```   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)
81```
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