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;; Copyright (C) 2001, 2004 Free Software Foundation, Inc.

;;

;; This file is part of GCC.

;;

;; GCC is free software; you can redistribute it and/or modify it under

;; the terms of the GNU General Public License as published by the Free

;; Software Foundation; either version 3, or (at your option) any later

;; version.

;;

;; GCC is distributed in the hope that it will be useful, but WITHOUT ANY

;; WARRANTY; without even the implied warranty of MERCHANTABILITY or

;; FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

;; for more details.

;;

;; Under Section 7 of GPL version 3, you are granted additional

;; permissions described in the GCC Runtime Library Exception, version

;; 3.1, as published by the Free Software Foundation.

;;

;; You should have received a copy of the GNU General Public License and

;; a copy of the GCC Runtime Library Exception along with this program;

;; see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see

;; .

;;

;; This code used to be expanded through interesting expansions in

;; the machine description, compiled from this code:

;;

;; #ifdef L_mulsi3

;; long __Mul (unsigned long a, unsigned long b) __attribute__ ((__const__));

;;

;; /* This must be compiled with the -mexpand-mul flag, to synthesize the

;;    multiplication from the mstep instructions.  The check for

;;    smaller-size multiplication pays off in the order of .5-10%;

;;    estimated median 1%, depending on application.

;;     FIXME: It can be further optimized if we go to assembler code, as

;;    gcc 2.7.2 adds a few unnecessary instructions and does not put the

;;    basic blocks in optimal order.  */

;; long

;; __Mul (unsigned long a, unsigned long b)

;; {

;; #if defined (__CRIS_arch_version) && __CRIS_arch_version >= 10

;;   /* In case other code is compiled without -march=v10, they will

;;      contain calls to __Mul, regardless of flags at link-time.  The

;;      "else"-code below will work, but is unnecessarily slow.  This

;;      sometimes cuts a few minutes off from simulation time by just

;;      returning a "mulu.d".  */

;;   return a * b;

;; #else

;;   unsigned long min;

;;

;;   /* Get minimum via the bound insn.  */

;;   min = a < b ? a : b;

;;

;;   /* Can we omit computation of the high part?       */

;;   if (min > 65535)

;;     /* No.  Perform full multiplication.  */

;;     return a * b;

;;   else

;;     {

;;       /* Check if both operands are within 16 bits.  */

;;       unsigned long max;

;;

;;       /* Get maximum, by knowing the minimum.

;;          This will partition a and b into max and min.

;;          This is not currently something GCC understands,

;;          so do this trick by asm.  */

;;       __asm__ ("xor %1,%0\n\txor %2,%0"

;;                : "=r" (max)

;;                :  "r" (b), "r" (a), "0" (min));

;;

;;     if (max > 65535)

;;       /* Make GCC understand that only the low part of "min" will be

;;          used.  */

;;       return max * (unsigned short) min;

;;     else

;;       /* Only the low parts of both operands are necessary.  */

;;       return ((unsigned short) max) * (unsigned short) min;

;;     }

;; #endif /* not __CRIS_arch_version >= 10 */

;; }

;; #endif /* L_mulsi3 */

;;

;; That approach was abandoned since the caveats outweighted the

;; benefits.  The expand-multiplication machinery is also removed, so you

;; can't do this anymore.

;;

;; For doubters of there being any benefits, some where: insensitivity to:

;; - ABI changes (mostly for experimentation)

;; - assembler syntax differences (mostly debug format).

;; - insn scheduling issues.

;; Most ABI experiments will presumably happen with arches with mul insns,

;; so that argument doesn't really hold anymore, and it's unlikely there

;; being new arch variants needing insn scheduling and not having mul

;; insns.

;; ELF and a.out have different syntax for local labels: the "wrong"

;; one may not be omitted from the object.

#undef L

#ifdef __AOUT__

# define L(x) x

#else

# define L(x) .x

#endif

        .global ___Mul

        .type   ___Mul,@function

___Mul:

#if defined (__CRIS_arch_version) && __CRIS_arch_version >= 10

;; Can't have the mulu.d last on a cache-line (in the delay-slot of the

;; "ret"), due to hardware bug.  See documentation for -mmul-bug-workaround.

;; Not worthwhile to conditionalize here.

        .p2alignw 2,0x050f

        mulu.d $r11,$r10

        ret

        nop

#else

        move.d $r10,$r12

        move.d $r11,$r9

        bound.d $r12,$r9

        cmpu.w 65535,$r9

        bls L(L3)

        move.d $r12,$r13

        movu.w $r11,$r9

        lslq 16,$r13

        mstep $r9,$r13

        mstep $r9,$r13

        mstep $r9,$r13

        mstep $r9,$r13

        mstep $r9,$r13

        mstep $r9,$r13

        mstep $r9,$r13

        mstep $r9,$r13

        mstep $r9,$r13

        mstep $r9,$r13

        mstep $r9,$r13

        mstep $r9,$r13

        mstep $r9,$r13

        mstep $r9,$r13

        mstep $r9,$r13

        mstep $r9,$r13

        clear.w $r10

        test.d $r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        movu.w $r12,$r12

        move.d $r11,$r9

        clear.w $r9

        test.d $r9

        mstep $r12,$r9

        mstep $r12,$r9

        mstep $r12,$r9

        mstep $r12,$r9

        mstep $r12,$r9

        mstep $r12,$r9

        mstep $r12,$r9

        mstep $r12,$r9

        mstep $r12,$r9

        mstep $r12,$r9

        mstep $r12,$r9

        mstep $r12,$r9

        mstep $r12,$r9

        mstep $r12,$r9

        mstep $r12,$r9

        mstep $r12,$r9

        add.w $r9,$r10

        lslq 16,$r10

        ret

        add.d $r13,$r10

L(L3):

        move.d $r9,$r10

        xor $r11,$r10

        xor $r12,$r10

        cmpu.w 65535,$r10

        bls L(L5)

        movu.w $r9,$r13

        movu.w $r13,$r13

        move.d $r10,$r9

        lslq 16,$r9

        mstep $r13,$r9

        mstep $r13,$r9

        mstep $r13,$r9

        mstep $r13,$r9

        mstep $r13,$r9

        mstep $r13,$r9

        mstep $r13,$r9

        mstep $r13,$r9

        mstep $r13,$r9

        mstep $r13,$r9

        mstep $r13,$r9

        mstep $r13,$r9

        mstep $r13,$r9

        mstep $r13,$r9

        mstep $r13,$r9

        mstep $r13,$r9

        clear.w $r10

        test.d $r10

        mstep $r13,$r10

        mstep $r13,$r10

        mstep $r13,$r10

        mstep $r13,$r10

        mstep $r13,$r10

        mstep $r13,$r10

        mstep $r13,$r10

        mstep $r13,$r10

        mstep $r13,$r10

        mstep $r13,$r10

        mstep $r13,$r10

        mstep $r13,$r10

        mstep $r13,$r10

        mstep $r13,$r10

        mstep $r13,$r10

        mstep $r13,$r10

        lslq 16,$r10

        ret

        add.d $r9,$r10

L(L5):

        movu.w $r9,$r9

        lslq 16,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        mstep $r9,$r10

        ret

        mstep $r9,$r10

#endif

L(Lfe1):

        .size   ___Mul,L(Lfe1)-___Mul