ifdef MODULO
75	xma.l f11 = f11, f9, f8		// r = q*(-b) + a
76	;;
77#endif
78	getf.sig r8 = f11		// transfer result to result register
79	br.ret.sptk.many rp
80END(NAME)