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root/arch/x86/math-emu/mul_Xsig.S

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/*---------------------------------------------------------------------------+
 |  mul_Xsig.S                                                               |
 |                                                                           |
 | Multiply a 12 byte fixed point number by another fixed point number.      |
 |                                                                           |
 | Copyright (C) 1992,1994,1995                                              |
 |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
 |                       Australia.  E-mail billm@jacobi.maths.monash.edu.au |
 |                                                                           |
 | Call from C as:                                                           |
 |   void mul32_Xsig(Xsig *x, unsigned b)                                    |
 |                                                                           |
 |   void mul64_Xsig(Xsig *x, unsigned long long *b)                         |
 |                                                                           |
 |   void mul_Xsig_Xsig(Xsig *x, unsigned *b)                                |
 |                                                                           |
 | The result is neither rounded nor normalized, and the ls bit or so may    |
 | be wrong.                                                                 |
 |                                                                           |
 +---------------------------------------------------------------------------*/
        .file   "mul_Xsig.S"


#include "fpu_emu.h"

.text
ENTRY(mul32_Xsig)
        pushl %ebp
        movl %esp,%ebp
        subl $16,%esp
        pushl %esi

        movl PARAM1,%esi
        movl PARAM2,%ecx

        xor %eax,%eax
        movl %eax,-4(%ebp)
        movl %eax,-8(%ebp)

        movl (%esi),%eax        /* lsl of Xsig */
        mull %ecx               /* msl of b */
        movl %edx,-12(%ebp)

        movl 4(%esi),%eax       /* midl of Xsig */
        mull %ecx               /* msl of b */
        addl %eax,-12(%ebp)
        adcl %edx,-8(%ebp)
        adcl $0,-4(%ebp)

        movl 8(%esi),%eax       /* msl of Xsig */
        mull %ecx               /* msl of b */
        addl %eax,-8(%ebp)
        adcl %edx,-4(%ebp)

        movl -12(%ebp),%eax
        movl %eax,(%esi)
        movl -8(%ebp),%eax
        movl %eax,4(%esi)
        movl -4(%ebp),%eax
        movl %eax,8(%esi)

        popl %esi
        leave
        ret


ENTRY(mul64_Xsig)
        pushl %ebp
        movl %esp,%ebp
        subl $16,%esp
        pushl %esi

        movl PARAM1,%esi
        movl PARAM2,%ecx

        xor %eax,%eax
        movl %eax,-4(%ebp)
        movl %eax,-8(%ebp)

        movl (%esi),%eax        /* lsl of Xsig */
        mull 4(%ecx)            /* msl of b */
        movl %edx,-12(%ebp)

        movl 4(%esi),%eax       /* midl of Xsig */
        mull (%ecx)             /* lsl of b */
        addl %edx,-12(%ebp)
        adcl $0,-8(%ebp)
        adcl $0,-4(%ebp)

        movl 4(%esi),%eax       /* midl of Xsig */
        mull 4(%ecx)            /* msl of b */
        addl %eax,-12(%ebp)
        adcl %edx,-8(%ebp)
        adcl $0,-4(%ebp)

        movl 8(%esi),%eax       /* msl of Xsig */
        mull (%ecx)             /* lsl of b */
        addl %eax,-12(%ebp)
        adcl %edx,-8(%ebp)
        adcl $0,-4(%ebp)

        movl 8(%esi),%eax       /* msl of Xsig */
        mull 4(%ecx)            /* msl of b */
        addl %eax,-8(%ebp)
        adcl %edx,-4(%ebp)

        movl -12(%ebp),%eax
        movl %eax,(%esi)
        movl -8(%ebp),%eax
        movl %eax,4(%esi)
        movl -4(%ebp),%eax
        movl %eax,8(%esi)

        popl %esi
        leave
        ret



ENTRY(mul_Xsig_Xsig)
        pushl %ebp
        movl %esp,%ebp
        subl $16,%esp
        pushl %esi

        movl PARAM1,%esi
        movl PARAM2,%ecx

        xor %eax,%eax
        movl %eax,-4(%ebp)
        movl %eax,-8(%ebp)

        movl (%esi),%eax        /* lsl of Xsig */
        mull 8(%ecx)            /* msl of b */
        movl %edx,-12(%ebp)

        movl 4(%esi),%eax       /* midl of Xsig */
        mull 4(%ecx)            /* midl of b */
        addl %edx,-12(%ebp)
        adcl $0,-8(%ebp)
        adcl $0,-4(%ebp)

        movl 8(%esi),%eax       /* msl of Xsig */
        mull (%ecx)             /* lsl of b */
        addl %edx,-12(%ebp)
        adcl $0,-8(%ebp)
        adcl $0,-4(%ebp)

        movl 4(%esi),%eax       /* midl of Xsig */
        mull 8(%ecx)            /* msl of b */
        addl %eax,-12(%ebp)
        adcl %edx,-8(%ebp)
        adcl $0,-4(%ebp)

        movl 8(%esi),%eax       /* msl of Xsig */
        mull 4(%ecx)            /* midl of b */
        addl %eax,-12(%ebp)
        adcl %edx,-8(%ebp)
        adcl $0,-4(%ebp)

        movl 8(%esi),%eax       /* msl of Xsig */
        mull 8(%ecx)            /* msl of b */
        addl %eax,-8(%ebp)
        adcl %edx,-4(%ebp)

        movl -12(%ebp),%edx
        movl %edx,(%esi)
        movl -8(%ebp),%edx
        movl %edx,4(%esi)
        movl -4(%ebp),%edx
        movl %edx,8(%esi)

        popl %esi
        leave
        ret


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